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Permit L08-013 - VALMONTE ARNELL - MLK WAY STORMWATER SENTIVIE AREA SPECIAL PERMISSION
NORTHFORK - MLK WY STORMWATER IMPROVEMENT SPECIAL PERMISSION REQUEST FOR A SENSITIVE AREAS ORDINANCE DEVIATION FOR WORK WITHIN A WETLAND (EAST OF I-5). L08-013 • City of Tukwila Department of Community Development NOTICE OF DECISION TO: Arnel Valmonte, Seattle Public Utilities, Applicant Amanda Azous, Herrera Environmental Consultants Susan Wall, Herrera Environmental Consultants King County Assessor, Accounting Division Washington State Department of Ecology King County Wastewater Treatment Division King County Land & Water Resources Jim Haggerton, Mayor Jack Pace, Director July 10, 2008 This letter serves as a notice of decision and is issued pursuant to TMC 18.104.170 on the following project and permit approval. I. PROJECT INFORMATION Project File Number: L08 -013 Applicant: Arnel Valmonte, Seattle Public Utilities Type of Permit Applied for: Special Permission from the DCD Director to do work within environmentally critical area sensitive areas. Project Description: Seattle Public Utilities (SPU) is proposing to make storm drainage improvements within an existing drainage ditch that's part of a larger conveyance system, on the east side of I -5 in the vicinity of the Boeing Access Road interchange. This work improve conveyance of stormwater to a wetland system on the west side of I -5, helping to improve water quality within the Duwamish River by preventing sewer overflows into the river, and preventing runoff into the river from Martin Luther King Way. Most of the project area is located within the City of Seattle. For the portion of the project site within the City of Tukwila, SPU is requesting a Type 2 Special Permission Director decision to clean and regrade a drainage ditch classified as a Type 2 wetland according to TMC 18.45.080. Temporary impacts in this area amount to a total of 0.03 acres of wetland in Tukwila. Impacts will be mitigated through removal of invasive vegetation and the addition of native plantings within the wetland and its buffer. Location: The east side of 1 -5, near Tukwila's northern City limits, in the vicinity of the Boeing Access Road interchange. Associated Files: N/A Comprehensive Plan Designation/Zoning District: Light Industrial (L/I) JR Page 1 of 3 H:\Special Permission\Norfolk wetlands'L08- 013_Norfolk Wetlands NOD.doc 07/08/2008 10:53 AM 6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • Phone: 206 - 431 -3670 • Fax: 206 - 431 -3665 • • H. DECISION SEPA Determination: The City of Seattle is the lead agency for this project. The City of Seattle SEPA Responsible Official has previously determined that the project, as proposed, does not create a probable significant environmental impact and issued a Determination of Non - Significance (DNS). Decision on Substantive Permit: The Community Development Director has determined that the application for a Special Permission to deviate from the City's Sensitive Areas Ordinance does comply with applicable City and state code requirements and has approved that application based on the findings and conclusions contained in the staff report, and subject to the following condition: A planting plan, including types, quantity, and locations of native plantings, shall be submitted and approved by the Department of Community Development as a condition of approval of this permit. As part of this plan, a maintenance and monitoring agreement shall be developed to provide for survival and/or replacement of any plantings during a 3 -year establishment period. III. YOUR APPEAL RIGHTS The Decision on this Permit Application is a Type 2 decision pursuant to Tukwila Municipal Code §18.104.010. Other land use applications related to this project may still be pending. No administrative appeal of a DNS. One administrative appeal to the Planning Commission of the Decision on the Permit itself is permitted. A party who is not satisfied with the outcome of the administrative appeal process may file an appeal in King County Superior Court from the Planning Commission decision. IV. PROCEDURES AND TIME FOR APPEALING In order to appeal the Community Development Director's decision on the Permit Application, a written notice of appeal must be filed with the Department of Community Development within 14 days of the issuance of this Decision; that is by Thursday, July 24, 2008. The requirements for such appeals are set forth in Tukwila Municipal Code 18.116. All appeal materials shall be submitted to the Department of Community Development. Appeal materials MUST include: 1. The name of the appealing party. 2. The address and phone number of the appealing party; and if the appealing party is a corporation, association or other group, the address and phone number of a contact person authorized to receive notices on the appealing party's behalf. 3. A statement identifying the decision being appealed and the alleged errors in the decision. JR Page 2 of 3 H:\Special Permission\Norfolk wetlands UA8 -013 Norfolk Wetlands NOD.doc 07/08/2008 11:08 AM • • 4. The Notice of Appeal shall identify (a) the specific errors of fact or errors in application of the law in the decision being appealed; (b) the harm suffered or anticipated by the appellant, and (c) the relief sought. The scope of an appeal shall be limited to matters or issues raised in the Notice of Appeal. 5. Appeal fee of $215. V. APPEAL HEARINGS PROCESS Any administrative appeal regarding the Permit shall be conducted as an open record hearing before the Planning Commission based on the testimony and documentary evidence presented at the open record hearing. The Planning Commission decision on the appeal is the City's final decision. Any party wishing to challenge the Planning Commission decision on this application must file an appeal pursuant to the procedures and time limitations set forth in RCW 36.70C. An appeal challenging a DNS may be included in such an appeal. If no appeal of the Planning Commission decision is properly filed in Superior Court within such time limit, the Decision on this permit will be final. VI. INSPECTION OF INFORMATION ON THE APPLICATION Project materials including the application, any staff reports, and other studies related to the permits are available for inspection at the Tukwila Department of Community Development, 6300 Southcenter Blvd., Suite 100, Tukwila, Washington 98188 from Monday through Friday between 8:30 a.m. and 5:00 p.m. The project planner is Jaimie Reavis, who may be contacted at 206 - 431 -3659 for further information. Property owners affected by this decision may request a change in valuation for their property tax purposes. Contact the King County Assessor's Office for further information regarding property tax valuation changes. The notice board must be removed at the expiration of the appeal period if no appeal is filed. (CW Departme of Community Development City of Tu ila JR Page 3 of 3 H:\Special Permission\Norfolk wetlands1L08- 013_Norfolk Wetlands NOD.doc 07/07/2008 9:53 AM • Cizj' of Tukwila Jim Haggerton, Mayor July 10, 2008 Department of Community Development Jack Pace, Director MEMORANDUM TO: Jack Pace, Director, Department of Community Development FROM: Jaimie Reavis, Assistant Planner RE: L08 -013, Special Permission, Director, Request for Sensitive Area Ordinance Deviation to allow temporary impacts to a Type 2 wetland. Seattle Public Utilities (SPU) is proposing to make stormwater conveyance system improvements within a Washington State Department of Transportation (WSDOT) drainage ditch on the east side of I -5 (see Exhibit A for map of project area, including portions in Seattle and Tukwila). A wetland delineation completed in 2006 determined that the ditch includes a Type 2 wetland according to TMC 18.45.080 (see Wetland D on Exhibit B, north and south). Work within Tukwila involves approximately 0.03 acres of temporary impacts to this wetland area. Herrera Environmental Consultants, Inc., on behalf of SPU, has applied for a special permission decision for a deviation from the requirements of the Sensitive Area Ordinance in order to allow them to do this work. SEPA The City of Seattle, as the lead agency for this project, has issued a Determination of Non - Significance (DNS). BACKGROUND Seattle Public Utilities (SPU) is proposing to clean and regrade a drainage ditch on the east side of I -5 to improve conveyance of stormwater (see Exhibit A for map of project area). The conveyance system that the ditch is a part of runs parallel to I -5 on the east side of the highway, extending north from Boeing Access Road to approximately 600 feet south of Norfolk Street. Initially constructed at the time I -5 was built in 1968, the purpose of the ditch was to convey runoff from areas east of I -5 to a culvert crossing underneath the highway. Lack of regular maintenance has resulted in siltation within the ditch of 1 to 3 feet of sediment. Work proposed by SPU is meant to restore the functionality of the conveyance system to prevent the overflow of stormwater to the sanitary sewer system, to reduce pollutant loading to the Duwamish River, and reduce flooding on Martin Luther King Way. A wetland delineation conducted in 2006 by SPU, covering the entire project area including the portions in Seattle and Tukwila, revealed that the project area includes a 1.4 -acre linear scrub - shrub ditch type wetland system, identified as Wetland D on the attached map (Exhibit B, north and south). The wetland buffer is virtually non - existent due to existing land uses on both sides of JR Page 1 of 5 H:\Special Permission\Norfolk wetlands\LO8 -013 SPU Wetland D_SR.doc 07/08/2008 10.56 AM 6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • Phone: 206 - 431 -3670 • Fax: 206 - 431 -3665 • • the wetland. Work proposed within Tukwila includes operating heavy equipment in Wetland D to remove accumulated sediment. Most of the work proposed will occur within the Seattle, and the City of Seattle has approved the work with an Environmentally Critical Areas exemption. Within Tukwila, the work will result in approximately 0.03 acres of impacts to Wetland D, classified as a Type 2 wetland according to TMC 18.45.080. Since the area of Wetland D will remain the same after the work is complete, and because no trees over 6 inches in diameter at breast height will be removed, the impacts to Wetland D are considered temporary. There will be no changes to the buffer of Wetland D associated with the proposed work by SPU, except for some enhancement along the west side. The work proposed by SPU can be classified as a permitted use according TMC section18.45.070 (B) Permitted Uses Subject to Administrative Review, under items (1) Maintenance and repair of existing uses where alteration or additional fill materials will be placed or heavy construction equipment used, and (9) Dredging, digging or filling within a sensitive area or its buffer, which may occur only with the permission of the Director according to a defined set of purposes, and in such a way as to minimize sedimentation in the water. An additional condition of allowing any dredging, digging or filling is that "upon completion of construction the area affected must be restored to an appropriate grade, replanted according to a plan approved by the Director, and provided with care until newly planted vegetation is established." DECISION CRITERIA Section 18.45.090B(1) of the Tukwila Municipal Code (TMC) states that "Alterations to wetlands are discouraged and are limited to the minimum necessary for project feasibility." Alteration to wetlands and their buffers is allowed only with permission of the Director, according to the criteria a f under TMC 18.45.090B(1). These criteria are listed in italics below, followed by a discussion of how the proposed project meets each: a. The alteration will not adversely affect water quality; Wetland D has a hydrologic connection to the Duwamish River; water from the WSDOT ditch flows west into two parallel culverts located under 1-5. Once reaching the west side of I -5, the water passes through two other regulated wetlands and then enters a piped system before discharging to the Duwamish River. The conveyance system which SPU is proposing to improve as a result of this application does not function properly due to lack of maintenance, resulting in pipe degradation and sedimentation of the drainage ditch. A result of this dysfunctional conveyance system is that stormwater backs up into an adjacent sanitary sewer system. King County has notified SPU that it will no longer allow stormwater to be discharged to the sanitary sewer system. Improvements to the conveyance system as proposed with this application will prevent stormwater from being discharged into the sanitary sewer system, reducing the chance that stormwater will cause combined sewer overflows to the Duwamish River. Another stated benefit of this project is to eliminate overflows of stormwater from the existing system that cause flooding on MLK Way, reducing the amount of pollution that enters the Duwamish River from this street. b. The alteration will not adversely affect fish, wildlife, or their habitat; The applicant conducted an analysis to determine the minimum amount of wetland disturbance /ditch regrading needed for acceptable conveyance system performance as an avoidance and minimization effort. Additionally, a 0.25 -acre access road was removed from the design to further reduce impacts to Wetland D. These measures allow a greater JR Page 2 of 5 HASpecial PermissionWorfolk wetlands1.08 -013 SPU Wetland D_SR.doc 07/07/2008 9:56 AM • • area of Wetland D to remain undisturbed. Additionally, the applicant describes the following practices that will be employed to prevent adverse affects to fish, wildlife, and habitat: Best Management Practices and minimization measures will be implemented during the design and construction phases of the project in order to minimize the potential impacts on fish and aquatic life. A temporary erosion and sedimentation control (TESC) plan and a spill prevention, control, and countermeasures (SPCC) plan is being prepared and would be implemented prior to the start of construction. Clearing limits will be marked to avoid impacts on sensitive areas and all equipment to be used for construction activities would be cleaned and inspected before it arrives at the project site to minimize potential fuel or lubricant leaks. The wetland and part of the buffer area will be enhanced through the removal of blackberries between the ditch and I -5. This area, as well as any impacted areas, will be replanted with native species to restore the area to an improved functional state. A planting plan, including types and locations of native plantings, shall be submitted and approved by the Department of Community Development as a condition of approval of this permit. As part of this plan, a maintenance and monitoring agreement shall be developed to provide for survival and/or replacement of any plantings during a 3 -year establishment period. c. The alteration will not have an adverse effect on drainage and/or storm water detention capabilities; The purpose of this project is to address problems currently occurring in a portion of the Norfolk/MLK Way subbasin by improving a stormwater conveyance system. This project will therefore not have an adverse effect on drainage and/or storm water detention capabilities. d. The alteration will not lead to unstable earth conditions or create an erosion hazard or contribute to scouring actions; The project involves clearing and regrading an existing ditch to remove accumulated sediment. According to the SEPA checklist for the project, excavated material will be taken to an SPU- approved storage facility. The site will be regraded to restore the original topography, and any disturbed areas will be replanted with native vegetation. Clearing and grading for the project shall follow an approved temporary erosion and sedimentation control (TESC) plan. e. The alteration will not be materially detrimental to any other property; and Regrading of the drainage ditch and associated conveyance system improvements will help address the existing problem of flooding of adjacent properties, including MLK Way and the sanitary sewer system. There are no negative impacts to other properties anticipated with this project. f The alteration will not have adverse effects on any other sensitive areas. The conveyance system improvements proposed by SPU will result in increased stormwater conveyance to two wetlands on the west side of I -5 that are currently part of SPU's water treatment system. These wetlands provide a stormwater detention function, as part of a system that is connected to the Duwamish River. While the proposed work may increase the amount of water flowing into these two wetlands, thereby increasing the JR Page 3 of 5 H: \Special Permission\Norfolk wetlands \L08 -013 SPU Wetland D_SR.doc 07/07/2008 9:56 AM • • flow of water from these wetlands to the Duwamish River, the system improvements will ultimately improve water quality by preventing sewer overflows from the sanitary sewer system and stormwater flows from MLK Way into the Duwamish River. MITIGATION SEQUENCING The applicant has demonstrated that reasonable efforts were made (as described above) to follow mitigation sequencing requirements of TMC 18.45.090C. MITIGATION PLAN TMC 18.45.090 B ALTERATIONS states that a mitigation or enhancement plan must be developed and must comply with the standards of mitigation required in TMC Chapter 18.45. The applicant is proposing to remove invasive species from the wetland and part of the buffer area, and to replant these areas with native plant species. Because the impacts to the wetland in Tukwila's jurisdiction are temporary, a 1:1 ratio for mitigation is acceptable. As a condition of approval, a planting plan that outlines the quantity, type, and location of plantings proposed, will be submitted for review and approval to the City of Tukwila Department of Community Development. As part of this plan, a maintenance and monitoring agreement shall be developed to provide for survival and/or replacement of any plantings during a 3 -year establishment period. COMMENTS A Notice of Application was mailed on June 2, 2008 to the applicant and to departments and agencies with jurisdiction pursuant to TMC 18.104.090. No comments were received related to this proposal. CONCLUSIONS 1. Clearing and regrading of the ditch, classified as a Type 2 wetland, is a permitted use per TMC 18.45.070 (B) under the following uses: (1) Maintenance and repair of existing uses and facilities where alteration or additional fill materials will be placed or heavy construction equipment used. (9) Dredging, digging, and filling 2. The proposed work will not have an adverse impact on water quality. This project will prevent negative impacts currently occurring due to the conveyance system's dysfunctional condition. The work will improve existing conditions by separating stormwater from the sanitary sewer system to prevent combined sewer and stormwater outflows to the Duwamish River, and will reduce flooding onto MLK Way that is currently resulting in runoff to the Duwamish River. 3. The applicant has conducted an avoidance and minimization analysis to determine the minimum amount of impact to Wetland D necessary for conveyance system functionality. These minimization and avoidance measures, as well as Best Management Practices, will be implemented during the design and construction phases of the project to minimize potential impacts to fish and wildlife. Invasive blackberries will be removed from the area between the Wetland D and I -5, and this area, as well as the area impacted during the proposed work, will be enhanced by JR Page 4 of 5 H:\Special PermissionWorfolk wetlands\L08-013 SPU Wetland D_SR.doc 07/07/2008 9:56 AM • adding native plantings, to be approved by the Tukwila Department of Community Development as a condition of approval of this permit. 4. The proposed work will improve drainage and stormwater detention capabilities. 5. The site will be regraded to restore the original topography and any disturbed areas will be replanted with native vegetation. Clearing and grading for the project will follow an approved temporary erosion and sedimentation (TESC) plan. 6. The proposed work will not be materially detrimental to any other property. 7. The proposed work will result in water quality improvements, preventing stormwater from entering the Duwamish River through sewer overflows flows and from runoff from MLK Way due to flooding. With improvements to the conveyance system as proposed, wetlands located on the west side of I -5 that are part of SPU's drainage system will function to detain and filter stormwater from the project area, reducing the amount of stormwater discharged into the Duwamish River and acting to filter out pollutants. 8. The proposed work will create temporary impacts to Wetland D. Mitigation measures employed by the applicant and reviewed as a condition of approval will enhance the quality of the vegetation within Wetland D and part of the buffer. RECOMMENDATION Staff recommends approval of the Special Permission permit with the following condition: A planting plan, including types, quantity, and locations of native plantings, shall be submitted and approved by the Department of Community Development as a condition of approval of this permit. As part of this plan, a maintenance and monitoring agreement shall be developed to provide for survival and/or replacement of any plantings during a 3- year establishment period. ATTACHMENTS: Exhibit A: Proposed Conveyance Improvements — Project Overview Exhibit B: Wetland Impacts (2 sheets showing project entire project area in Seattle and Tukwila, north and south) cc: Arnel Valmonte, Seattle Public Utilities Amanda Azous, Herrera Environmental Consultants Susan Wall, Herrera Environmental Consultants Department of Ecology King County Assessors Office King County Wastewater Treatment Division King County Land & Water Resources JR Page 5 of 5 H:\Special Permission\Norfolk wetlands1L08 -013 SPU Wetland D_SR.doc 07/07/2008 9:56 AM 3 • • ; Match 6 +sting Grad Regrade Channel 12- PSD 104 Control Structure 12" PSD ..1......ELATTLE CORPORATE LINT TUKWIZZEORMAIM417 :LEGEND 118118111611181:162116111 sesegaingannouvra. :Proposed improvement Wetland Ditch Storm drain 1400t topotraphic contour 5-foot topographic contour - Section line Property/easement boundary -°City limit 36- Wi 54" PSD. Fittpgate • 10' i frit 10' 4 H '5161ERNIMBRIftweszm Flow Diversion ,trui.turiiiawn Existing 24" f.t FfP Sediment Tra p Abandon in Place Edsting 26- CMP Ahartdon in Place • & Manhole 601 50 100' .152ra!■TI AdOiecc SdEdir: 1"1, 167 TETRA TECH vninviettatedloom 1420 Fifth Avenue, 8088 600 Seatt/e: Washington 68101 Phone: 206418341300 Fax: 206418341301 Date: DECEMBER 18, 2007 PROPOSED CONVEYANCE IMPROVEMENTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Applicant: SEATTLE PUBLIC UTILITIES Project Location: CG A 7-71 M A AIM "1-1 11/1A/11 A Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Exhibit A ART PROJECT WETLAND 0 \` 0 \ 15 0 15 30 SCALE IN FEET DITCH CENTE CONSTRUCTION LIMIT ADJACENT PROPERTY OWNERS: OPAPE MATERIAL HANDLING NOTE: WETLAND AREA TEMPORARILY DISTURBED: TOTAL PROJECT SEDIMENT EXCAVATION VOLUME: TOTAL PROJECT FILL VOLUME: EXCAVATION WITHIN WETLAND D: FILL WITHIN WETLAND D: DATUM: NAVD -88 6,234 SO FT (0.14 ACRES) 334 CU YDS 105 CU YDS FOR OUTLET PROTECTION 133 CU YDS 6 CU YDS PAD LEGEND: - - - - PROJECT LIMITS CONSTRUCTION LIMITS -� FENCE -11- PROPOSED CONTOURS -12- EXISTING CONTOURS s, EXISTING WETLAND HERRERA 2200 Sixth Avenue Suite 1100 Seattle, Washington 98121 -1820 206441-0080 206-441 -8108 FAX ENWROMMDMM WAnm.mm Date: DECEMBER 18, 2007 WETLAND IMPACTS Application for: PROPOSED STORMWATER CONVEYANCE IM PROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA. Exhibit B (h 0r411-.) Pj 12'PSD 39LF, S =2.3X OIL CONTROL STRUCTURE 15 SEDIMENT TRAP WITH 3H :I V SIDE SLOPES 0 15 30 SCALE IN FEET EXTEND EXISTING CONCRETE BLOCK RETAINING WALL 12' PSD 29LF, S =0.30X FLOW DIVERSION STRUCTURE 0 CET\ OF SEATTLE TLE CITY OF TUKWILA LEGEND: '—OUTLE r cr UM36`C.IP Or FOUP40 BY SURVEY T PROTECTION PAD — — — — PROJECT LIMITS CONSTRUCTION LIMITS FENCE —11— PROPOSED CONTOURS ---- --12 -- - -- EXISTING CONTOURS 1 EXISTING WETLAND CONSTRUCTION LIMIT ADJACENT PROPERTY OWNERS: 0 PAPE MATERIAL HANDLING OLINDAHL CEDAR HOMES NOTE: WETLAND AREA TEMPORARILY DISTURBED: 6,234 SO FT (0.14 ACRES) W W TOTAL PROJECT SEDIMENT EXCAVATION VOLUME: 334 CU YDS TOTAL PROJECT FILL VOLUME: 105 CU YDS FOR OUTLET PROTECTION PAD EXCAVATION WITHIN WETLAND D: 133 CU YDS FILL WITHIN WETLAND D: 6 CU YDS DATUM: NAVD -88 END PROJECT 0 HERRERA 2200 Sixth Avenue Suite 1100 Seattle, Washington 98121 -1820 200441 -9080 208-441 -9108 FAX ENVIRONMENTAL CONSULTANTS NOTNow*.herroalnescrA Date: DECEMBER 18, 2007 WETLAND IMPACTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: 0=AT1"I C AAIr 1-111,1A /11 A Exhibit B (50vf ) up eitg of -Tukwila IP Dept. Of Community Development AFFIDAVIT OF DISTRIBUTION I, o r /r L Ot'a/) % HEREBY DECLARE THAT: Notice of Public Hearing x ` Determination of Non - Significance Notice of Public Meeting , Mitigated Determination of Non - Significance Project Number: Log - 44.3 Board of Adjustment Agenda Packet Determination of Significance & Scoping Notice Y Board of Appeals Agenda Packet Mailer's signature: 9i2-7, Notice of Action L� j Planning Commission Agenda Packet Official Notice Short Subdivision Agenda Notice of Application Shoreline Mgmt Permit Notice of Application for Shoreline Mgmt Permit — _ FAX To Seattle Times Classifieds Mail: Gail Muller Classifieds PO Box 70 - Seattle WA 98111 ` , %( Other:�Q V /%�„ ,�� C L� C'el 5'/°'" 71'7 1d4/ / C Was mailed to each of the addresses listed /attached on this I day of in the y ear 200g/ v Project Name : a.,6 / Q / l re 6,4•K :1P , 6 r ri‘42 d Project Number: Log - 44.3 Mailing requested by: Y f 2 Mailer's signature: 9i2-7, L� j C: \DOCUMENTS AND SETTINGS\ TERI -S\ DESKTOP \AFFIDAVITO ISTRIBUTION.DOC Tes • • CHECKLIST: ENVIRONMENTAL REVIEW /SHORELINE PERMIT MAILINGS FEDERAL AGENCIES ( ) U.S. ARMY CORPS OF ENGINEERS ( ) FEDERAL HIGHWAY ADMINISTRATION ( ) DEPT OF FISH & WILDLIFE ( ) U.S. ENVIRONMENTAL PROTECTION AGENCY ( ) U.S. DEPT OF H.U.D. ( ) NATIONAL MARINE FISHERIES SERVICE WASHINGTON ST AN TE AGENCIES ( ) OFFICE OF ARCHAEOLOGY ( ) TRANSPORTATION DEPARTMENT ( ) DEPT NATURAL RESOURCES ( ) OFFICE OF THE GOVERNOR ( ) DEPT OF COMM. TRADE & ECONOMIC DEV. ( ) DEPT OF FISHERIES & WILDLIFE KING COUNTY AGENCIES ( ) BOUNDARY REVIEW BOARD ( ) FIRE DISTRICT #11 ( ) FIRE DISTRICT #2 tCK.C. WASTEWATER TREATMENT DIVISION () K.C. DEPT OF PARKS & REC >Q'K.C. ASSESSORS OFFICE ( ) TUKWILA SCHOOL DISTRICT ( ) TUKWILA LIBRARY ( ) RENTON LIBRARY () KENT LIBRARY ( ) CITY OF SEATTLE LIBRARY ( ) QWEST ( ) SEATTLE CITY LIGHT ( ) PUGET SOUND ENERGY ( ) HIGHLINE WATER DISTRICT ( ) SEATTLE WATER DEPARTMENT ( ) COMCAST SCHOOLS /LIBRARIES UTILITIES CITY AGENCIES ( ) KENT PLANNING DEPT ( ) TUKWILA CITY DEPARTMENTS: ( ) PUBLIC WORKS () FIRE ( ) POLICE () FINANCE ( ) PLANNING ( ) BUILDING ( ) PARKS & REC. () MAYOR ( ) CITY CLERK OTHER LOCAL AGENCIES () PUGET SOUND REGIONAL COUNCIL ( ) SW K C CHAMBER OF COMMERCE ( ) MUCKLESHOOT INDIAN TRIBE ( ) CULTURAL RESOURCES PROGRAM** ( ) FISHERIES PROGRAM*" ( ) WILDLIFE PROGRAM **Send SEPA Checklist and full set of plans w/ NOA MEDIA ( ) SEATTLE TIMES ( ) SOUTH COUNTY JOURNAL P:\ADMINISTRATIV E \FORMS \CHECKLIST.DOC ( ) DEPT OF SOCIAL & HEALTH SERV. DEPT OF ECOLOGY, SHORELAND DIV, NW Regional Office DEPT OF ECOLOGY, SEPA DIVISION* ( ) OFFICE OF ATTORNEY GENERAL * SEND CHKLIST W/ DETERMINATIONS * SEND SITE MAPS WITH DECISION () HEALTH DEPT ( ) PORT OF SEATTLE ( ) K.C. DEV & ENVIR SERVICES -SEPA INFO CNTR () K.C. TRANSIT DIVISION - SEPA OFFICIAL krK.C. LAND & WATER RESOURCES ( ) FOSTER LIBRARY () K C PUBLIC LIBRARY ( ) HIGHLINE SCHOOL DISTRICT ( ) SEATTLE SCHOOL DISTRICT ( ) RENTON SCHOOL DISTRICT ( ) OLYMPIC PIPELINE ( ) VAL -VUE SEWER DISTRICT ( ) WATER DISTRICT #20 ( ) WATER DISTRICT #125 ( ) CITY OF RENTON PUBLIC WORKS () BRYN MAWR - LAKERIDGE SEWERNVATER DISTRICT ( ) RENTON PLANNING DEPT ( ) CITY OF SEA -TAC ( ) CITY OF BURIEN ( ) TUKWILA PLANNING COMMISSION MEMBERS ( ) TUKWILA CITY COUNCIL MEMBERS ( ) CITY OF SEATTLE - SEPA INFO CENTER - DCLU ( ) STRATEGIC PLANNING OFFICE* " NOTICE OF ALL SEATTLE RELATED PLNG PROJ. ( ) DUWAMISH INDIAN TRIBE* ( ) P.S. AIR POLLUTION CLEAN AGENCY ( ) SOUND TRANSIT ( ) DUWAMISH RIVER CLEAN -UP COALITION* * SEND NOTICE OF ALL APPLICATIONS ON DUWAMISH RIVER ( ) HIGHLINE TIMES ( ) CI.TUKWILA.WA.US.WWW PLIC NOTICE MAILINGS FOR AMITS SEPA MAILINGS Mail to: (comment period starts on date of mailing) Dept. of Ecology Environmental Review Section *Applicant *Other agencies as necessary (checked off on attached list) *Any parties of record * send only the staff report, site plan and the SEPA Determination KC Transit Division — SEPA Official would like to receive information about all projects that might affect transit demand Send These Documents to DOE: SEPA Determination (3 -part from Sierra) Findings (staff report, usu. with MDNS) SEPA Checklist (filled out by applicant) Drawings/Plans of project (site plan, elevations, etc. from PMT's) Affidavit of Distribution (notice was mailed or sent to newspaper) SHORELINE MAILINGS: Notice of Application for a Substantial Development Permit must be mailed to owners and to property owners within 500 feet of subject property, comments are due 30 days after the notice of application is mailed /posted. The notice of Application for Shoreline Substantial Development Permit must include a statement that any person desiring to submit written comments on the application or desiring to receive notification of the fmal decision on the application may do so within 30 days of the notice of application. If a hearing will be held on the application, the hearing notice must include the information that written comments may be submitted, or oral presentation made at the hearing. Notice is sent to the NW Regional Office Shorelands & Environmental Assistance Program. Shoreline Permit Notice of Decision: Mail to: (within 8 days of decision; 21 -day appeal period begins date received by DOE) Department of Ecology Shorelands Section, NW Regional Office State Attorney General *Applicant *Indian Tribes *Other agencies as necessary (checked off on attached list). *My parties of record * send only the staff report, site plan and the SEPA Determination Send These Documents to DOE and Attorney General: Permit Data Sheet Shoreline Substantial Development Permit (3 -part from Sierra) Findings (staff report or memo) Shoreline Permit Application Form (filled out by applicant) Drawings/Plans of project (site plan, elevations, etc. from PMT's) — Site plan, with mean high water mark & improvements — Cross - sections of site with structures & shoreline — Grading Plan — Vicinity map SEPA determination (3 -part from Sierra) Findings (staff report or memo) SEPA Checklist (filled out by applicant) Any background studies related to impacts on shoreline Notice of Application Affidavit of Distribution (notice was mailed) P:I ADMINISTRATNE \FORMS\CHECKLIST.DOC Mr. Arnel Valmonte - SPU 700 Fifth Ave., Suite 4900 P.O. Box 34018 Seattle, WA 98124 -4018 Amanda Azous Herrera Environmental Consultants 2200 Sixth Ave, Suite 1100 Seattle, WA 98121 Susan Wall Herrera Environmental Consultants 101 E Broadway, Suite 610 Missoula, Montana 59802 Performance Standard 3 During the first -, second -, third -, and fifth -year monitoring events, no more than 20 percent of the total plant coverage will consist of invasive species. Invasive species may include, but are not limited to, Scot's broom, reed canarygrass, nonnative blackberry, holly, birdsfoot trefoil, cherry laurel, and English ivy. No percent coverage of Japanese knotweed will be allowed on the site. Performance Standard 4 During the second -, third -, and fifth -year monitoring events, the plant communities will achieve a density of 15 percent coverage by the second year, 40 to 50 percent coverage by the third year, and 60 to 80 percent coverage by the fifth year. Native volunteer species may contribute up to 20 percent of the contribution. Maintenance and Monitoring Plan for Wetland D Restoration Norfolk- MLK Way Stormwater Improvements Project Maintenance SPU or its contractor will be responsible for maintaining plantings for 1 year after the restoration is completed. After that time, SPU will assume complete responsibility for maintenance of the site. Maintenance activities will include weeding, watering, replacing dead or distressed plants, repairing damage due to herbivores or vandals, and removing trash. All nonnative materials or materials that are not biodegradable, such as protective fencing, will be removed from the site at the end of the 1 year maintenance period or when no longer needed. Monitoring Plan Monitoring will be conducted by SPU or its contractor during years 1, 2, 3, and 5 after restoration to confirm that the site restoration performance standards, as defined below, are being met. Vegetation success will be monitored and photo points will be established to visually document the observed conditions. Incidental observations of wildlife will be made during each monitoring visit. These data will be documented by SPU in annual monitoring reports and presented to the City of Seattle for each year of monitoring. If the monitoring results indicate that the site is not meeting the goals and objectives as defined in the site enhancement performance standards, then contingency measures will be implemented by SPU. Contingency measures that may be necessary include removing invasive species, increasing the frequency of watering, adjusting planting mixes to reflect hydrological changes, replanting as needed to meet the performance standards, and installing or removing protective fencing. Site Restoration Performance Standards The following performance standards will be used to measure the success of the restoration during monitoring visits and to identify and guide any adaptive management measures that may be required to address problem situations. Performance Standard 1 During the first -year monitoring event, no more than 2 percent of the woody plant materials will have died or become stressed to the point that the survival of the plant is in question. Performance Standard 2 During the first -year monitoring event, no area of bare soils measuring more than 2 feet by 2 feet will be visible. Stem densities in these areas, including those of herbaceous plants, will exceed 10 stems per square foot. Areas of mulch surrounding planted native species will not be considered areas of bare soil. a WETLAND SEED MIX - ZONE 1: COMMON NAME SPECIES % MD( LBS PLS/ ACRE AMERICAN SLOUGHGRASS BECKMANNIA SYZIGACHNE 30.0% 1.8 NORTHWESTERN MANNAGRASS GLYCERIA OCCIDENTAL'S 30.0% 9.7 TUFTED HAIRGRASS DESCHAMPSIA CESPITOSA 20.0% 0.5 MEADOW BARLEY HORDEUM BRACHYANTHERUM 20.0% 14.4 TOTAL: SHRUB PLANTING - ZONES 2 AND 3: 26.4 COMMON NAME SPECIES PLANTING ZONE CONTAINER SIZE SPACING NUMBER OF PLANTS NOTES RED TWIG DOGWOOD CORNUS SERICEA ZONE 2 1 GALLON 3 FOOT 122 PLANT IN ONE STAGGERED ROW, AT LEAST 5 FEET FROM EDGE OF EXCAVATED AREA. NOOTKA ROSE ROSA NUTKANA ZONE 3 1 GALLON 6 FOOT ON CENTER 143 SHRUB PLANTING NOTES - ZONES 2 AND 3: 1. PLANTS WILL BE CONTAINER GROWN AND FROM SEED SOURCES FROM WEST OF THE CASCADES AND FROM A SIMILAR ELEVATION. 2. EACH TREE AND SHRUB WILL HAVE A FERTILIZER PACK PLACED IN THE BOTTOM OF THE PLANTING HOLE PRIOR TO BACKFILLING. FERTILIZERS WILL BE SLOW RELEASE PRODUCTS THAT WILL NOT RESULT IN NUTRIENT RUNOFF INTO AQUATIC SYSTEMS. 3. MULCH (3 INCHES DEEP) WILL BE PLACED IN AN (18 INCH DIAMETER) RING AROUND EACH PLANT TO PREVENT INVASIVE SPECIES OR NATIVE GRASSES FROM OUT — COMPETING THE PLANT AND TO HELP MAINTAIN SOIL MOISTURE. WEED CONTROL NOTES - ZONE 3: 1. INVASIVE WEEDS ON THE RESTORATION SITE WILL BE ERADICATED USING A COMBINATION OF MECHANICAL REMOVAL AND TREATMENT WITH A NON— RESIDUAL HERBICIDE. 2. AN INTEGRATED PEST MANAGEMENT (IPM) APPROACH WILL BE TAKEN THAT WILL USE PHYSICAL METHODS OF CONTROL WHENEVER POSSIBLE. 3. ONLY THOSE HERBICIDES APPROVED BY THE DEPARTMENT OF ECOLOGY FOR USE IN AQUATIC AREAS WILL BE USED. 4. AN APPLICATION MUST BE SUBMITTED TO THE CITY OF SEATTLE FOR APPROVAL OF ANY HERBICIDE USE. 5. ALL HERBICIDES WILL BE APPLIED AS AUTHORIZED BY LAW AND AT THE APPLICATION RATES AND CONDITIONS SPECIFIED BY THE MANUFACTURER OF THE PRODUCT. 6. A LICENSED HERBICIDE APPLICATOR WILL BE HIRED TO APPLY ALL HERBICIDES. 7. ORGANIC MATERIAL GENERATED BY WEED REMOVAL WILL BE DISPOSED OF AS SPECIFIED BY THE CITIES OF SEATTLE AND TUKWILA. WEED CONTROL METHODS - ZONE 3: SPECIES AND COMMON NAME CONTROL METHOD HERBICIDE APPLICATION FOLLOWUP TREATMENT RUBUS ARMENIACUS (HIMALAYAN BLACKBERRY) CUT PRIOR TO SEED SET AND APPLY HERBICIDE TO CUT STEMS AND RESPROUTS. APPLY GLYPHOSATE WITH A DYE FOR MARKING TREATED PLANTS. APPLY TO RESPROUTING INDIVIDUALS IN LATE SUMMER OR FALL WHEN RE— GROWTH IS AT LEAST 2 FT TALL. FOLLOW UP CUTTING AND TREATMENT OF SPROUTS YEARLY FOR THREE YEARS. CYTISUS SCOPARIUS (SCOTCH BROOM) MECHANICALLY REMOVE PLANTS. CUT NEAR GROUND LEVEL WHEN PLANTS BEGIN ACTIVE GROWTH. NONE FOLLOW WITH REMOVAL OF SPOUTS YEARLY FOR 3 YEARS. LEGEND: —10 -13- SITE BOUNDARY LIMITS OF DISTURBANCE PROPOSED CONTOURS EXISTING CONTOURS EXISTING WETLAND ZONE 1 ZONE 2 ZONE 3 15 7.5 0 I i=1 15 30 11 SCALE IN FEET O Q0 o ! 0 0000 17 O #7. 7 ; ,ff " " ---zgrArafr AI A .4 r • sia(�IUt> :::::.. Nalle AL .01 AeArangAta,r5 s • • �uE g� ... nii�_m __ •7 7• _7_y..-- '��c.- W3iA.VWM2 � '�WMC�lgyya� �� •� -•.Y • W ' _ ♦ • �pppp�ppppp� ♦ - � +iii � • _ • a Mf • ������ 1 �.Ii ��r4rair --wi �I I ♦• 1 �� I��I�I�II- �I' 1 ♦1� • i1 p 11� w� a •1. t A I a pi• - -_♦ir rc1.!!1� •� 112 • '� • _ ♦�♦ /�G t' . i A li.. I r I. • t.. may- - ��.�'' �•''Tf;•�::::. �.aora '�• ;1 . ;:rrrrr:'......... ...... �`I 1 �'II`!'_�111 �'II` 1♦ ♦1 �'II`. •.�.1 �. III ._ ♦�i.1`.'�� - ■ . ■ Zttt 15 20 0 0 90% Col HERRERA 2200 Sixth Avenue Suite 1100 Seattle. Washington 98121 -1820 206-441 -9080 206 - 441 -9108 FAX ENVIRONMENTAL CONSULTANTS tOp1NAw.IrrtNWnC.mm 0 tY2 1 IF THIS a4a DOES NOT MEASURE 1' THEN DRAWING S NOT PLOTTED TO ORIGINAL SCALE. APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 9Y: DIRECTOR. CONTWCTOIG SERVICES NAME OR INITIALS AND DATE DESIGNED S. WALL (04/2008) CHECKED A AZOUS (04/2008) INITIALS AND DATE REVIEWED: DES. SLOT CONST. PROJ. MGR. DRAWN L1URt®GE (04/2008) CHECKED A AZOUS (04/2009) RECEIVED REVISED AS BUILT ML 0 I.00 N MISONICE RM 0E CRY CT YATLE MOON) PING MO tiEWY dme NO ORES OOOME11t! CNLID f01 111 IELaxI R.a.1 O' MME= M1OL/ 20 cottoptke CONVEYANCE PROJECT PLANTING PLAN FOR TEMPORARILY DISTURBED AREAS ieeattle Public Utilities ORCONNICE NO. APPROVED FUND•. SCALE AS NOTED INSPECTOR'S 80010 City of Seattle Chuck Clarke, Director NORFOLK -MLK WAY SUBBASIN STORMWATER IMPROVEMENTS 0 PC C333205 R/W co VAULT PLAN NO. SHEET 1 of 1 3 ea* Dept. Of Community AFFIDAVIT of .J u1 wita • Development OF DISTRIBUTION / � ii ► L_� _ . �' HEREBY DECLARE THAT: ,' Project Number: 6 0 Mailer's Signature: PeiP&my0 Notice of Public Hearing Mailin : re , uested b • : ALF / Determination of Non - Significance Notice of Public Meeting Mitigated Determination of Non - Significance Board of Adjustment Agenda Packet Determination of Significance & Scoping Notice Board of Appeals Agenda Packet Notice of Action Planning Commission Agenda Packet Official Notice Short Subdivision Agenda IV' Notice of Application Shoreline Mgmt Permit Notice of Application for Shoreline Mgmt Permit _ _ FAX To Seattle Times Classifieds Mail: Gail Muller Classifieds PO Box 70 - Seattle WA 98111 Other: Was mailed to each of the addresses listed/attached on this c2 day of in the year 20 5 C:\DOCUMENTS AND SETTINGS\ TERI- S SKTOP \AFFIDAVITOFDISTRIBUTION.DOC project Name: L.5. ZZ �1:) / /! 2/ ZD - ,' Project Number: 6 0 Mailer's Signature: PeiP&my0 WWII -/ Mailin : re , uested b • : ALF / C:\DOCUMENTS AND SETTINGS\ TERI- S SKTOP \AFFIDAVITOFDISTRIBUTION.DOC CITY OF TUKWILA NOTICE OF APPLICATION PROJECT INFORMATION Seattle Public Utilities (SPU) is proposing to make storm drainage and water quality improvements on the east side of I -5 in the vicinity of the Boeing Access Road interchange. Most of the project area is located within the City of Seattle. For the portion of the project site within the City of Tukwila, SPU is requesting a Type 2 Special Permission Director decision to clean and regrade a drainage ditch classified as a Type 2 wetland according to TMC 18.45.080. Temporary impacts in this area amount to a total of 0.03 acres of wetland in Tukwila. Impacts are proposed to be mitigated through removal of invasive vegetation and the addition of native plantings. Projects applied for include: L08 -013, Special Permission Director SEPA: The City of Seattle has issued Determination of Non - Significance (DNS) for as the lead agency for this project. Studies required with the applications include: A wetland delineation report and wetland mitigation plan. FILES AVAILABLE FOR :PUBLIC REVIEW The application is available for review at the City of Tukwila, Department of Community Development (DCD), located at 6300 Southcenter Blvd #100. OPPORTUNITY FOR PUBLIC COMMENT Your written comments on the project are requested. They must be delivered to DCD at the address above or postmarked no later than 5:00 P.M., Monday, June 16, 2008. APPEALS You may request a copy of any decision, information on hearings, and your appeal rights by calling DCD at (206) 431 -3670. For further information on this proposal, contact Jaimie Reavis at (206) 431 -3659, jreavis@ci.tukwila.wa.us or visit our offices at 6300 Southcenter Boulevard, Suite #100, Monday through Friday, 8:30 a.m. to 5:00 p.m. Application Filed: April 10, 2008 Notice of Completeness Issued: May 2, 2008 Notice of Application Issued: June 2, 2008 01. .. �� 11.11 " - lms rarIBEINIIM ��& ... 111II PUG T CREEK NATURAL AREA *� ,r..� ■�>. MITIGATION SITE "11 �� x,11 ������ ' ''.hindrillion 11117111f/A. Igh NM. ..iuramm. SIN, or • sai ,71�- -lid■ �/� PROJECT SITE COORDINATES: SECTIONS 3 AND 10, TOWNSHIP 23 NORTH, RANGE 4 EAST LAT. 47°30'35 "N, LONG. 122 °16'58'W MITIGATION SITE COORDINATES: LAT. 47 °33'131N, LONG. 122 °21'30°W DATUM: NAVD -88 t 3 2200 8EM Avenue Bulb 1100 Seattle. Weahingt01 98121 -1820 208.4414080 208•414108 FAX Date: DECEMBER 18, 2007 VICINITY MAP Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 1 of 6 City of Tukwila Department of Community Development 6300 Southcenter Boulevard 0 Suite 100 Tukwila, WA 98188 -2599 Mr. Arnel Valmonte - SPU 700 Fifth Ave., Suite 4900 P.O. Box 34018 Seattle, WA 98124 -4018 City of Tukwila Department of Community Development 6300 Southcenter Boulevard O Suite 100 Tukwila, WA 98188 -2599 Amanda Azous Herrera Environmental Consultants 2200 Sixth Ave, Suite 1100 Seattle, WA 98121 Susan Wall Herrera Environmental Consultants 101 E Broadway, Suite 610 Missoula, Montana 59802 • • • CHECKLIST: ENVIRONMENTAL REVIEW /SHORELINE PERMIT MAILINGS FEDERAL AGENCIES U.S. ARMY CORPS OF ENGINEERS A1WEDERAL HIGHWAY ADMINISTRATION () DEPT OF FISH & WILDLIFE ( ) U.S. ENVIRONMENTAL PROTECTION AGENCY ( ) U.S. DEPT OF H.U.D. ( ) NATIONAL MARINE FISHERIES SERVICE WASHINGTON STATE AGENCIES ( ) OFFICE OF ARCHAEOLOGY ( ) TRANSPORTATION DEPARTMENT ( ) DEPT NATURAL RESOURCES ( ) OFFICE OF THE GOVERNOR ( ) DEPT OF COMM. TRADE & ECONOMIC DEV. )DEPT OF FISHERIES & WILDLIFE KING COUNTY AGENCIES ( ) BOUNDARY REVIEW BOARD ( ) FIRE DISTRICT #11 ,(J FIRE DISTRICT #2 4K.C. WASTEWATER TREATMENT DIVISION ( ) K.C. DEPT OF PARKS & REC ( ) K.C. ASSESSORS OFFICE ( ) TUKWILA SCHOOL DISTRICT ( ) TUKWILA LIBRARY ( ) RENTON LIBRARY ( ) KENT LIBRARY ( ) CITY OF SEATTLE LIBRARY ( ) QWEST ( ) SEATTLE CITY LIGHT ( ) PUGET SOUND ENERGY ( ) HIGHLINE WATER DISTRICT ( ) SEATTLE WATER DEPARTMENT () COMCAST SCHOOLS /LIBRARIES UTILITIES CITY AGENCIES ( ) KENT PLANNING DEPT ( ) TUKWILA CITY DEPARTMENTS: () PUBLIC WORKS ( ) FIRE () POLICE () FINANCE ( ) PLANNING ( ) BUILDING ( ) PARKS & REC. () MAYOR ( ) CITY CLERK OTHER LOCAL AGENCIES ( ) PUGET SOUND REGIONAL COUNCIL () SW K C CHAMBER OF COMMERCE j.JVIUCKLESHOOT INDIAN TRIBE ) CULTURAL RESOURCES PROGRAM** J4FISHERIES PROGRAM** ( ) WILDLIFE PROGRAM **Send SEPA Checklist and full set of plans w/ NOA MEDIA ( ) SEATTLE TIMES ( ) SOUTH COUNTY JOURNAL P:\ADMINISTRATIVE \FORMS \CHECKLIST.DOC ( ) DEPT OF SOCIAL & HEALTH SERV. ( ) DEPT OF ECOLOGY, SHORELAND DIV, NW Regional Office DEPT OF ECOLOGY, SEPA DIVISION* ( OFFICE OF ATTORNEY GENERAL * SEND CHKLIST W/ DETERMINATIONS * SEND SITE MAPS WITH DECISION ( ) HEALTH DEPT ( ) PORT OF SEATTLE DEV & ENVIR SERVICES -SEPA INFO CNTR ( ) K.C. TRANSIT DIVISION - SEPA OFFICIAL 4)4K.C. LAND & WATER RESOURCES ( ) FOSTER LIBRARY () K C PUBLIC LIBRARY ( ) HIGHLINE SCHOOL DISTRICT ( ) SEATTLE SCHOOL DISTRICT ( ) RENTON SCHOOL DISTRICT ( ) OLYMPIC PIPELINE ( ) VAL -VUE SEWER DISTRICT ( ) WATER DISTRICT #20 ( ) WATER DISTRICT #125 ( ) CITY OF RENTON PUBLIC WORKS ( ) BRYN MAWR - LAKERIDGE SEWERNVATER DISTRICT () RENTON PLANNING DEPT ( ) CITY OF SEA -TAC () CITY OF BURIEN ( ) TUKWILA PLANNING COMMISSION MEMBERS ( ) TUKWILA CITY COUNCIL MEMBERS ( ) CITY OF SEATTLE - SEPA INFO CENTER - DCLU ( ) STRATEGIC PLANNING OFFICE* * NOTICE OF ALL SEATTLE RELATED PLNG PROJ. UWAMISH INDIAN TRIBE* ( P.S. AIR POLLUTION CLEAN AGENCY ( ) SOUND TRANSIT 4 pUWAMISH RIVER CLEAN -UP COALITION* * SEND NOTICE OF ALL APPLICATIONS ON DUWAMISH RIVER ( ) HIGHLINE TIMES ( ) CI.TUKWILA.WA.US.WWW PUBLIC NOTICE MAILINGS FOR PERMITS SEPA MAILINGS Mail to: (comment period starts on date of mailing) Dept. of Ecology Environmental Review Section *Applicant *Other agencies as necessary (checked off on attached list) *Any parties of record * send only the staff report, site plan and the SEPA Determination KC Transit Division — SEPA Official would like to receive information about all projects that might affect transit demand Send These Documents to DOE: SEPA Determination (3 -part from Sierra) Findings (staff report, usu. with MDNS) SEPA Checklist (filled out by applicant) Drawings/Plans of project (site plan, elevations, etc. from PMT's) Affidavit of Distribution (notice was mailed or sent to newspaper) SHORELINE MAILINGS: Notice of Application for a Substantial Development Permit must be mailed to owners and to property owners within 500 feet of subject property, comments are due 30 days after the notice of application is mailed/posted. The notice of Application for Shoreline Substantial Development Permit must include a statement that any person desiring to submit written comments on the application or desiring to receive notification of the final decision on the application may do so within 30 days of the notice of application. If a hearing will be held on the application, the hearing notice must include the information that written comments may be submitted, or oral presentation made at the hearing. Notice is sent to the NW Regional Office Shorelands & Environmental Assistance Program. Shoreline Permit Notice of Decision: Mail to: (within 8 days of decision; 21 -day appeal period begins date received by DOE) Department of Ecology Shorelands Section, NW Regional Office State Attorney General *Applicant *Indian Tribes *Other agencies as necessary (checked off on attached list). *My parties of record * send only the staff report, site plan and the SEPA Determination Send These Documents to DOE and Attorney General: Permit Data Sheet Shoreline Substantial Development Permit (3 -part from Sierra) Findings (staff report or memo) Shoreline Permit Application Form (filled out by applicant) Drawings/Plans of project (site plan, elevations, etc. from PMT's) — Site plan, with mean high water mark & improvements — Cross- sections of site with structures & shoreline - Grading Plan — Vicinity map SEPA determination (3 -part from Sierra) Findings (staff report or memo) SEPA Checklist (filled out by applicant) Any background studies related to impacts on shoreline Notice of Application Affidavit of Distribution (notice was mailed) P:\ADMINISTRATIVE \FORMS \CHECKLIST.DOC HERRERA ENVIRONMENTAL CONSULTANTS 2200 Sixth Avenue Suite 1100 Seattle Washington 98121 (206) 441 -9080 FAX 441 -9108 101 E Broadway Suite 610 Missoula Montana 59802 (406) 721-4204 FAX 721 -4232 322 NW Fifth Avenue Suite 315 Portland Oregon 97209 (503) 228 -4301 FAX 228 -3373 435 Holgerson Road Sequim Washington 98382 (360) 683 -9109 FAX 683 -3671 April 9, 2008 Sandra Whiting City of Tukwila Department of Community Development 6300 Southcenter Boulevard Tukwila, WA 98188 Subject: Special Permission Director Permit Dear Sandra: Enclosed is a copy of the Special Permission Director Permit Application and supporting materials for the Norfolk- MLK Way Stormwater Improvements Project regarding temporary project impacts on a portion of a wetland in the WSDOT right - of -way east of I -5 within the City of Tukwila. The enclosed materials include plan sheets for the stormwater conveyance improvements project, a Special Permission Director Application checklist, and a Request for Sensitive Area Ordinance Deviation for temporary alteration of a wetland. Sincerely, Herrera Environmental Consultants, Inc. Amanda Azous Senior Scientist Enclosures: Plans for stormwater conveyance improvements; Special Permission Director Application and Checklist; Request for Sensitive Area Ordinance Deviation AA final revised _special _permission_tukwila.doc April 2, 2008 • Cizy of Tukwila Jim Haggerton, Mayor Department of Community Development Jack Pace, Director NOTICE OF INCOMPLETE APPLICATION Arnel Valmonte Seattle Public Utilities Seattle Municipal Tower, 700 Fifth Ave. Seattle, WA 98124 -4018 RE: Special Permission Director, Environmentally Sensitive Areas Deviation L08 -013 Dear Arnel: Your application for a Special Permission Director decision to allow a buffer reduction for a wetland located west of I -5 and north of the Boeing Access Road interchange has been determined to be incomplete. In order to be a complete application, the following must be sub miffed to the permit center: a. $365 application fee. Upon receipt of these items, the City will re- review them for completeness and will mail you written notification of completeness or incompleteness within 14 days. This application will expire if we do not receive the additional information within ninety days of the date of this letter unless an extension is granted pursuant to Section 18.104.070(E). If you have any questions with this matter you may call me at (206) 431 -3659. Sincerely, aimie Reavis Assistant Planner JR Page 1 of 1 H: \Special Permission\Norfolk - Boeing Access Road wetiands.DOC 04/01/2008 5:17:00 PM 6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • Phone: 206 - 431 -3670 • Fax: 206 - 431 -3665 c=1,1iP+R- 1 Vr►N C' CITY OF TUKWILA Department of Community Development 6300 Southcenter Boulevard, Tukwila, WA 98188 Telephone: (206) 431 -3670 FAX (206) 431 -3665 E -mail: tukplan(dci.tukwila.wa.us V t (VED 1/APR 20 , oe aacioilitamirirr SPECIAL PERMISSION DIRECTOR APPLICATION FOR STAFF USE ONLY Permits Plus Type: P -SP Planner: File Number: Application Complete (Date: ) Project File Number: Application Incomplete (Date: ) Other File Numbers: NAME OF PROJECT /DEVELOPMENT:Nnrfn1lc-MT.x wny Srnrmwntor TmprnuPmr.nt Proiect LOCATION OF PROJECT/DEVELOPMENT: Give street address or, if vacant, indicate lot(s), block and subdivision, access street, and nearest intersection. West of I -5 in the vicinity of South Boeing Access Road interchange LIST ALL TAXLOTNUMBERS (this information may be found on your tax. statement). 0323049273 and 0171049241 DEVELOPMENT COORDINATOR : The individual who: • has decision making authority on behalf of the owner /applicant in meetings with City staff, • has full responsibility for identifying and satisfying all relevant and sometimes overlapping development standards, and • is the primary contact with the City to whom all notices and reports will be sent. Name: Arne1 Valmonte �Seattla Public Utilities Address: Seattle Municipal Tower, 700 Fifth Ave. Seattle, WA 98124 -4018 Phone: 206 -615 -1438 E -mail arnel.valmonte @seattle.gov Signature: FAX: Date: P:1Planning Forms\Applications\2007 Applications \SPDirector- 12 -07.doc • ' 't LL•CIVtU APR 2 8 2008 CO1\ TPLETE APPLICATION CHECKLIST The materials listed below must be submitted with your application unless specifically waived in writing by the Public Works Department and the Department of Community Development. Please contact each Department if you feel that certain items are not applicable to your project and should be waived. Application review will not begin until it is determined to be complete. ADDITIONAL MATERIALS MAY BE REQUIRED. The initial application materials allow project review to begin and vest the applicant's rights. However, the City may require additional information as needed to establish consistency with development standards. City staff are available to answer questions about application materials at 206 - 431 -3670 (Department of Community Development) and 206 -433 -0179 (Department of Public Works). Check items submitted .� ::;'; application . Information Required ; .:. Nfay be waived in' unusual cases, upon approval of both-Pa-bile-Works and,- . Tanning APPLICATION MATERIALS: X 1. Application Checklist one (1) copy, indicating items submitted with application. X 2. Permit Fee (LDR = $240, Other zones = $365). X 3. Written description of the project, the deviation being requested and response to the applicable decision criteria. ZONING CODE PARKING DEVIATION 4. A complete description of the proposed construction relative to parking areas, and all supporting agreements. 5. Dimensional site plan(s) to demonstrate parking area consistent with Zoning Code requirements. 6. Parking studies as needed to demonstrate adequate parking is provided. LANDSCAPE DEVIATION 7. Landscape plan — two (2) copies showing size and species of existing and proposed plant materials, required perimeter landscape types, parking areas, buildings, walkways, transit facilities, property lines, dimensions and area of planting beds and any calculations necessary to demonstrate compliance with review criteria SENSITIVE AREA ORDINANCE DEVIATIONS X 8. Site Plan — two (2) copies showing all buildings, parking areas, walkways, property lines, planting areas, sensitive areas, their buffers and setbacks. X 9. Sensitive area studies and a ance cent plans to justify -requ st � '�'i�o vt � and demonstrate that the �.a1 not result in a direct or indirect short-term or long- term adverse impact to the sensitive area per TMC 18.45.090 D. SIGN CODE APPROVAL/DEVIATION 10. Complete "Permanent Sign Permit Application" with all supporting materials and fees ($115). 11. The following information should be given on the plans: North arrow, title, scale and date; P:1Planning Forms\Applications12007 Applications \SPDirector- 12 -07.doc • • APR�8 'Illii COMMUNITY DEVELOPMENT Check items:..:: submitted : , :.. wi 0Plicatiou : ' • Infot ation:RRequired : May be waned in. unusual cases, upon approval of both Public Arks and Planning ... _ Vicinity map showing location and names of adjacent roads; Property lines; Locations of all buildings on site; Dimensioned elevations of building drawn to scale (for wall signs); Elevations, dimensions and materials of proposed sign(s) including advertising copy; Color elevation of proposed sign. CARGO CONTAINER APPROVAL 12. Site plan showing the location of the container(s) in relationship to parking areas, property lines, buildings, streets, trails, landscape areas and setbacks. 13. Description of the proposed screening. 14. Dimensions of proposed cargo container. SINGLE- FAMLLY DESIGN STANDARD EXCEPTIONS 15. Dimensioned and scalable building elevations with keyed colors and materials. 16. The site plan must include a graphic scale, north arrow, proposed house footprint, any existing structures, lot lines, setbacks, adjacent streets, driveways, parking areas, any sensitive areas and any fences, rockeries or retaining walls. P:1Planning FormslApplications12007 Applications1SPDirector- 12 -07.doc • RECEIVE. R 2 8 2000 COMAUNITY DEVELOPMENT Request for Sensitive Area Ordinance Deviation Norfolk- MLK Way Stormwater Improvements Project Prepared for City of Tukwila Department of Community Development 6300 Southcenter Boulevard Tukwila, WA 98188 Prepared by Herrera Environmental Consultants 2200 Sixth Avenue, Suite 1100 Seattle, Washington 98121 Telephone: 206/441 -9080 April 9, 2008 • • Project Description Request for Sensitive Area OrdiiRi APR 2 8 HOF EQ�VELOP DEVELOPMENT Seattle Public Utilities (SPU) proposes improvements to the conveyance and treatment systems in the Norfolk -MLK Way subbasin to reduce frequent overflow of stormwater to the sanitary sewer system, restore the conveyance capacity of the system, reduce pollutant loading to the lower Duwamish Waterway, and reduce flooding on Martin Luther King Jr. Way. The proposed stormwater system improvements include conveyance improvements to be constructed in the summer of 2008 and storm water treatment improvements to be constructed in the summer of 2009. This application applies to the conveyance improvements, involving regrading the upper segment of the WSDOT ditch that parallels I -5 The project area is in the vicinity of the South Boeing Access road interchange on I -5 as shown on Sheet 1 of the attached plan sheets. The WSDOT ditch has not been maintained and consequently has silted in with 1 to 3 feet of sediment for much of its length resulting in greatly reduced hydraulic capacity. The ditch would be cleaned and regraded in the 340 -foot section extending from 100 feet upstream of the outfall from the piped drainage system to 240 feet downstream. A backhoe would be used to reshape the ditch to a trapezoidal shape with 5 -foot bottom width and 3:1 side - slopes. The upstream and downstream invert of the regraded ditch would match the existing grade. The depth of cut along the ditch would vary from about 2.5 feet at the pipe outfall to zero at the downstream end of the project area. Sensitive Area Existing Conditions The project site is located within the Norfolk drainage basin. The site generally slopes and drains to the south and west toward the Duwamish River, although development features and microtopography block stormwater flows from draining into the river. Topography on the east side of the site is generally flat, except where existing wetlands and stormwater ponds and swales are present at lower elevations. Existing stormwater ponds and a drainage swale collect and treat stormwater from the portion of I -5 within the northern part of the Norfolk Drainage Basin. Delineated wetland boundary On May 5, 2006, a wetland biologist performed a wetland delineation within the WSDOT ditch regrading area (SPU 2006). One wetland (designated as Wetland D) was identified, and is shown on Sheet 2. The southern portion of this wetland is located within the City of Tukwila. Condition of wetland and wetland buffer Wetland D is a 1.4 acre linear scrub -shrub ditch type wetland system with vegetation dominated by reed canarygrass, nightshade, hardhack, Sitka willow and black cottonwood. Blackberry, Scots broom and Nootka rose are found in the adjacent upland. In this area, the I -5 embankment as final revised specialpermission tukwila.doc April 9, 2008 1 Herrera Environmental Consultants - wain APR 2 8 2009 • tCEIVED COMMUNITY DEVELOPMENT Request for Sensitive Area Ordinance Deviation forms the west bank of Wetland D, and fill for the commercial /industrial area forms the east bank. Hydrogeomorphically, the WSDOT ditch is classified as a depressional and flat wetland. There is evidence of seasonal flooding approximately 0.5 to 2 feet in depth. Water sources for this wetland include storm water from the Norfolk basin and precipitation. Stormwater discharges into the wetland from the existing 36 -inch diameter pipe and is conveyed northward about 950 feet in the ditch before reaching a set of parallel culverts under I -5. The emergent portion of Wetland D is dominated by reed canary grass (Phalaris arundinacea) and climbing nighshade (Solanum dulcamara). Hardstem bulrush (Scirpus acutus) is present in the southern end. Shrub areas are dominated by Douglas spirea (Spireae douglasii) and common cattail (Typha latifolia). The deciduous tree layer is dominated by Sitka willow (Salix sitchensis) and black cottonwood (Populus trichocarpa) (SPU 2006). According to the Tukwila Municipal Code, this is a Type 2 wetland. Type 2 wetlands require an 80 -foot buffer according the City of Tukwila Sensitive Areas Ordinance (18.45.080) however there is no effective buffer adjacent to Wetland D within the project area. Requested sensitive area ordinance deviation SPU requests permission to operate equipment in Wetland D for the purpose of maintaining the ditch by removing sediment that has discharged from the conveyance system and built up in the wetland. The proposed work in Wetland D will comply with the following Tukwila Municipal Code 18.45.090.B.1 requirements for alteration of a wetland: a. The alteration will not adversely affect water quality; b. The alteration will not adversely affect fish, wildlife, or their habitat; c. The alteration will not have an adverse effect on drainage and/or stormwater detention capabilities; d. The alteration will not lead to unstable earth conditions or create an erosion hazard or contribute to scouring actions; e. The alteration will not be materially detrimental to any other property; and f. The alteration will not have adverse effects on any other sensitive areas. Impacts Regrading the WSDOT ditch will result in temporary impacts on 0.03 acres of wetland within the City of Tukwila (Wetland D), as shown on Sheets 3 and 4. Coordination with other regulatory agencies This activity is being proposed under USACE Nationwide Permit 41 - Reshaping Existing Drainage Ditches. Compensatory mitigation is not required under this permit. Impacts to Wetland D have been discussed with the Washington Department of Ecology and will not require mitigation because the impacts are considered temporary due to the fact that no trees over 6 inches diameter at breast height will be removed. In addition impacts to Wetland D have been discussed with the Seattle Department of Planning and Development (DPD). The threshold of as final revised special permission tukwila.dac April 9, 2008 2 Herrera Environmental Consultants • • Request for Sensitive Area Ordinance Deviation development per SMC 25.09.160.B.1.a is 100 square feet of permanent wetland impact for a Category III wetland. Therefore no mitigation is required for these impacts per SMC 25.09.160.B.1.a. Seattle DPD has approved the work with an Environmentally Critical Areas exemption. Avoidance and minimization measures To minimize wetland impacts on the WSDOT ditch, the minimum amount of ditch regrading needed for acceptable conveyance system performance was calculated in the hydraulic modeling performed for the preliminary engineering study. Regrading the entire WSDOT ditch would provide greater conveyance improvement, however it would result in substantially more disturbance to Wetland D. In addition, a 0.25 acre access road was removed from the design to further reduce impacts to Wetland D. Best management practices and minimization measures will be implemented during the design and construction phases of the project in order to minimize the potential impacts on fish and aquatic life. A temporary erosion and sediment control (TESC) plan and a spill prevention, control, and countermeasures (SPCC) plan will be prepared prior to the start of construction. Clearing limits will be marked to avoid impacts on critical areas and all equipment to be used for construction activities will be cleaned and inspected before it arrives at the project site to minimize potential leaks. Compensation for temporary impacts Impacted areas will be planted with native species to restore the area to an improved functional state. In addition the blackberries growing between the ditch and Interstate 5 will be removed and the site planted with appropriate native species. References SPU. 2006. Wetland Delineation Report. Prepared for Arnel Valmonte, project manager, SPU Engineering Division by Michael Bonoff, Wetland Biologist, SPU Environment, Science and Technology Section. as final revised special permission tukwila.doc April 9, 2008 3 Herrera Environmental Consultants $ t 1s 1 g 3000 6000 SCALE 1" = 3000' PUGET CREEK NATURAL AREA MITIGATION SITE BO ING FIEL KING COUNTY INTERNATIONAL AIRPOR 1 HIE LI 1111111111111L. noTHEINIVIIII IIIPmEllillren 11111110 IIINS I 11111 INE 1,' PROJECT SITE COORDINATES: SECTIONS 3 AND 10, TOWNSHIP 23 NORTH, RANGE 4 EAST LAT. 47 °30'35 "N, LONG. 122 °16'58 "W MITIGATION SITE COORDINATES: LAT. 47 °33'13 "N, LONG. 122 °21'30"W DATUM: NAVD -88 8 112TH ST HERRERA CONSULTANTS 2200 Sixth Avenue Suite 1100 Seattle, Washington 98121 -1820 209-441 -9080 208 -441 -9108 FAX Date: DECEMBER 18, 2007 VICINITY MAP Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 1 of 6 Match Existing Grade Regrade Channel 2" PSD Oil Control Structure 01;127 PSD � TUSEATTLE CORPORATE LIMIT NWILA CORPORA LIMIT LEGEND Proposed improvement CS=ET Wetland Ditch Storm drain 1 -tool topographic contour 5-foot topographic contour — Section line Property /easement boundary City limit Sediment Trap Abandon in Place Existing 36" CMP 517 0 50' 100' Approx Scale: 1-= 150' 36" wf Duckbill Flapgate 10'MH, • 10'MH"'t Abandon in Place Existing 24" CMP & Manhole TETRA TECH www.tetratech.com 1420 Fltlh Avenue, Suite 800 Seattle, Washington 98101 Phone: 208. 8839300 Fax: 208-083.9301 Date: DECEMBER 18, 2007 PROPOSED CONVEYANCE IMPROVEMENTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 2 of 6 g e 3 0 Y � 9 00 TART PROJECT WETLAND O '6 O 0 15 0 15 30 SCALE IN FEET 0 DITCH CENTE CONSTRUCTION LIMIT S E ADJACENT PROPERTY OWNERS: (9 PAPE MATERIAL HANDLING NOTE: J4 WETLAND AREA TEMPORARILY DISTURBED (SEATTLE): 4,792 SQ FT (0.11 ACRES) WETLAND AREA TEMPORARILY DISTURBED (TUKWILA): 1,307 SQ FT (0.03 ACRES) TOTAL PROJECT SEDIMENT EXCAVATION VOLUME: 334 CU YDS TOTAL PROJECT FILL VOLUME: 105 CU YDS FOR OUTLET PROTECTION EXCAVATION WITHIN WETLAND D: 133 CU YDS FILL WITHIN WETLAND D: 6 CU YDS DATUM: NAVD -88 PAD LEGEND: — — — — PROJECT LIMITS CONSTRUCTION LIMITS FENCE 11 — PROPOSED CONTOURS —12— EXISTING CONTOURS EXISTING WETLAND C-1 HERRERA 2200 Slth Avenue Suhe 1100 Seattle, Washington 98121 -1820 208- 441 -9080 206- 441 -9108 FAX ENVIRONMENTAL CONSW.TANIS MlpJhww.lvnea4nmm Date: DECEMBER 18, 2007 WETLAND IMPACTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 3 of 6 12'PSD 39LF, OIL CONTROL STRUCTURE 15 0 15 30 SEDIMENT TRAP WITH 3H:1V SIDE SLOPES SCALE IN FEET EXTEND EXISTING CONCRETE BLOCK RETAINING WALL 12' PSD 29LF, S =0.30% O FLOW DIVERSION STRUCTURE CITY OF SEATTLE CITY OF TUKWILA LEGEND: UTLE NOT F0U LF ASPH 36' CM P BY SURVEY T PROTECTION PAD V — — — — PROJECT LIMITS CONSTRUCTION LIMITS FENCE —11— PROPOSED CONTOURS 12 EXISTING CONTOURS EXISTING WETLAND CONSTRUCTION LIMIT ADJACENT PROPERTY OWNERS: 0 PAPE MATERIAL HANDLING 0 LINDAHL CEDAR HOMES E NOTE: WETLAND AREA TEMPORARILY DISTURBED (SEATTLE): WETLAND AREA TEMPORARILY DISTURBED ( TUKWILA): TOTAL PROJECT SEDIMENT EXCAVATION VOLUME: TOTAL PROJECT FILL VOLUME: EXCAVATION WITHIN WETLAND D: FILL WITHIN WETLAND 0: DATUM: NAVD -88 cc� 4,792 SQ FT (0.11 ACRES) 1,307 SQ FT (0.03 ACRES) 334 CU YDS 105 CU YDS FOR OUTLET PROTECTION PAD 133 CU YDS 6 CU YDS END PROJECT 0 HERRERA 2200 Sixth Avenue Suite 1100 Seattle, Washington 98121 -1820 208. 441 -9080 208.441 -9108 FAX ENVIRONMENTAL CONSULTANTS ING'iw.nw.ertmeb,c.mm Date: DECEMBER 18, 2007 WETLAND IMPACTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 4 of 6 gs LEGEND: 10 0 10. 20 SCALE IN FEET - - - - PROJECT LIMITS CONSTRUCTION LIMITS FENCE -11 - PROPOSED CONTOURS 12 EXISTING CONTOURS EXISTING WETLAND 20 10 0 +00 DATUM: NAVD -88 PLAN — DITCH (NORTH) SCALE: 1' =20' EXISTING GROUND SURFACE WETLAND D 0+20 0 +40 SEDIMENT TO BE REMOVED \� \ 0 +60 SECTION — DITCH (NORTH) SCALE: 1' =20' 1 0+80 1+00 0 20 10 1+20 GI HERRERA 2200 Shah Avenue Suite 1100 Seattle, Washington 98121 -1820 208 - 441.9080 208 - 441-9108 FAX CONSUL TAM'S htl;dhww.lvmabcmn Date: DECEMBER 18, 2007 GRADING PLAN AND SECTION Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 5 of 6 LEGEND: —1 1 — 12 PROJECT LIMITS CONSTRUCTION LIMITS FENCE PROPOSED CONTOURS EXISTING CONTOURS EXISTING WETLAND 10 0 10 20 SCALE IN FEET 20- 10- 0 +00 DATUM: NAVD -88 PLAN — SEDIMENT TRAP (SOUTH) SCALE: 1' =20' —WETLAND D-- EXCAVATION AREA 0 +20 0 +40 0 +60 SECTION — SEDIMENT TRAP (SOUTH) SCALE: 1' =20' 0 EXISTING GROUND SURFACE PROPOSED GROUND SURFACE -10 0 +80 1 +00 1 +20 20 C'G HERRERA 2200 Sbcth Avenue Suite 1100 Seattle, Washington 98121 -1820 208 -441 -9080 208- 441 -9108 FAX E a,30t EMAI corvsu was h4rmiw..harera`ncmn Date: DECEMBER 18, 2007 GRADING PLAN AND SECTION Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 6 of 6 • Apo ,A D NORFOLK - MLK WAY SUB BASIN STORMWATER IMPROVEMENTS WETLAND DELINEATION REPORT JUNE 7, 2006 Prepared for Arnel Valmonte, Project Manager Seattle Public Utilities, Engineering Division Prepared by Michael Bonoff, Wetland Biologist SPU Environment, Science and Technology Section • • SUMMARY Seattle Public Utilities (SPU) needs to make drainage and water quality improvements in the most southern portion of the Norfolk Drainage Basin (MLK sub basin). The current performance level of the drainage system is well below design conditions caused by sedimentation within a particular pipe and wetland ditch segment. The scrub shrub wetland of 1.4 acres is a narrow linear system conveying storm water north alongside of and underneath I -5. Seattle's Critical Area Ordinance requires a 60 foot buffer. STUDY AREA DESCRIPTION The project area in Seattle borders Tukwila and runs along the east side of I -5 for a thousand feet or less (See the Vicinity and Location map). METHODS Literature Review Existing engineering and geo technical reports were reviewed. Air photos available through the City's GIS were examined. Delineation Approach The routine onsite determination method described in the Washington Department of Ecology Washington State Wetlands Identification and Delineation Manual methodology was used to delineate wetlands. The Ecology manual requires the use of the three - wetland parameter methodology when determining the presence or absence of wetlands. With few exceptions, all three parameters including wetland hydrology, hydric soils and hydrophytic vegetation must be present for an area under normal circumstances to meet the wetland criteria. Michael Bonoff, an SPU biologist and Wetland Scientist performed the delineation. An auger was used to sample soils in and around the wetlands. Then the representative soil pits were dug to a depth of 18 inches using a sharpshooter shovel. The south face of each pit was used for the soil observations and photos. A squeeze water bottle was used to moisten dry soils and determine their color using a Munsell Color Chart. Each hole was marked with blue wire flagging to show the wetland number and the upland or wetland location. Photos were taken of the soil pits and surrounding area (See Attachment 1). Vegetative sampling was conducted at each soil pit and dominant plant species and its percent cover was established. Data forms were compiled for each location (See Attachment 2). 2 • • Orange `wetland delineation boundary" ribbons ( #s 1 -13) were placed in that portion of the wetland that comprises the primary project location. Other areas were visually surveyed and these boundaries were established on aerial photos. Not all wetland areas could be physically accessed. Interstate 5 and a dense embankment of blackberry prevented access from the west and chain link fencing adjacent to the WDOT cloverleaf prevented access from the south. In other locations, the deciduous forest canopy, dense shrub layer and ponded water prevented physical access. The wetland boundaries are shown on the aerial, map #2. Reconnaissance A reconnaissance level inspection of the project site within the wetland was conducted by Michael Bonoff in 2000. RESULTS LITERATURE REVIEW Wetlands Identified The WSDOT plan set (1994) shows a uniformly linear wetland approximately 1400 feet long, averaging 35 feet wide. The wetland area is roughly 1.1 acres. A reconnaissance level inspection of the project area (Bonoff 2000) concluded that an emergent wetland existed from the drainage outfall to several hundred feet north. Soils SPU's Material Lab (2004) boring in the project area indicated that the first 7 feet consisted of high chroma colored silt with brown pockets underlain with silty sand and sand. Wildlife and Birds Red winged blackbirds were seen in Typha pockets in the south end of the wetland. Common garter snakes were seen on dry grasses both days in the project area. Hydrology The wetland hydrology is provided by several sources of storm water runoff. Primarily, storm water from the Norfolk basin is discharged into the wetland. Improvements made in 1979 and 1999 to improve drainage in the 224 acre MLK Way sub basin of the Norfolk drainage basin were connected to a privately owned 36 inch 3 • • diameter pipe that drains into the open ditch/wetland along I -5. The drainage feature carries storm water northward about 950 feet before reaching a cross drain under the freeway. The ditch now has filled with 1 to 3 feet of sediment within much of its alignment. This obstruction combined with sediment in the 36 -inch pipe has greatly reduced the drainage system hydraulic capacity. During rain events, flow now backs up into the city's sanitary sewer causing an overflow into the adjacent King County combined sewer system. In addition, city records indicate that storm water is discharged from parking areas of the warehouse properties immediately to the east. Storm water from the Boeing Access Road I -5 cloverleaf discharges in the south portion of the wetland and moves northward during rain events. The 24 -inch culvert under the freeway is elevated above depressed portions of the wetland so it does not continuously overflow into the culvert. Stormwater is also carried under the freeway through a 48 inch culvert. There is permanently ponded water in the wetland's south end and in portions of the ditch alignment. Land Use The I -5 embankment on the west confines the low corridor containing the wetland and the industrial warehousing and associated parking fill on the east. The WSDOT cloverleaf confines the south end. The wooded corridor continues north of the wetland. The open space corridor average width is 30 feet and contains a wetland of varying widths and the remnants of the 1960 era drainage ditch. FIELD RESULTS Soils Soils pits (S.P.$) were established across the mid section of the project area (S.P. #1 Upl and Wet) and in the north (S.P. #2 Upl and Wet). The soils pit locations are shown on aerial, Map #2, except for S.P. #2 Upl. The latter is located in the Norfolk Street right of way crossing the wooded corridor north of the wetland. Wetland Soil Pit # 1 consisted of a uniform dark brown silty loam (10YR 3/2) with abundant olive (5Y 5/6) redoximorphic features. Wetland S.P. #2 consisted of a uniform silty loam with a dark gray matrix color (10YR 4/1) and yellowish brown redox (7.5YR 5/6). These masses were abundant (25% of the matrix) and 3 -4 mm in size. Upland Soil Pit #1 consisted of 0 -8 inches depth of brown sand (10YR 4/3). This A horizon was underlain with 8 -16 inches depth of dark brown sand (10 YR 3/2) with strong brown abundant redox (7 YR 5/8 and 7 YR 4/6). These masses were 3 -5 mm in size. Upland Soil Pit #2 A horizon consisted of a (10YR 4/2) brown sandy loam with 1/4 4 • • inch pebbles. The B horizon consisted of (10YR 5/3) sand with pebbles up to 2 inches in diameter. Hydrology Wetland soil pits had standing water at 14 inches depth or less and the soils were saturated to the surface. Upland S.P #1 had a dry A horizon and a moist B horizon. There was no saturation on the bottom of the 18 -inch deep hole. Upland S.P. #2 was dry. There was evidence of seasonal flooding across the depressed portion of the vegetated corridor estimated to be between Y2 to 2 feet in depth. Shallow standing water was seen throughout the emergent areas and standing water of several feet deep was seen in the shrub and tree areas. No water movement was observed. Vegetation The wetland vegetation was dominated in the emergent areas by reed canary grass (Phalarus arundinacea) and nightshade (Solanum dulcama). Hardstem bulrush (Scirpus acutus) was present in the south end. The shrub areas were dominated by hardhack (Spirea douglasii) and cattail (Typha latifolia) in slight depressions. The deciduous tree layer was dominated by Sitka willow (Salix sitchensis) and black cottonwood (Populus balsamifera) up to 10 and 24 -inch diameters respectively. The upland buffer areas were dominated by blackberry (Rubus procerus) with smaller amounts of Scots broom (Cytisus scoparius) and nootka rose (Rosa nutkana). The shrubby nature of the buffer was complimented by landscape plantings of 8 inch diameter Shore pine (Pinus contorta) on the Lindal and other properties along the east wetland margin. These trees are more than 15 feet tall and provide > 75% crown closure. Invasive and Manmade Influences: The wetland was confined by I -5 and industrial fill. The modification to the natural environment allowed several invasive species to dominate the wetland and buffer. These were blackberry, reed canary grass and nightshade. Wetland Delineation A Palustrine Scrub Shrub (PSS) wetland was delineated of approximately 1.4 acres. The deciduous forest canopy covered about 45% of the wetland and vegetated buffer combined but less than 30% of the wetland. The dense shrub under story covered more than a third of the wetland itself. The reed canary grass meadow areas consisted of about 20 % of the wetland. WETLAND FUNCTIONS AND RATING The wetland was evaluated according to the Washington State Rating System. It was classified as a Depressional and Flats Wetland based on the outlet being above the lowest points and an intermittent wetland flow. 5 • • The total score is 42 points, within the 30 -50 range for a Category III wetland. The Hydrologic functions are moderate for storage and protection of aquatic resources downstream as well as high water quality functions with complete vegetation cover and a large seasonally ponded area. The Habitat functions rate 10 points which is below the Moderate level rating of 20 -28 points. The wetland contains 2 vegetation types, 2 water regimes and moderate interspersion combined with low functions for species richness, buffer values and connectivity in the landscape. The wetland can be characterized as an isolated habitat confined by a major transportation corridor and dense commercial uses. On the other hand, the wetland hydrology is part of the routing of MLK sub basin stormwater to the Duwamish River. The most important wetland function is stormwater quality improvement as a result of the filtration of sediment by the reed canary grass and shrubs. Some metal uptake occurs in the Typha plant community and to a lesser degree the shrub communities as well. Category III wetlands require a 60 foot water quality buffer according to the City of Seattle, Critical Areas Ordinance (25.09.160 C.1.b.). No additional Habitat buffer is required. REFERENCES Knable, Rob, 2006. Seattle DPD Wetland Biologist. Personal communication, May 10, 2006. Washington Department of Ecology, 2004. Washington State Wetland Rating System for Western Washington. Pub #04 -06 -025 Washington Department of Ecology, 1997. Washington State Wetland Identification and Delineation Manual. Pub. #96 -94. Munsell Color, 1988. Munsell Soil Color charts. Kollmorgen Instruments Corp., Baltimore, MD. Seattle Public Utilities, 2005. Norfolk — MLK Way Sub -Basin Stormwater Improvements Project Development Plan #1. June 22, 2005. Seattle Public Utilities Materials Laboratory, 2004. Geotechnical Report — MLK Way/Norfolk Drainage Structures, Seattle, Washington. Log boring B -1. January 2004. Washington State Department of Transportation, 1994. Wetland Delineation Map, subject area shown as wetland #10. From plan set (Parsons Brincker) April 1994. USDA Natural Resources Conservation District, 1996, Key to Field Indicators of Hydric Soils, Version 3.2, July 1996. 6 • RECEIVED • MAR 0 6 2008 C41211MUNiTY Department of Community.Developmeht DEVELOPMENT SPECIAL 6300 Southeenter Baulevarzl, Tukwila, IVA 98188 Teleplunni: (206) 01-3670 FAX (ION 43i-3665 1?-mail;.tukplattaioi.tukwila.wa.us CITY OF TUKWILA PERMISSION DIRECTOR FOR STAFF USE ONLY Pertnits Phis Type: P,SP Pkinncr: criiiiii e gia,,,,...c File Number: o — 0 13 Application COTIlplete (Date: Project File Number: Application Incomplete (Date: Qther Ole Numbers: NAME OF PROJECT/DEVELOPMENT: _F-riantX ettlent_. LOCATION OF PROSECT/DEVE L OPM EN T: Give .free: address or. if vacant, indicate toffs), Nock and subdivision, access street, and nearest intention. West of 1-5 in the vicinity of South Boeing Access Road interchange LISTALL MX LOT ArUMBERS (this information may befoul& on _your tax statement). 012104(4791 and n393049241 DEVELOPMENT COORDINATOR The individual who: e has decision making authority on behalf of the owno/applicant in meetings with City staff, * has full responsibility far identifying and satisfying all relevant and sometimes overlapping development standards, and • iS the primary contact with the City to who mall notice s and reports will be sent. Name: Arnel Valmonte .Seatt7e Publ tr Pt iripc Address: Seattle Kunicipal Tower, 700 Fifth Ave. Seattle, WA 98124-4018 phont: 206-615-1438 FAX: Email: arnal.valtriontafteat tle ,gov Signature: Date: P:inannIn FOIntS;APpliOlie4a)01 OkppriCiltiknt4:SPDif VOC‘r• • The materials listed below must be submitted witb y.titit application unless specifically waived in writing by die Public Woks Departinent and the Deli/mm.1v. of Community Development. Please contaei.Utch DePtilliiient if you feel hat certain itcnia are not applicable to your project and should be waived. Application- review will .not begin until it is determined tO,he complete, ADDITIONAL MATERIALS MAY RE REQUIRED. The initial application materials allow project review to begin and vest the applicant's rights. However, the City may require additional information as needed to establish consistency with developniem standards, City stair are available to answer questions about application materials at 206-431-367D (Depanment of Cointrtunity Development) and 206-433-0179 (Department of Public Works). -•:'CIieek items .. „Stibndtted ' -,.......!,I,:h • .- .n6166141, Information,Required.. ,, :Maybe waived, in,tvgaziataises,.,,iPpfl,approal. 'both-P:61k: Work kand Plcurnifig ... APPLICATION AlikTERIALS: I. At lic tion Checklist one (1 co + iidic3tin items t ' wi I, lication. 2. Pernik Fee (LDR= $24o, Other tones = S365). X 3, Written description of the project, the ( eviation being requested and response to the applicable decision criteria. ZONING CODE PARKING DEVIATION 4. A complete description of the pmposed construction relative to parking areas, and all supporting agreements. 5. Dimensional site plan(s) to demonstrate parking area consistent with Zoning Code requirements. 6. Parking studies as needed to demonstrate adequate parking is provided. LANDSCAPE DEVIATION ' ' • 7. Landscape plan - two (2) copies showing size and species of existing and pmposed plant materials, required perimeter landscape types, parking areas. buildings. walkways. transit facilities. property lines, dirnensiens and area of planting beds and any calculations necessary to demonstrate compliance with review criteria, SENSITIVE AREA ORDINANCE DEVIATIONS X 8. Site Plan — two (2) copies showing all buildings, parking areas, walkways, propoiy lines, planting arms, sensitive areas. their buffers and setbacks. X — 9. Sensitive area studies and erthaman tent plans to justify a requested buffer or setback reduction and demonstrate that the reduction will not result in, a duvet :or indirect short-tczna VT long- term adverse impact to the sensi6vc ari.1 per TMC 18A5.09() I), • SIGN CODE .APPROVALIDEVIATION . 10. Complete "Permanent Sign Permit Application" with all supporting materials and lees (5115). I L. The following information should be given 00 Lilo plans: North amwe, title, scale and dale;- r:Tbinang FwaikApplioli4.43124707 Applitaiwns:SPDircour-12-0I.duc :Check:itcii s-, • " ruhiiii ed�:.' s5''uL nppiicntioit;:;.. : IA.furmation Required: • • lay-be •itarlv-e i in unusual cases. on ,approval of /NA Public TVorks a' PI 1.0 ng: : >:..-. Vicinity map showing location and names of adjacent roads; Pruperty lines; ' 'r Locations of all buildings on site Dimensioned elevations of building drawn to scale•(for wall signs); Elevations, dimensions and materials of proposed sign(s) including advertising copy: Color elevation of proposed sign. CARGO COMMINER APPROVAL 12. Site plan showing the location of the container(s) in relationship' to parking was, property lines, buildings, strivers, trails, landscape tires and setbacks. 13,.... Description ofthe proposed scttening. 14. Dimensions of proposed cargo container. SINGLE- FAMILY DESIGN STANDARD. EXCEPTIONS IS. Dnnensioned and scalable builtli r elevations with ko *eti colors and mat ials. 16. 'Tltt: site plan must include a graphic scale, north arrow, proposed house footprint, any •existing structures, lot lines, setbacks. adjatent streets, dtiv ways, parking areas. any sensitive areas and any fences, rockeries or retaining vaills. P:sPttinning CunmtAppt,catiwp-2O» App Liratina ;SPUiTeccor- I:- L17.dn: Please consult the Zoning Code or Sign Code as to the appropriate criteria lbr your specific proposals. In addition all approvals must beconsiStent with the Tukwila Comprehensive Plan (MC 18.100030). Planning Division staff are available to discuss the decision criteria you must respond to and necessary supporting materials. PARKING DEVIATION E3 Covenant Parking: where required Parking is provided off-site (TMC 18:56.070MA El Complementary Parking: where up w 10% of a development's useable. floor arca is determined to be linked to remaining arca, such that it need not provide the. normally required parking (TMC 18.56.070(0)); o Reduction of the minimum required parking. of up to 10%, through an administiativc variance (TMC 18.56.140). A parking reduction may be allowed after: a, All shared parking strategies arc explored. b. On-site park and rideopportunities'are fatly explored. c. The site is in compliance with.the City's commute trip reductionordinance or, if not an affected employer ;Is defined by the City's ordinance, agrees to .become affected. d. The site is at least 300 feet away from a single-family residential zone. e. A report is submitted providing a basis for less parking and mitigation necessary to offset any negative effects. In addition to the above requirements, the Director require specific measures not listed to ensure that all impacts with reduced parking are mitigated. Any spillover patting that cannot bc mitigated to the satisfaction of the Director wilt serve as the basis for denial. LANDSCAPE Dm ATtONS The landscape perimeter may be averaged if the total required .square tbotage is achieved: LUIICS.S the landscaping requirement has been increased due to proximity to LDR, MDR or }{DR.. Landscape perimeter averaging may be _allowed as a Type 2 special permission decision ifall of the following criteria are trier . Plant material can be clustered to more effectively screen .parking areas and blank building walls. 2. Perimeter averaging enables significant trees or existing built features to he retained. PAP1411i1init Fo.v.m.:Applioulank111.117 ApplitatianstSPOirectar- 2-0 7..tioc 3. 'Perimeter averaeing is used to r • ice the number of driveways and curb cutsan ' w joint use of parklog facilities b neighboring businesses. 4, Width of the perimeter landsctipiag is not reduced to the point that activities on, thcsite become enuisatice to neighbors. 5. Averaging does not diminish the quality of the site landscape as a whole. O In theIVIDR.and HDR zones up to 20% of the tninitnum required front yard landscaped am may be developed for pedestrian and transit faciliti. O In the RCC and TUC zones required landscaping may include:a mix of plant materials, pedestrian amenities and features, outdoor cafe-type seatinglincl similar features. Required plant materials will be reduced in proportion to the amount of perimeterarca devoted to pedestrian oriented space. $ENSIT1VE AREA ORDINANCE DEVIATIONS O Setbacks TMC 18.45.080 F. All comrnettial and industrial developments shall be set back 15 feet and all residential development shall be set back ten feet, measured from the foundation to the buffer's edge_ The Director may waive setback requirements when a site plan demonstrates there will be no impacts to the butlerzone from construction or occasional maintenance activities. 53 Buffers Teelt 18.45.080 0 The Director may reduce the standard wetlaridtwetercottrse buffers on a case-by-ca.se basis, provided the buffer does not contain slopes 15%.orgreater. The approved buffer width shall not result in greater than a50% reduction in width. Any buffer reduction proposal must demonstrate to the satisfaction of the Director that it will not result in direct or indirect, short-term or iong-term adverse impacts to wedands or watercourses. and that: a. Additional protection to wetlands will be'provided through the implementation of a buffer enhancement plan; b. The existing condition of the buffer is degraded; c. Buffer enhancement' includes, but is not limited to the following: (1) Planting vegetation that would increase value for fish and wildlife habitat or improve water quality; (2) Enhancement of wildlife habitat by incorporating structures that arc likely to be used by wildlife, including wood duck boxes, bat boxes, snags, root wadsistumps, birdhouses and heron nesting areas; or (3) 'Removing non-native plat species and noxious weeds from the buffer area and replanting the area subject to- TMC 18.45.0800.2.c.(1) above, tPlamning Fonns'Arpl icasinag11107 Appt ic iaSbircusr.i 417.d SIGN DEVIATIONS • • o In the single family zone (LDR): signs for all conditional use and public facilities (INK! 1932.080); o In multi-thmily zones where signs face multi-family, eomMercial,and industrial .zones: signs of conditiOnallypermitted tiScs, all public facilities and frecStanding signs (TMC 1932.100). In Commercial and Industrial (TMC 19.32.170) Zones: o Signs of conditionally permitted uses, all public facilities and all free-standing signs, that .-abut or face single family .zones (TMC 19.32,120) and MUlti-faMily zones (TMC 19.32.130); O Any multi-tenant office building sign. which has over 50% nFth e total allowed wall sign area (TMC 19.32.140(B)(4)); o A 50% increase in .wall sign arca for each doubling of the Zoning Codc maximum building setback up to 6%.of the wall area upon which the sign will be mounted up to a maximum of 500 sq. rt. (TMC 19.32.140(A)(2) and ((2)). Shopping Mall business wall signs (TMC 19.32:150(A)): O To allow one wall sign to have more than 50% of the business's total allowable sign area in one sign. o To allow one freestanding sign to have more than 50% of the site's total allowable.sign area in one sign. CARGO CONTAINERS Approval criteria for cargo containers to be installed in the LDR, MDR, and HDR zones for institutional uses and in the RC, RCM. TUC or CfLA zones for permitted or conditional uses: O Only two cargo containers will be allowed per lot, maximum length 30 feet. O The container islocated to minimize the visual impact. to adjacent properties, r.nrks, trails and lights-of-way as determined.by the Director. 0 The cargo container is sufficiently screened from adjacent properties, parks, trails and rights- of-way, as determined by the Director. Screening may bc a combination of solid fencing, landscaping, or the placement of the cargo containers behind. between or within buildings. O If located adjacent to a building, the cargo container must be painted to match the building's color. O Cargo containers may not occupy any required off-street parking spaces. O Cargo containers shall meet all %setback requirements for the zone. O Outdoor cargo containers may not be refrigerated. o Outdoor cargo containers may not be stacked. SINGLE-FAMILX DESIGN STANDARD EXCEPTIONS The design standards required at 18.50.05() (5) and (6) may be modified by the DCD Director. Appl icarionASPn ittrz.v - 1 2, .01404 • CITY OF TUKWILA Depurthient of Community.Developmcttt 6300 Southeenter Boulevard, Tukwila, WA 98/88 T 1ephoire, (20 431 -3670 FAX 0006) 431 -3655 1s- nrail :'tukplatttu~ :i,tukwi.la.%vn,u� • SPECIAL PERMISSION DIRECTOR FOR STAFF USE ON.L P Permits Plus Type: F-SP Planner: File Number; Application Complete (Date: ) Project File 'umber: Application Incomplete (Dale. ) (thei• File Numb'ers: NAME OFFROJECT /DEVELOPMEN +T: ,. o Meat-- LOCATION OF PROJECT /DEVELOP \4 ENT: Give street address <n J vocxmt, indicate dvt/sj, block and subdivision, access street, and nearest intcrseadutt. West of I -5 in the vicinity of South Boeing Access Rond interchange LIST ALL TAX LOT NUMBERS (this in formation may ha„frmnd on.yourtar state 04. 4S24J DEVELOPMENT COORDINATOR : The individual who: O has decision making authority on behalf of the owns /applicant in meetings with City staff, o has full responsibility for identifying and satisfying all relevant iinti•stinietimes overlapping development standards, and • is the primary contact with the City to whom all notice s tux] reports will be sent. Name: rrnal VaJi=ionte — Seattle Paihlir 11ci1itIas Address: Seattle Municipal Tower, 700 Fifth Ave'. Seattle, WA 95124 -4018 Phone: 206- 615 -1438 FAX: E -mail: nrrrnl.valnonte @seattia.gov Signature: CJittc;: PnP?snnlnn Feon.VApplitoJiortS -00i AppliealiVxlSPOituclor- t2 -07.'k' The anatetials listed below must be submitted with your application tad= spot:if:wally waived in writing by the Public Works Depanment and thc Department of Community Development. Please cantata:00 Department if you feel that. certain iterns are not applicable U your project and Should IX, waived. ApplicatiOn'teview will not begin until it is determined to be complete. ADDITIONAL MATERIALS MAY BE REQUIRED. 'Ilte initial application materials allow project review to begin and vest the applicant's rights. However, the City may require additional information as needed to establish consistency with development standards. City staff are available to answer questions about application materials at 206-431-3670 (Department of Cout-wilily Development) and 206-433-0179 (Department of Public Woik.$). chak Aierus • . submitted .agnilleation, . ' Information,Rerptired:. . . . . . . . • • • • -.Afrty be Waived ip runstualtii0s;4ifignoOrpiin1.afbeil.lePublia'Workp and Planning • APPLICATION MATERIALS: 1. Application Checklist one (1) copy, indicatinp, items submitted with application. X 2. Penult Fee (LDR .= S240. Oilier 20010S = S365). X 3. Written description of the pmject. the deviation being rtritiefiled and response 10 I he Iippkahle decision criteria. ZONING CODE PARR1NG DEVIATION 4. A t:omplete description of the proposed construction relative to p3rking areas, and all supporting alncenients. 5. Dimensional site plan(i) to demonstrate parking area consistent with Zoning Code requirements. 6. Parkin studies as needed to demonstrate adequate parking is provided. LANDSCAPE:, DEVIATION 7. Landscape plan - two (2) copies showing size and six:cies of existing and proposed plant materials, required perimeter landscape types, parking areas, buildings. walkways. transit Iluil hies, property lines, dimensions and an of planring beds and any calculations necessary to denionsn-ate compliance with review criteria, SENSITIVE AREA ORDINANCE DEVIATIONS X 8. Site Plan — r.vo (2) copies showing all buildings. parking areas, walkways, property lines, planting areas, sensitive areas, their buffers and setbacks. X 9. Sensitive area studies and enhancement plans to justify a requested buffer or setback nxl major, and demonstrate that the riatiudioti will not result in a direet or itxtirtiet shori-ttam or long- term adverse impact to thc sensitive arca pch- Tkte 1845.090). SIGN CODE APPROVAUDEVIATION ID. Complete "Pemianent Sign Permit Application" with all mipponing martinis and is (S115). I I . The following information should be given .on the plans: North arrow, tide.. scale and date; PAPlanntnu ForiuMpplwaliosW207 Applivuor&SPIiircow-12.07.doc ., .,::::---":•:;'.'w1w., ,.= ..:. . . . ....: ' - - - - , . ..... qr.E1r1.11t1.04*Iiiird; 410 „ .. ... . ..yery..4e-tilived ininnuiutd oases. upon opproval 0 f both Ififiblio TV,Orks and. Planiibi:' :,::•:, :::..".::':: - —.• .. • -:-:- Vicinity map showing, location and name...s.of Eidjateot roads; Property (Ina; . Locations of all buildings on site; Dinamsioncd elevations of building drawn toscale (for wall sips); Elevations. dimensions and materials of proposed sign(s) including advertising copy; Color elevation of proposed sign. CARGO CONTAINER APPROVAL 12. Site plan showing the location of the Contitinek(s) in ielationship to parking areas , property lines, buildings, streets. trails,landsoape areas and setbacks. 13. Description ofthe proposed scneening. 14. Dimensions of proposed cargo container. SINGLE-FAMILY DESIGN STANDARD EXCEPTIONS 1.5. Dimensioned and scalable building elevations with keyed colors and materials. 16. 'Tht site plan must include a graphic satle, north arrow, proposed house footprint, any 'isting structures, lot lines, setback& adjaoertt streets. dtiverways, parking areas, any sensitive areas and any fences, rockeries or reining wall& it'sPlannittg rvnns4Appluzikna-2007 Applicckticr-i',SPOirector-12-1.17.dor Please consult the Zoning Code or Sign Code as to the appropriate criteria for your specific proposals. In addition I'll approvals must be consistent with the Tukwila Comprehensive Plan (TMC 18.100030). Planning Division staff' are available w discuss the decision criteria you must respond to and necessary supporting materials. PARKING DEVIATION O Covenant Parking: where required parking., is provided .off-site (TMC 18.56.070(B)); El Complementary Parking: where up to 10% of a development's useable floor area is determined to be linked to remaining area, such that it need not pirrvide the normally required parking (TMC 18.56.070(D)); o Reduction of the minimum required parking of up to 10%, through tm administrative variance (TMC 18.56.140). A parking reduction may be allowed after a. All shared parking strategies are explored. b. 00-site park and ride opportunities' are fully explored. c. The site is in compliancewith the City's commute.-trip reduction mlinance-or, if not an alleeted employers defined by the City's ordinance, agrees to -become affected. d. The :site is at least 300 feet away from a single-family residential zone. e. .A report is submitted providing a basis for less parking and mitigation necessiuy to offset any negative effects. In addition to the above requirements, the Director may require specific measures not listed to ensure that all impacts with reduced parking are mitigated. Any spillover parkin that cannot be mitigated to the satisfaction of the Dirtor will serve as. the basis .for denial. LANDSCAPE DEVIATIONS O The landscape perimeter may bc averaged if the total required square footage is-achieved, unless the landscaping requirement has been increased due to proximity to LDR, MDR or HDR. Landscape perimeter averaging may be allowed as a Type 2 special permission decision if all of the following criteria are met: 1. Plant material can be clustered to more effectively screen patithra areas aud blank building walls. 2. Perimeter averagMg enables significant trees or existing built features to he retained. P:Inann inE Folits'ApplicarinnA',2(1117 Appl kat it.)estS l'i)i recor4 2.0 7,din 3. Perimeter averaaing, is used to re e the number of driveways and curb cuts, and • w joint use of parking facilities bet neighboring businesses. t 4. Widthot the perimeter landscaping is not reduced to the point that activities on, the site become a nuisance to neighbors. 5. Averaging does not diminish the quality of the sitelandscape as a i.•vhole. o In the:MDR and HDR zones up to 20% oft& iiiittimtint required front yard landscaped area may be developed for pedestrian and transit facilities. O hythe RCC.and TUC zones required landscaping may include a mix of plant materials, pedestrian amenities and features, outdoor cafe-type seating and similar features. Required plant materials will be reduced in proportion to the amount of perimeter area devoted to pixlestrian. oriented space. SENSITIVE AREA ORDINANCE DEVIATIONS O Setbacks TMC 18.45M80 F. All commerciatand industrial developniems.shall bc set back 15 feet and all residential development shall bc set back ten feet, measured from the foundation to the buffer's edge. The Director may waive setback requirements when a site plan demonstrates there will be no impacts to the butler zone from construction or oeeasional maintenance activities. IJ Buirers TMC 18.45.080 to Tice Director may reduce the standard wetland/watercourse buffers on a case-by-ease basis, provided the buffer does not contain slopes l% or greater. The approved buffer width shall not result in greater than a50% reduction in width. Any buffer reduction proposal must demonstrate to the satisfaction of the Direetorsthatit wjll not result in direct or indirect, short-term orlong-term 'adverse impacLc.to wetlands or watercourses, and that a. Additional protection to wetlands will beprovided throttRh the iMplementation of a buffer enhancement plan; b. The existing condition of the butler is degraded; c. Buffer enhancement includes, but is not limited to the f011owing; (1) Planting vegetation that would increase value for fish and wildlife habitat or improve water quality; (2) Enhancement of wildlife habitat by incorporating stinctures that are likely to be used by wildlife; including wood duck boxes, bat boxes, snags, root wads/stumps, birdhouses and hcronnesting areas; or (3) Removing non-native plat species and noxious weeds from the buffer area and replanting,the area subject to TMC 18.45.0800.2.c..(1) above, PAPianning ranns■Applicatin4a(137 Applicl.itikxtalVity r-i2-07.dAt 4 S1GN DEVIATIONS o In the single family zone (1...DR.): signs for all conditional uses and public facilities (TMC 19.32.080); O In multi-family zones where signs atee multi-family, commercial and industrial zones: signs of conditionally permitted uses, all public facilities and fitx,s• 4'11(411g signs (TMC 19.32.100). In Commercial and lndu.strial (T?v1C 19.32.170) Zones: o Signs ofconditionally permitted uses, all public facilities and all free-standine signs, that ...abut or face single family zones (TMC 19,32.120) and multi-family zones (TMC 19:32.150); • Any multi-tenant office building sign which has over 50% NW total allowed wall sign area (TMC 1932.140(3)(4)); o A 50% increase in wall sign area for caoh doubling. of the Zoning Code maximum building setback tip to 6% of the wall area upon which the sign will be mounted up to as maximum of 500 sq. it (TMC 19.32.140(A)(2) and (C)). Shopping Mall husinetti wall signs (TMC 19.32.150(A)): O To .allow one wall sign to have more than 50% of the business's total allowable sign area in one sign. O Ter allow one freestanding sign to have more than 50%-of the site's total allowable.sign amt in one sign. CARGO CONTAINERS Approval criteria for cargo containers to .be installed in the LDR, MDR, and 1-IDR zones for institutional uses and in the RC, RCM, TUC or CAI zones for permitted or conditional uses: O Only two cargo containers will be allowed per lot, maximum length 30 feet. O The container is located to minimize the visual .impact to adjacent properties, parks„ trails and rights-of-way as determined by the Director. O The cargo container is sufficiently sereene.d from adjacent pp:mei:ties, parks, trails and rights- of-way, as determined by the .Dimctor. Screening may be a combination of solid fencing, landscaping, or the placement of the cargo containers behind, between or within buildings. O If located adjacent to a building, the cargo container must be painted to match the building's color. O Cargo container may not occupy any required off-street parking spaces. O Cargo containers shall meet all setback requirements for the zone. O Outdoor cargo containers may not be refrigerated. O Outdoor cargo containers may not be stacked. SINGLE-FAMILY DESIGN STANDARD EXCEPTIONS. The design standards required at 18.50.050 (5) and (6) may be tnodifted by the.DCD Director. P:•.P13rining Farror, Npplientions■.20fil ApplicationASPiliaxIot - • Sandra Whiting - Re: SPU stormwater improvements project Page 1 of 2 From: Sandra Whiting To: Susan Wall Date: 03/24/2008 1:11 PM Subject: Re: SPU stormwater improvements project CC: Amanda Azous; Jaimie Reavis Hi Susan, Tukwila does allow off -site mitigation if the criteria for off -site mitigation in our Sensitive Areas Ordinance are met (see below). The City also allows mitigation outside of Tukwila with approval of the Director if some additional conditions are met (see below). This approval would be covered in the same Special Permission for the buffer reduction on Wetland B under project 2, but you will need to explain how the mitigation at Puget Creek meets the criteria in your letter requesting the Special Permission. It appears that the proposed mitigation at Puget Creek will meet our criteria. Here are the sections of the Sensitive Areas Ordinance referenced above (TMC 18.45.090) that you will need to demonstrate: E. MITIGATION LOCATION - 1. On -site mitigation shall be provided, except where the applicant can demonstrate that: a. On -site mitigation is not scientifically feasible due to problems with hydrology, soils, waves or other factors; or b. Mitigation is not practical due to potentially adverse impact from surrounding land uses; or c. Existing functional values created at the site of the proposed restoration are significantly greater than lost wetland functional values; or d. Established regional goals for flood storage, flood conveyance, habitat or other wetland functions have been established and strongly justify location of mitigation at another site. 2. Off -site mitigation shall occur within the same watershed where the wetland loss occurred. (we interpret this to mean the Green /Duwamish watershed) 3. Mitigation sites located within the Tukwila city limits are preferred. However, the Director may approve mitigation sites outside the city upon finding that: a. Adequate measures have been taken to ensure the non - development and long -term viability of the mitigation site; and b. Adequate coordination with the other affected local jurisdiction has occurred. 4. In selecting mitigation sites, applicants shall pursue siting in the following order of preference: a. Upland sites that were formerly wetlands; b. Idled upland sites generally having bare ground or vegetative cover consisting primarily of exotic introduced species, weeds or emergent vegetation; c. Other disturbed upland; file: / /C: \Documents %20and %20Settings\ Sandra \Local %20Settings \Temp \XPGrpWise \47E7A89... 03/24/2008 • • d. Existing degraded wetland. Sandra Sandra Whiting Urban Environmentalist City of Tukwila Department of Community Development 6300 Southcenter Blvd., Suite 100 Tukwila, WA 98188 206 - 431 -3663 Page 2 of 2 »> Susan Wall <swall @herrerainc.com> 03/24/2008 10:48 am »> Hi Sandra - I wanted to confirm with you that the mitigation plan for the impacts in Tukwila on Wetland D (the WSDOT ditch) is acceptable. There will be 0.03 acres of impact within the City of Tukwila. Most of the impact will be in the City of Seattle. I just want to confirm that mitigation in the City of Seattle, at the Puget Creek Natural Area (as described in the mitigation plan attached to the JARPA), is acceptable. Also - I left you a phone message regarding answers to the questions you asked last week after your site visit. You can give me a call when you get in. Thanks - Susan Wall Herrera Environmental Consultants, Inc. 406/721 -4204 file : / /C: \Documents %20and %20 Settings \Sandra \Local %20Settings \Temp \XPGrp Wise \47E7A89... 03/24/2008 4 250ft CityGIS Copyright © 2006 All Rights Reserved. The information contained herein is the proprietary property of the contributor supplied under license and may not be approved except as licensed by Digital Map Products. • • Sandra Whiting - SPU Norfolk Stormwater project Page 1 of 1 From: Sandra Whiting To: Jaimie Reavis Date: 03/24/2008 1:22 PM Subject: SPU Norfolk Stormwater project Jaimie, Susan from Herrera responded to my questions last week as follows: 1. Vegetation to be retained in existing buffer: the madrones and the prunus (wild cherry) will be retained. 2. They have discussed not planting trees within 20 ft of the overhead lines with City Light - that distance is acceptable. 3. There will be a fence around the sediment management area and the restored buffer. 4. The flagging we saw down in the wetland near the impact area is not Herrera's, so it appears that where they thought the wetland boundary was located coincides with what we thought. 5. Since it is unclear when a determination would be made if soil amendments would be needed (or who would make it), I told Susan that the City will make it a condition of the approval that the buffer enhancement area be amended prior to planting). Sandra file: //C : \Documents %20and %20Settings\ Sandra \Local %20 Settings \Temp \XPGrpWise \47E7AB2... 03/24/2008 • Sandra Whiting - access to Wetland B From: Susan Wall <swall @herrerainc.com> To: Sandra Whiting <swhiting @ci.tukwila.wa.us> Date: 03/06/2008 1:06 PM Subject: access to Wetland B • Page 1 of 1 Sandra - Amanda says the best way to see Wetland B is to access the site from the East Marginal Way Boeing Access Road exit going south on 1 -5. As you make the turn on the off-ramp there is a small pullout area with a short barb wire fence blocking auto access but you can easily walk around it and Wetland B is immediately to the west. Sue W. file: / /C:\ Documents %20and %20Settings \Sandra \Local %20Settings \Temp \XPGrpWise \47CFEC6... 03/06/2008 HERRERA ENVIRONMENTAL CONSULTANTS 2200 Sixth Avenue Suite 1100 Seattle Washington 98121 (206) 441-9080 FAX 441 -9108 101 E Broadway Suite 610 Missoula Montana 59802 (406) 721-4204 FAX 721 -4232 322 NW Fifth Avenue Suite 315 Portland Oregon 97209 (503) 228-4301 FAX 228 -3373 435 Holgerson Road Sequim Washington 98382 (360) 683 -9109 FAX 683 -3671 • February 22, 2008 Sandra Whiting City of Tukwila Department of Community Development 6300 Southcenter Boulevard Tukwila, WA 98188 Subject: Special Permission Director Permit Dear Sandra: al(2)c,ci•Dc.) Std W -cc"3"‘ k=rl () air °� Enclosed is a copy of the Special Permission Director Permit Application and supporting materials for the Norfolk - MLK Way Stormwater Treatment Improvements Project requesting a buffer reduction for a wetland located west of I -5 in the vicinity of the South Boeing Access Road interchange, in the city of Tukwila. In addition the project will impact a portion of a wetland in the WSDOT right -of -way east of I -5 within the City of Tukwila. The enclosed materials include a copy of the Joint Aquatic Resources Permit Application (JARPA) describing impacts and mitigation for wetland impacts, a Special Permission Director Application checklist, a Request for Sensitive Area Ordinance Deviation, site plan (2 copies), wetland mitigation plan, and a written description of the project including the deviation being requested and response to the applicable decision criteria. Sincerely, Herrera Environmental Consultants, Inc. AMA-Acto-- Amanda Azous Senior Scientist Enclosures: JARPA for stormwater conveyance improvements; includes Wetland Mitigation Plan - Norfolk -MLK Jr. Way Subbasin Stormwater Improvements as Attachment B Special Permission Director Application and Checklist Request for Sensitive Area Ordinance Deviation 0 AB 06- 03354 -100 special permission_tukwila • • Request for Sensitive Area Ordinance Deviation Norfolk - MLK Way Stormwater Improvements Project Prepared for City of Tukwila Department of Community Development 6300 Southcenter Boulevard Tukwila, WA 98188 Prepared by Herrera Environmental Consultants 2200 Sixth Avenue, Suite 1100 Seattle, Washington 98121 Telephone: 206/441 -9080 February 21, 2008 • • Request for Sensitive Area Ordinance Deviation: Norfolk — MLK Way Stormwater Improvements Project Project Description SPU proposes improvements to the conveyance and treatment systems in the Norfolk -MLK Way subbasin to reduce frequent overflow of stormwater to the sanitary sewer system, restore the conveyance capacity of the system, reduce pollutant loading to the lower Duwamish Waterway, and reduce flooding on Martin Luther King Jr. Way. The proposed stormwater system improvements include replacement of an existing 36 -inch CMP storm drainage line with a 64 -inch reinforced concrete pipe; regrading the upper segment of the WSDOT ditch that parallels I -5; and construction of a stormwater treatment pond on a parcel of land owned by -the City of Seattle. The project area is in the vicinity of the South Boeing Access road' ntereliange on 1 -5 as shown in Figure 1, JARPA Attachment B (Wetland Mitigation Plan - ilVorfo-lk'MLKJii•• Way Subbasin Stormwater Improvements). The portion of the project that requires a Sensitive Area Ordinance-Deviation is construction of the treatment pond. The proposed stormwater pond would be a 2 -cell deep Wet pond (8 feet deep) in the southern portion of the City of Seattle owned property. A7portio_n ofthe- project:: impacts- wwetlandsbufferJocatedmithififthe.€ity of�:Tukwila. That portion is therconstr •uctionzofan'access'road"to a °sed menf;management'area-to be located on a parcel of land south of the treatment pond (see,;Figure 4, JAARPA Attachment B). This area would provide a staging area for sediment dewatering Ming ng periodic maintenance activities. No excavation, grading, or fill would bedore in the sediment management area. The access road would be constructed between the po 0,and the sediment management area. Six inches of crushed rock, covered with4tops'oilwould bepplied to the maintenance access road and the sediment man agement area nd l ese areas;would be seeded with grass and allowed,to ieegetatea a w fter= construction'is-corriplete. Theioad4sa expected- to- beaneeded.at=mossevveery fve- .years form.aintenancexactivities. WhenTtheiroad- is.neededfor maintenance- activ,.ities,,� exfisting large egetatiorrwill_be mow._ed.rfor aecessiandnonce; the ,,maintenance :is= complete;mthed Cil roadzwil be d:to:revegetate. Sensitive AreaExisting Conditions The project site is located within the Norfolk drainage basin. The site generally slopes and drains to the south and west toward the Duwamish River, although development features and microtopography block stormwater flows from draining into the river. Topography on the east side of the site is generally flat, except where existing wetlands and stormwater ponds and swales are present at lower elevations. Existing stormwater ponds and a drainage swale collect and treat stormwater from the portion of I -5 within the northern part of the Norfolk Drainage Basin. AB /06- 03354 -100 apecialsennission aJnvila February 21, 2008 1 Herrera Environmental Consultants Request for Sensitive Area Ordinance Deviation: Norfolk — MLK Way Stormwater Improvements Project Delineated wetland boundary On December 2, 2005, wetland biologists performed wetland delineations within the stormwater improvements project area. One wetland (designated as Wetland B) was identified within the City of Tukwila and is shown on Figure 2, JARPA Attachment B. Another wetland, Wetland A, was identified in the City of Seattle (HEC 2007). Condition of wetland and wetland buffer Wetland B appears to have been connected to Wetland A in the past, although the wetlands are now separated by a WSDOT stormwater pipeline. Wetland B covers 0.97 acres;. =The wetland contains three wetland classes: open water, emergent, and scrub - shrub. Under the hydrogeomorphic classification system, Wetland B is considered a depressional outflowwetland (Brinson 1993). Water sources for this wetland include precipitatioriAigh ground water, and runoff from the adjacent disturbed upland to the east. Drainage channels - created in the bare soils on the adjacent upland drain water and sediment into the wetland. No outlet for" this wetland has been observed or identified on the project site (PDP #1; SPU 2005). Water levels within the wetland were observed to vary from surface saturation to a depth of over 6 feet during the December field visit (HEC 2007). 7j... The palustrine emergent portions of this wetland includeya permanently flooded area and a seasonally flooded area. Common cattail (Typha latifolza) dominates the permanently flooded area. The seasonally flooded area contains,reed canarygrass (Phalaris arundinacea) with a subdominant growth of Cooley's hedgenettk(Stachys cooleyae). Other emergent plants in this area include small - fruited bulrusha(Scirpusmicrocarpus), climbing nightshade (Solanum dulcamara), and purple lsestrifelLythrum alicaria), which is a noxious weed. The scrub -shrub class is dominated by willows (Salix spp.), red -osier dogwood (Cornus sericea), Himalayan blackberry (Rubus armeniacus), Oregon ash (Fraxinus latifolia) and Douglas spirea (Spireae douglasii) (HEC 2007). The wetland is located in the City of Tukwila; therefore, Tukwila regulations apply. According to the Tukwila muiucipal code, Wetland B meets the criteria for a Type 1 wetland, for which 100 -foot buffers are;required. The Wetland B buffer is a former recreational motorcycle track with a substantial amount of bare soil and weeds. This buffer is currently in poor ecological condition. In its current condition the buffer does not function to protect the wetland from pollutants and sedimentation from the surrounding impervious surface and bare soils. Requested buffer reduction and justification The requested buffer reduction is 50 %, resulting in a 50 foot buffer for Wetland B. Buffer enhancement will greatly improve the ecological health and functioning of the buffer by AB /06-03334 -100 spc ial j crvnission i dnvila February 21, 2008 2 Herrera Environmental Consultants • • Request for Sensitive Area Ordinance Deviation: Norfolk — MLK Way Stormwater Improvements Project removing non - native plant species and noxious weeds and planting vegetation that would increase value for wildlife habitat and improve water quality protection. Impacts The treatment pond maintenance access road would encroach on the 100 foot buffer of Wetland B, located in the City of Tukwila; however a,reduction ofrAdth of"tha bufferofiWetland,B to 5500- feetuitl this:p rme it vZi d avoid`al1= impacts -to the buffer•associated:wiih the-a sslroad and_ sediment - management: area: - hZSpecialTermis`sion= Director P-er-mittwouldgequre e ancement.o£ the remaininge50- footbuffer: Mitigation Avoidance and minimization measures Best management practices and minimization measures will C mp1emented during the design and construction phases of the project in order to minimize the ,.potential impacts on fish and aquatic life. A temporary erosion and sediment control (TESC) plan and a spill prevention, control, and countermeasures (SPCC) plan wil1,,be prepared •prior to the start of construction. Clearing limits will be marked to avoid impacts on criti altareas and all equipment to be used for construction activities will be cleaned and inspected before it arrives at the project site to minimize potential leaks. Buffer enhancement,*" • (Approxiriiately10 15:acres#bf the.baffe "r - "of- Wetland- -&would=be enhanced -W site, as shown on Figure 5 and Kan Sheet 13, JARPA Attachment B. Enhancement of the Wetland B buffer will include native tree and shrub planting and seeding within 50 feet of Wetland B. Invasive weeds will be eradicated using a combination of mechanical removal and treatment with a nonresiduallher" b d"e°3 Only those herbicides approved by the Department of Ecology for use in aquatic areas will be used for site preparation. All herbicides will be applied as authorized by law and at the application rates and conditions specified by the manufacturer of the product. A licensed herbicide applicator will be hired to apply all herbicides (HEC 2008). Buffer enhancement plantings will consist of predominantly containerized plant material grown in deep pots (10 -14 inches) to reduce the shock of planting and provide for the best adaptation to localized soil and moisture conditions. Plants will be installed between November and February, while dormant, to reduce stress on the plants and encourage the best possible survival (HEC 2008). AB /06- 03354 -100 special permission_iuk.4k February 21, 2008 3 Herrera Environmental Consultants • • Request for Sensitive Area Ordinance Deviation: Norfolk — MLK Way Stormwater Improvements Project Plant species will be selected from the list in Table 1. Shrub species will be planted in natural - appearing clusters of three to seven plants. Placement of the plants within the clusters will vary between 3 feet on center and 6 feet on center. Each tree and shrub will have a fefilizer pack" placed in the bottom of the planting hole prior to backfilling. Fertilizers will be slow release products that will not result in nutrient runoff into aquatic systems. Mulch (3 inches deep) will be placed in an (18- inch - diameter) ring around each plant to prevent invasive species or native grasses from out - competing the plant and to help maintain soil moisture (HEC 2008). Table 1. Tree and shrub plantings for Wetland B buffer enhancement. Common name Scientific name Douglas fir Pseudotsuga menziesii Black cottonwood Populus balsamifera ssp:,:trichocarpa Vine maple Acer circinatum Serviceberry Amelanchier alnifolia Douglas' hawthorn Crataegus douglasii Baldhip rose Rosa gymnocarpa Elderberry Sambucus racemosa var. arborsecens Common snowberry Symphoricarposalbus References HEC. 2007. Wetland Delineation — NorfglkBasin Drainage and Water Quality Improvements, Seattle and Tukwila Washington. .Prepared for Seattle Public Utilities by Herrera Environmental Consultants, Inc. Seattle;.Waghingtoia. HEC. 2008. Wetland Mitigationn?lan - MKL Way Subbasin Stormwater Improvements Project. Prepared for Seattle Public Utilities by Herrera Environmental Consultants, Inc. Seattle, Washington. SPU. 2005. NorfolkiIv1LK Way Sub -Basin Stormwater Improvements Project Development Plan #1 — C333205-report. Prepared by Tetra -Tech for Seattle Public Utilities. AB /06 -03354 -100 sp cialscmiission_ndnvila February 21, 2008 4 Herrera Environmental Consultants 1 • NORFOLK - MLK WAY SUB BASIN STORMWATER IMPROVEMENTS WETLAND DELINEATION REPORT JUNE 7, 2006 ,jA�G,, D Prepared for Arnel Valmonte, Project Manager Seattle Public Utilities, Engineering Division Prepared by Michael Bonoff, Wetland Biologist SPU Environment, Science and Technology Section • • SUMMARY Seattle Public Utilities (SPU) needs to make drainage and water quality improvements in the most southern portion of the Norfolk Drainage Basin (MLK sub basin). The current performance level of the drainage system is well below design conditions caused by sedimentation within a particular pipe and wetland ditch segment. The scrub shrub wetland of 1.4 acres is a narrow linear system conveying storm water north alongside of and underneath I -5. Seattle's Critical Area Ordinance requires a 60 foot buffer. STUDY AREA DESCRIPTION The project area in Seattle borders Tukwila and runs along the east side of I -5 for a thousand feet or less (See the Vicinity and Location map). METHODS Literature Review Existing engineering and geo technical reports were reviewed. Air photos available through the City's GIS were examined. Delineation Approach The routine onsite determination method described in the Washington Department of Ecology Washington State Wetlands Identification and Delineation Manual methodology was used to delineate wetlands. The Ecology manual requires the use of the three - wetland parameter methodology when determining the presence or absence of wetlands. With few exceptions, all three parameters including wetland hydrology, hydric soils and hydrophytic vegetation must be present for an area under normal circumstances to meet the wetland criteria. Michael Bonoff, an SPU biologist and Wetland Scientist performed the delineation. An auger was used to sample soils in and around the wetlands. Then the representative soil pits were dug to a depth of 18 inches using a sharpshooter shovel. The south face of each pit was used for the soil observations and photos. A squeeze water bottle was used to moisten dry soils and determine their color using a Munsell Color Chart. Each hole was marked with blue wire flagging to show the wetland number and the upland or wetland location. Photos were taken of the soil pits and surrounding area (See Attachment 1). Vegetative sampling was conducted at each soil pit and dominant plant species and its percent cover was established. Data forms were compiled for each location (See Attachment 2). 2 • • Orange `wetland delineation boundary" ribbons ( #s 1 -13) were placed in that portion of the wetland that comprises the primary project location. Other areas were visually surveyed and these boundaries were established on aerial photos. Not all wetland areas could be physically accessed. Interstate 5 and a dense embankment of blackberry prevented access from the west and chain link fencing adjacent to the WDOT cloverleaf prevented access from the south. In other locations, the deciduous forest canopy, dense shrub layer and ponded water prevented physical access. The wetland boundaries are shown on the aerial, map #2. Reconnaissance A reconnaissance level inspection of the project site within the wetland was conducted by Michael Bonoff in 2000. RESULTS LITERATURE REVIEW Wetlands Identified The WSDOT plan set (1994) shows a uniformly linear wetland approximately 1400 feet long, averaging 35 feet wide. The wetland area is roughly 1.1 acres. A reconnaissance level inspection of the project area (Bonoff 2000) concluded that an emergent wetland existed from the drainage outfall to several hundred feet north. Soils SPU's Material Lab (2004) boring in the project area indicated that the first 7 feet consisted of high chroma colored silt with brown pockets underlain with silty sand and sand. Wildlife and Birds Red winged blackbirds were seen in Typha pockets in the south end of the wetland. Common garter snakes were seen on dry grasses both days in the project area. Hydrology The wetland hydrology is provided by several sources of storm water runoff. Primarily, storm water from the Norfolk basin is discharged into the wetland. Improvements made in 1979 and 1999 to improve drainage in the 224 acre MLK Way sub basin of the Norfolk drainage basin were connected to a privately owned 36 inch 3 diameter pipe that drains into the open ditch/wetland along I -5. The drainage feature carries storm water northward about 950 feet before reaching a cross drain under the freeway. The ditch now has filled with 1 to 3 feet of sediment within much of its alignment. This obstruction combined with sediment in the 36 -inch pipe has greatly reduced the drainage system hydraulic capacity. During rain events, flow now backs up into the city's sanitary sewer causing an overflow into the adjacent King County combined sewer system. In addition, city records indicate that storm water is discharged from parking areas of the warehouse properties immediately to the east. Storm water from the Boeing Access Road I -5 cloverleaf discharges in the south portion of the wetland and moves northward during rain events. The 24 -inch culvert under the freeway is elevated above depressed portions of the wetland so it does not continuously overflow into the culvert. Stormwater is also carried under the freeway through a 48 inch culvert. There is permanently ponded water in the wetland's south end and in portions of the ditch alignment. Land Use The I -5 embankment on the west confines the low corridor containing the wetland and the industrial warehousing and associated parking fill on the east. The WSDOT cloverleaf confines the south end. The wooded corridor continues north of the wetland. The open space corridor average width is 30 feet and contains a wetland of varying widths and the remnants of the 1960 era drainage ditch. FIELD RESULTS Soils Soils pits (S.P.$) were established across the mid section of the project area (S.P. #1 Upl and Wet) and in the north (S.P. #2 Upl and Wet). The soils pit locations are shown on aerial, Map #2, except for S.P. #2 Upl. The latter is located in the Norfolk Street right of way crossing the wooded corridor north of the wetland. Wetland Soil Pit # 1 consisted of a uniform dark brown silty loam (10YR 3/2) with abundant olive (5Y 5/6) redoximorphic features. Wetland S.P. #2 consisted of a uniform silty loam with a dark gray matrix color (10YR 4/1) and yellowish brown redox (7.5YR 5/6). These masses were abundant (25% of the matrix) and 3 -4 mm in size. Upland Soil Pit #1 consisted of 0 -8 inches depth of brown sand (10YR 4/3). This A horizon was underlain with 8 -16 inches depth of dark brown sand (10 YR 3/2) with strong brown abundant redox (7 YR 5/8 and 7 YR 4/6). These masses were 3 -5 mm in size. Upland Soil Pit #2 A horizon consisted of a (10YR 4/2) brown sandy loam with 1/4 4 inch pebbles. The B horizon consisted of (10YR 5/3) sand with pebbles up to 2 inches in diameter. Hydrology Wetland soil pits had standing water at 14 inches depth or less and the soils were saturated to the surface. Upland S.P #1 had a dry A horizon and a moist B horizon. There was no saturation on the bottom of the 18 -inch deep hole. Upland S.P. #2 was dry. There was evidence of seasonal flooding across the depressed portion of the vegetated corridor estimated to be between '/2 to 2 feet in depth. Shallow standing water was seen throughout the emergent areas and standing water of several feet deep was seen in the shrub and tree areas. No water movement was observed. Vegetation The wetland vegetation was dominated in the emergent areas by reed canary grass (Phalarus arundinacea) and nightshade (Solanum dulcama). Hardstem bulrush (Scirpus acutus) was present in the south end. The shrub areas were dominated by hardhack (Spirea douglasii) and cattail (Typha latifolia) in slight depressions. The deciduous tree layer was dominated by Sitka willow (Salix sitchensis) and black cottonwood (Populus balsamifera) up to 10 and 24 -inch diameters respectively. The upland buffer areas were dominated by blackberry (Rubus procerus) with smaller amounts of Scots broom (Cytisus scoparius) and nootka rose (Rosa nutkana). The shrubby nature of the buffer was complimented by landscape plantings of 8 inch diameter Shore pine (Pinus contorta) on the Lindal and other properties along the east wetland margin. These trees are more than 15 feet tall and provide > 75% crown closure. Invasive and Manmade Influences: The wetland was confined by I -5 and industrial fill. The modification to the natural environment allowed several invasive species to dominate the wetland and buffer. These were blackberry, reed canary grass and nightshade. Wetland Delineation A Palustrine Scrub Shrub (PSS) wetland was delineated of approximately 1.4 acres. The deciduous forest canopy covered about 45% of the wetland and vegetated buffer combined but less than 30% of the wetland. The dense shrub under story covered more than a third of the wetland itself. The reed canary grass meadow areas consisted of about 20 % of the wetland. WETLAND FUNCTIONS AND RATING The wetland was evaluated according to the Washington State Rating System. It was classified as a Depressional and Flats Wetland based on the outlet being above the lowest points and an intermittent wetland flow. 5 • • The total score is 42 points, within the 30 -50 range for a Category III wetland. The Hydrologic functions are moderate for storage and protection of aquatic resources downstream as well as high water quality functions with complete vegetation cover and a large seasonally ponded area. The Habitat functions rate 10 points which is below the Moderate level rating of 20 -28 points. The wetland contains 2 vegetation types, 2 water regimes and moderate interspersion combined with low functions for species richness, buffer values and connectivity in the landscape. The wetland can be characterized as an isolated habitat confined by a major transportation corridor and dense commercial uses. On the other hand, the wetland hydrology is part of the routing of MLK sub basin stormwater to the Duwamish River. The most important wetland function is stormwater quality improvement as a result of the filtration of sediment by the reed canary grass and shrubs. Some metal uptake occurs in the Typha plant community and to a lesser degree the shrub communities as well. Category III wetlands require a 60 foot water quality buffer according to the City of Seattle, Critical Areas Ordinance (25.09.160 C.1.b.). No additional Habitat buffer is required. REFERENCES Knable, Rob, 2006. Seattle DPD Wetland Biologist. Personal communication, May 10, 2006. Washington Department of Ecology, 2004. Washington State Wetland Rating System for Western Washington. Pub #04 -06 -025 Washington Department of Ecology, 1997. Washington State Wetland Identification and Delineation Manual. Pub. #96 -94. Munsell Color, 1988. Munsell Soil Color charts. Kollmorgen Instruments Corp., Baltimore, MD. Seattle Public Utilities, 2005. Norfolk — MLK Way Sub -Basin Stormwater Improvements Project Development Plan #1. June 22, 2005. Seattle Public Utilities Materials Laboratory, 2004. Geotechnical Report — MLK Way/Norfolk Drainage Structures, Seattle, Washington. Log boring B -1. January 2004. Washington State Department of Transportation, 1994. Wetland Delineation Map, subject area shown as wetland #10. From plan set (Parsons Brincker) April 1994. USDA Natural Resources Conservation District, 1996, Key to Field Indicators of Hydric Soils, Version 3.2, July 1996. 6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 JARPA Norfolk - Martin Luther King Jr. Way Subbasin Stormwater Improvements Prepared for Seattle Public Utilities February 2008 ENVIRONMENTAL' CONSULTANTS t00% Rebected Pape? JARPA Norfolk- Martin Luther King Jr. Way Subbasin Stormwater Improvements Prepared for Seattle Public Utilities Seattle Municipal Tower 700 5th Avenue Seattle, Washington 98124 -4018 Prepared by Herrera Environmental Consultants, Inc. 2200 Sixth Avenue, Suite 1100 Seattle, Washington 98121 Telephone: 206/441 -9080 February 12, 2008 Contents JARPA Attachment A Wetland Delineation Report— Norfolk Basin Drainage and Water Quality Improvements Seattle and Tukwila, Washington Attachment B Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Stormwater Improvements Attachment C Wetland Delineation Report—Puget Creek Natural Area Attachment D SEPA Checklist and DNS Attachment E Coastal Zone Consistency Analysis 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Agency Reference #: Circulated by: Project Tracking Number: AGENCY USE ONLY UPDATED: March 19, 2007. Date Received: (local govt or agency) DARPA FORM LAST __Washington State JOINT AQUATIC RESOURCES PERMIT APPLICATION (JARPA) Form ",S#ep1,t Rea x" di �me Fo P'!,` �try y` c r,4• S # pr 3C e k ork 4 d n St� e4C p net Go to www.epermitting.org Use black ink. Use internet "Help" Check correct buttons to answer permit boxes. questions completely. Use final review checklist at www.epermitting.org. See JARPA Contacts at www.epermitting.org for correct form and instructions. for correct mailing addresses. ❑ Fish Habitat Enhancement Projects per RCW 77.55.181. You must submit copy of completed JARPA form and Fish Habitat Enhancement JARPA Addition to your Local Govemment Planning Dep't and WA Dep't of Fish and Wildlife (WDFW) Area Habitat Biologist on same day. Note for Local Governments: You must submit comments to WDFW within 15 working days. Based on instructions at www.epermittina.orq, I am sending copies of this application to the following: (check all that apply) ❑Local Government for Shoreline: ❑Substantial Development ❑Conditional Use nVariance ❑Exemption ❑Revision nFloodplain Management ©Critical Areas Ordinance (Applied for Exception to Exemption) ❑Washington Department of Fish and Wildlife for Hydraulic Project Approval (Submit 2 copies to WDFW Region) Washington Department of Ecology for 401 Water Quality Certification (to Regional Office - Federal Permit Unit) Washington Department of Natural Resources for Aquatic Resources Use Authorization Notification Corps of Engineers for: 13 Section 404 permit nSection 10 permit ❑Coast Guard for: nGeneral Bridge Act Permit nPrivate Aids to Navigation (for non -bridge projects) ❑For Department of Transportation projects only: This project will be designed to meet conditions of the most current Ecology /Department of Transportation Water Quality Implementing Agreement PROJECT TITLE: Norfolk -MLK Way Subbasin Stormwater Improvements Project PROJECT DESCRIPTION: SPU proposes to repair a damaged drainage system in the Norfolk -MLK Way subbasin. The project area is located in the vicinity of the South Boeing Access road interchange on 1 -5 (Sheet 1). Stormwater runoff from the subbasin is conveyed through a series of pipes to an existing ditch on the east side of 1 -5 that is owned by WSDOT (Sheet 2). A portion of the piped drainage system between Martin Luther King, Jr Way S (MLK Way) and 1 -5 is damaged, causing stormwater to back up into an adjacent sanitary sewer system. King County has notified SPU that it will no longer allow stormwater to be discharged to the sanitary sewer system. The proposed project involves replacing the damaged and undersized drain line (36 -inch CMP) and regrading a section of the WSDOT ditch that has become clogged with sediment to restore the hydraulic capacity of the existing system. Although privately- owned, the damaged pipe is a key component of the Norfolk -MLK Way drainage system. In addition to restoring hydraulic capacity, the project will also eliminate overflows of stormwater from the Norfolk -MLK Way drainage system to the sanitary sewer system and reduce flooding on Martin Luther King Jr. Way S. The damaged line will be replaced with a 64 -inch, ductile -iron pipe to provide the necessary conveyance capacity. The new 64 -inch pipe would be 480 feet long, with an upstream invert elevation of 11.12 feet NAVD88 and a downstream invert elevation of 10.75 feet NAVD88. Office of Regulatory Assistance JARPA JARPA FORM LAST UPDATED: March 19, 2007 For help call 800 - 917 -0043 or visit www.epermitting.org 1 A small sediment trap and spill control structure will be installed at the downstream end of the new 64 -inch pipe to facilitate future maintenance of the ditch as well as to protect the WSDOT ditch from spills that may occur in the drainage basin. Low flows will be routed to the spill control structure via a 4 -foot by 6 -foot concrete flow diversion structure. Higher flows will be discharged directly to the sediment trap. The sediment trap will be constructed by excavating a 33 -foot by 5 -foot depression along the east side of the ditch. The spill control structure will consist of a 12 -ft diameter manhole equipped with a baffle to retain oil, grease, and other floatable materials, and will discharge to the sediment trap. SPU has been conducting source control activities (e.g., business inspections and source tracing) in the Norfolk -MLK Way subbasin since 2001. Several illicit connections /discharges were discovered and have been eliminated. A spill control structure has been included in the project design as a precaution to protect the downstream WSDOT ditch, given the industrial nature of the businesses operating in the basin. Regrading of the ditch and construction of the sediment trap will involve work in a regulated wetland (Wetland D, see Sheets 3 and 4). The WSDOT ditch is located within Wetland D (Sheets 5 and 6). Mitigation for impacts to Wetland D will include wetland re- establishment and enhancement activities (described in detail in the attached wetland mitigation plan) at the Puget Creek Natural Area, owned by the City of Seattle Parks Department. Replacement of the existing storm drain and construction of the flow diversion and spill control structures will not involve work in waters of the U.S. SECTION A - Use for all permits covered by this application. Be sure to ALSO complete Section C (Signature Block) for all permit applications. hetP'' 1. APPLICANT Seattle Public Utilities MAILING ADDRESS Seattle Municipal Tower, 700 5th Avenue, Suite 4900, PO 34018, Seattle, WA 98124 -4018 WORK PHONE 206 -615 -1438 E -MAIL ADDRESS arnel.valmonteaeseattle.gov HOME PHONE 206 - 291 -5167 FAX # 206 - 233 -1532 If an agent is acting for the applicant during the permit process, complete #2. Be sure agent signs Section C (Signature Block) for all permit applications EU 2. AUTHORIZED AGENT MAILING ADDRESS WORK PHONE E -MAIL ADDRESS HOME PHONE FAX # hpslp 3. Relationship of applicant to SPU will obtain construction easements Cedar Homes, Inc. to install the easement from WSDOT to allow which will be located in the WSDOT PURCHASER LESSEE Handling, Steeler Inc., and an operation and maintenance trap and spill control -5. property: OWNER II f from Pape Material new 64 -inch storm drain SPU to maintain the sediment right -of -way east of 1 and Lindahl structures, 4. Name, address and phone number of property owner(s) if other than applicant: h tp 5. Location (street address, including city, county and zip code, where proposed activity exists or will occur) The project site is located east of 1 -5 in the vicinity of the South Boeing Access Road interchange, in the cities of Seattle and Tukwila, King County, Washington. ' ` Local govemment with jurisdiction (city or county) City of Seattle, City of Tukwila Office of Regulatory Assistance JARPA JARPA FORM LAST UPDATED: March 19, 2007 For help call 800 - 917 -0043 or visit www.epermitting.orq 2 1 1 1 1 1 t 1 1 1 1 1 1 1 1 1 1 1 1 1 Waterbody you are working in WSDOT ditch Is this waterbody on the 303(d) List ❑ YES If YES, what parameter(s)? NO FM Waterway WRIA # 9 Shoreline designation Not applicable Zoning designation WSDOT right -of- way: not subject to zoning City of Seattle: Industrial General 2 City of Tukwila: Manufacturing industrial center /light industrial %. Section Section 3 and 10 Township 23 North Range 4 East Government Lot DNR stream type if known Latitude and Longitude: Lat. 47 °30'35" N Long. 122 °16'58" W Tax Parcel Number 0323049202, 0323049222, 0323049224, 0323049213, and 0323049238 Eirl 6. Describe (a) the current use of the property, (b) structures existing on the property, and (c) existing environmental conditions. Have you completed any portion of the proposed activity on this property? ❑ YES p NO For any portion of the proposed activity already completed on this property, indicate month and year of completion. (a) The project site is part of the 1 -5 corridor and located approximately 1,500 feet north of South Boeing Access Road. Adjacent uses are commercial and industrial. Two businesses, Pape Material Handling and Steeler, Inc., are located north of the proposed 64 -inch replacement storm drain line. A business park is located east of the project site. The Boeing Access Road interchange on 1 -5 is located south of the project site. (b) There are no structures on the property but it is adjacent to an area with commercial, industrial, and warehouse buildings. (c) The project site vicinity is relatively flat and highly industrialized, with a high percentage of impervious area. Stormwater runoff from adjacent streets and properties ultimately discharges to the Duwamish Waterway. The area of the WSDOT ditch where the proposed cleaning and regrading would take place is located between the business park to the east and 1 -5 to the west. The WSDOT ditch extends north from South Boeing Access Road and conveys sormwater northward along 1 -5 from the outlet of the 36 -inch pipe on the Pape property to a set of parallel culverts under 1 -5, approximately 600 feet south of South Norfolk Street. The WSDOT ditch has not been maintained and consequently has silted in with 1 to 3 feet of sediment for much of its length resulting in greatly reduced hydraulic capacity. Once reaching the west side of 1 -5, flow passes through two other regulated wetlands and then enters a piped system before discharging to the Duwamish Waterway. The WSDOT ditch is located within a 1.4 acre linear scrub -shrub ditch type wetland system with vegetation dominated by reed canarygrass, nightshade, hardhack, Sitka willow and black cottonwood (Wetland D). A wetland delineation report covering Wetland D is provided in Attachment A of this JARPA. Blackberry, Scots broom and Nootka rose are found in the Office of Regulatory Assistance JARPA JARPA FORM LAST UPDATED: March 19, 2007 For help call 800 - 917 -0043 or visit www.epermittinq.orq 3 adjacent upland. In this area, the 1 -5 embankment forms the west bank of Wetland D, and fill for the commercial /industrial area forms the east bank. Hydrogeomorphically, the WSDOT ditch is classified as a depressional and flat wetland. There is evidence of seasonal flooding approximately 0.5 to 2 feet in depth. The City of Seattle uses the Washington State Wetland Rating System for Western Washington (Ecology Publication #04 -06 -025) to rate wetland functions. Wetland D is a Category III wetland under the Washington State Department Ecology rating system for western Washington. Category 111 wetlands require a 60 -foot buffer according the City of Seattle Critical Areas Ordinance (25.09.160 C.1.b) however there is no effective buffer adjacent to Wetland D within the project area. UM Is the property agricultural land? ❑ YES YES p NO NO en Are you a USDA program participant? help 7a. Describe the proposed work that needs aquatic permits: Complete plans and specifications should be provided for all work waterward of the ordinary high water mark or line, including types of equipment to be used. If applying for a shoreline permit, describe all work within and beyond 200 feet of the ordinary high water mark. If you have provided attached materials to describe your project, you still must summarize the proposed work here. Attach a separate sheet if additional space is needed. The portion of the proposed project that requires Section 404 and 401 permits is the regrading work and the installation of a sediment trap in Wetland D. The WSDOT ditch would be cleaned and regraded in the 340 -foot section extending from 100 feet upstream of the outfall from the piped drainage system to 240 feet downstream. A backhoe would be used to reshape the ditch to a trapezoidal shape with 5 -foot bottom width and 3:1 side - slopes. The upstream and downstream invert of the regraded ditch would match the existing grade. The depth of cut along the ditch would vary from about 2.5 feet at the pipe outfall to zero at the downstream end of the project area. The grading would start approximately 100 feet upstream of the 64 -inch pipe to provide a transition between the existing and regraded sections of the ditch. Total excavation volume would be about 334 cubic yards, of which 91 cubic yards would be within Wetland D. Excavated material will be taken to an approved SPU facility. The proposed project would not increase the hydraulic capacity of the ditch beyond the original design capacity, nor would it expand the area drained by the ditch as originally designed. The location of the centerline of the regraded ditch will be in approximately the same location as the original centerline. Regrading work and installation of the sediment trap will be performed in late summer /early fall of 2008. Replacement of the conveyance pipeline is planned for construction in the fall /winter of 2008. Plans and cross - sections for the work requiring Section 404 and 401 permits are provided in Sheets 3 through 6. PREPARATION OF DRAWINGS: See sample drawings and guidance for completing the drawings. ONE SET OF ORIGINAL. OR GOOD QUAUTY REPRODUCIBLE DRAWINGS MUST BE ATTACHED. NOTE: Applicants are encouraged to submit photographs of the project site, but these DO NOT substitute for drawings. THE CORPS OF ENGINEERS AND COAST GUARD REQUIRE DRAWINGS ON 8-1/2 X 11 INCH SHEETS. LARGER DRAWINGS MAY BE REQUIRED BY OTHER AGENCIES. Office of Regulatory Assistance JARPA JARPA FORM LAST UPDATED: March 19, 2007 For help call 800 - 917 -0043 or visit www.eriermittinq.orq 4 7b. Describe the purpose of the proposed work and why you want or need to perform it at the site. Please explain any specific needs that have influenced the design. WSDOT installed the ditch in 1968 when 1 -5 was constructed to convey runoff from areas east of 1 -5 to the culvert crossing under the highway. The ditch has been poorly maintained and as a result has filled in with sediment. This, in addition to the damaged 36 -inch storm drain, which is privately - owned, has reduced the hydraulic capacity of the conveyance system, resulting in flooding along MLK Way. Damage to the existing storm drain has also caused stormwater to back up and overflow into an adjacent sanitary sewer, which runs north to a pump station on South Norfolk St. The sanitary sewer ties into the King County interceptor system on the north side of South Norfolk St. The County has notified the City that it will no longer allow stormwater from the MLK Way subbasin into its system. If the existing system is not repaired, construction of drainage improvements along MLK Way as part of the Sound Transit light rail system is expected to exacerbate flooding along MLK Way as roadway runoff will be more efficiently collected and conveyed to the damaged system. SPU has agreed to repair the damaged drainage system and take over ownership /maintenance of the existing privately - owned pipe to serve Sound Transit. Conveyance alternatives considered for this project were evaluated in terms of construction cost, constructability, operation and maintenance accessibility, impacts to critical areas, and ability to meet performance criteria. Three conveyance alternatives were evaluated. Conveyance Alternative 1: Regrade WSDOT ditch Conveyance Alternative 2: Replace existing 36 -inch pipe with new outfall to ditch Conveyance Alternative 3: Install new culvert under 1 -5 and connect to WSDOT trunk storm drain outfall SPU video - inspected the 36 -inch line in 2005 and determined that it was damaged throughout its length and needed to be replaced. As a result, Conveyance Alternative 2, which only involved replacing the damaged pipeline, became a required element of the two remaining alternatives. Conveyance Alternative 3 would avoid permanent wetland impacts; however it was determined to not be feasible due to high construction costs and adverse constructability issues. Conveyance Alternative 1 was selected even though the very flat gradient between the conveyance pipeline and the two culverts leading across 1 -5 (a one -foot drop over 1500+ feet), would result in impacts on Wetland D. These impacts are unavoidable in order to re- establish the historical drainage pattern; however, hydraulic modeling was used to minimize the wetland impact footprint to the maximum extent possible. In addition, an access road originally planned for the project was eliminated in order to further minimize permanent wetland impacts. 7c. Describe the potential impacts to characteristic uses of the water body. These uses may include fish and aquatic life, water quality, water supply, recreation and aesthetics. Identify proposed actions to avoid, minimize, and mitigate detrimental impacts and provide proper protection of fish and aquatic life. Identify which guidance documents you have used. Attach a separate sheet if additional space is needed. Characteristic Uses: The WSDOT ditch serves as a stormwater conveyance system. Regrading the WSDOT ditch would disturb approximately 6,234 sq ft (0.14 acre) of Wetland D due to the removal of approximately 133 cubic yards of sediment deposited within the wetland boundary. The proposed clearing and regrading will not result in a Toss of available fish habitat because the area is not accessible to fish. Office of Regulatory Assistance JARPA JARPA FORM LAST UPDATED: March 19, 2007 For help call 800 - 917 -0043 or visit www.eperrnittinq.orq 5 The proposed conveyance improvements will temporarily disturb wetland habitat in the 340 feet of the WSDOT ditch that would be regraded until vegetation is re- established, but the remaining 710 feet of the existing wetland will remain in its current condition. This project is not expected to affect listed fish species that inhabit the Duwamish River because it ill not add new pollutant loads to the Duwamish but rather will restore the existing drainage system to its previous functioning condition. The project will not result in a permanent change in any of the primary constituent elements for Chinook salmon or bull trout critical habitat. w Avoidance and Minimization Measures: To minimize wetland impacts on the WSDOT ditch, the minimum amount of ditch regrading needed for acceptable conveyance system performance was calculated in the hydraulic modeling performed for the preliminary engineering study. Regrading the entire WSDOT ditch would provide greater conveyance improvement, however it would result in substantially more disturbance to Wetland D. Best management practices and minimization measures will be implemented during the design and construction phases of the project in order to minimize the potential impacts on fish and aquatic life. temporary erosion and sediment control (TESC) plan and a spill prevention, control, and countermeasures (SPCC) plan will be prepared prior to the start of construction. Clearing limits will be marked to avoid impacts on critical areas and all equipment to be used for construction activities ill be cleaned and inspected before it arrives at the project site to minimize potential Teaks. A w Compensation This activity is being proposed under USACE Nationwide Permit 41 - Reshaping Existing Drainage Ditches. Compensatory mitigation is not required under this permit; however the City of Seattle requires mitigation under its Critical Areas Ordinance (SMC 25.09.160) therefore compensation for permanent wetland impacts would be provided by restoring and enhancing freshwater wetlands and wetland buffers in the Puget Creek Natural Area (See Sheet 1 for Vicinity Map). This 7.85 acre property is located within the WRIA 9 basin, approximately 4.5 miles northwest of the project site. It contains a headwater forested wetland that feeds Puget Creek, which drains to the Duwamish River. Compensation for permanent wetland impacts would be provided by restoring and enhancing wetlands and wetland buffers within the Puget Creek Natural area. Compensation will include restoring (re- establishing) 0.14 acres of wetland and enhancing 0.56 acres of existing wetland by removing noxious weeds and restoring native plant communities. The proposed restoration and enhancement at Puget Creek Natural Area meet the City of Seattle and Washington State Department of Ecology guidelines of 1:1 re- establishment plus 4:1 enhancement for Category III wetlands. All enhanced wetland areas within Puget Creek Natural Area would also have restored buffers at least 85 feet wide as required by the City of Seattle (SMC 25.09.160). These activities would compensate for the grading impacts on Wetland D. See Attachment B Final Draft Norfolk - Martin Luther King Jr. Way Subbasin Stormwater Improvements Wetland Mitigation Plan for additional details on the mitigation plan. Also see Attachment C for a wetland delineation report covering the Puget Creek Natural Area. UM 7d. For in -water construction work, will your project be in compliance with the State of Washington water quality standards for turbidity (WAC 173.201A -410)? p YES ❑ NO asm 8. Will the project be constructed in stages? El YES ❑ NO Stage 1 will widen the WSDOT ditch. Stage 2 will replace the damaged pipeline. Proposed starting date: Stage 1 ( the portion of the project that requires aquatic permits) will start in August 2008 Estimated duration of activity: Stage 1 -12 weeks , estimated completion - Fall, 2008 Office of Regulatory Assistance, JARPA JARPA FORM LAST UPDATED: March 19, 2007 For help call 800- 917 -0043 or visit www.epermittinq.orq 6 1 1 1 1 1 1 1 1 t 1 1 1 1 1 1 1 Office of Regulatory Assistance JARPA JARPA FORM LAST UPDATED: March 19, 2007 For help call 800 - 917 -0043 or visit www.epermittinq.orq 7 heip 9. Check if any temporary or permanent structures will be placed: • Waterward of the ordinary high water mark or line for fresh or tidal waters AND /OR • Waterward of the mean higher high water for tidal waters? BM 10. Will fill material (rock, fill, bulkhead, or other material) be placed: • Waterward of the ordinary high water mark or line for fresh waters? If YES, VOLUME (cubic yards) / AREA (acres) • Waterward of the mean higher high water for tidal waters? If YES, VOLUME (cubic yards) / AREA (acres) fit? ` 11. Will material be placed in wetlands? x YES n NO If YES: 6 cu yds of rock will be used for an outlet protection pad. 133 A Impacted area in acres: 0.003 heIls B. Has a delineation been completed? If YES, please submit with application. x YES • NO =1 C. Has a wetland report been prepared? If YES, please submit with application x YES • NO UM D Type and composition of fill material (e.g., sand, etc.) Rock h tr E Material source: From an approved SPU facility. EMI F. List all soil series (type of soil) located at the project site, and indicate if they are on the county's list of hydric soils. Soils information can be obtained from the natural Resources Conservation Service (NRCS). Soil maps from the NRCS to not contain any soil information for the project site. This area is considered urban, where soils have not been mapped. 103 G. WILL PROPOSED ACTIVITY CAUSE FLOODING OR DRAINING OF WETLANDS? • YES E NO If YES, IMPACTED AREA IS ACRES OF DRAINED WETLANDS. NOTE: If your project will impact greater than 1/10 of an acre of wetland, submit a mitigation plan to the Corps and Ecology for approval along with the JARPA form. NOTE: A 401 water quality certification may be required from Ecology in addition to an approved mitigation plan if your project wetland impacts are greater than 1/10 ac Please submit the JARPA form and mitigation plan to Ecology for 401 certification review. t etp 12. Stormwater Compliance: This project is (or will be) designed to meet ecology's most current stormwater manual, or an Ecology approved local stormwater manual. ❑ YES x NO If YES — Which manual will your project be designed to meet? liTEI If NO — For Clean Water Act Section 401 and 404 permits only — Please submit to Ecology for approval, along with this JARPA application, documentation that demonstrates the stormwater runoff from your project or activity will comply with the water quality standards, WAC 173.201(A). This is a repair project and as such does not trigger requirements for stormwater treatment or detention under the Ecology manual. The project has been designed in accordance with SPU design standards. help 13. Will excavation or dredging be required in water or wetlands? x YES If YES: WSDOT ditch/Wetland D A. Volume: 91 (cubic yards) /area 0.14 (acre) B. Composition of material to be removed: Silt, silty sand, and sand C. Disposal site for excavated material: Excavated material will be disposed of at an approved SPU facility. D. Method of dredging: Material will be removed with a backhoe 14. Has the State Environmental Policy Act (SEPA) been completed x YES • NO SEPA Lead Agency: Seattle Public Utilities SEPA Decision: DNS, MDNS, EIS, Adoption, Exemption DNS Decision Date (end of comment period) 2/7/08 (3/17/08) SUBMIT A COPY OF YOUR SEPA DECISION LETTER TO WDFW AS REQUIRED FOR A COMPLETE APPLICATION Office of Regulatory Assistance JARPA JARPA FORM LAST UPDATED: March 19, 2007 For help call 800 - 917 -0043 or visit www.epermittinq.orq 7 hgIP 15. List other Applications, approvals or certifications from other federal, state or local agencies for any structures, described in the application (i.e. preliminary plat approval, health review, federal energy regulatory commission license (FERC), Forest whether work has been completed and indicate all existing work on Nationwide Permits, identify whether your project has or will need an and /or stormwater. construction discharges or other activities district approval, building permit, SEPA practices application, etc.). Also, indicate drawings. NOTE: For use with Corps NPDES permit for discharging wastewater TYPE OF APPROVAL ISSUING AGENCY IDENTIFICATION NO DATE OF APPLICATION Grading and drainage permit City of Seattle Department of Planning and Development NAME ADDRESS Grading permit City of Tukwila Public Works Department 9892 40th Ave. South, Seattle, WA 98118 206 - 722 -5800 NPDES permit Washington State Department of Ecology 206 - 725 -2500 Approx. 2/15/08 General permit for work in the right -of -way wsooT SEPA review Seattle Public Utilities (See Attachment D) 2/1/08 DNS Received Special Permission Director Permit City of Tukwila City of Seattle Environmentally Critical Areas Ordinance Exemption Analysis City of Seattle 2/12/08 Coastal Zone Consistency Certification Washington State Department of Ecology (See Attachment E) 2/12/08 ESA Letter of No Effect Seattle Public Utilities 2/5/08 activity you're applying for or for any activity directly related to the activity " 16. Has any agency denied approval for the described herein? • YES x NO If YES, explain: SECTION B - Use for Shoreline and Corps of Engineers permits only: gaZ 17a. Total cost of project. This means the fair etc. The estimated construction cost is $830,000. nIP, 17b. If a project or any portion of a project receives consultation. Please indicate if you will market value of the project, including materials, labor, machine rentals, funding from a federal agency, that agency is responsible for ESA receive federal funds and what federal agency is providing those funds. YES, please list the federal agency. FEDERAL FUNDING • YES x NO If heIP. 18. Local government with jurisdiction: City of Seattle, City of Tukwila h IP' 19. Provide names, addresses and telephone numbers of adjoining property owners, lessees, etc. Please note: Shoreline Management Compliance may inquire additional notice — consult your local government. NAME ADDRESS PHONE NUMBER Pape Material Handling 9892 40th Ave. South, Seattle, WA 98118 206 - 722 -5800 Steeler Inc. 10023 Martin Luther King Jr. Way South, Seattle, WA 98178 206 - 725 -2500 Lindahl Cedar Homes 4300 S 104th PI , Seattle, WA , 98178 206 - 725 -0900 Office of Regulatory Assistance, JARPA JARPA FORM LAST UPDATED: March 19, 2007 For help call 800 - 917 -0043 or visit www.epermittinq.orq 8 1 1 1 1 1 1 1 1 1 1 1 t 1 1 1 1 1 1 1 t 1 1 1 1 1 t 1 1 1 1 1 7 1 1 1 SECTION C. This section MUST be completed foreny permit covered by this application Ila 20. Application is hereby made for a permit or permits to authorize the activities described herein. I certify that familiar with the Information contained in this application, and that to the best of my knowledge and belief, information is true, Complete, and accurate. I further Certify that I possess the authority to undertake the proposed activities. I hereby grant to the agendeE to which this application is made, the right to enter the above - described location to inspect the proposed, in- progress or completed work. I agree to start work alter all necessary permits have been received. I am such ONLY _/DA TE y/2D NATURE OF APPLICANT DATE . SIGNATURE OF AUTHORIZED AGENT I HEREBY APPLICATION PERMIT. DESIGNATE TO ACT AS MY AGENT IN MATTERS RELATED TO THIS THE FOR PERMIT(S). I UNDERSTAND THAT IF A FEDERAL PERMIT IS ISSUED, I MUST SIGN SIGNATURE OF APPLICANT DATE - SIGNATURE OF LANDOWNER PUBLIC ENTITY LANDOWNERS, E.G. DNR) _.(EXCEPT THIS APPLICATION MUST BE SIGNED BY THE APPLICANT AND THE AGENT, IF AN AUTHORIZED AGENT IS DESIGNATED. 18 U.S.0 §1001 provides that Whoever, in any manner wt hln the jurisdiction of any department or agency of the United States knowingly falsifies, conceals, or covers up by any trick, scheme, or device a material fad or makes any false, fictitious, or fraudulent statements or representations or makes or uses any false writing or document knowing same to contain any false, fictitious, or fraudulent statement or entry, shall be fined not more than $10,000 or imprisoned not more than 5 years or both. COMPLETED BY: LOCAL OFFICIAL . .A. Nature of. the existing shoreline:.(Describe type of.shoreine, such es marine;: stream, lake, lagoon, marsh, bog,. . swamp; flood :;. plain, .f oodway, delta; type of teeth, such. aa.aocretion, erosion, high bank, low bank, or dike; materiel . such as 'sip d.• gravel, mud, clay;.rock, riprap; and:extent and type.of buikheading, if anY): • : ... 8. In the event that any of the proposedbuildiriga or siruc#uree will •exceed a height of thirty -five feet above the average -grade level, indicate the approximate location of and number of residential units,. existing and potential, that will have an • C. If the application involves a conditional use or variance, se t forth In tuft that portlorrof the mister program which -provides that the proposed use may be a conditional use, or in the case of a variance, from which.the variance Is being sought These Agencies are Equal Opportunity and Affirmative Action employers. For *pedal accommodation needs, please contact the appropriate agency in the instructions Office of Regulatory Assistance JARPA JARPA FORM LAST UPDATED: March 19.2007 For help cal 800-917-0043 or vlsft www.eoermittlna.org 9 121 I PUGET 4 ri_ arra in now III 101E11 II mmougin ummom I 11111111111111101 I 1111112111111111111111111 mu mmHg =lino °a a z „r 3000 0 3000 6000 SCALE 1' = 3000' CREEK NATURAL AREA MITIGATION SITE rillr640\14, 6 4+ *N41" =LI KING '1,.' ■��� BO ING FIEL COUN INTERNATIONAL AIRPO ST L ►rj11 AN mon __R MU PROJECT SITE COORDINATES: SECTIONS 3 AND 10, TOWNSHIP 23 NORTH, RANGE 4 EAST LAT. 47 °30'35 "N, LONG. 122 °16'58"W MITIGATION SITE COORDINATES: LAT. 47 °33'13 "N, LONG. 122 °21'30 "W DATUM: NAVD -88 2200 Sixth Avenue SUSS 1100 Seattle, Washington 88121 -1820 208 -441 -8080 208- 041 -0108 FAX w m ISWArbonsnin°a Date: DECEMBER 18, 2007 a: PROJECT L C TIONI WAY 1 VICINITY MAP Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Bosto myzEss Ro LIM rt srN \�� ST CI 0 Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 1 of 6 t Match Existing Grade Regrade Chanriel 12' PSD Oil Control Structure 7? #2" PSD 64" PSD SEATTLE CORPORATE LIM/T TUKWILA CORPORATE LIMIT LEGEND Proposed improvement Wetland Ditch t, • - •-- --• • 4 Storm drain 1-toot topographic contour 5-foot topographic contour — Section line Property/easement boundary City limit 10 MN .36",u/ .Duckbill Flapgate 10*.MH Sediment Trap Abandon in Place Existing 36" CMP 10' PAH .Abandon in Place Existing 24" Chic. Manbole 50' 0 02 10d 15521■1 Alwrox. Scale: 1 150' TETRA TECH vnvaietrateeh.com 1420 Fifth Avenue, Suite 600 Seattle, Washington 98101 Phone: 20640334300 Fax: 20648341301 Date: DECEMBER 18, 2007 PROPOSED CONVEYANCE IMPROVEMENTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 2 of 6 START PROJECT (a) 15 0 15 30 SCALE IN FEET 0 ADJACENT PROPERTY OWNERS: OPAPE MATERIAL HAN DUNG NOTE: WETLAND AREA TEMPORARILY DISTURBED: TOTAL PROJECT SEDIMENT EXCAVATION VOLUME: TOTAL PROJECT FILL VOLUME: EXCAVATION WITHIN WETLAND D: FILL WITHIN WETLAND D: DATUM: NAVD -88 6.234 SQ FT (0.14 ACRES) 334 CU YDS 105 CU YDS FOR OUTLET PROTECTION 133 CU YDS 6 CU YDS PAD LEGEND: — — — — PROJECT LIMITS CONSTRUCTION LIMITS FENCE —11— PROPOSED CONTOURS —12— EXISTING CONTOURS EXISTING WETLAND HERRERA 2200 Shan Avenue Suite 1100 Seattle, Washington 98121 -1820 209 -441 -9080 206-441-9108 FAX CONSSATANTS htlWJlwwA ,s n Date: DECEMBER 18, 2007 WETLAND IMPACTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 3 of 6 12 PSD 39LF, S==2.3% OIL CONTROL STRUCTURE 15 0 15 30 SCALE IN htEr SEDIMENT TRAP WITH 3H:IV SIDE SLOPES EXTEND CRETE 12 PSD 29LF, S==0.30% FLOW DIVERSION STRUCTURE 0 CITY OF SEATTLE CITY OF T KU WILA LEGEND: ammiwswo .►1'i` AsPH —J 36 "CMP BY SURVEY PROTECTION PAD PROJECT LIMITS ❑ CONSTRUCTION LIMITS FENCE 11- PROPOSED CONTOURS -12- EXISTING CONTOURS EXISTING WETLAND CONSTRUCTION LIMIT ADJACENT PROPERTY OWNERS: 0 PAPE MATERIAL HANDLING OLINDAHL CEDAR HOMES NOTE: WETLAND AREA TEMPORARILY DISTURBED: 6,234 SQ FT (0.14 ACRES) TOTAL PROJECT SEDIMENT EXCAVATION VOLUME: 334 CU YDS TOTAL PROJECT FILL VOLUME: 105 CU YDS FOR OUTLET PROTECTION PAD EXCAVATION WITHIN WETLAND D: 133 CU YDS FILL WITHIN WETLAND 0: 6 CU YDS DATUM: NAVD -88 END PROJECT 0 GI HERRERA 2200 Sbcth Avenue Suite 1100 Seattle, Washington 98121 -1820 206- 441-9080 208- 441 -9108 FAX o VSULTANTS emJu..,,,. WSfl om Date: DECEMBER 18, 2007 WETLAND IMPACTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 4 of 6 10 0 10 20 SCALE IN FEET LEGEND: - - - - PROJECT LIMITS 'CONSTRUCTION LIMITS FENCE -1 1- PROPOSED CONTOURS —1 2 — EXISTING CONTOURS 20 10 LXISTING WETLAND PLAN — DITCH (NORTH) SCALE: 1' =20' EXISTING GROUND SURFACE WETLAND D SEDIMENT TO BE REMOVED 0 +00 DATUM: NAVD -88 0 +20 0 +40 0 +60 SECTION — DITCH (NORTH) SCALE: 1' =20' 0 0 +80 -20 -10 1 +00 1 +20 0 C-1 HERRERA 2200 Sixth Avenue Suite 1100 Seattle, Washington 98121 -1820 208- 441 -9080 208- 441 -9108 FAX ENVIRONMENTAL . 00l6I4.TARTS Itlirlfrenwolunwrainexam Date: DECEMBER 18, 2007 GRADING PLAN AND SECTION Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 5 of 6 LEGEND: — — — — PROJECT LIMITS CONSTRUCTION LIMITS FENCE —11 — PROPOSED CONTOURS —12— EXISTING CONTOURS l EXISTING WETLAND \`` VW 0 10 20 SCALE IN FEET CITY OF SEATTLE CITY or TUKWILA 20 0 PROTECTION PAD PLAN — SEDIMENT TRAP (SOUTH) SCALE: 1"=20' EXCAVATION AREA 0 EXISTING GROUND SURFACE — //% /\\ -20 PROPOSED GROUND SURFACE -10 1 +00 1 +20 0+00 DATUM: NAVD -88 0 +20 SECTION — SEDIMENT TRAP (SOUTH) SCALE: 1 " =20' O C-I HERRERA 2200 Sixth Avenue Suite 1100 Seattle, Washington 98121 -1820 208441 -9080 206 -441 -9108 FAX ENVIRONMENTAL CONSIA.TANTI le,'/Iww. mnwira m Date: DECEMBER 18, 2007 GRADING PLAN AND SECTION Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 6 of 6 'tlad De im a Delineation Report Norfolk Basin rain a e and � uality Imp►r rve en s d T.aa Washington WETLAND DELINEATION Norfolk Basin Drainage and Water Quality Improvements Seattle and Tukwila, Washington Prepared for Seattle Public Utilities February 2007 ENVIRONMENTAL - COW$ULTANTS WETLAND DELINEATION Norfolk Basin Drainage and Water Quality Improvements Seattle and Tukwila, Washington Prepared for Seattle Public Utilities 700 Fifth Avenue Suite 4900 Seattle, Washington 98124 Prepared by Herrera Environmental Consultants, Inc. 2200 Sixth Avenue, Suite 1100 Seattle, Washington 98121 Telephone: 206/441 -9080 February 23, 2007 Contents Introduction 1 Project Location and Study Area Description 1 Study Objectives 1 Methods and Materials 5 Review of Available Information 5 Wetland Delineation 5 Hydrophytic Vegetation 6 Hydric Soils 7 Wetland Hydrology 7 Wetland Functional Assessment 8 Wetland Classification and Rating 8 Results 11 Analysis of Available Information 11 Topographic Information 11 Soil Mapping 11 Water Resource Information 11 Wetland Information 12 Analysis of Wetland Conditions 12 Wetland A 12 Wetland B 19 Wetland C 20 Evaluation of Wetland Functions 20 Regulatory Implications 23 Federal Regulations 23 Clean Water Act, Section 404 23 Washington State Regulations 23 Clean Water Act, Section 401 23 City of Seattle Municipal Code 24 References 25 Appendix A Appendix B Appendix C Appendix D Wetland Data Forms Photographic Documentation Wetland Functional Assessment Forms Washington Department of Ecology Wetland Rating Forms Tables Table 1. Plant indicator status categories. 6 Table 2. Wetland functional assessment scores for Wetlands A, B, and C. 21 Figures Figure 1. Vicinity map, Norfolk basin drainage and water quality improvements project, Seattle and Tukwila, Washington. 3 Figure 2. Norfolk drainage basin analyzed for the drainage and water quality improvements project, Seattle and Tukwila, Washington. 13 Figure 3. Wetlands identified by the National Wetlands Inventory within the Norfolk basin drainage and water quality improvements project site, Seattle and Tukwila, Washington. 15 Figure 4. Wetland map of the study area for the Norfolk basin drainage and water quality improvements project, Seattle and Tukwila, Washington. 17 ii Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements Introduction This wetland delineation was conducted for the proposed Norfolk basin drainage and water quality improvements project in Seattle and Tukwila, Washington. Seattle Public Utilities (SPU) proposes to repair a broken drainage pipe and expand stormwater facilities on both sides of Interstate 5 (I -5) near Boeing Access Road. This report has been prepared to support associated permit applications that will be submitted to federal, state, and local agencies to assist in their review of potential impacts resulting from the proposed action. This report satisfies one portion of the environmental review for this project. The project location and study objectives are discussed below. Project Location and Study Area Description The Norfolk basin drainage and water quality improvements project site and study area are located within Sections 3 and 10, Township 23 North, Range 8 East. The project site is located on the east and west sides of I -5 between South 113th Street (approximately 2,000 feet south of South Boeing Access Road) and South Norfolk Street (approximately 2,000 feet north of South Boeing Access Road) in the cities of Seattle and Tukwila, King County, Washington (Figure 1). The study area for this wetland delineation is located within a portion of the northwest quadrant of the project site. The study area boundaries are I -5 to the west, BNSF Railway Company (BNSF) right -of -way to the east, South Boeing Access Road to the south, and South Norfolk Street to the north (see Figure 1). A sewer line running east –west bisects the project site along the boundary between Seattle and Tukwila (see Figure 1.) A private developer owns the property in the eastern portion of the study area that lies within Tukwila. The private landowners are in the process of developing the property into a motorcycle race course. The City of Tukwila owns the remaining portion of the land that extends to the BNSF right -of -way. Within the City of Seattle portion of the study area, there are three stormwater ponds and a drainage Swale within the Washington State Department of Transportation (WSDOT) I -5 right - of -way, and wetlands extend to the BNSF right -of -way to the west. The stormwater ponds and the wetlands are separated by a gravel road running north – south. Study Objectives This wetland delineation was conducted in accordance with requirements of the cities of Seattle and Tukwila and the U.S. Army Corps of Engineers. The specific objectives of this effort include the following: Imp /03- 02391 -600 norfolk wednnd delineanan.doc June 21, 2006 1 Herrera Environmental Consultants Wetland Delineation— Norfolk Basin Drainage and Water Quality Improvements • Investigate the presence of wetlands within the study area between I -5 and the BNSF right -of -way following methods specified in the Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987) and the Washington State Wetlands Identification and Delineation Manual (Ecology 1997). ■ Describe and evaluate habitat functions of the existing wetlands according to Methods for Assessing Wetland Functions: Volume 1, Riverine and Depressional Wetlands in the Lowlands of Western Washington (Hruby et al. 1999). • Categorize wetlands using the U.S. Fish and Wildlife Service classification system (Cowardin et al. 1979), the hydrogeomorphic classification system (Brinson 1993), the Washington Department of Ecology Wetlands Rating System (Ecology 2004), and critical area regulations of the cities of Seattle and Tukwila. • Discuss the recommended buffer widths for each wetland class according to Seattle and Tukwila city regulations. Also discuss mitigation requirements for potential wetland impacts. Imp /o3 J239I.60o ,,orfolk wetland ddinrndon.doc Herrera Environmental Consultants 2 June 21, 2006 it 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Figure 1. Vicinity map, Norfolk basin drainage and water quality improvements project, Seattle and Tukwila, Washington. 111, I =MIMI v' miaow f INF 1 5l nus .,,., ' , , .., ,... :r U .. �p C 27 I," < i ; ..N„` i < ,�I 1 .. •',l a ��� ST �� .. i • Seattle 014 t1 ' :'� 11, -m■ �Lm, 'eal � ER ST�� ST ,,. �E 7p — 51WEPUE c N 0:..4 I AUSTIN � I ellevue so li ' r srsr. <a II ST ST ST "N ° HOLDEN $ . location $ N ; — s , 1,11.111111111, t r IL:i rs1 1,, �I101 i M , to 1tki , n .lit9P ftlA d S THISTLE till 72 S 'LL v ! CLOVE '�- " ���`� I EE 1( o..44`. L l! A > n �® �- \1 \ice- 6 _ � :4 \\ �. „ \ � `. 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F �} :F =! \\� \��F L,i \� f N' x"71 � "- /' 1 r6 \ �rB ' ILIGUSTA ST la` a 1i„ .y \ §' . y et.4 ost. -� S'.sc ` 4 4b 1 it.. e. \ ' -;599 1 G" �' l i r 9 U s 120TH I N N N�' Yr_ \ -'- ST • � 11i! iw '' .f � \\ %! a ti; '•\ •. ` % >i 3 11 J I PER .5 .75 .. ° ' `' As \\ t•\ p�Ii • sN 'e sr �,� t E$j ,J§ \�` BEE G.N § i.A!* \ S In 5 121ST .25 1 s use M. 9� yyy bb $ 'Y/ g 1 K1lanetrraj�y1 – 0 .5 1.0 4`,+i ' an { -, i 'N. 3 �,r '9.st �+*1=ZZDZI iO tad Ile ISP!FTREFIIF.at F11401X. SC1A' 03\A®IIIIPF:M ��R>s/Z7r MI Figure 1. Vicinity map, Norfolk basin drainage and water quality improvements project, Seattle and Tukwila, Washington. Wetland Delineation— Norfolk Basin Drainage and Water Quality Improvements Methods and Materials This wetland delineation involved reviewing available information, performing wetland delineations within the study area, assessing wetland functions and values, and classifying the wetlands. These methods are described below. Review of Available Information An information review was performed to evaluate potential wetlands in the project area prior to conducting onsite observations. The following information was collected and reviewed for this delineation report: • Aerial photograph of the project site and study area (City of Seattle) • National Wetlands Inventory map of wetland areas within the project vicinity (USFWS 1988) • Natural Resources Conservation Service soil survey maps and soil descriptions for the project area (NRCS 2003) • Historical wetland delineation reports prepared by IES Associates (IES 1991) and Skillings - Connolly, Inc. (Skillings - Connolly 1993) • Preliminary drainage report prepared by Contours and Concepts Engineer, LLC (Contours and Concepts 2001). Wetland Delineation The wetland delineation was performed in accordance with the Washington State Wetlands Identification and Delineation Manual (Ecology 1997), which is consistent with the 1987 Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987). The three - parameter approach used to identify and delineate wetlands relies on the presence of field indicators for hydrophytic vegetation, hydric soils, and hydrology. These three parameters are defined and described in the subsections that follow. This wetland delineation was performed according to procedures specified under the routine determination method (Ecology 1997). To identify potential wetlands, field conditions were evaluated by wetland biologists who walked the entire study area. In each area that appeared to have wetland characteristics, data on dominant plant species, soil conditions in test pits, and evidence of hydrologic conditions were recorded on routine wetland delineation forms. Adjacent upland areas were also analyzed based Imp /03-02391-600 nn,f Ik ImPanddelinmuon.dx June 21, 2006 5 Herrera Environmental Consultants Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements on these three parameters. Based on these data, a wetland or upland determination was made for each area examined. Potential wetland areas within the project area were identified as distinct vegetation units to which the three parameters (hydrophytic vegetation, hydric soils, and hydrology) were applied. A vegetation unit is an area determined to have similar physical or plant characteristics. Features such as species uniformity, species dominance, distinct topographic breaks, and obvious similarities in soil or hydrologic indicators are characteristics that define a vegetation unit. Hydrophytic Vegetation Hydrophytic vegetation has the ability to grow, effectively compete, reproduce, or persist in anaerobic soil conditions that have resulted from periodic or long -term saturation. Evidence of hydrophytic vegetation includes visual observations of plant species growing in areas of prolonged inundation or soil saturation and observations of physiological, morphological, and reproductive adaptations. Numerous field indicators of hydrophytic vegetation may be used, although the most common indicator is defined as greater than 50 percent of the dominant species in each vegetation stratum having a wetland indicator status of obligate wetland (OBL), facultative wetland (FACW), or facultative (FAC). This wetland delineation is based on the U.S. Fish and Wildlife Service draft 1996 list of plant indicator status (USFWS 1996). The plant indicator status categories are explained in Table 1. Table 1. Plant indicator status categories. Indicator Status Indicator Symbol Definition Obligate wetland plants OBL Plants that occur almost always (estimated probability >99 %) in wetlands under natural conditions but also occur rarely (estimated probability <1 %) in nonwetlands Facultative wetland plants FACW a Plants that usually occur (estimated probability >67 %) in wetlands under natural conditions but also occur (estimated probability 1% to 33 %) in nonwetlands Facultative plants FAC a Plants with a similar likelihood (estimated probability 33% to 67 %) of occurring in both wetlands and nonwetlands Facultative upland plants FACU a Plants that sometimes occur (estimated probability 1% to 33 %) in wetlands but occur more often (estimated probability >67% to 99 %) in nonwetlands Obligate upland plants UPL Plants that rarely occur (estimated probability <1 %) in wetlands under natural conditions Wet Dry OBL -* FACW —>FAC — FACU - UPL a The " +" suffix indicates plants with a somewhat higher probability of occurring in wetlands. The " —" suffix indicates plants with a somewhat lower probability of occurring in wetlands. Source: Environmental Laboratory (1987). Imp 1 0302391400 norfolk wetland delinmtinn.doc Herrera Environmental Consultants 6 June 21, 2006 Wetland Delineation— Norfolk Basin Drainage and Water Quality Improvements Dominant species are those that contribute more than other species to the character of a plant community. To determine dominance, plant species are divided into three strata: trees, shrubs, and herbaceous species. For each stratum, dominance is measured by one of three factors (height, areal coverage, or basal area). For this wetland delineation, dominance was recorded as a percentage of areal coverage for each species within its stratum. The dominant species within each stratum are those that, when ranked in descending order of areal coverage and totaled, exceed 50 percent. In addition, dominant species include those that constitute 20 percent or more of the total dominance measure for that stratum. Plant species were identified using Flora of the Pacific Northwest (Hitchcock and Cronquist 1987), A Field Guide to the Common Wetland Plants of Western Washington and Northwestern Oregon (Cooke 1997), and Wild Plants of Greater Seattle (Jacobsen 2001). The indicator status of each plant species is based on the Pacific Northwest list of plant species that occur in wetlands (USFWS 1996). Hydric Soils A hydric soil is defined as a soil that, in an undrained condition, is saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions near the surface (Ecology 1997). Hydric soils data were obtained by digging test pits at least 16 inches deep and 4 inches wide. The most common field indicator of hydric nonsandy soils is soil color (i.e., hue, value, and chroma), which is evaluated using Munsell soil color charts. Hydric soil colors are examined immediately below the A horizon or at 10 inches below the soil surface, whichever is shallower. Hydric soils include gley (i.e., gray) soils, low chroma soils in an unmottled matrix, or soils with mottles within a low chroma matrix. Mottles are features that resemble spots of contrasting color due to oxidation and reduction processes (FR 1998; NRCS 1998). Other hydric indicators for nonsandy soils include the presence of organic soils (e.g., histosols and histic epipedons), sulfidic material (e.g., hydrogen sulfide), aquic or peraquic moisture regimes, reduced soil conditions, and the presence of iron or manganese concretions (NRCS 1998). The presence of hydric soils can be further confirmed by verifying their position on soil survey maps and their listing on the hydric soils list (NRCS 1995; 2004). For sandy soils, soil color, particularly chroma, is not always a reliable hydric indicator. Hydric soil indicators for sandy soils include high content of organic matter in the surface horizon, streaking of subsurface horizons by organic matter, organic pans (i.e., spodic horizons), sulfidic material, and aquic or periaquic moisture regimes. Wetland Hydrology Evidence of wetland hydrology is found where soils are periodically inundated or saturated to the surface for a sufficient duration during the growing season. A sufficient duration is defined as a period of consecutive days totaling 12.5 percent or more of the overall growing season. The growing season is the period of consecutive frost -free days, or the longest period during which the soil temperature stays above biological zero (41 degrees Fahrenheit) at 19.7 inches below the 1 Hp /03-02391 -600 norfolk wetland delineation.doc June 21, 2006 7 Herrera Environmental Consultants Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements surface. As a general rule of thumb, the growing season for western Washington lowlands extends 245 days between March 1 and October 31 (Ecology 1997). In the field, the primary hydrologic indicators are examined within the soil test pits that are dug to observe hydric soil conditions. Hydrologic indicators include the presence of standing water in the pit at a depth of 12 inches or less and saturation in the root zone. Secondary field indicators include watermarks, drift lines, sediment deposits, drainage patterns within wetlands, oxidized rhizopheres surrounding living roots, water - stained leaves, and local soil survey data verified in the field. Wetland Functional Assessment Wetland functions were assessed using the method presented in Methods for Assessing Wetland Functions: Volume 1, Riverine and Depressional Wetlands in the Lowlands of Western Washington (Hruby et al. 1999). This method is approved by Washington Department of Ecology (Ecology) for evaluating wetland functions in Washington. This method was developed using mechanistic models to determine the performance of each wetland function addressed by this methodology. This method assesses functions related to water quality, functions related to hydrology (water quantity), and habitat suitability. Functions are evaluated for each wetland based on the hydrogeomorphic classification of each aquatic unit. Data are collected and recorded on data sheets that are specific to each hydrogeomorphic class. The results of the functional assessment are presented as an index (score) between 1 and 10, with 10 representing the highest level of performance. The performance indices are presented for each individual function that was assessed. Wetland Classification and Rating Four wetland classification systems were used for this delineation report. Wetlands observed in the project area were classified according to the U.S. Fish and Wildlife Service system (Cowardin et al. 1979), which is based on the evaluation of attributes such as vegetation class, hydrologic regime, salinity, and substrate. In addition, wetlands were classified according to the hydrogeomorphic system, which uses the geomorphic setting and sources of hydrology to define wetland classes (Brinson 1993). Wetlands were also rated using the Ecology wetland rating system for western Washington (Ecology 2004). This rating method is a four- tiered wetland categorization system based on wetland acreage, species diversity, and number of wetland classes. In this system, wetlands are ranked in four categories, with Category I wetlands exhibiting outstanding features and Category IV wetlands exhibiting minimal attributes. Imp /03-0 1391 -600 tmrfo Ik wetland delmeation.da Herrera Environmental Consultants 8 June 21, 2006 Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements Guidelines specified in the City of Seattle Municipal Code (Seattle 20062) and the City of Tukwila were also followed to classify wetlands for the purpose of establishing wetland buffer widths. In both codes, wetlands are ranked in four classes, with Class I wetlands exhibiting outstanding features and Class IV wetlands exhibiting lower quality attributes. Imp /03-02391-6M eon Il wetland delixmion.d c June 21, 2006 9 Herrera Environmental Consultants Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements Results Analysis of Available Information Several sources of existing information regarding wetlands within the study area were reviewed and evaluated prior to conducting the fieldwork. These sources included topographic maps, soil maps, water resource information, wetland inventories, and previous delineation reports. Topographic Information The project site within the Norfolk drainage basin generally slopes and drains to the south and west toward the Duwamish River, although development features and microtopography block stormwater flows from draining into the river (Figure 2). Topography on the east side of the study area is generally flat, except where existing wetlands and stormwater ponds and swales are present at lower elevations. The terrain drops steeply by approximately 10 feet where the wetlands are extending across the BNSF property line. Soil Mapping Soil maps from the Natural Resources Conservation Service and King County do not contain any soil information for the project site. This area is considered urban, where soils have not been mapped. Water Resource Information The project site and study area are located within the Norfolk drainage basin, which eventually drains west to the Duwamish River. Flooding problems have occurred in the drainage basin, particularly in the Martin Luther King Junior Way subbasin where a major drainage pipe has broken and sediment accumulation in the ditch along the east side of I -5 has caused flows to back up during storm events. As a result, only a portion of the stormwater that is expected to flow under I -5 reaches the west side. Stormwater ponds and a drainage swale on the west side of I -5 within the study area collect and treat stormwater from the portion of I -5 within the northern part of the Norfolk drainage basin. This drainage flows into wetlands within the study area that are adjacent to the BNSF right -of- way. Although these wetlands should drain to the west through a culvert under the railroad tracks and into the Duwamish River, the culvert slopes to a higher elevation and therefore does not drain the wetlands. The Norfolk — MLK Way Sub -Basin Stormwater Improvements Project Development Plan #1 — C333205 report (SPU 2005) provides more information about drainage issues within the project area. Imp /0.3-01391-600 norfolk ,.zdmddd6 0o.d�c June 21, 2006 11 Herrera Environmental Consultants Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements Wetland Information The National Wetlands Inventory identifies five wetlands within the project site, including one in the study area (Figure 3). Four of the five wetlands are palustrine emergent (PEM) wetlands (three are seasonally flooded [PEMC], and one is semipermanently flooded [PEMF]). The fifth wetland is an excavated palustrine open -water wetland that is permanently flooded and contains an unconsolidated bottom (USFWS 1999). One of the seasonally flooded palustrine emergent wetlands identified on the National Wetlands Inventory map lies within the study area, but that wetland is smaller than the wetlands delineated in the study area. Analysis of Wetland Conditions On December 2, 2005, project wetland biologists performed wetland delineations within the study area depicted in Figure 1. This involved examining the study area for plant communities that are indicative of wetland conditions. Three wetland areas (designated as Wetlands A, B, and C) were identified within the study area (Figure 4). Appendix A contains the wetland data forms for both wetland and upland soil test pits dug during the December site visit. Appendix B contains representative photographs of the three wetlands within the study area. Appendix C provides the Ecology wetland functional assessment forms for these three wetlands. Appendix D provides the Ecology wetland rating field data forms for these wetlands. The following subsections describe each wetland, including the vegetation, soils, hydrology, and wetland classification. Wetland A Wetland A is a 1.95 -acre permanently flooded wetland that contains three wetland classes: open water, emergent, and scrub -shrub (see Figure 4). The wetland is located in the City of Seattle between the BNSF right -of -way and the gravel road that separates it from the WSDOT stormwater ponds and swale. Wetland A receives water from precipitation, high ground water, and the stormwater swale that cuts through the gravel road and drains to the wetland. Because the wetland has a constricted outlet, water resides in the wetland permanently and appears to have existed that way for a long period of time (10 years or more). Water depths observed in Wetland A during the site visit ranged between 10 inches and 6 feet or greater. Under the hydrogeomorphic classification system, Wetland A is considered a depressional closed wetland (Brinson 1993). The open -water portion of the wetland contains some submerged vegetation but becomes deep enough (6.6 feet or deeper) so that surface vegetation no longer grows. The palustrine emergent portions of this wetland include a permanently flooded area and a seasonally flooded area. Common cattail (Typha latifolia) dominates the permanently flooded area. Other emergent plants in this area include small - fruited bulrush (Scirpus microcarpus), climbing nightshade (Solanum dulcamara), and purple loosestrife (Lythrum salicaria), which is a noxious weed. The Imp /03-02391 -600 /mom Ik wedandddinearton.doc Herrera Environmental Consultants 12 June 21, 2006 ML KING WAY SUB -BASIN Figure 2. Norfolk drainage basin analyzed for the drainage and water quality improvements project, Seattle and Tukwila, Washington. National Wetlands Inventory (USFWS 1999) PEMC Palustrine emergent wetland, seasonally flooded PEMF Palustrine emergent wetland, semipermanently flooded Palustrine unconsolidated bottom permanently flooded, excavated N Figure 3. Wetlands identified by the National Wetlands Inventory within the Norfolk basin drainage and water quality improvements project site, Seattle and Tukwila, Washington. Figure 4. Wetland map of the study area for the Norfolk basin drainage and water quality improvements project, Seattle and Tukwila, Washington. Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements seasonally flooded area is located in the northern portion of the wetland and is dominated by reed canarygrass (Phalaris arundinacea) with a subdominant growth of Cooley's hedgenettle (Stachys cooleyae). The scrub -shrub class is located at the periphery of the wetland, where water levels are lower. The scrub -shrub class is dominated by willows (Salix spp.), red -osier dogwood (Cornus sericea), and Himalayan blackberry (Rubus armeniacus). Soils observed in the study area include black (10YR 3/1) muck and silty clay loam soils that contained redoximorphic features at 7 inches and below the soil surface. According to the Washington Department of Ecology rating system, Wetland A is a Category II wetland (Ecology 2004). The City of Seattle uses the same rating system and would require a 100 -foot buffer for this disturbed wetland under regulations scheduled to be issued on May 9, 2006. According to the City of Tukwila, Wetland A meets the criteria for a Type 1 wetland, which requires a 100 -foot buffer. Wetland B Wetland B appears to have been connected to Wetland A in the past, although the wetlands are now separated by a WSDOT stormwater pipeline (see Figure 4). Wetland B covers 0.97 acres. The wetland is very similar to Wetland A in that it has three wetland classes: open water, emergent, and scrub - shrub. Under the hydrogeomorphic classification system, Wetland B is considered a depressional outflow wetland (Brinson 1993). Water sources for this wetland include precipitation, high ground water, and runoff from the adjacent disturbed upland to the east. Drainage channels created in the bare soils on the adjacent upland drain water and sediment into the wetland. No outlet for this wetland has been observed or identified on the project site, according to the project development plan (PDP #1; SPU 2005). Water levels within the wetland were observed to vary from surface saturation to a depth of over 6 feet during the December field visit. The vegetation in Wetland B is similar to that in Wetland A. Additional vegetation found in Wetland B that was not present in Wetland A includes Oregon ash (Fraxinus latifolia) and Douglas spirea (Spireae douglasii). Soils observed within Wetland B consist of very dark brown (10 YR 3/1) gravelly sandy loam. Soils produced a sulfidic odor during excavation at soil pit locations, indicating permanent or long -term saturation, which creates anoxic conditions. According to the Washington Department of Ecology rating system, Wetland B is a Category II wetland (Ecology 2004). The wetland is located in the City of Tukwila; therefore, Tukwila regulations apply. According to the Tukwila municipal code, Wetland B meets the criteria for a Type 1 wetland, for which 100 -foot buffers are required. Imp /03 -02391 -600 norf lk wetlanddelineo0on.doc June 21, 2006 19 Herrera Environmental Consultants Wetland Delineation— Norfolk Basin Drainage and Water Quality Improvements Wetland C Wetland C is a small ditch wetland covering 0.02 acres located at the north end of the study area (north of Wetland A; see Figure 4). Most of the plants in Wetland C are nonnative invasive species. The wetland is dominated by reed canarygrass. Other plants that occur in the wetland include Douglas spirea, bull thistle (Circium vulgare), and Himalayan blackberry. Under the hydrogeomorphic classification system, Wetland C is considered a depressional outflow wetland (Brinson 1993). Water sources for this wetland include precipitation, high ground water, and some surface runoff from surrounding areas. Soils were saturated to the surface during the December field visit. Soils observed within the wetland consist of very dark brown (10 YR 3/1) sandy clay loam. The soils exhibited redoximorphic features throughout the excavated soil column (16 inches), indicating alternate saturation and drying of soils. According to the Washington Department of Ecology rating system, Wetland C is a Category III wetland (Ecology 2004). The Ecology rating system is also used by the City of Seattle, which requires 60 -foot buffers for Category III wetlands larger than 100 square feet that have low - functioning buffers. (Neither Wetland C nor its buffers is located within the City of Tukwila; hence this wetland was not rated under Tukwila regulations.) Evaluation of Wetland Functions The performance scores for the various functions of Wetlands A, B, and C are presented in Table 2, and the wetland functional assessment forms are provided in Appendix C. The results of the functional assessment are presented as an index (score) between 1 and 10, with 10 representing the highest level of performance. The performance indices are presented for each individual function assessed. Wetlands A and B have similar ratings for each function. These wetlands have high potential for providing water quality improvement functions including removing sediments, nutrients, and other pollutants. Wetlands A and B also have high potential to reduce peak flows due to their large storage area and severely constricted outlets. These wetlands are rated moderate for habitat suitability for all types of animals, although fish would not use these wetlands because there is no access to them. Both wetlands have low species richness because of moderate potential for primary production and export. The wetlands also rate low for ground water recharge. Wetland C has high potential for providing water quality improvement functions including removing sediments, nutrients, and other pollutants. Unlike Wetlands A and B, this wetland has high potential for ground water recharge due to its more moderately drained soils. The wetland is rated moderate for reducing peak flows, although it is relatively small. The wetland provides low habitat functions and species richness, because it contains only one wetland class and is dominated by nonnative vegetation. However, the wetland has high potential for primary production and export. Imp /03-02391-600 noe/Ik wmiand delineadon.dor Herrera Environmental Consultants 20 June 21, 2006 Wetland Delineation— Norfolk Basin Drainage and Water Quality Improvements Table 2. Wetland functional assessment scores for Wetlands A, B, and C. Wetland Function Score Wetland A Wetland B Wetland C Potential for removing sediment 8 9 8 Potential for removing nutrients 7 8 10 Potential for removing heavy metals and toxic organics 6 7 9 Potential for reducing peak flows 8 8 5 Potential for reducing decreasing downstream erosion 5 4 3 Potential for ground water recharge 1 3 10 General habitat suitability 4 4 1 Habitat suitability for invertebrates 6 4 0 Habitat suitability for amphibians 3 3 1 Habitat suitability for anadromous fish NA NA NA Habitat suitability for resident fish NA NA NA Habitat suitability for wetland - associated birds 4 4 1 Habitat suitability for wetland- associated mammals 4 3 0 Native plant richness 3 3 1 Primary production and export 6 6 9 NA = not applicable. Imp /03 -02391 -600 rmrIb lk werkmddelimmnon.doc June 21, 2006 21 Herrera Environmental Consultants Wetland Delineation— Norfolk Basin Drainage and Water Quality Improvements Regulatory Implications Federal, state, and local wetland regulations may apply to the Norfolk basin drainage and water quality improvements project. Federal laws regulating wetlands include Section 404 of the Clean Water Act (33 United States Code [USC] 1344). Washington state laws and programs designed to control the loss of wetland acreage include Section 401 of the Clean Water Act (administered through the state Department of Ecology), the State Environmental Policy Act (SEPA) of 1971, the hydraulic code rules (Chapter 222 -110 of the Washington Administrative Code [WAC]), and the Shoreline Management Act. The cities of Seattle and Tukwila regulate activities within or adjacent to wetlands and streams under their environmentally sensitive areas ordinances. Federal Regulations Clean Water Act, Section 404 Section 404 of the Clean Water Act regulates the filling of wetlands within waters of the United States (33 USC 1344). Section 404 is administered by the U.S. Army Corps of Engineers, which issues permits for activities that involve filling wetlands. Such permits include nationwide (general) permits for small areas of fill and individual permits for projects that require larger areas of fill. Because no direct wetland impacts (only wetland buffer impacts) are anticipated to result from this project, a Section 404 permit is unlikely to be required. Section 404 of the Clean Water Act does not regulate impacts on wetland buffers (i.e., upland areas designated adjacent to wetlands to protect the wetlands). Washington State Regulations Clean Water Act, Section 401 Section 401 of the Clean Water Act regulates water quality within waters of the United States. Water quality certification is administered by the U.S. Environmental Protection Agency (U.S. EPA) and Ecology. If a Section 404 permit is required, then a Section 401 water quality review permit also must be obtained. Ecology also regulates wetlands that are determined by the Corps of Engineers to be isolated. Isolated wetlands are those that are not connected to other jurisdictional waters through surface or subsurface connection. If wetlands are determined to be adjacent and not isolated, they are regulated by the Corps of Engineers. Imp /03 -02391 -600 nab lk wiland delineafion.doc June 21, 2006 23 Herrera Environmental Consultants Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements Again, no wetland impacts are anticipated to result from the proposed action; therefore, this provision does not apply to this project. City of Seattle Municipal Code The Seattle Municipal Code for environmentally critical areas regulates activities that occur in or near wetlands and streams and other critical areas. The environmentally critical areas regulations have recently been revised and were issued on May 9, 2006. The City of Seattle ranks wetlands using the Ecology (2004) wetland rating system. Class I wetlands have the largest number of wetland functions and provide the highest level of functions and values. Class IV wetlands provide the least number of functions and have the lowest value. Wetland buffer widths are designated according to the wetland rating (Seattle 2006). According to the city rating system, Wetland A is a Class II wetland. The 100 -foot buffer on the east side of Wetland A contains the following (moving east from the wetland): 1) approximately 20 feet of vegetation, 2) a gravel road, and 3) a portion of the WSDOT stormwater facilities. These characteristics define the wetland buffer as having low quality. Class II wetlands that have a low - quality existing buffer require a 100 -foot buffer, according to the Seattle Municipal Code (2006). Imp /03 -02391 -600 tmr/lk wetlanddelimmion.doc Herrera Environmental Consultants 24 June 21, 2006 Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements References Brinson, M.M. 1993. A Hydrogeomorphic Classification for Wetlands. Technical Report WRP -DE-4. U.S. Army Corps of Engineers, Waterways Experiment Station, Vicksburg, Mississippi. Contours and Concepts. 2001. Preliminary Drainage Report for the Colonial Estates Phase III Development. Contours and Concepts Engineer, LLC, Tenino, Washington. Cooke, S. 1997. A Field Guide to the Common Wetland Plants of Western Washington and Northwestern Oregon. Seattle Audubon Society, Seattle, Washington. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. Publication FWS /OBS- 79/31. U.S. Department of the Interior, Fish and Wildlife Service. 131 pp. Ecology. 1993. Washington State Wetlands Rating System, Western Washington. Publication 93- 74. Washington Department of Ecology, Olympia, Washington. Ecology. 1997. Washington State Wetlands Identification and Delineation Manual. Publication 96 -94. Washington Department of Ecology, Olympia, Washington. Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Wetlands Research Program Technical Report Y -87 -1. AD /A176 734. U.S. Army Corps of Engineers, Waterway Experiment Station, Environmental Laboratory, Vicksburg, Mississippi. FR 47:138:31810. Title 33: Navigation and Navigable Waters; Chapter II, Regulatory Programs of the Corps of Engineers. Federal Register 47: 138: 31810. June 10, 1982. FR 51:219:41206. 40 CFR Parts 320 through 330: Regulatory Programs of the Corps of Engineers; Final Rule Federal Register 51: 219: 41206 - 41260. August 3, 1986. FR 59:362:16835. Changes in Hydric Soils of the United States. Federal Register 59: 16835. July 13, 1994. (current hydric soil criteria). Hitchcock, C.L., and A. Cronquist. 1987. Flora of the Pacific Northwest. University of Washington Press, Seattle, Washington. Hruby, T., T. Granger, K. Brunner, S. Cooke, K. Dublanica, R. Gersib, L. Reinelt, K. Richter, D. Sheldon, E. Teachout, A. Wald, and F. Weinmann. 1999. Methods for Assessing Wetland Functions. Volume 1, Riverine and Depressional Wetlands in the Lowlands of Western Washington; Part 1, Assessment Methods. Publication 99 -115. Washington State Department of Ecology, Olympia, Washington. Imp /03- 02391.600 nab Ik wetland delinmion.doc June 21, 2006 25 Herrera Environmental Consultants Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements NRCS. 1995. Hydric Soils of Washington. U.S. Department of Agriculture, Natural Resource Conservation Service. Obtained January 29, 2004 from agency USDA ftp site: <ftp: / /ftp- fc. sc.egov. usda. gov /NSSC /Hydric_Soils/Lists /wa.pdf>. NRCS. 1998. Field Indicators of Hydric Soils in the United States. Version 4.0. Edited by G.W. Hurt, P.M. Whited, and R.F. Pringle. U.S. Department of Agriculture, Natural Resources Conservation Service, Fort Worth, Texas. NRCS. 2004. Soil Survey of King County Area, Washington. U.S. Department of Agriculture, Natural Resources Conservation Service, in cooperation with Washington State Department of Natural Resources and Washington State University, Agricultural Research Center. U.S. Government Printing Office, Washington, D.C. Obtained on February 23, 2006 from agency website: < http:// www .ncgc.nres.usda.gov/branch/ssb /products /ssurgo / >. SPU. 2005. Norfolk – MLK Way Sub -Basin Stormwater Improvements Project Development Plan #1– C333205 report. Prepared by TetraTech for Seattle Public Utilities. Seattle, City of. 2006. Seattle Municipal Code, Chapter 25. Obtained February 24, 2006, from MRSC website: < http:// www.olympiamunicipalcode.org/ >. USFWS. 1988. National Wetlands Inventory map of Lacey, Washington, quadrangle. U.S. Department of Interior, Fish and Wildlife Service. Obtained on January 29, 2004 from agency website: < http : / /wetlands.fws.gov /fags.htm >. USFWS. 1996. List of Plant Species That Occur in Wetlands (Region 9). U.S. Department of Interior, Fish and Wildlife Service. USGS. 1983. Topographic map of Seattle, Washington, quadrangle. Scale 1:25,000. U.S. Geological Survey. Imp /03- 02391-600 nnrlo !k wetland ddbrcm nn.dor Herrera Environmental Consultants 26 June 21, 2006 APPENDIX A Wetland Data Forms �S '�'.i. Y'-�'�.::::•.:rif��.'> cif :.. :;:.DATA :FORIV�' P rbjewUSite -.- IV.. TDIk rr. :Applicant/Owner .. Investigator D (;_.1- m.• •, oNormat Crrcurestancos eve. on mises ..� the site $ignificanEly distiied (Atyp'rca! Situationl) Es'the•area a potential Problem Area? `VEGETATION Dominant Plant Species 3.j�. elt Stratum ` Indicator Dominant Pfart Species Strata to in 10: 11. _0 T2. Percent of Dominant Species that are OBL, FACW or FAO (excluding FACIJ HYDROLOGY RECORDED DATA (Describe in Remarks): Stream, Lake, or Tide Gauge O Aerial Photographs .. • 0 Other • 0 No Recorded Data Available FIELD OBSERVATIONS: • Depth of Surface Watef' �r (in.) Depth to Free Water in Pit: • (in.) Depth to Saturated Soil: • O. (in.). WETLAND HYDROLOGY INDICATORS: . PRIMARY INDICATORS: 7 inundates ,ai Saturates in Upper 12 Inches D Water Marks O Drift Lines • 0 Sediment Deposits Drainage Pntterns.in Wetlands . SECONDARY INDICATORS (2 or more required): 0.Oxidized Root Channels in Upper 12 lnches O Water Stained Leaves .Local Sol! Surrey Data 7.FAC Neurtii Test ;a Other (Eclair. in Remarks) . ?aptJaltNarne t. rieand Phase).' (Subgroup): ylik0F1LCDESCRIPTION Mottle n.tias:t' ',.Teturestiuct,Cuonorere, • AerIth, • ," Matrix Color 'Mottle Coors oundance/Co . Inches). -Horizon; t. (Monsell moist " (Munsetl Moist) HYDRIC SOIL INDICATO Histoiol • O Histic Epipedon ' • O Sulfidic Odor Actuic Moisture Regime • Hydric Sol Present? RS . Reducing COnditions p Organic Streaking in Sandy Soils Greyed or Low-Chroma Colors 0 Listed on Local Hydric Soils List P Concretions 0 Listed on National Hydric Soils List 0 High Organic Streaking in - 0 Other (Explain in Remarks) ' • Swine Layer in Sandy Soils ' . WETLAND DETERMINATION Hydrophytic Vegetation Present? Wetland Hydrology Present? Hydric Soils Present? • Is this sampling point a Wetland?. 'F r kts I v 101G, ?Iry witim • tiv S rektc P' .56c, "4"1 wiL MITA C 5111A Ae- 5PCftit tJoVA.(11•Cil' So 4/A wy., clAi I to, ktV .00. hi; fw 1,It 1 ut,I.V4C. •DATA FORK! • Projea/Site: APPiicant/Owner Investigator: Do Normal Circumstances exist on this site? ' lsthe site s'ignifi'cantly disturbed :(Atypical Situation ?) > -= :Is the area a potential Problem Area? T_. VEGETATION ROUTINE WETLAND DETEf MINATION 1987 COE Wetlands Detaimr : atio Vanua! 1"-1 '•Date " :' 1 QS� t.(.',County: State: W; • Yes =: 'sk`o_ : .Community ID: Transectt ID: Yes No Plot ID: [ f p'' Z I,{Q Dominant Plant Species Stratum Indicator Percent of Dominant Species that are OBL, FACW or FAC (excluding FACU): Remarks: G {?1VV IV'0� t t U 5 l wv fill %1i,tex( HYDROLOGY RECORDED DATA (Describe in Remarks). Stream, Lake, or Tide Gauge D Aerial Photographs 7 Other 0 No Recorded Data Available FIELD OBSERVATIONS: Depth of Surface Water. Depth to Free Water in Pit: Depth to Saturated Soil: WETLAND HYDROLOGY INDICATORS: PRIMARY INDICATORS: Inc' dated O Saturated in Upper 12 inches O Water Marks 0 Drift Lines Sediment Deposits D Dra r,aae Patterns in Wetlands SECONDARY INDICATORS (2 or more recsir•:d) D Oxi^aed Roo; Channels in Upper 12 Inci s ❑ Water Stained Leaves . • U Lcca: Sod Survey Data D FAGNei.tral Test Ott-e! :.Explain in Remarks) Remarks: �� 1 Ad ..SOILS ,' C ":Map Unit Name (Serves and Phase): Taxonomy (Subgroup)• • PROFILE DESCRIPTION Depth : ;-• Matrix Color " (Inches) . Horizon - (Munsell Moist) Drainage Ctass. FeldObseriafrons } Confirm Mapped Type? Abundance/Contrast cce/Contrast TexNructu e, etc. •'HYDRIC SOIL INDICATORS • Q Histosol ❑ Histic Epipedon ,❑'Sutfidtc Odor ❑ O Aquic Moisture Regime 0 Hydric Soil Present? Reducing Conditions. Gleyed or Law - Chroma Colors Concretions High Organic Streaking in Surface Layer in Sandy Soils ❑ Organic Streaking in Sandy Soils 0 Listed on Local Hydric Soils List ❑ Listed on National Hydric Soils List ❑ Other (Explain in Remarks) H WETLAND DETERMINATION n Hydrophytic Vegetation Present? H Wetland Hydrology Present? Hydric Soils Present? Rel Is this sampling point a.Wetland? Remarks: • so,-t wv i1, . DATA. FORM •: ProteCUSite: v= ApplicanVOwner. : . Taxo nomy' (Subgroup): PROFILE DESCRIPTION Depth • Matrix Color (Incie) Horizon . (Monett Moist) Drainage Class: Field Observations Confirm Mapped Type? ..Yes No Matoe Texture, Concretions, Abundance/Contrast Structure, etc.. HYDRIC SOIL INDICATORS O Histosol ❑ ❑ Hisfic Epipedon ❑ ❑ Sulfidic Odor ❑ ❑ Aquic Moisture Regime ❑ Hydric Soi! Present? Remarks: Reducing Conditions. Gleyed or Low- Chroma Colors Concretions High Organic Streaking in Surface Layer in Sandy Soils ❑ Organic Streaking in Sandy Soils ❑ Listed on Local Hydric Soils List ❑ Listed on National Hydric Soils List ❑ Other (Explain in Remarks) Yes , �fiJq, WETLAND DETERMINATION Hydrophyfic Vegetation Present? fi Welland Hydrology Present? Hydric Soils Present? Is this sampling point a Welland? Remade _ Yes Yes Yes t Yes 1 1 1 1 TAIORM ' • 1 • .�Pioject/Site• I� °1/ 1 1( ..., Applicant/Owner: =Investigator: .i: Do Normal Circumstances . exist on this site? y- Is the site significantly disturbed (Atypical Situation ?) Is the area a potential Problem Areal ROUTINE WETLAND DETERMINATION 1987 COE Wetlands Determl Lion annul Date: County: State: Community ID' ttgnsect Plot ID: Ir l W VEGETATION Dominant Plant Species • Stratum Indicator Dominant Plant Species • 1 1 u,r , lab .g. 2. i Cnee 10. Percent of Dominant Species that are OBL, •FACW or FAC (exGuing FACU): HYDROLOGY RECORDED DATA (Describe in Remarks): O Stream, Lake, or Tide Gauge Aerial Photographs ID Other 0 No Recorded Data Available • FIELD OBSERVATIONS: Depth of Surface Water. Depth to Free Water in Pit: '1 0 Depth to Saturated Soil: PRIMARY INDICATORS: J Inundated Saturated in Lipp,. 12 Iccnes Water Marks 7 Drill Lines 0 Sediment Deposits 0 Drainage Pates ir. W yards SECONDARY INDICATORS (2 or more required): 0 Oxidized Root Channels i5 Upper 12 Inches Water Stained Leaves J Local Soil Survey Data ❑ FAC-Neutral Test J Other (Explain, i;rRemar _t SOILS Map Unit Name (Series and Phase) Drainage Class: : Taxonomy (Subgroup): Field Observations Confirm Mapped Type? yel;'°'No :, PROFILE DESCRIPTION Depth Matrix Color Mottle Colors Mottle • Texture,iConcretions, (Incchees) Horizon (Munsellr�Moist) (Mansell Moist} Abundance/Contrast -, • ,Structure, etc. O Histosol Histic Epipedon ❑ Sullidic Odor 0 Aquic Moisture Regime Reducing Conditions IEySd sr LOW- Chroma Colcrs .] Cor..creticns ❑ High Organic Streaking in Sur`ace Layer in Sandy Soils .0 Organic Streaking in Sandy Soits 0 Listed on Local Hydric SoilS List Listed'on National Hydric Soils List Other (Explain in Remarks) " WETLAND DETERMINATION Hydrophytic Vegetation Present? Wetland Hydrology Present? Hydric Soils Present? Is this sampling point a Welland? 1 1 1 1 i 1 1 1 1 1 it . ?, DATA FORM 1587 COE'Wetlands Determination Manual • ProjecUSite: • /1/601—/k-- j'(1AAM Date: (/'zq-6C .: Applicant/Owner: . County: r-f A ir. investigator /% State: !�)4.- Do Normal Circumstances exi of this site? .: �- c,: , • es . F9r Community 10: (��� •" , Is the site significantly dtstUtbed(Alyptcal Situation ?) ,. No Transect ID: Is the area a potetjijPt m Area No Plot ID: p-c Y Dominant Plant Species' Stratum .:.. •. :1. 1-/ /Let La.lt1rti » 2. S an Gr, delc ="' • 3. 2t lu5' kr'tv1?,rt • '4: f or r=rrr 5- Percent of Dominant Species that are OBL, FACW or FAC (excluding FACU). Remarks: Indicator Dominant Plant Species Go s. q^ -10. gz, 11. .2p 12. 13. '14. 15. 16. • Stratum Indicator HYDROLOGY RECORDED DATA (Describe in Remarks: Stream, Lake, or Tide Gauge Aerial Photographs Other t0 No Recorded Data Available FIELD OBSERVATIONS: Depth of Surface Water: IL (in.) Depth to Free Water in Pit: O • fin.; Depth to Saturated'Soii: 0 fir.) • WETLAND HYDROLOGY INDICATORS: PRIMARY INDICATORS: ' rktnundated • J Saturated in Upper 12 Inches J 'Water Marks J Drift Lines • Sediment Deposits >5 Dramage Patterns in Wetlands SECONDARY INDICATORS (2 or more required): Oxidized Root Cha�rels in Upper 12 Inches J Water Stained Leaves J Loca: Soil Survey Data FAC- Neutra Test J Other ;Explain in Remarks) Remarks: SOILS Map Unit Name (Series and Phase): • Taxonomy (Subgroup): PROFILE DESCRIPTION • Depth Matrix Color Mottle Colors (Inches) Horizon (Munsell Moist) (Munson Moist) id y2 3/1 Drainage Class: Field Observations Confirm Mapped Type? . Yes No Mottle Texture, Concretions, Abundance/Contrast Structure, etc. HYDRIC SOIL INDICATORS Q Hlstosol b Reducir•,g Conditions O Histic EpiFedon J G:e,ed or Low- Chroma Colors SUlfidic Odor J Ccr•creiions ❑ Aquic Moisture Regime J H: ;ri Organic Streaking in .'ace Layer in Sandy Soils Hydric Soil Present? Remarks: WETLAND DETERMINATION Hydrophilic Vegetation Present? Wetland Hydrology Present? Hydric Soils Present? Is this sampling point a Wetland? Remarks: ' nL f 'C I „ ' w 3 X1 I ��i SaY5pp•fiOtrows - t�yjr,�5 {�4 &�� SrrCat zpr,c,„fr twat `12_4A 9. ❑ Organic Streaking in Sandy Soils 0 Listed on Local Hydric Soils List O Listed on National Hydric Soils List 0 Other (Explain in Remarks) Yes No No No No No APPENDIX B Photographic Documentation Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements Norfolk Basin Drainage and Water Quality Improvements Photographic Log Photo Number Photo Description 1 View of upland to the east of Wetland A, facing south - southwest. Area is a portion of Wetland A's buffer, and is dominated by blackberry and reed canary grass. 2 View of upland to the east of Wetland A, facing west - southwest. Area is a portion of Wetland A's buffer, and is dominated by blackberry and reed canary grass. 3 View of southern third of Wetland A from within wetland, facing north 4 View of center of Wetland A from within wetland, facing north 5 View of south portion of Wetland B from the upland to the east, facing south- southwest 6 View of Tukwila property drainage ditch and Wetland B from the upland east of Wetland B, facing west 7 View of Tukwila property with Wetland B on the left, from the south end of the Tukwila property, facing north 8 View of ditch between Tukwila property and I -5 Southbound from east side of Tukwila property, facing south wp2 03-02391 -600 aps -b photolog.d. June 21, 2006 B -1 Herrera Environmental Consultants O O i O r O O O d O O M■ O O O D = O O= Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements rp2 03- 02391-600 apr- bpburolog.doe June 20, 2006 B -2 Herrera Environmental Consultants I OM N ant MN UM S M SIN Ma @NMN WE NES ME We O MO MI Wetland Delineation — Norfolk Basin Drainage and Water Quality Improvements w737 03- 02391-600goz- bphofolog.doc June 20, 2006 B -3 Herrera Environmental Consultants APPENDIX C Wetland Functional Assessment Forms Norfolk Basin Drainage and Water Quality Improvements WA State Wetland Function Assessment Date 2- Dec -05 WL-C DO AU surrounded by dikes with control structure DI Area of AU D2 Area of contributing basin $ t.. client watershed) 0 0.79 323.75 0 0.39 323.75 0 0.008 323.75 D3.1 Undeveloped Forest D3.2 Agriculture (field and pasture) D3.3 Clear cut logging ( <5yrs since clearing) D3.4 Urban/commercial D3.5 High density residential (> lresidence /acre) D3.6 Low density residential ( <= 1 residence /acre) D3.7 Undevel I led areas, 0 0 0 73 0 24 3 0 0 0 73 0 24 3 0 0 0 73 0 24 3 D4 Channels or streams in AU with identifiable banks D4.1 Channels have . ermanentl flowin water 1 1 1 1 0 0 D4.3 Onl surface outflow is throu a culvert D8.1 Percent ponded or inundated for >1 month 60 75 100 D8.2 Percent of AU with permanent standing water 40 75 0 D8.3 Percent of AU with permanent open water 20 20 0 D8.4 Percent of AU with unvegetated bars or mudflats 0 0 0 D8.5 Unvegetated bars or mudflats 0 0 0 +},`}i.�•"N ?rfi- ho-�i'f a'ie ct'w E wK:j D9.1 Permanently Flooded D9.2 Seasonally Flooded D9.3 Occasionally Flooded ( <= 1 month) D9.4 Saturated but seldom inundated D9.5 Pemanently flowing stream D9.6 Intermittently flowing stream D10 Avera:e annual height of floodin_ D11.1 Cross section 1 D11.2 Cross section 2 D11.3 Cross section 3 D12.1 0 -20cm ( <8in) D12.2 20- 100cm(8 -4Oin) D12.3 > 100cm ( >40in) 1 1 1 0 0 1.7 1 1 1 0 0 1.7 0 0 1 0 0 0.3 0 0 1 0 0 1 1 1 0 0 1 1 0 0 D13.1 Unconstricted or only slightly constricted 0 0 0 D13.2 Moderately constricted 0 0 0 D13.3 Severel constricted 1 1 D14.1 Forest - evergreen D 14.2 Forest - deciduous D14.3 Scrub -shrub - evergreen D 14.4 Scrub Shrub - deciduous D14.5 Emergent D14.6 Aquatic Bed D15 Does D8.3 + D8.4 + sum (D14.1 to D14.6) = 100 ? D16 D17 % area of AU with >75% closure of can % area of herbaceous understory 0 10 0 0 0 0 0 0 20 10 0 20 50 100 30 20 0 1 1 20 10 0 80 10 0 1 D 19.1 number of native plant species D19.2 number of non - native plant species D20 The number of plant assemblages D21 The maximum number of strata D21.1 "vine" stratum dominated by non - native Blackberries D22 Mature trees . esent in AU 9 3 4 2 1 0 6 1 2 4 1 2 1 1 1 0 D23.1 Sphagnum bog component is > 75% of area in AU D23.2 Sphagnum bog component is 50 % -75% of area in AU D23.3 Sphagnum bog component is 25 %-49% of area in AU D23.4 Sphagnum bog component is 1 - 25% of area in AU D23.5 NO S•haa.umbo co onent in AU 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 D24.1 % area of non -native species >75% D24.2 % area of non -native species 50 -75% D24.3 %area of non -native species 25 -49% D24.4 % area of non -native species 1 -24% D24.5 NO cover of non - natives in the AU 0 0 1 0 0 0 0 1 0 0 1 0 0 0 0 D25 structure cate ones in a• uatic bed ve etation 0 0 0 D26.1 pH of interstitial water D26.2 pH of open or standing water D27 AU is within 8 km (5mi) of estuary D28 AU is within 1.6km (1 mi) of a lake D29 AU is within 5km (3 mi) of an open field ( D30 >1 hectare (2.5 ac) of preferred woody vegetation D31 snags D31.1 At least one snag has a DBH greater than 30cm D32 Overhanging vegetation D33 AU has upland islands D34 Undercut banks present D35 Key for rating egg - laying structures for amphibians D36 Tannins present in surface waters D37 Steep banks suitable for denning D38 Interspersion between vegetation and open water D39 Interspersion between Cowardin vegetation classes 0 0 0 5.9 5.9 5.9 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 0 2 4 0 0 0 0 1 1 0 1 1 0 2 1 0 D4 1 D42 D43 D44 D45 EDGE of AU: BUFFER of AU: 1 1 1 CORRIDORS of AU: 0 0 0 large woody debris in AU outside of perm. water 1 0 0 D46.1 D46.2 D46.3 D46.4 D46.5 D46.6 D46.7 D46.8 lar • e wood debris in . ermanent water of AU deciduous leaf litter 3 1 0 1 1 other plant litter 1 1 1 decomposed organic 1 1 0 exposed cobbles 0 0 exposed gravel 0 0 exposed sand 0 0 exposed silt 1 0 1 e . osed cla 1 0 0 D47.1 D47.2 D47.3 D47.4 D48.1 D48.2 D48.3 Peat 0 0 Muck 0 0 0 Mineral with clay fraction <30% 1 1 1 Cla cla fraction >30% High 1 0 0 0 0 0 Moderate 0 0 1 Slow 1 1 0 APPENDIX D Washington Department of Ecology Wetland Rating Forms WETLAND RATING FORM - WESTERN WASHINGTON Name of wetland (if known): Wetland A Location: SEC: 3 TWNSHP: 23N RNGE: 8 East (attach map with outline of wetland rating form) Person(s) Rating Wetland: DHH, JW Affiliation: Herrera Date of site visit: 12/2/2005 SUMMARY OF RATING Category based on FUNCTIONS provided by wetland I ❑ II 0 III ❑ IV ❑ Category I = Score >=70 Category II = Score 51 -69 Category III = Score 30 -50 Category IV = Score <30 Score for Water Quality Functions Score for Hydrologic Functions Score for Habitat Functions TOTAL score for functions Category based on SPECIAL CHARACTERISTICS of wetland I ❑ II ❑ Does not Apply Final Category (choose the "highest" category from above) 26 24 12 62 II Check the appropriate type and class of wetland being rated. Estuarine Natural Heritage Wetland Bog Mature Forest Old Growth Forest Coastal Lagoon Interdunal None of the above 0 0 0 0 0 0 0 Depression! Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Western Washington 1 Herrera Environmental Consultants Does the wetland being rated meet any of the criteria below? If you answer YES to any of the questions below, you will need to protect the wetland according to the regulations regarding the special characteristics found in the wetland. SP 1. Has the wetland been documented as a habitat for any federally listed Threatened or Endangered (T /E) plant or animal species? For the purposes of this rating system, "documented" means the wetland is on the appropriate state or federal database. SP2. Has the wetland been documented as habitat for any state listed Threatened or Endangered plant or animal species? For the purposes of this rating system, "documented" means the wetland is on the appropriate state database. SP3. Does the wetland contain individuals of Priority species listed by the WDFW for the state? 19 SP4. Does the wetland have a local significance in addition to its functions? For example, the wetland has been identified in the Shoreline Master Program, the Critical Areas Ordinance, or in a local management plan as having special significance. To complete the next part of the data sheet, you will need to determine the HydroReomorphic Class of the wetland being rated . The hydrogeomorphic classification groups wetlands into those that function in similar ways. This simplifies the questions needed to answer how well the wetland functions. The Hydrogeomorphic Class of a wetland can be determined using the key below. See p. 24 for more detailed instructions on classifying wetlands. Depression/ Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Western Washington 2 Herrera Environmental Consultants Classification of Vegetated Wetlands for Western Washington Wetland Name: Wetlands A Date: 12/2/2005 1. Are the water levels in the wetland usually controlled by tides (i.e., except during floods)? NO - go to 2 ❑ YES - the wetland class is Tidal Fringe If YES, is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)? ❑ YES - Freshwater Tidal Fringe ❑ NO - Saltwater Tidal Fringe (Estuarine) If your wetland can be classified as a Freshwater Tidal Fringe, use the forms for Riverine wetlands. If it is Saltwater Tidal Fringe, it is rated as an Estuarine wetland. Wetlands that were called estuarine in the first and second editions of the rating system are called Saltwater Tidal Fringe in the Hydrogeomorphic Classification. Estuarine wetlands were categorized separately in the earlier editions, and this separation is being kept in this revision. To maintain consistency between editions, the term "Estuarine" wetland is being kept. Please note, however, that the characteristics that define Category I and II estuarine wetlands have changed (see p. xx). 2. Is the topography within the wetland flat and precipitation is only source ( >90 %) of water to it? IO NO - go to 3 ❑ YES - the wetland class is Flats If your wetland can be classified as a "Flats" wetland, use the form for Depressional wetlands. 3. Does the wetland meet both of the following criteria? ❑ The vegetated part of the wetland is on the shores of a body of open water (without any vegetation on the surface) where at least 20 acres (8 ha) are permanently inundated (ponded or flooded); 12 At least 30% of the open water area is deeper than 6.6 feet (2 m)? NO - go to 4 ❑ YES - the wetland class is Lake - fringe (Lacustrine Fringe) 4. Does the wetland meet all of the following criteria? ❑ The wetland is on a slope (slope can be very gradual); ❑ The water flows through the wetland in one direction (unidirectional) and usually comes from seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks. ❑ The water leaves the wetland without being impounded? NOTE: Surface water does not pond in these type of wetlands except occasionally in very small and shallow depressions or behind hummocks (depressions are usually <3 feet in diameter and less than I foot deep). NO - go to 5 ❑ YES - the wetland class is Slope 5. Is the wetland in a valley, or stream channel, where it gets inundated by overbank flooding from that stream or river? The flooding should occur at least once every two years, on the average, to answer "yes." The wetland can contain depressions that are filled with water when the river is not flooding. D NO - go to 6 ❑ YES - the wetland class is Riverine 6. Is the wetland in a topographic depression in which water ponds, or is saturated to the surface, at some time of the year? This means that any outlet, if present, is higher than the interior of the wetland. ❑ NO - go to 7 D YES - the wetland class is Depressional Depressional Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Western Washington 3 Herrera Environmental Consultants 7. Is the wetland located in a very flat area with no obvious depression and no stream or river running through it and providing water? The wetland seems to be maintained by higher ground water in the area. The wetland may be ditched, but has no obvious natural outlet. El NO - go to 8 ❑ YES - the wetland class is Depressional 8. Your wetland seems to be difficult to classify. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small stream within a depressional wetland has a zone of flooding along its sides. Sometimes we find characteristics of several different hydrogeomorphic classes within one wetland boundary. Use the following table to identify the appropriate class to use for the rating system if you have several HGM classes present within your wetland. NOTE: Use this table only if the class that is recommended in the second column represents 10% or more of the total area of the wetland being rated. If the area of the second class is less than 10 %, classify the wetland using the first class. - y ' is "� fit,. �m�� �.-t ,y �s �,?� .rs. a. drx pix�hYiY ,.� /M1yv .t git_txxdi - 't<� ,Tri- k� Slope + Riverine Riverine ❑ Slope + Depressional Depressional El Slope + Lake -fringe Lake -fringe ❑ Depressional + Riverine along stream within boundary Depressional ❑ Depressional + Lake -fringe Depressional ❑ Saltwater Tidal Fringe and any other class of freshwater wetland Treat as ESTUARINE under wetlands with special characteristics ❑ If you are unable still to determine which of the above criteria apply to your wetland, or you have more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the rating. Depressional Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Western Washington 4 Herrera Environmental Consultants 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 B it it 0 it 1 1 1 1 1 1 1 1 1 1 1 1 „1 rw1M? :1,w fl{ ' r �1E= r 1 v N t y'e E 'w. -� n'h'R'4 G .a'r' s ,..w y ro .h. ....`vww �! }7�V rpr Sz �C3,�e'�F �P r aAi "� � ,_� ,s Kq �, z - Y-,-• .N - ".' (....,_. �t4��.:•‘:.' -T.Yr S P 1 1 EM _ 7.E:u..v,.u.1 MIL - -e. ,S .uv�.LSe D 1. Does the wetland have the potential to improve water quality? (seep. 38) f .„'i ° ;. D 1.1 Characteristics of surface water flows out of the wetland: ❑ Wetland is a depression with 110 surface water outlet. Points = 3 2 J Wetland has an intermittently flowing, or highly constricted Points = 2 outlet. ❑ Wetland has an unconstricted surface outlet. Points =1 ❑ Wetland is flat and has no obvious outlet and/or outlet is a Points =1 ditch. D 1.2 The soil 2 inches below the surface is clay, organic, or smells anoxic (hydrogen sulfide or rotten eggs): 4 4 YES Points = 4 ❑ NO Points = 0 D 1.3 Characteristics of persistent vegetation (emergent, shrub, and/or forest class): ❑ Wetland has persistent, ungrazed vegetation <95% of area. Points = 5 3 4 Wetland has persistent, ungrazed vegetation <1/2 of area. Points = 3 ❑ Wetland has persistent, ungrazed vegetation <1 /10 of area. Points =1 ❑ Wetland has persistent, ungrazed vegetation <1 /10 of area Points = 0 D 1.4 Characteristics of seasonal ponding or inundation. This is the area of the wetland that is ponded for at least 2 months, but dries out sometime during the year. Do not count the area that is permanently ponded. Estimate area as the average condition 5 out of 10 years. 4 J Area seasonally ponded is >1/2 total area of wetland. Points = 4. ❑ Area seasonally ponded is >1/4 total area of wetland. Points = 2 ❑ Area seasonally ponded is <1/4 total area of wetland. Points = 0 NOTE: See text for indicators of seasonal and permanent inundation. Total for D 1 Add the points in the boxes above 11 D 2. Does the wetland have the opportunity to improve water quality? (seep. 44) Multiplier Answer YES if you know or believe there are pollutants in ground water or surface water coming into the wetland that would otherwise reduce water quality in streams, lakes, or ground water downgradient from the wetland. Note which of the following conditions provide the sources of pollutants: ❑ Grazing in the wetland or within 150 feet. Untreated stormwater discharges to wetland. ❑ Tilled fields or orchards within 150 feet of wetland. J A stream or culvert discharges into wetland that drains developed areas, residential areas, farmed fields, roads, or clear -cut logging. J Residential, urban areas, golf courses are within 150 feet of wetland. ❑ Wetland is fed by ground water high in phosphorus or nitrogen. ❑ Other: 2 YES - multiplier is 2 NO - multiplier is 1 TOTAL - Water Quality Functions Multiply the score from D 1. by D 2 Add score to table on p. 1 26 Depressional Wetland Rating WLA 03- 02391 -600 Wetland Rating Form - Western Washington 5 Herrera Environmental Consultants -r, � e .E .� --. ar �- mar K� { . -< ., ._ Fl p ..e t ii v y ' .1r h,r - tb PiY R ski t� f�F�- (r lr... 4 �q r!� €Hl4U VI "'4 SA ..ik�� `F" 4 "...r.•evot p.p , Fy.,..* e -♦:,- '1 Kl' c vIGS.$.'='2R � Qt JP� 1: tik F„14�.'. Pt. l f. L6�1 �,,wJJ�1 S 1P{ikj 1, A�F Ybn YJt1 ' . .... .. .. »....>t ..... c'1'Ki < .1 D 3. Does wetland have the potential to reduce flooding /erosion? (seep. 46) D 3.1 Characteristics of surface water flows out of the wetland: 2 • Wetland has no surface water outlet. Points = 4 0 Wetland has an intermittently flowing, or highly constricted outlet. Points = 2 ❑ Wetland is flat and has no obvious outlet and/or outlet is a small Points =1 ditch. ❑ Wetland has an unconstricted surface outlet. Points = 0 D 3.2 Depth of storage during wet periods. Estimate the height of ponding above the bottom of the outlet. 7 El Marks of ponding are 3 feet or more above the surface. Points = 7 ❑ The wetland is a "headwater" wetland. Points = 5 • Marks of ponding between 2 feet to <3 feet from surface. Points = 5 ❑ Marks are at least 0.5 feet to <2 feet from surface. Points = 3 ❑ Wetland is flat but has small depressions on the surface that trap Points =1 water. ❑ Marks of ponding less than 0.5 feet. Points = 0 D 3.3 Contribution of wetland to storage in the watershed. Estimate the ratio of the area of upstream basin contributing surfae water to the wetland to the area of the wetland itself 3 • The area of the basin is <10 times the area of the wetland. Points = 5 4 The area of the basin is 10 to 100 times the area of the wetland. Points = 3 ❑ The area of the basin is >100 times the area of the wetland. Points = 0 ❑ Wetland is in the Flats class (basin = wetland, by definition). Points = 5 Total for D 3 Add the points in the boxes above] 12 D 4. Does wetland have the opportunity to reduce flooding/erosion? (seep. 49) Answer YES if the wetland is in a location in the watershed where the flood storage, or reduction in water velocity, helps protect downstream property and aquatic resources from flooding or excessive and/or erosive flows. Answer NO if the water coming into the wetland is controlled by a structure such as flood gate, tide gate, flap valve, reservoir, etc. OR you estimate that more than 90% of the water in the wetland is from ground water. Note which of the following indicators of opportunity apply: ❑ Wetland is in a headwater of a river or stream that has flooding problems. ❑ Wetland drains to a river or stream that has flooding problems. Multiplier -' Wetland has no outlet and impounds surface runoff water that might otherwise flow into a river or stream that has flooding problems. ❑ Other: 2 YES - multiplier is 2 NO - multiplier is 1 TOTAL - Hydrologic Functions Multiply the score from D 3. by D 4 Add score to table on p. 1 24 Depressional Wetland Rating WLA 03- 02391 -600 Wetland Rating Form - Western Washington 6 Herrera Environmental Consultants 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 H 1. Does the wetland have the potential to provide habitat for many species? H 1.1 Vegetation structure (see p. 72) Check the types of vegetation classes present (as defined by Cowardin) if the class covers more than 10% of the area of the wetland or 1/4 acre. Aquatic bed • Emergent plants • Scrub /shrub (areas where shrubs have >30% cover) ❑ Forested (areas where trees have >30% cover) ❑ Forested areas have 3 out of 5 strata (canopy, sub - canopy, shrubs, herbaceous, moss/ground- cover) Add the number of vegetation types that qual. If you have: 4 types or more Points = 4 3 types Points = 2 2 types Points =1 1 type Points = 0 El 2 H 1.2 Hydroperiods (seep. 73) Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover more than 10% of the wetland or 1/4 acre to count (see text for descriptions of hydroperiods). • Permanently flooded or inundated 4 or more types present Points = 3 • Seasonally flooded or inundated 3 types present Points = 2 Occasionally flooded or inundated 2 types present Points = 1 Saturated only ❑ Permanently flowing stream or river in, or adjacent to, the wetland ❑ Seasonally flowing stream in, or adjacent to, the wetland ❑ Lake fringe wetland = 2 points ❑ Freshwater tidal wetland = 2 points El El 3 H 1.3 Richness of Plant Species (seep. 75) Count the number of plant species in the wetland that cover at least 10 sq. ft. (different patches of the same species can be combined to meet the size threshold). You do not have to name the species. Do not include Eurasian Milfoil, reed canarygrass, purple loosestrife, Canadian Thistle. If you counted: List species below if you want to: >19 species Points = 2 5 -19 species Points = 1 <5 species Points = 0 1 Depressional Wetland Rating WLA 03- 02391 -600 Wetland Rating Form - Westem Washington 7 Herrera Environmental Consultants H 1.4 Interspersion of Habitats (see p. 76) Decide from the diagrams below whether interspersion between types of vegetation (described in H 1.1) or vegetation types and unvegetated areas (can include open water or mudflats) is high, medium, low, or none. None = 0 points Low =1 point Moderate = 2 points [riparian braided channels] High = 3 points NOTE: If you have four or more vegetation types or three vegetation types and open water, the rating is always "high ". 2 H 1.5 Special Habitat Features (see p. 77) Check the habitat features that are present in the wetland. The number of checks is the number of points you put into the next column. ❑ Large, downed, woody debris within the wetland ( >4 inch in diameter and 6 feet long). Standing snags (diameter at the bottom >4 inches) in the wetland. ❑ Undercut banks are present for at least 6.6 feet (2 m) and/or overhanging vegetation extends at least 3.3 feet (1 m) over a stream for at least 33 feet (10 m). ❑ Stable steep banks Of fine material that might be used by beaver /muskrat for denning ( >30° slope) OR signs of recent beaver activity are present. At least 1/4 acre of thin - stemmed presistent vegetation or woody branches are present in areas that are permanently or seasonally inundated (structures for egg - laying by amphibians ). ❑ Invasive plants cover less than 25% of the wetland area in each stratum of plants. 0 Comments: 2 10 Depressional Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Westem Washington 8 Herrera Environmental Consultants 0 0 e t it it 11 B v it 1 1 1 1 0 1 H 2. H 2.1 Does the wetland have the opportunity to provide habitat for many species? Buffers (seep. 80) «r° Choose the description that best represents condition of buffer of wetland. The highest scoring criterion that applies to the wetland is to be used in the rating. See text for definition of "undisturbed." ❑ 100 m (330 feet) of relatively undisturbed vegetated areas, rocky Points = 5 areas, or open water >95% of circumference. No developed areas within undisturbed part of buffer (relatively undisturbed also means no grazing). ❑ 100 m (330 feet) of relatively undisturbed vegetated areas, rocky Points = 4 areas, or open water >50% of circumference. ❑ 50 m (170 feet) of relatively undisturbed vegetated areas, rocky Points = 4 areas, or open water >95% circumference. _ . ❑ 100 m (330 feet) of relatively undisturbed vegetated areas, rocky Points = 3 areas, or open water for >25% circumference. 1 ❑ 50 m (170 feet) of relatively undisturbed vegetated areas, rocky Points = 3 areas, or open water for >50% circumference. If buffer does not meet any of the criteria above: ❑ No paved areas (except paved trails) or buildings within 25 m (80 Points = 2 feet) of wetland >95% circumference. Light to moderate grazing, or lawns are OK. ❑ Nopaved areas or buildings within 50 m of wetland for >50% Points = 2 circumference. Light to moderate grazing, or lawns are OK. ❑ Heavy grazing in buffer. Points =1 ❑ Vegetated buffers are <2 m wide (6.6 feet) for more than 95% of Points = 0 the circumference (e.g., tilled fields, paving, basalt bedrock extend to edge of wetland). J Buffer does not meet any of the criteria above. Points =1 H 2.2 Corridors and Connections (see p. 81) H 2.2.1 Is the wetland part of a relatively undisturbed/unbroken vegetated corridor (riparian or upland) at least 150 feet wide, has at least 30% cover of shrubs, forest, or native undisturbed prairie, that connects to estuaries, other wetlands, or undisturbed uplands that are at least 250 acres in size? (Dams in riparian corridors, heavily used gravel roads, and paved roads are considered breaks in the corridor.) YES = 4 points (go to H 2.3) NO = go to H 2.2.2 H 2.2.2 Is the wetland part of a relatively undisturbed/unbroken vegetated corridor (either riparian or upland) at least 50 feet wide, has at least 30% cover of shrubs or forest, and connects to estuaries, other wetlands, or undisturbed uplands that are at least 25 acres in size OR a 1 Lake - fringe wetland, if it does not have an undisturbed corridor as in the question above? YES = 2 points (go to H 2.3) NO = go to H 2.2.3 H 2.2.3 Is the wetland: — within 5 miles (8 km) of a brackish or salt water estuary OR within 3 miles of a large field or pasture ( >40 acres) OR within 1 mile of a lake greater than 20 acres? YES =1 point NO = 0 points Depressional Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Western Washington 9 Herrera Environmental Consultants H 2.3 Near or Adjacent to Other Priority Habitats Listed by WDFW (seep. 82) Which of the following priority habitats are within 330 feet (100 m) of the wetland? (See text for a more detailed description of these priority habitats.) ❑ Riparian: Area adjacent to aquatic systems with flowing water that contains elements of both aquatic and terrestrial ecosystems which mutually influence each other. ❑ Aspen stands: Pure or mixed stands of aspen >0.8 ha (2 acres). ❑ Cliffs: Greater than 7.6 m (25 feet) high and occuring below 5,000 feet. ❑ Old- growth forests: (old growth west of Cascade crest) Stands of at least 2 tree species, forming a multi - layered canopy with occasional small openings; with at least 20 trees/ha (8 /acre) >81 cm (32 inches) in diameter or >200 years of age. ❑ Mature forests: Stands with average diameters exceeding 53 cm (21 inches) dbh; crown cover may be <100 %; decay, decadence, numbers of snags, and quantity of large downed material is generally less than found in old- growth; 80- 200 years old west of Cascade crest. ❑ Prairies: Relatively undisturbed areas (indicated by dominance of native plants) where grasses /forbs form the natural climax plant community. ❑ Talus: Homogenous areas of rock rubble (average size 0.15 - 2.0 m [0.5 - 65 feet]), composed of basalt, andesite, and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs. ❑ Caves: Naturally occurring cavity, recess, void, or system of interconnected passages. ❑ Oregon white oak: Woodland stands of pure oak or oak/conifer associations where canopy coverage of the oak component is 25 %. ❑ Urban Natural Open Space: A priority species resides within or is adjacent to the open space and uses it for breeding and/or regular feeding; and/or the open space functions as a corridor connecting other priority habitats , especially those otherwise isolated; and/or the open space is an isolated remnant of natural habitat >4 ha (10 acres) and is surrounded by urban development. ❑ Estuary /estuary -like: Deepwater tidal habitats & adjacent tidal wetlands, usually semi - enclosed by land but with open, partly obstructed, or sporadic access to open ocean; ocean water at least occasionally diluted by freshwater runoff from land. Salinity may be periodically increased above that of open ocean by evaporation. Along some low- energy coastlines, there is appreciable dilution of sea water. Estuarine habitat extends upstream and landward to where ocean- derived salts measure <0.5 ppt. during period of avg. annual low flow. Includes both estuaries and lagoons. ❑ Marine /estuarine shorelines: Include intertidal and subtidal zones of beaches; may also include backshore and adjacent components of the terrestrial landscape (e.g., cliffs, snags, mature trees, dunes, meadows) important to shoreline associated fish and wildlife and that contribute to shoreline function (e.g., sand/rock/log recruitment, nutrient contribution, erosion control). If wetland has: 3+ priority habitats = 4 points 1 priority habitat =1 point 2 priority habitats = 3 points No habitats = 0 points Depressional Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Western Washington 10 Herrera Environmental Consultants H 2.4 Wetland Landscape (seep. 84) Choose the one description of the landscape around the wetland that best fits. ❑ There are at least 3 other wetlands within 1/2 mile, and the Points = 5 connections between them are relatively undisturbed (light grazing between wetlands OK, as is lake shore with some boating, but connections should NOT be bisected by paved roads, fill, fields, or other development). ❑ The wetland is Lake -fringe on a lake with little disturbance and Points = 5 there are 3 other Lake -fringe wetlands within 1/2 mile. ❑ There are at least 3 other wetlands within 1/2 mile, BUT the Points = 3 connections between them are disturbed. ❑ The wetland is Lake -fringe on a lake with disturbance, and there Points = 3 are 3 other Lake - fringe wetlands within 1/2 mile. ❑ There is at least 1 wetland within 1/2 mile. ❑ There are no wetlands within 1/2 mile. Points = 2 Points = 0 2 12 Depressional Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Western Washington 11 Herrera Environmental Consultants CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS Please determine if the wetland meets the attributes described below and choose the appropriate answers and Category. SC 1. Estuarine Wetlands (seep. 86) Does the wetland meet the following criteria for Estuarine wetlands? ❑ The dominant water regime is tidal, ❑ Vegetated, and ❑ With a salinity greater than 0.5 ppt. ❑ YES = Go to SC 1.1 p NO SC 1.1 Is the wetland within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area Preserve, State Park, or Educational, Environmental, or Scientific Reserve designated under WAC 332 -30 -151? ❑ YES = Category I El NO = Go to SC 1.2 SC 1.2 Is the wetland at least 1 acre in size and meets at least two of the following three conditions? ❑ The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has <10% cover of non - native plant species. If the non- native Spartina spp. are the only species that cover X10% of the wetland, then the wetland should be given a dual rating (I/II). The area of Spartina would be rated a Category II while the relatively undisturbed upper marsh with native species would be a Category I. Do not, however, exclude the area of Spartina in determining the size threshold of 1 acre. ❑ At least 3/4 of the landward edge of the wetland has a 100 foot buffer of shrub, forest, or ungrazed or unmowed grassland. ❑ The wetland has at least two of the following features: tidal channels, depressions with open water, or continguous freshwater wetlands. ❑ YES = Category I El NO = Category II Depressional Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Westem Washington 12 Herrera Environmental Consultants SC 2. Natural Heritage Wetlands (seep. 87) Natural Heritage wetlands have been identified by the Washington Natural Heritage Program/DNR as either high quality undisturbed wetlands or wetlands that support state Threatened, Endangered, or Sensitive plant species. SC 2.1 Is the wetland being rated in a Section/Township /Range that contains a Natural Heritage wetland? (This question is used to screen out most sites before you need to contact WNHP/DNR.) S/T/R information from Appendix D 11 or accessed from WNHP/DNR web site ❑ ❑ YES - contact WNHP/DNR (see p. 79) and go to SC 3.2 ❑ NO SC 2.2 Has DNR identified the wetland as a high quality undisturbed wetland or as a site with state Threatened or Endangered plant species? ❑ YES = Category I SI NO SC 3. Bogs (see p. 87) Does the wetland (or part of the wetland) meet both the criteria for soils and vegetations in bogs? Use the key below to identify if the wetland is a bog. If you answer Yes, you will still need to rate the wetland based on its function. 1. Does wetland have organic soil horizons (i.e., layers of organic soil), either peats or mucks, that compose 16 inches or more of the first 32 inches of the soil profile? (See Appendix B for a field key to identify organic oils.) El YES - go to Q. 3 ❑ NO - go to Q. 2 2. Does the wetland have organic soils, either peats or mucks, that are <16 inches deep over bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on a lake or pond? ❑ YES - go to Q. 3 ❑ NO - is not a bog for purpose of rating 3. Does wetland have more than 70% cover of mosses at ground level, AND other plants, if present, consist of the "bog" species listed in Table 3 as a significant component of the vegetation ( >30% of total shrub and herbaceous cover consists of species in Table 3)? El YES - is a bog for purpose of rating ❑ NO - go to Q. 4 NOTE: If you are uncertain about the extent of mosses in the understory you may substitute that criterion by measuring the pH of the water that seeps into a hole dug at least 16" deep. If the pH is less than 5.0 and the "bog" plant species in Table 3 are present, the wetland is a bog. 4. Is wetland forested ( >30% cover) with sitka spruce, subalpine fir, western redcedar, western hemlock, lodgepole pine, quaking aspen, Englemann's spruce, or western white pine, WITH any of the species (or combination of species) on bog species plant list in Table 3 as a significant component of the ground cover ( >30% coverage of total shrub/herbaceous cover)? ❑ YES - Category I NO - is not a bog for purpose of rating Depressional Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Western Washington 13 Herrera Environmental Consultants SC 4. Forested Wetlands (seep. 90) Does the wetland have at least 1 acre of forest that meets one of these criteria for the Department of Fish and Wildlife's forests as priority habitat? If you answer Yes, you will still need to rate the wetland based on its functions. ❑ Old- growth forests: (west of Cascade Crest) Stands of at least 2 tree species, forming a multi- layered canopy with occasional small openings; with at least 8 trees /acre (20/hectare) that are at least 200 years of age OR have a diameter at breast height (dbh) of 32 inches (81 cm) or more. NOTE: The criterion for dbh is based on measurements for upland forests. 200 - year -old trees in wetlands will often have a smaller dbh because their growth rates are often smaller. The DFW criterion is an "OR" so old - growth forests do not necessarily have to have trees of this diameter. ❑ Mature forests: (west of the Cascade Crest) Stands where the largest trees are 80 - 200 years old OR have average diameters (dbh) exceeding 21 inches (53 cm); crown cover may be less than 100 %; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that found in old- growth. ❑ YES = Category I ❑ NO SC 5. Wetlands in Coastal Lagoons (seep. 91) Does the wetland meet all of the following criteria of a wtland in a coastal lagoon? ❑ The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks. ❑ The lagoon in which the wetland is located contains surface water that is saline or brackish ( >.5 ppt) during most of the year in at leat a portion of the lagoon (needs to be measured near the bottom). ❑ YES = go to SC 5.1 ❑ NO - not a wetland in a coastal lagoon SC 5.1 Does the wetland meet all of the following 3 conditions? ❑ The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing), and has less than 20% cover of invasive plant species (see list of invasive species on p. 74). ❑ At least 3/4 of the landward edge of the wetland has a 100 foot buffer of shrub, forest, or ungrazed or unmowed grassland. ❑ The wetland is larger than 1 /10 acre (4,350 square feet). ❑ YES = Category I S NO = Category II Depression! Wetland Rating WLA 03 -02391 -600 Wetland Rating Form - Western Washington 14 Herrera Environmental Consultants SC 6. Interdunal Wetlands (see p. 93) Is the wetland west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? ❑ YES - go to SC 6.1 ❑ NO - not an interdunal wetland for rating If you answer Yes, you will still need to rate the wetland based on its functions. In practical terms, that means the following geographic areas: • Long Beach Peninsula - lands west of SR 103 • Grayland- Westport - lands west of SR 105 • Ocean Shores - Copalis - lands west of SR 1115 and SR 109. SC 6.1 Is wetland 1 acre or larger, or is it in a mosaic of wetlands that is 1 acre or larger? ❑ YES = Category II ❑ NO - go to SC 6.2 SC 6.2 Is the wetland between 0.1 and 1 acre, or is it in a mosaic of wetlands that is between 0.1 and 1 acre? ❑ YES = Category III Depressional Wetland Rating WLA 03- 02391 -600 Wetland Rating Form - Western Washington 15 Herrera Environmental Consultants 11 0 8 11 11 1 it 1 t 11 n it 1 1 1 1 WETLAND RATING FORM - WESTERN WASHINGTON Name of wetland (if known): Wetland B Location: SEC: 3 TWNSHP: 23N RNGE: 8 East (attach map with outline of wetland rating form) Date of site visit: 12/2/2005 Person(s) Rating Wetland: DHH, JW Affiliation: Herrera SUMMARY OF RATING Category based on FUNCTIONS provided by wetland I ❑ II s in ❑ IV ❑ Category I = Score > =70 Category II = Score 51 -69 Category III = Score 30 -50 Category IV = Score <30 Score for Water Quality Functions Score for Hydrologic Functions Score for Habitat Functions TOTAL score for functions Category based on SPECIAL CHARACTERISTICS of wetland I ❑ II ❑ Does not Apply 0 Final Category (choose the "highest" category from above) 26 24 12 62 II Check the appropriate type and class of wetland being rated. lW^ a? .._,,,,-- ■� Estuarine Natural Heritage Wetland ■� Bog 0 Mature Forest • Old Growth Forest ■� Coastal Lagoon Interdunal 0 None of the above ■� Depressions/ Wetland Rating WLB-03 -02391 -600 Wetland Rating Form - Westem Washington 1 Herrera Environmental Consultants Does the wetland being rated meet any of the criteria below? If you answer YES to any of the questions below, you will need to protect the wetland according to the regulations regarding the special characteristics found in the wetland. SP 1. Has the wetland been documented as a habitat for any federally listed Threatened or Endangered (T /E) plant or animal species? For the purposes of this rating system, "documented" means the wetland is on the appropriate state or federal database. SP2. Has the wetland been documented as habitat for any state listed Threatened or Endangered plant or animal species? For the purposes of this rating system, "documented" means the wetland is on the appropriate state database. SP3. Does the wetland contain individuals of Priority species listed by the WDFW for the state? SP4. Does the wetland have a local significance in addition to its functions? For example, the wetland has been identified in the Shoreline Master Program, the Critical Areas Ordinance, or in a local management plan as having special significance. El To complete the next part of the data sheet, you will need to determine the Hvdrogeomorphic Class of the wetland being rated . The hydrogeomorphic classification groups wetlands into those that function in similar ways. This simplifies the questions needed to answer how well the wetland functions. The Hydrogeomorphic Class of a wetland can be determined using the key below. See p. 24 for more detailed instructions on classifying wetlands. Depressionai Wetland Rating WLB -03 -02391 -600 Wetland Rating Form - Westem Washington 2 Herrera Environmental Consultants Classification of Vegetated Wetlands for Western Washington Wetland Name: Wetlands B Date: 12/2/2005 1. Are the water levels in the wetland usually controlled by tides (i.e., except during floods)? IS NO - go to 2 ❑ YES - the wetland class is Tidal Fringe If YES, is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)? ❑ YES - Freshwater Tidal Fringe ❑ NO - Saltwater Tidal Fringe (Estuarine) If your wetland can be classified as a Freshwater Tidal Fringe, use the forms for Riverine wetlands. If it is Saltwater Tidal Fringe, it is rated as an Estuarine wetland. Wetlands that were called estuarine in the first and second editions of the rating system are called Saltwater Tidal Fringe in the Hydrogeomorphic Classification. Estuarine wetlands were categorized separately in the earlier editions, and this separation is being kept in this revision. To maintain consistency between editions, the term "Estuarine" wetland is being kept. Please note, however, that the characteristics that define Category I and II estuarine wetlands have changed (see p. xx). 2. Is the topography within the wetland flat and precipitation is only source ( >90 %) of water to it? NO - go to 3 ❑ YES - the wetland class is Flats If your wetland can be classified as a "Flats" wetland, use the form for Depressional wetlands. 3. Does the wetland meet both of the following criteria? ❑ The vegetated part of the wetland is on the shores of a body of open water (without any vegetation on the surface) where at least 20 acres (8 ha) are permanently inundated (ponded or flooded); ID El At least 30% of the open water area is deeper than 6.6 feet (2 m)? NO - go to 4 ❑ YES - the wetland class is Lake - fringe (Lacustrine Fringe) 4. Does the wetland meet all of the following criteria? ❑ The wetland is on a slope (slope can be very gradual); ❑ The water flows through the wetland in one direction (unidirectional) and usually comes from seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks. ❑ The water leaves the wetland without being impounded? NOTE: Surface water does not pond in these type of wetlands except occasionally in very small and shallow depressions or behind hummocks (depressions are usually <3 feet in diameter and less than 1 foot deep). NO - go to 5 ❑ YES - the wetland class is Slope 5. Is the wetland in a valley, or stream channel, where it gets inundated by overbank flooding from that stream or river? The flooding should occur at least once every two years, on the average, to answer "yes." The wetland can contain depressions that are filled with water when the river is not flooding. NO - go to 6 ❑ YES - the wetland class is Riverine 6. Is the wetland in a topographic depression in which water ponds, or is saturated to the surface, at some time of the year? This means that any outlet, if present, is higher than the interior of the wetland. ❑ NO - go to 7 0 YES - the wetland class is Depressional Depression& Wetland Rating WLB-03-02391-600 Wetland Rating Form - Western Washington 3 Herrera Environmental Consultants 7. Is the wetland located in a very flat area with no obvious depression and no stream or river running through it and providing water? The wetland seems to be maintained by higher ground water in the area. The wetland may be ditched, but has no obvious natural outlet. NO - go to 8 ❑ YES - the wetland class is Depressional 8. Your wetland seems to be difficult to classify. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small stream within a depressional wetland has a zone of flooding along its sides. Sometimes we find characteristics of several different hydrogeomorphic classes within one wetland boundary. Use the following table to identify the appropriate class to use for the rating system if you have several HGM classes present within your wetland. NOTE: Use this table only if the class that is recommended in the second column represents 10% or more of the total area of the wetland being rated. If the area of the second class is less than 10 %, classify the wetland using the first class. yr Rpn,W..,=57, . il y i Jr� Slope + Riverine Riverine ❑ Slope + Depressional Depressional J Slope + Lake - fringe Lake -fringe • Depressional + Riverine along stream within boundary Depressional • Depressional + Lake -fringe Depressional • Saltwater Tidal Fringe and any other class of freshwater wetland Treat as ESTUARINE under wetlands with special characteristics • If you are unable still to determine which of the above criteria apply to your wetland, or you have more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the rating. Depressional Wetland Rating WL.8 -03 -02391 -600 Wetland Rating Form - Western Washington 4 Herrera Environmental Consultants 1 1 1 1 1 1 t 1 t 1 1 1 1 1 1 1 1 it 0 v 0 1 i 1 1 If 1 11 It 1 a �•_. .�Ea y20.f'.�`fI�4 . fit P4 {.fie 'Y 4r9i W' C..y {! -_ t ,BEY z ry ry D 1. Does the wetland have the • otential to improve water quality? see p. 38) D 1.1 Characteristics of surface water flows out of the wetland: ❑ Wetland is a depression with no surface water outlet. Points = 3 2 4 Wetland has an intermittently flowing, or highly constricted Points = 2 outlet. ❑ Wetland has an unconstricted surface outlet. Points =1 ❑ Wetland is flat and has no obvious outlet and/or outlet is a Points =1 ditch. D 1.2 The soil 2 inches below the surface is clay, organic, or smells anoxic (hydrogen sulfide or rotten eggs): 4 ✓ YES Points = 4 ❑ NO Points = 0 D 1.3 Characteristics of persistent vegetation (emergent, shrub, and/or forest class): ❑ Wetland has persistent, ungrazed vegetation <95% of area. Points = 5 3 4 Wetland has persistent, ungrazed vegetation <1/2 of area. Points = 3 ❑ Wetland has persistent, ungrazed vegetation <1 /10 of area. Points =1 ❑ Wetland has persistent, ungrazed vegetation <1 /10 of area Points = 0 D 1.4 Characteristics of seasonal ponding or inundation. This is the area of the wetland that is ponded for at least 2 months, but dries out sometime during the year. Do not count the area that is permanently ponded. Estimate area as the average condition 5 out of 10 years. 4 131 J Area seasonally ponded is >1/2 total area of wetland. Points = 4 ❑ Area seasonally ponded is >1/4 total area of wetland. Points = 2 ❑ Area seasonally ponded is <1/4 total area of wetland. Points = 0 NOTE: See text for indicators of seasonal and permanent inundation. Total for D 1 Add the points in the boxes above D 2. Does the wetland have the opportunity to improve water quality? (seep. 44) Multiplier Answer YES if you know or believe there are pollutants in ground water or surface water coming into the wetland that would otherwise reduce water quality in streams, lakes, or ground water downgradient from the wetland. Note which of the following conditions provide the sources of pollutants: ❑ Grazing in the wetland or within 150 feet. J Untreated stormwater discharges to wetland. ❑ Tilled fields or orchards within 150 feet of wetland. A stream or culvert discharges into wetland that drains developed areas, residential areas, farmed fields, roads, or clear -cut logging. el Residential, urban areas, golf courses are within 150 feet of wetland. ❑ Wetland is fed by ground water high in phosphorus or nitrogen. ❑ Other: 2 YES - multiplier is 2 NO - multiplier is 1 TOTAL - Water Quality Functions Multiply the score from D 1. by D 2 Add score to table on p. 1 26 Depressional Wetland Rating WLB-03 -02391 -600 Wetland Rating Form - Westem Washington 5 Herrera Environmental Consultants x 1` (" l l3 9c — T" h l f + s - :Mt s Twn `., :° pps esiZaD 4 i+ R1 V d1 0d;, Cl.i,d9� fl ri__,_ j ∎31 tj p ✓P p? D 3. Does wetland have the Potential to reduce floodinglerosion? (see p. 46) P 11a� D 3.1 Characteristics of surface water flows out of the wetland: 2 • Wetland has no surface water outlet. Points = 4 4 Wetland has an intermittently flowing, or highly constricted outlet. Points = 2 ❑ Wetland is flat and has no obvious outlet and/or outlet is a small Points =1 ditch. ❑ Wetland has an unconstricted surface outlet. Points = 0 D 3.2 Depth of storage during wet periods. Estimate the height of ponding above the bottom of the outlet. 7 J Marks of ponding are 3 feet or more above the surface. Points = 7 • The wetland is a "headwater" wetland. Points = 5 • Marks of ponding between 2 feet to <3 feet from surface. Points = 5 ❑ Marks are at least 0.5 feet to <2 feet from surface. Points = 3 • Wetland is flat but has small depressions on the surface that trap Points =1 water. • Marks of ponding less than 0.5 feet. Points = 0 D 3.3 Contribution of wetland to storage in the watershed. Estimate the ratio of the area of upstream basin contributing surfae water to the wetland to the area of the wetland itself. ❑ The area of the basin is <10 times the area of the wetland. Points = 5 3 El The area of the basin is 10 to 100 times the area of the wetland. Points = 3 ❑ The area of the basin is >100 times the area of the wetland. Points = 0 • Wetland is in the Flats class (basin = wetland, by definition). Points = 5 Total for D 3 Add the points in the boxes above 12 D 4. Does wetland have the opportunity to reduce flooding /erosion? (see p. 49) Answer YES if the wetland is in a location in the watershed where the flood storage, or reduction in water velocity, helps protect downstream property and aquatic resources from flooding or excessive and/or erosive flows. Answer NO if the water coming into the wetland is controlled by a structure such as flood gate, tide gate, flap valve, reservoir, etc. OR you estimate that more than 90% of the water in the wetland is from ground water. Note which of the following indicators of opportunity apply: ❑ Wetland is in a headwater of a river or stream that has flooding problems. ❑ Wetland drains to a river or stream that has flooding problems. Multiplier El Wetland has no outlet and impounds surface runoff water that might otherwise flow into a river or stream that has flooding problems. ❑ Other: 2 YES - multiplier is 2 NO - multiplier is 1 TOTAL - Hydrologic Functions Multiply the score from D 3. by D 4 Add score to table on p. 1 24 Depressional Wetland Rating WLB -03 -02391 -600 Wetland Rating Form - Westem Washington 6 Herrera Environmental Consultants 1 1 1 1 1 1 t 1 1 1 1 t 1 1 1 1 1 1 11 1. Does the wetland have the potential to provide habitat for many species? H 1.1 Vegetation structure (see p. 72) Check the types of vegetation classes present (as defined by Cowardin) if the class covers more than 10% of the area of the wetland or 1/4 acre. Aquatic bed • Emergent plants Scrub /shrub (areas where shrubs have >30% cover) ❑ Forested (areas where trees have >30% cover) ❑ Forested areas have 3 out of 5 strata (canopy, sub - canopy, shrubs, herbaceous, moss /ground - cover) Add the number of vegetation types that qualify. If you have: 4 types or more Points = 4 3 types Points = 2 2 types Points = 1 1 type Points = 0 2 H 1.2 Hydroperiods (seep. 73) Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover more than 10% of the wetland or 1/4 acre to count (see text for descriptions of hydroperiods). • Permanently flooded or inundated 4 or more types present Points = 3 • Seasonally flooded or inundated 3 types present Points = 2 • Occasionally flooded or inundated 2 types present Points =1 Saturated only ❑ Permanently flowing stream or river in, or adjacent to, the wetland ❑ Seasonally flowing stream in, or adjacent to, the wetland ❑ Lake fringe wetland = 2 points ❑ Freshwater tidal wetland = 2 points El 3 H 1.3 Richness of Plant Species (seep. 75) Count the number of plant species in the wetland that cover at least 10 sq. ft. (different patches of the same species can be combined to meet the size threshold). You do not have to name the species. Do not include Eurasian Milfoil, reed canarygrass, purple loosestrife, Canadian Thistle. List species below.if you want to: If you counted: >19 species Points = 2 5 -19 species Points =1 <5 species Points = 0 1 Depression/ Wetland Rating WLB-03 -02391 -600 Wetland Rating Form - Westem Washington 7 Herrera Environmental Consultants H 1.4 Interspersion of Habitats (seep. 76) Decide from the diagrams below whether interspersion between types of vegetation (described in H 1.1) or vegetation types and unvegetated areas (can include open water or mudflats) is high, medium, low, or none. None = 0 points Low =1 point Moderate = 2 points [riparian braided channels] High = 3 points NOTE: If you have four or more vegetation types or three vegetation types and open water, the rating is always "high ". 2 H 1.5 Special Habitat Features (seep. 77) Check the habitat features that are present in the wetland. The number of checks is the number of points you put into the next column. ❑ Large, downed, woody debris within the wetland ( >4 inch in diameter and 6 feet long). Standing snags (diameter at the bottom >4 inches) in the wetland. ❑ Undercut banks are present for at least 6.6 feet (2 m) and/or overhanging vegetation extends at least 3.3 feet (1 m) over a stream for at least 33 feet (10 m). ❑ Stable steep banks of fine material that might be used by beaver /muskrat for denning ( >30° slope) OR signs of recent beaver activity are present. At least 1/4 acre of thin- stemmed presistent vegetation or woody branches are present in areas that are permanently or seasonally inundated (structures for egg - laying by amphibians ). ❑ Invasive plants cover less than 25% of the wetland area in each stratum of plants. El 2 Comments: 10 Depression! Wetland Rating WLB -03- 02391 -600 Wetland Rating Form - Westem Washington 8 Herrera Environmental Consultants 8 0 0 1 11 t 1 1 1 t 1 1 1 w 1 1 H 2. H 2.1 Does the wetland have the opportunity to provide habitat for many species? Buffers (see p. 80) ^•.,-. Choose the description that best represents condition of buffer of wetland. The highest scoring criterion that applies to the wetland is to be used in the rating. See text for definition of "undisturbed." • 100 m (330 feet) of relatively undisturbed vegetated areas, rocky Points = 5 areas, or open water >95% of circumference. No developed areas within undisturbed part of buffer (relatively undisturbed also means no grazing). • 100 m (330 feet) of relatively undisturbed vegetated areas, rocky Points = 4 areas, or open water >50% of circumference. • 50 m (170 feet) of relatively undisturbed vegetated areas, rocky Points = 4 areas, or open water >95% circumference. ❑ 100 m (330 feet) of relatively undisturbed vegetated areas, rocky Points = 3 areas, or open water for >25% circumference. 1 ❑ 50 m (170 feet) of relatively undisturbed vegetated areas, rocky Points = 3 areas, or open water for >50% circumference. If buffer does not meet any of the criteria above: • No paved areas (except paved trails) or buildings within 25 m (80 Points = 2 feet) of wetland >95% circumference. Light to moderate grazing, or lawns are OK. ❑ No paved areas or buildings within 50 m of wetland for >50% Points = 2 circumference. Light to moderate grazing, or lawns are OK. • Heavy grazing in buffer. Points =1 • Vegetated buffers are <2 m wide (6.6 feet) for more than 95% of Points = 0 the circumference (e.g., tilled fields, paving, basalt bedrock extend to edge of wetland). Buffer does not meet any of the criteria above. Points =1 H 2.2 Corridors and Connections (seep. 81) H 2.2.1 Is the wetland part of a relatively undisturbed/unbroken vegetated corridor (riparian or upland) at least 150 feet wide, has at least 30% cover of shrubs, forest, or native undisturbed prairie, that connects to estuaries, other wetlands, or undisturbed uplands that are at least 250 acres in size? (Dams in riparian corridors, heavily used gravel roads, and paved roads are considered breaks in the corridor.) YES = 4 points (go to H 2.3) NO = go to H 2.2.2 H 2.2.2 Is the wetland part of a relatively undisturbed/unbroken vegetated corridor (either riparian or upland) at least 50 feet wide, has at least 30% cover of shrubs or forest, and connects to estuaries, other wetlands, or undisturbed uplands that are at least 25 acres in size OR a 1 Lake - fringe wetland, if it does not have an undisturbed corridor as in the question above? YES = 2 points (go to H 2.3) NO = go to H 2.2.3 H 2.2.3 Is the wetland: — within 5 miles (8 km) of a brackish or salt water estuary OR within 3 miles of a large field or pasture ( >40 acres) OR within 1 mile of a lake greater than 20 acres? YES =1 point NO = 0 points Depression! Wetland Rating WLB -03 -02391 -600 Wetland Rating Form - Western Washington 9 Herrera Environmental Consultants H 2.3 Near or Adjacent to Other Priority Habitats Listed by WDFW (seep. 82) Which of the following priority habitats are within 330 feet (100 m) of the wetland? (See text for a more detailed description of these priority habitats.) D Riparian: Area adjacent to aquatic systems with flowing water that contains elements of both aquatic and terrestrial ecosystems which mutually influence each other. ❑ Aspen stands: Pure or mixed stands of aspen >0.8 ha (2 acres). ❑ Cliffs: Greater than 7.6 m (25 feet) high and occuring below 5,000 feet. ❑ Old- growth forests: (old growth west of Cascade crest) Stands of at least 2 tree species, forming a multi- layered canopy with occasional small openings; with at least 20 trees/ha (8 /acre) >81 cm (32 inches) in diameter or >200 years of age. ❑ Mature forests: Stands with average diameters exceeding 53 cm (21 inches) dbh; crown cover may be <100 %; decay, decadence, numbers of snags, and quantity of large downed material is generally less than found in old- growth; 80- 200 years old west of Cascade crest. ❑ Prairies: Relatively undisturbed areas (indicated by dominance of native plants) where grasses /forbs form the natural climax plant community. ❑ Talus: Homogenous areas of rock rubble (average size 0.15 - 2.0 m [0.5 - 65 feet]), composed of basalt, andesite, and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs. ❑ Caves: Naturally occurring cavity, recess, void, or system of interconnected passages. ❑ Oregon white oak: Woodland stands of pure oak or oak/conifer associations where canopy coverage of the oak component is 25 %. ❑ Urban Natural Open Space: A priority species resides within or is adjacent to the open space and uses it for breeding and/or regular feeding; and/or the open space functions as a corridor connecting other priority habitats , especially those otherwise isolated; and/or the open space is an isolated remnant of natural habitat >4 ha (10 acres) and is surrounded by urban development. ❑ Estuary/estuary-like: Deepwater tidal habitats & adjacent tidal wetlands, usually semi - enclosed by land but with open, partly obstructed, or sporadic access to open ocean; ocean water at least occasionally diluted by freshwater runoff from land. Salinity may be periodically increased above that of open ocean by evaporation. Along some low- energy coastlines, there is appreciable dilution of sea water. Estuarine habitat extends upstream and landward to where ocean- derived salts measure <0.5 ppt. during period of avg. annual low flow. Includes both estuaries and lagoons. ❑ Marine /estuarine shorelines: Include intertidal and subtidal zones of beaches; may also include backshore and adjacent components of the terrestrial landscape (e.g., cliffs, snags, mature trees, dunes, meadows) important to shoreline associated fish and wildlife and that contribute to shoreline function (e.g., sand/rock/log recruitment, nutrient contribution, erosion control). If wetland has: 3+ priority habitats = 4 points 1 priority habitat = 1 point 2 priority habitats = 3 points No habitats = 0 points Depressional Wetland Rating WLB -03 -02391 -600 Wetland Rating Form - Western Washington 10 Herrera Environmental Consultants Wetland Landscape (seep. 84) Choose the one description of the landscape around the wetland that best fits. ❑ There are at least 3 other wetlands within 1/2 mile, and the connections between them are relatively undisturbed (light grazing between wetlands OK, as is lake shore with some boating, but connections should NOT be bisected by paved roads, fill, fields, or other development). ❑ The wetland is Lake -fringe on a lake with little disturbance and there are 3 other Lake -fringe wetlands within 1/2 mile. ❑ There are at least 3 other wetlands within 1/2 mile, BUT the connections between them are disturbed. ❑ The wetland is Lake -fringe on a lake with disturbance, and there are 3 other Lake - fringe wetlands within 1/2 mile. ❑ There is at least 1 wetland within 1/2 mile. ❑ There are no wetlands within 1/2 mile. Depression& Wetland Rating WLB -03- 02391 -600 Wetland Rating Form - Westem Washington 11 Herrera Environmental Consultants CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS Please determine if the wetland meets the attributes described below and choose the appropriate answers and Category. SC 1. Estuarine Wetlands (see p. 86) Does the wetland meet the following criteria for Estuarine wetlands? ❑ The dominant water regime is tidal, ❑ Vegetated, and ❑ With a salinity greater than 0.5 ppt. ❑ YES =Go toSC1.1 S NO SC 1.1 Is the wetland within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area Preserve, State Park, or Educational, Environmental, or Scientific Reserve designated under WAC 332 -30 -151? ❑ YES = Category I 0 NO = Go to SC 1.2 SC 1.2 Is the wetland at least 1 acre in size and meets at least two of the following three conditions? ❑ The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has <10% cover of non- native plant species. If the non- native Spartina spp. are the only species that cover X10% of the wetland, then the wetland should be given a dual rating (I/11). The area of Spartina would be rated a Category II while the relatively undisturbed upper marsh with native species would be a Category 1. Do not, however, exclude the area of Spartina in determining the size threshold of 1 acre. ❑ At least 3/4 of the landward edge of the wetland has a 100 foot buffer of shrub, forest, or ungrazed or unmowed grassland. ❑ The wetland has at least two of the following features: tidal channels, depressions with open water, or continguous freshwater wetlands. ❑ YES = Category I ID NO = Category II Depressiona! Wetland Rating WLB -03 -02391 -600 Wetland Rating Form - Western Washington 12 Herrera Environmental Consultants SC 2. Natural Heritage Wetlands (see p. 87) Natural Heritage wetlands have been identified by the Washington Natural Heritage Program/DNR as either high quality undisturbed wetlands or wetlands that support state Threatened, Endangered, or Sensitive plant species. SC 2.1 Is the wetland being rated in a Section/Township /Range that contains a Natural Heritage wetland? (This question is used to screen out most sites before you need to contact WNHP/DNR.) S/T/R information from Appendix D El or accessed from WNHP/DNR web site ❑ ❑ YES - contact WNHP/DNR (see p. 79) and go to SC 3.2 ❑ NO SC 2.2 Has DNR identified the wetland as a high quality undisturbed wetland or as a site with state Threatened or Endangered plant species? ❑ YES = Category I 0 NO SC 3. Bogs (seep. 87) Does the wetland (or part of the wetland) meet both the criteria for soils and vegetations in bogs? Use the key below to ident if the wetland is a bog. If you answer Yes, you will still need to rate the wetland based on its function. 1. Does wetland have organic soil horizons (i.e., layers of organic soil), either peats or mucks, that compose 16 inches or more of the first 32 inches of the soil profile? (See Appendix B for a field key to identify organic oils.) ❑ YES - go to Q.3 ❑ NO -go to Q.2 2. Does the wetland have organic soils, either peats or mucks, that are <16 inches deep over bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on a lake or pond? ❑ YES - go to Q. 3 ❑ NO - is not a bog for purpose of rating 3. Does wetland have more than 70% cover of mosses at ground level, AND other plants, if present, consist of the "bog" species listed in Table 3 as a significant component of the vegetation ( >30% of total shrub and herbaceous cover consists of species in Table 3)? ❑ YES - is a bog for purpose of rating ❑ NO - go to Q. 4 NOTE: If you are uncertain about the extent of mosses in the understory you may substitute that criterion by measuring the pH of the water that seeps into a hole dug at least 16" deep. If the pH is less than 5.0 and the "bog" plant species in Table 3 are present, the wetland is a bog. 4. Is wetland forested ( >30% cover) with sitka spruce, subalpine fir, western redcedar, western hemlock, lodgepole pine, quaking aspen, Englemann's spruce, or western white pine, WITH any of the species (or combination of species) on bog species plant list in Table 3 as a significant component of the ground cover ( >30% coverage of total shrub/herbaceous cover)? ❑ YES - Category I NO - is not a bog for purpose of rating Depressional Wetland Rating WLB -03- 02391 -600 Wetland Rating Form - Western Washington 13 Herrera Environmental Consultants SC 4. Forested Wetlands (see p. 90) Does the wetland have at least 1 acre of forest that meets one of these criteria for the Department of Fish and Wildlife's forests as priority habitat? If you answer Yes, you will still need to rate the wetland based on its functions. ❑ Old- growth forests: (west of Cascade Crest) Stands of at least 2 tree species, forming a multi - layered canopy with occasional small openings; with at least 8 trees/acre (20/hectare) that are at least 200 years of age OR have a diameter at breast height (dbh) of 32 inches (81 cm) or more. NOTE: The criterion for dbh is based on measurements for upland forests. 200 - year -old trees in wetlands will often have a smaller dbh because their growth rates are often smaller. The DFW criterion is an "OR" so old - growth forests do not necessarily have to have trees of this diameter. ❑ Mature forests: (west of the Cascade Crest) Stands where the largest trees are 80 - 200 years old OR have average diameters (dbh) exceeding 21 inches (53 cm); crown cover may be less than 100 %; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that found in old - growth. ❑ YES = Category I ❑ NO SC 5. Wetlands in Coastal Lagoons (seep. 91) Does the wetland meet all of the following criteria of a wtland in a coastal lagoon? ❑ The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks. ❑ The lagoon in which the wetland is located contains surface water that is saline or brackish ( >.5 ppt) during most of the year in at leat a portion of the lagoon (needs to be measured near the bottom). ❑ YES = go to SC 5.1 ❑ NO - not a wetland in a coastal lagoon SC 5.1 Does the wetland meet all of the following 3 conditions? ❑ The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing), and has less than 20% cover of invasive plant species (see list of invasive species on p. 74). ❑ At least 3/4 of the landward edge of the wetland has a 100 foot buffer of shrub, forest, or ungrazed or unmowed grassland. ❑ The wetland is larger than 1 /10 acre (4,350 square feet). ❑ YES = Category I El NO = Category II Depressionai Wetland Rating WLB -03 -02391 -600 Wetland Rating Form - Western Washington 14 Herrera Environmental Consultants SC 6. Interdunal Wetlands (seep. 93) Is the wetland west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? ❑ YES - go to SC 6.1 ❑ NO - not an interdunal wetland for rating If you answer Yes, you will still need to rate the wetland based on its functions. In practical terms, that means the following geographic areas: • Long Beach Peninsula - lands west of SR 103 • Grayland- Westport - lands west of SR 105 • Ocean Shores - Copalis - lands west of SR 1115 and SR 109. SC 6.1 Is wetland 1 acre or larger, or is it in a mosaic of wetlands that is 1 acre or larger? ❑ YES = Category II ❑ NO - go to SC 6.2 SC 6.2 Is the wetland between 0.1 and 1 acre, or is it in a mosaic of wetlands that is between 0.1 and 1 acre? ❑ YES = Category III Depressional Wetland Rating WLB-03 -02391 -600 Wetland Rating Form - Westem Washington 15 Herrera Environmental Consultants WETLAND RATING FORM - WESTERN WASHINGTON Name of wetland (if known): Location: SEC: 3 Wetland C Person(s) Rating Wetland: TWNSHP: 23N DHH, JW RNGE: 8 East (attach map with outline of wetland rating form) Date of site visit: 12/2/2005 Affiliation: Herrera SUMMARY OF RATING Category based on FUNCTIONS provided by wetland I ❑ Category I = Score > =70 Category II = Score 51 -69 Category III = Score 30 -50 Category IV = Score <30 El IV ❑ Score for Water Quality Functions Score for Hydrologic Functions Score for Habitat Functions TOTAL score for functions Category based on SPECIAL CHARACTERISTICS of wetland I ❑ II ❑ Does not Apply Final Category (choose the "highest" category from above) 28 6 3 37 III Check the appropriate type and class of wetland being rated. Estuarine Natural Heritage Wetland Bog Mature Forest Old Growth Forest Coastal Lagoon Interdunal None of the above 0 Depressional Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Westem Washington 1 Herrera Environmental Consultants Does the wetland being rated meet any of the criteria below? If you answer YES to any of the questions below, you will need to protect the wetland according to the regulations regarding the special characteristics found in the wetland. ""'TS -^.,i� P "Y �.- f{�33.++K y 4.'S^�",�5'✓.«.,..a- +..c'e` us.: "4« a :arj..i.e,.wsJ .a�,,Y�aaJ.i ..9 gYffi4- *,.'*•t Errs{ 1pj`ah -.:. -w .v� . t�.m- a�-f _ - �'-g'+'•. r+r�et:.- -r .s uy. r _..�a 'i.."; =.�fl� SP 1. .'_..�.._��:,.,�.�..,....�_ Has the wetland been documented as a habitat for any federally listed Threatened or Endangered (T /E) plant or animal species? For the purposes of this rating system, "documented" means the wetland is on the appropriate state or federal database. El SP2. Has the wetland been documented as habitat for any state listed Threatened or Endangered plant or animal species? For the purposes of this rating system, "documented" means the wetland is on the appropriate state database. D El SP3. Does the wetland contain individuals of Priority species listed by the WDFW for the state? ill J SP4. Does the wetland have a local significance in addition to its functions? For example, the wetland has been identified in the Shoreline Master Program, the Critical Areas Ordinance, or in a local management plan as having special significance. To complete the next part of the data sheet, you will need to determine the Hydrogeomorphic Class of the wetland being rated . The hydrogeomorphic classification groups wetlands into those that function in similar ways. This simplifies the questions needed to answer how well the wetland functions. The Hydrogeomorphic Class of a wetland can be determined using the key below. See p. 24 for more detailed instructions on classifying wetlands. Depression& Wetland Rating WL -C-03 -02391 -600 Wetland Rating Fomi - Western Washington 2 Herrera Environmental Consultants 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Classification of Vegetated Wetlands for Western Washington Wetland Name: Wetland C Date: 12/2/2005 1. Are the water levels in the wetland usually controlled by tides (i.e., except during floods)? NO - go to 2 ❑ YES - the wetland class is Tidal Fringe If YES, is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)? ❑ YES - Freshwater Tidal Fringe ❑ NO - Saltwater Tidal Fringe (Estuarine) If your wetland can be classified as a Freshwater Tidal Fringe, use the forms for Riverine wetlands. If it is Saltwater Tidal Fringe, it is rated as an Estuarine wetland. Wetlands that were called estuarine in the first and second editions of the rating system are called Saltwater Tidal Fringe in the Hydrogeomorphic Classification. Estuarine wetlands were categorized separately in the earlier editions, and this separation is being kept in this revision. To maintain consistency between editions, the term "Estuarine" wetland is being kept. Please note, however, that the characteristics that define Category I and II estuarine wetlands have changed (see p. xx). 2. Is the topography within the wetland flat and precipitation is only source ( >90 %) of water to it? NO - go to 3 ❑ YES - the wetland class is Flats If your wetland can be classified as a "Flats" wetland, use the form for Depressional wetlands. 3. Does the wetland meet both of the following criteria? ❑ The vegetated part of the wetland is on the shores of a body of open water (without any vegetation on the surface) where at least 20 acres (8 ha) are permanently inundated (ponded or flooded); El ❑ At least 30% of the open water area is deeper than 6.6 feet (2 m)? NO - go to 4 ❑ YES - the wetland class is Lake - fringe (Lacustrine Fringe) 4. Does the wetland meet all of the following criteria? ❑ The wetland is on a slope (slope can be very gradual); ❑ The water flows through the wetland in one direction (unidirectional) and usually comes from seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks. ❑ The water leaves the wetland without being impounded? NOTE: Surface water does not pond in these type of wetlands except occasionally in very small and shallow depressions or behind hummocks (depressions are usually <3 feet in diameter and less than 1 foot deep). NO - go to 5 ❑ YES - the wetland class is Slope El 5. Is the wetland in a valley, or stream channel, where it gets inundated by overbank flooding from that stream or river? The flooding should occur at least once every two years, on the average, to answer "yes." The wetland can contain depressions that are filled with water when the river is not flooding. NO - go to 6 ❑ YES - the wetland class is Riverine El 6. Is the wetland in a topographic depression in which water ponds, or is saturated to the surface, at some time of the year? This means that any outlet, if present, is higher than the interior of the wetland. ❑ NO - go to 7 !0 YES - the wetland class is Depressional Depressional Wetland Rating WL- C- 03-02391 -600 Wetland Rating Form - Western Washington 3 Herrera Environmental Consultants 7. Is the wetland located in a very flat area with no obvious depression and no stream or river running through it and providing water? The wetland seems to be maintained by higher ground water in the area. The wetland may be ditched, but has no obvious natural outlet. NO - go to 8 ❑ YES - the wetland class is Depressional • 8. Your wetland seems to be difficult to classify. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small stream within a depressional wetland has a zone of flooding along its sides. Sometimes we find characteristics of several different hydrogeomorphic classes within one wetland boundary. Use the following table to identify the appropriate class to use for the rating system if you have several HGM classes present within your wetland. NOTE: Use this table only if the class that is recommended in the second column represents 10% or more of the total area of the wetland being rated. If the area of the second class is less than 10 %, classify the wetland using the first class. e ` Y�,,- 9�*!G�(6Jr5 "uv�...�- �rFSner�aJ n �N�+���r'� -r�P b{��, l' )f2.crL ".T'' �A�Lrt'�#� r�r9� 'Si1�:5`A'°`�iY.&'Sm..,efaw.e »'�'a0.'L'?'3°'r S'i'�Ls�z^�t�.�..N"AMw� '+ '}Y�_` �P+i �"t. r�➢.,.v..' �F}—.,+2*�yr7, x,4,9 p�.�Y$+ta- Mi;Xgn?' .�„�. �.a{.�,•n.yne1- *R4�%'.�...3 S'v- 1vS�uuJ �v�i, iY+ Slope + Riverine Riverine • Slope + Depressional Depressional J Slope + Lake -fringe Lake -fringe ❑ Depressional + Riverine along stream within boundary Depressional • Depressional + Lake - fringe Depressional ❑ Saltwater Tidal Fringe and any other class of freshwater wetland Treat as ESTUARINE under wetlands with special characteristics ❑ If you are unable still to determine which of the above criteria apply to your wetland, or you have more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the rating. Depressional Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Westem Washington 4 Herrera Environmental Consultants 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 B 0 0 1 1 1 1 1 1 1 � u � 3 y�ue� w' q-e: cF 4,:.,ot� t h`e rte. tn� H! o..p.,_ �Ctl 'k` 1' Z.L..�..�,._L.:__"T:3F_'.�.E... ��.^,...,^�.�£. _....° D 1. Does the wetland have the otential to improve water quality? (seep. 38) D 1.1 Characteristics of surface water flows out of the wetland: 3 J Wetland is a depression with no surface water outlet. Points = 3 ❑ Wetland has an intermittently flowing, or highly constricted Points = 2 outlet. ❑ Wetland has an unconstricted surface outlet. Points =1 ❑ Wetland is flat and has no obvious outlet and/or outlet is a Points =1 ditch. D 1.2 The soil 2 inches below the surface is clay, organic, or smells anoxic (hydrogen sulfide or rotten eggs): 4 4 YES Points = 4 ❑ NO Points = 0 D 1.3 Characteristics of persistent vegetation (emergent, shrub, and/or forest class): 5 4 Wetland has persistent, ungrazed vegetation <95% of area. Points = 5 ❑ Wetland has persistent, ungrazed vegetation <1/2 of area. Points = 3 ❑ Wetland has persistent, ungrazed vegetation <1/10 of area. Points =1 ❑ Wetland has persistent, ungrazed vegetation <1 /10 of area Points = 0 D 1.4 Characteristics of seasonal ponding or inundation. This is the area of the wetland that is ponded for at least 2 months, but dries out sometime during the year. Do not count the area that is permanently ponded. Estimate area as the average condition 5 out of 10 years. ❑ Area seasonally ponded is >1/2 total area of wetland. Points = 4 2 J Area seasonally ponded is >1/4 total area of wetland. Points = 2 ❑ Area seasonally ponded is <1/4 total area of wetland. Points = 0 NOTE: See text for indicators of seasonal and permanent inundation. Total for D 1 Add the points in the boxes above 14 D 2. Does the wetland have the opportunity to improve water quality? (seep. 44) Multiplier Answer YES if you know or believe there are pollutants in ground water or surface water coming into the wetland that would otherwise reduce water quality in streams, lakes, or ground water downgradient from the wetland. Note which of the following conditions provide the sources of pollutants: ❑ Grazing in the wetland or within 150 feet. ❑ Untreated stormwater discharges to wetland. ❑ Tilled fields or orchards within 150 feet of wetland. ❑ A stream or culvert discharges into wetland that drains developed areas, residential areas, farmed fields, roads, or clear -cut logging. Residential, urban areas, golf courses are within 150 feet of wetland. ❑ Wetland is fed by ground water high in phosphorus or nitrogen. ❑ Other: 2 YES - multiplier is 2 NO - multiplier is 1 TOTAL - Water Quality Functions Multiply the score from D 1. by D 2 Add score to table on p. 1 28 Depressions! Wetland Rating WL -C -03 -02391 -600 Wetland Rating Form - Western Washington 5 Herrera Environmental Consultants [i _ ("-i F �" r S•,a 'F'"a tie r B ✓, a� W. ? d t s t o t - . -,r -"- a -... �` ---. '. �l Y,. �"'4."�ti C'_. V'� A - J.-- :-- L•_...- `^i -7. '4'i X d � Y .f '4 k i., ?"t t v E.�' tj t , rstnI iE w5E k.i5 •:... %::,.`.,, ��i�r% u ?Gi.�'+."z_ as;t"iM��r —r:_ -ORS OC`�1 e5.........�` LF - -:: ._ .,....".....r•�tC3:ses+:�d:u�� D 3. Does wetland have the potential to reduce flooding/erosion? (see p. 46) 3.1 Characteristics of surface water flows out of the wetland: ❑ Wetland has no surface water outlet. Points = 4 2. i Wetland has an intermittently flowing, or highly constricted outlet. Points = 2 ❑ Wetland is flat and has no obvious outlet and/or outlet is a small Points =1 ditch. ❑ Wetland has an =constricted surface outlet. Points = 0 D 3.2 Depth of storage during wet periods. Estimate the height of ponding above the bottom of the outlet. ❑ Marks of ponding are 3 feet or more above the surface. Points = 7 1 • The wetland is a "headwater" wetland. Points = 5 • Marks of ponding between 2 feet to <3 feet from surface. Points = 5 ❑ Marks are at least 0.5 feet to <2 feet from surface. Points = 3 -, Wetland is flat but has small depressions on the surface that trap Points =1 water. • Marks of ponding less than 0.5 feet. Points = 0 D 3.3 Contribution of wetland to storage in the watershed. Estimate the ratio of the area of upstream basin contributing surfae water to the wetland to the area of the wetland itself ❑ The area of the basin is <10 times the area of the wetland. Points = 5 ❑ The area of the basin is 10 to 100 times the area of the wetland. Points = 3 0 Multiplier J The area of the basin is >100 times the area of the wetland. Points = 0 ❑ Wetland is in the Flats class (basin = wetland, by definition). Points = 5 Total for D 3 Add the points in the boxes above D 4. Does wetland have the opportunity to reduce flooding/erosion? (seep. 49) Answer YES if the wetland is in a location in the watershed where the flood storage, or reduction in water velocity, helps protect downstream property and aquatic resources from flooding or excessive and/or erosive flows. Answer NO if the water coming into the wetland is controlled by a structure such as flood gate, tide gate, flap valve, reservoir, etc. OR you estimate that more than 90% of the water in the wetland is from ground water. Note which of the following indicators of opportunity apply: • Wetland is in a headwater of a river or stream that has flooding problems. ❑ Wetland drains to a river or stream that has flooding problems. 0 Wetland has no outlet and impounds surface runoff water that might otherwise flow into a river or stream that has flooding problems. ❑ Other: 2 YES - multiplier is 2 NO - multiplier is 1 — TOTAL - Hydrologic Functions Multiply the score from D 3. by D 4 Add score to table on p. 1 6 Depressional Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Westem Washington 6 Herrera Environmental Consultants 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 a a 0 0 11 11 1 1 1 1 1 1 1 1 1 1 --.7.,..-v—; q:.: "p •.�'d- t "' y.�" wcaar3�ma s ¢Fwtma'c�.i >^"b aa` ,*'•Rx (,(... k• ' J ,1 tel: ' - }-- r.jF {4,�r. �9 IT -r"°,+d rF�T� ! z F.�t aY�2 ��rl -f �l Y o- ',, ,�;. r _d'm �-.«„ .C" � °•^R•S �.a ,_raMr�.:..n..._:rs ��._..___.��r. �^*� .._:.�, �'� „a..,. . ._,—� ..�:,� .,.,t:.,..xa .esJ- _.- <...:. •_ el�t� 'r�-,� r,�v3.��. M....,� .�.�:... H 1. Does the wetland have the otential to provide habitat for many species? H 1.1 Vegetation structure (see p. 72) 0 Check the types of vegetation classes present (as defined by Cowardin) if the class covers more than 10% of the area of the wetland or 1/4 acre. ❑ Aquatic bed 4 Emergent plants ❑ Scrub /shrub (areas where shrubs have >30% cover) ❑ Forested (areas where trees have >30% cover) ❑ Forested areas have 3 out of 5 strata (canopy, sub - canopy, shrubs, herbaceous, moss /ground - cover) Add the number of vegetation types that qualify. If you have: 4 types or more Points = 4 3 types Points = 2 2 types Points =1 1 type Points = 0 H 1.2 Hydroperiods (seep. 73) 1 Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover more than 10% of the wetland or 1/4 acre to count (see text for descriptions of hydroperiods). ❑ Permanently flooded or inundated 4 or more types present Points = 3 • Seasonally flooded or inundated 3 types present Points = 2 Occasionally flooded or inundated 2 types present Points =1 4 Saturated only ❑ Permanently flowing stream or river in, or adjacent to, the wetland ❑ Seasonally flowing stream in, or adjacent to, the wetland ❑ Lake fringe wetland = 2 points ❑ Freshwater tidal wetland = 2 points H 1.3 Richness of Plant Species (seep. 75) 0 Count the number of plant species in the wetland that cover at least 10 sq. ft. (different patches of the same species can be combined to meet the size threshold). You do not have to name the species. Do not include Eurasian Milfoil, reed canarygrass, purple loosestrife, Canadian Thistle. If counted: >19 species_ Points = 2 5 -19 species Points =1 List species below if you want to: <5 species Points = 0 Depressional Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Western Washington 7 Herrera Environmental Consultants H 1.4 Interspersion of Habitats (seep. 76) Decide from the diagrams below whether interspersion between types of vegetation (described in H 1.1) or vegetation types and unvegetated areas (can include open water or mudflats) is high, medium, low, or none. None = 0 points Low =1 point High = 3 points NOTE: If you have four or more vegetation types or three vegetation types and open water, the rating is always "high ". Moderate = 2 points [riparian braided channels] 0 H 1.5 Special Habitat Features (seep. 77) Check the habitat features that are present in the wetland. The number of checks is the number of points you put into the next column. ❑ Large, downed, woody debris within the wetland ( >4 inch in diameter and 6 feet long). ❑ Standing snags (diameter at the bottom >4 inches) in the wetland. ❑ Undercut banks are present for at least 6.6 feet (2 m) and/or overhanging vegetation extends at least 3.3 feet (1 m) over a stream for at least 33 feet (10 m). ❑ Stable steep banks of fine material that might be used by beaver /muskrat for denning ( >30° slope) OR signs of recent beaver activity are present. ❑ At least 1/4 acre of thin- stemmed presistent vegetation or woody branches are present in areas that are permanently or seasonally inundated (structures for egg - laying by amphibians). ❑ Invasive plants cover less than 25% of the wetland area in each stratum of plants. Comments: 0 1 Depressional Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Westem Washington 8 Herrera Environmental Consultants 6 11 11 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 H 2. H 2.1 Does the wetland have the opportunity to provide habitat for many species? n Wig. Buffers (seep. 80) Choose the description that best represents condition of buffer of wetland. The highest scoring criterion that applies to the wetland is to be used in the rating. See text for definition of "undisturbed." ❑ 100 m (330 feet) of relatively undisturbed vegetated areas, rocky Points = 5 areas, or open water >95% of circumference. No developed areas within undisturbed part of buffer (relatively undisturbed also means no grazing). ❑ 100 m (330 feet) of relatively undisturbed vegetated areas, rocky Points = 4 areas, or open water >50% of circumference. ❑ 50 m (170 feet) of relatively undisturbed vegetated areas, rocky Points = 4 areas, or open water >95% circumference. ❑ 100 m (330 feet) of relatively undisturbed vegetated areas, rocky Points = 3 areas, or open water for >25% circumference. 1 ❑ 50 m (170 feet) of relatively undisturbed vegetated areas, rocky Points = 3 areas, or open water for >50% circumference. If buffer does not meet any of the criteria above:. ❑ No paved areas (except paved trails) or buildings within 25 m (80 Points = 2 feet) of wetland >95% circumference. Light to moderate grazing, or lawns are OK. ❑ No paved areas or buildings within 50 m of wetland for >50% Points = 2 circumference. Light to moderate grazing, or lawns are OK. ❑ Heavy grazing in buffer. Points =1 ❑ Vegetated buffers are <2 m wide (6.6 feet) for more than 95% of Points = 0 the circumference (e.g., tilled fields, paving, basalt bedrock extend to edge of wetland). 4 Buffer does not meet any of the criteria above. Points =1 H 2.2 Corridors and Connections (seep. 81) H 2.2.1 Is the wetland part of a relatively undisturbed/unbroken vegetated corridor (riparian or upland) at least 150 feet wide, has at least 30% cover of shrubs, forest, or native undisturbed prairie, that connects to estuaries, other wetlands, or undisturbed uplands that are at least 250 acres in size? (Dams in riparian corridors, heavily used gravel roads, and paved roads are considered breaks in the corridor.) YES =4 points (go toH2.3) NO =go toH2.2.2 H 2.2.2 Is the wetland part of a relatively undisturbed/unbroken vegetated corridor (either riparian or upland) at least 50 feet wide, has at least 30% cover of shrubs or forest, and connects to estuaries, other wetlands, or undisturbed uplands that are at least 25 acres in size OR a 1 Lake - fringe wetland, if it does not have an undisturbed corridor as in the question above? YES = 2 points (go to H 2.3) NO = go to H 2.2.3 H 2.2.3 Is the wetland: — within 5 miles (8 km) of a brackish or salt water estuary OR within 3 miles of a large field or pasture ( >40 acres) OR within 1 mile of a lake greater than 20 acres? YES =1 point NO = 0 points Depression! Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Western Washington 9 Herrera Environmental Consultants H 2.3 Near or Adjacent to Other Priority Habitats Listed by WDFW (seep. 82) Which of the following priority habitats are within 330 feet (100 m) of the wetland? (See text for a more detailed description of these priority habitats.) ❑ Riparian: Area adjacent to aquatic systems with flowing water that contains elements of both aquatic and terrestrial ecosystems which mutually influence each other. ❑ Aspen stands: Pure or mixed stands of aspen >0.8 ha (2 acres). ❑ Cliffs: Greater than 7.6 m (25 feet) high and occuring below 5,000 feet. ❑ Old- growth forests: (old growth west of Cascade crest) Stands of at least 2 tree species, forming a multi- layered canopy with occasional small openings; with at least 20 trees/ha (8 /acre) >81 cm (32 inches) in diameter or >200 years of age. ❑ Mature forests: Stands with average diameters exceeding 53 cm (21 inches) dbh; crown cover may be <100 %; decay, decadence, numbers of snags, and quantity of large downed material is generally less than found in old - growth; 80- 200 years old west of Cascade crest. ❑ Prairies: Relatively undisturbed areas (indicated by dominance of native plants) where grasses /forbs form the natural climax plant community. ❑ Talus: Homogenous areas of rock rubble (average size 0.15 - 2.0 m [0.5 - 65 feet]), composed of basalt, andesite, and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs. ❑ Caves: Naturally occurring cavity, recess, void, or system of interconnected passages. ❑ Oregon white oak: Woodland stands of pure oak or oak/conifer associations where canopy coverage of the oak component is 25 %. ❑ Urban Natural Open Space: A priority species resides within or is adjacent to the open space and uses it for breeding and/or regular feeding; and/or the open space functions as a corridor connecting other priority habitats , especially those otherwise isolated; and/or the open space is an isolated remnant of natural habitat >4 ha (10 acres) and is surrounded by urban development. ❑ Estuary/estuary -like: Deepwater tidal habitats & adjacent tidal wetlands, usually semi - enclosed by land but with open, partly obstructed, or sporadic access to open ocean; ocean water at least occasionally diluted by freshwater runoff from land. Salinity may be periodically increased above that of open ocean by evaporation. Along some low- energy coastlines, there is appreciable dilution of sea water. Estuarine habitat extends upstream and landward to where ocean- derived salts measure <0.5 ppt. during period of avg. annual low flow. Includes both estuaries and lagoons. ❑ Marine /estuarine shorelines: Include intertidal and subtidal zones of beaches; may also include backshore and adjacent components of the terrestrial landscape (e.g., cliffs, snags, mature trees, dunes, meadows) important to shoreline associated fish and wildlife and that contribute to shoreline function (e.g., sand/rock/log recruitment, nutrient contribution, erosion control). If wetland has: 3+ priority habitats = 4 points 1 priority habitat =1 point 2 priority habitats = 3 points No habitats = 0 points Depressional Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Western Washington 10 Herrera Environmental Consultants Wetland Landscape (see p. 84) Choose the one description of the landscape around the wetland that best fits. ❑ There are at least 3 other wetlands within 1/2 mile, and the Points = 5 connections between them are relatively undisturbed (light grazing between wetlands OK, as is lake shore with some boating, but connections should NOT be bisected by paved roads, fill, fields, or other development). ❑ The wetland is Lake -fringe on a lake with little disturbance and Points = 5 there are 3 other Lake -fringe wetlands within 1/2 mile. ❑ There are at least 3 other wetlands within 1/2 mile, BUT the Points = 3 connections between them are disturbed. ❑ The wetland is Lake -fringe on. a lake with disturbance, and there Points = 3 are 3 other Lake -fringe wetlands within 1/2 mile. ❑ There is at least 1 wetland within 1/2 mile. Points = 2 ❑ There are no wetlands within 1/2 mile. Points = 0 Depressional Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Westem Washington 11 Herrera Environmental Consultants CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS Please determine if the wetland meets the attributes described below and choose the appropriate answers and Category. SC I. Estuarine Wetlands (seep. 86) Does the wetland meet the following criteria for Estuarine wetlands? ❑ The dominant water regime is tidal, ❑ Vegetated, and ❑ With a salinity greater than 0.5 ppt. ❑ 'YES =Go toSC1.1 El NO SC 1.1 Is the wetland within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area Preserve, State Park, or Educational, Environmental, or Scientific Reserve designated under WAC 332 -30 -151? ❑ YES = Category I SI NO =Go toSC1.2 SC 1.2 Is the wetland at least 1 acre in size and meets at least two of the following three conditions? ❑ The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has <10% cover of non - native plant species. If the non- native Spartina spp. are the only species that cover >10% of the wetland, then the wetland should be given a dual rating (NI). The area of Spartina would be rated a Category II while the relatively undisturbed upper marsh with native species would be a Category 1. Do not, however, exclude the area of Spartina in determining the size threshold of 1 acre. ❑ At least 3/4 of the landward edge of the wetland has a 100 foot buffer of shrub, forest, or ungrazed or unmowed grassland. ❑ The wetland has at least two of the following features: tidal channels, depressions with open water, or continguous freshwater wetlands. ❑ YES = Category I D NO = Category II Depressional Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Westem Washington 12 Herrera Environmental Consultants SC 2. Natural Heritage Wetlands (seep. 87) Natural Heritage wetlands have been identified by the Washington Natural Heritage Program/DNR as either high quality undisturbed wetlands or wetlands that support state Threatened, Endangered, or Sensitive plant species. SC 2.1 Is the wetland being rated in a Section/Township/Range that contains a Natural Heritage wetland? (This question is used to screen out most sites before you need to contact WNHP/DNR.) S/T/R information from Appendix D ❑ or accessed from WNHP/DNR web site ❑ ❑ YES - contact WNHP/DNR (seep. 79) and go to SC 3.2 ❑ NO SC 2.2 Has DNR identified the wetland as a high quality undisturbed wetland or as a site with state Threatened or Endangered plant species? ❑ YES = Category I El NO SC 3. Bogs (seep. 87) Does the wetland (or part of the wetland) meet both the criteria for soils and vegetations in bogs? Use the key below to identify if the wetland is a bog. If you answer Yes, you will still need to rate the wetland based on its function. 1. Does wetland have organic soil horizons (i.e., layers of organic soil), either peats or mucks, that compose 16 inches or more of the first 32 inches of the soil profile? (See Appendix B fora field key to identify organic oils.) ❑ YES - go to Q. 3 ❑ NO - go to Q.2 2. Does the wetland have organic soils, either peats or mucks, that are <16 inches deep over bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on a lake or pond? ❑ YES - go to Q. 3 ❑ NO - is not a bog for purpose of rating 3. Does wetland have more than 70% cover of mosses at ground level, AND other plants, if present, consist of the "bog" species listed in Table 3 as a significant component of the vegetation ( >30% of total shrub and herbaceous cover consists of species in Table 3)? ❑ YES - is a bog for purpose of rating ❑ NO - go to Q. 4 NOTE: If you are uncertain about the extent of mosses in the understory you may substitute that criterion by measuring the pH of the water that seeps into a hole dug at least 16" deep. If the pH is less than 5.0 and the "bog" plant species in Table 3 are present, the wetland is a bog. 4. Is wetland forested ( >30% cover) with sitka spruce, subalpine fir, western redcedar, western hemlock, lodgepole pine, quaking aspen, Englemann's spruce, or western white pine, WITH any of the species (or combination of species) on bog species plant list in Table 3 as a significant component of the ground cover ( >30% coverage of total shrub/herbaceous cover)? ❑ YES - Category I El NO - is not a bog for purpose of rating Depressional Wetland Rating WL -C-03- 02391 -600 Wetland Rating Form - Western Washington 13 Herrera Environmental Consultants SC 4. Forested Wetlands (seep. 90) Does the wetland have at least 1 acre of forest that meets one of these criteria for the Department of Fish and Wildlife's forests as priority habitat? If you answer Yes, you will still need to rate the wetland based on its functions. El Old- growth forests: (west of Cascade Crest) Stands of at least 2 tree species, forming a multi- layered canopy with occasional small openings; with at least 8 trees /acre (20/hectare) that are at least 200 years of age OR have a diameter at breast height (dbh) of 32 inches (81 cm) or more. NOTE: The criterion for dbh is based on measurements for upland forests. 200 - year -old trees in wetlands will often have a smaller dbh because their growth rates are often smaller. The DFW criterion is an "OR" so old -growth forests do not necessarily have to have trees of this diameter. ❑ Mature forests: (west of the Cascade Crest) Stands where the largest trees are 80 - 200 years old OR have average diameters (dbh) exceeding 21 inches (53 cm); crown cover may be less than 100 %; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that found in old - growth. El YES = Category I ❑ NO SC 5. Wetlands in Coastal Lagoons (see p. 91) Does the wetland meet all of the following criteria of a wtland in a coastal lagoon? ❑ The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks. ❑ The lagoon in which the wetland is located contains surface water that is saline or brackish ( >.5 ppt) during most of the year in at leat a portion of the lagoon (needs to be measured near the bottom). ❑ YES = go to SC 5.1 ❑ NO - not a wetland in a coastal lagoon SC 5.1 Does the wetland meet all of the following 3 conditions? ❑ The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing), and has less than 20% cover of invasive plant species (see list of invasive species on p. 74). ❑ At least 3/4 of the landward edge of the wetland has a 100 foot buffer of shrub, forest, or ungrazed or unmowed grassland. ❑ The wetland is larger than 1 /10 acre (4,350 square feet). ❑ YES = Category I J NO = Category II Depressional Wetland Rating WL -C-03 -02391 -600 Wetland Rating Form - Westem Washington 14 Herrera Environmental Consultants SC 6. Interdunal Wetlands (see p. 93) Is the wetland west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? ❑ YES - go to SC 6.1 ❑ NO - not an interdunal wetland for rating If you answer Yes, you will still need to rate the wetland based on its functions. In practical terms, that means the following geographic areas: • Long Beach Peninsula - lands west of SR 103 • Grayland- Westport - lands west of SR 105 • Ocean Shores - Copalis - lands west of SR 1115 and SR 109. SC 6.1 Is wetland 1 acre or larger, or is it in a mosaic of wetlands that is 1 acre or larger? ❑ YES = Category II ❑ NO - go to SC 6.2 SC 6.2 Is the wetland between 0.1 and 1 acre, or is it in a mosaic of wetlands that is between 0.1 and 1 acre? ❑ YES = Category III Depressional Wetland Rating WL -C-03- 02391 -600 Wetland Rating Form - Westem Washington 15 Herrera Environmental Consultants ATTACHMENT B Wetland Mitigation Plan Norfolk- Martin Luther King Jr. Way Subbasin Stormwater Improvements WETLAND MITIGATION PLAN Norfolk - Martin Luther King Jr. Way Subbasin Stormwater Improvements Prepared for Seattle Public Utilities February 2008 Final Draft WETLAND MITIGATION PLAN Norfolk - Martin Luther King Jr. Way Subbasin Stormwater Improvements Prepared for Seattle Public Utilities Seattle Municipal Tower 700 5th Avenue Seattle, Washington 98124 -4018 Prepared by Herrera Environmental Consultants, Inc. 2200 Sixth Avenue, Suite 1100 Seattle, Washington 98121 Telephone: 206/441 -9080 February 11, 2008 Final Draft Contents Project Overview v Introduction 1 Project Location 1 Responsible Parties 2 Project Descriptions 2 Project 1 — Conveyance: Improvements Purpose and Description 5 Project 2 — Stormwater Treatment Improvements Purpose and Description 6 Description of Impacted Wetlands 9 Regulatory Framework 11 Federal Regulations 11 State Regulations 11 Local Regulations 11 Mitigation 13 Impact Minimization 13 Mitigation Goals 14 Mitigation Objectives 21 On -site Mitigation — Norfolk Stormwater Treatment Improvements Site 21 Site Description 21 Mitigation Site Ownership 21 Site Restoration Plan 22 General Planting Specifications 22 Site Preparation 24 Site Protection 24 Maintenance 24 Monitoring Plan 24 Site Restoration Performance Standards 25 Offsite Mitigation — Puget Creek Natural Area 26 Site Description 26 Mitigation Site Ownership 26 Rationale for Selection of Mitigation Site 29 Site Constraints 29 Ecological Assessment of Proposed Mitigation Site 30 Wetland Re- establishment and Wetland and Upland Enhancement Plan 30 General Planting Specifications 33 Site Protection 37 Maintenance 37 Monitoring Plan 37 Site Enhancement Performance Standards 38 Implementation Schedule 39 References 41 Appendix A Project Plan Sheets Tables Table 1. Project 1 — Conveyance Improvements: wetland and buffer mitigation requirements. vi Table 2. Project 2 — Stormwater Treatment Improvements: wetland and buffer mitigation requirements. vi Table 3. Summary of Puget Creek Natural Area mitigation activities viii Table 4. Zone 1 tree and shrub plantings for on -site upland shrub buffer restoration. 23 Table 5. Zone 1 grass seed mix and application rate for on -site upland shrub buffer restoration 23 Table 6. Zone 2 grass seed mix and application rate for on -site transitional buffer restoration 23 Table 7. Zone 1 tree, shrub and herbaceous plantings in the Puget Creek Natural Area wetland re- establishment area. 34 Table 8. Zone 1 grass seed mix and application rate in the Puget Creek Natural Area wetland re- establishment area. 34 Table 9. Zone 2 tree and shrub plantings in the Puget Creek Natural Area wetland enhancement area. 35 Table 10. Zone 2 grass seed mix and application rate in the Puget Creek Natural Area wetland enhancement area. 35 Table 11. Zone 3 tree and shrub plantings in the Puget Creek Natural Area wetland buffer enhancement area. 36 Table 12. Zone 3 grass seed mix and application rate in the Puget Creek Natural Area wetland buffer enhancement area 36 Table 13. Zone 4 tree and shrub plantings in the Puget Creek Natural Area habitat enhancement area. 36 Table 14. Zone 4 grass seed mix and application rate in the Puget Creek Natural Area habitat enhancement area. 37 ii 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Figures Figure 1. Vicinity map for the Norfolk -Martin Luther King Jr. Way subbasin stormwater improvements project sites and the Puget Creek Natural Area proposed mitigation site, Seattle and Tukwila, Washington. 3 Figure 2. Wetlands within the Norfolk -Martin Luther King Jr. Way subbasin stormwater improvements project sites, Seattle and Tukwila, Washington. 7 Figure 3. Wetland impacts for Project 1 of the Norfolk MLK -Way subbasin stormwater improvement projects, Seattle and Tukwila, Washington. 15 Figure 4. Wetland and buffer impacts for Project 2 of the Norfolk MLK -Way subbasin stormwater improvement projects, Seattle and Tukwila, Washington. 17 Figure 5. On -site mitigation for wetland buffer impacts for Project 2 of the Norfolk MLK -Way subbasin stormwater improvement projects, Seattle and Tukwila, Washington. 19 Figure 6. Puget Creek Natural Area Wetland Mitigation Strategy, Seattle, Washington. 27 iii Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin Project Overview This mitigation plan describes mitigation for wetland and buffer impacts resulting from two projects proposed by Seattle Public Utilities (SPU) to improve storm drainage conveyance problems and degraded water quality in the Norfolk and MLK Way subbasins. The Norfolk and MLK Way subbasins are two of the eight subbasins that make up the Norfolk drainage basin which extends from Boeing Field to Beacon Avenue South. Portions of the drainage areas served by this system are owned by the cities of Tukwila and Seattle. The Norfolk -MLK Way subbasin stormwater improvements include two independent projects, constructed in different years, and funded separately. The two projects are: • Project 1 – Conveyance Improvements: replacement of a 36 -inch CMP storm drainage line and regrading of a Washington Department of Transportation (WSDOT) ditch east of I -5 ■ Project 2 – Stormwater Treatment Improvements: construction of a stormwater treatment facility to treat runoff before it is discharged to the Duwamish Waterway. Each project meets the U.S. Army Corps of Engineers definition of "independent utility" in that each project will be constructed and fully operational, even if the other is not constructed. The two projects are functionally independent and the conveyance project can function with, or without, the future stormwater treatment facility. Project 1 – Conveyance Improvements has one wetland within the project limits, Wetland D. Wetland D, also referred to as the WSDOT ditch, is located along the east side of northbound I -5 in both the cities of Seattle and Tukwila. Stormwater runoff from the MLK Way subbasin flows north through Wetland D; then flows west into two parallel culverts located under I -5. Once reaching the west side of I -5, flow passes through two other regulated wetlands (Wetland S and Wetland A, within the project limits of Project 2), and then enters a piped system before discharging to the Duwamish Waterway. Project 2 – Stormwater Treatment Improvements has four wetlands within the project limits that include wetlands A, B, C, and S. Wetland A and Wetland S are entirely within the Seattle city limits, and both wetlands are adjacent to the west side of the Burlington Northern Santa Fe (BNSF) Railway Company tracks. Wetland B is located south of Wetland A, almost entirely within the Tukwila city limits, with only the northern edge extending slightly into Seattle. Wetland C is located north of Wetland A, in the jurisdiction of the City of Seattle. Construction activities associated with the two projects comprising the Norfolk/MLK Way subbasin stormwater improvements would result in temporary and permanent impacts on wetlands within each project site. Project 1 – Conveyance Improvements will regrade the WSDOT ditch (Wetland D) on the east side of I -5, and will result in 0.14 acres of permanent v Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin impacts to Wetland D. There is no buffer to Wetland D so there are no buffer impacts resulting from this project. Project 2 – Stormwater Treatment Improvements will construct a treatment pond and perimeter maintenance access road that will result in permanent impacts on Wetland S and its buffer, and Wetland A and its buffer. These impacts will consist of approximately 0.36 acres of impact on Wetland S, 1.79 acres of impact to the buffer of Wetland S; 0.01 acres of impact on Wetland A, and 0.58 acres of impact on the buffer of Wetland A. Areas of permanent impact on wetlands and their buffers are summarized in Tables 1 and 2. Table 1. Project 1– Conveyance Improvements: wetland and buffer mitigation requirements. Area Impacted Impacted Feature (acres) Mitigation Strategy Wetland Re- establishment Requirement (acres) Ratio 1:1 Wetland Enhancement Requirement (acres) Ratio 4:1 Buffer Enhancement/ Replacement Requirement (acres) Ratio 1:1 Wetland D 0.14 1:1 Wetland Re- establishment plus (WSDOT Ditch) 4:1 Wetland Enhancement 0.14 0.56 There are no buffer impacts on Wetland D Table 2. Project 2 – Stormwater Treatment Improvements: wetland and buffer mitigation requirements. Impacted Feature Area Impacted (acres) Mitigation Strategy Wetland Re- establishment Requirement (acres) Ratio 1:1 Wetland Re- establishment Requirement (acres) Ratio 2:1 Wetland Enhancement Requirement (acres) Ratio 4:1 with Re- establishment Buffer Enhancement/ Replacement Requirement (acres) Ratio 1:1 Wetland S (WSDOT Mitigation Site) Wetland S Buffer (WSDOT Mitigation Site) Wetland A Wetland A Buffer Wetland B Buffer 0.36 1:1 Wetland Re- establishment plus 4:1 Wetland Enhancement 1.79 1:1 Enhancement of Degraded Buffer 0.36 0.01 2:1 Wetland Re- establishment 0.58 1:1 Enhancement of degraded buffer 0.15 1:1 Enhancement of 50% of remaining degraded buffer TOTAL 0.383 0.023 1.44 1.79 0.58 0.15 1.44 2.37 Compensation for permanent wetland impacts on Wetland A, Wetland D, Wetland S, and their buffer zones would be provided outside the boundaries of the project areas but would be in -kind and within the Green - Duwamish Drainage basin. This would be accomplished by restoring and enhancing freshwater wetlands and wetland buffers in the Puget Creek Natural Area. The Puget Creek Natural area drains to Puget Sound via the Duwamish Waterway WRIA 9 as do the affected wetlands in both Project 1 – Conveyance Improvements and Project 2 – Stormwater vi Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin Treatment Improvements. Compensation for impacts to the buffer of Wetland B will occur on- site within the City of Tukwila. All mitigation for wetland impacts from Project 1 – Conveyance Improvements would be provided off -site, by removing fill material from 0.14 acres of former wetland, regrading the site to restore the original topography, and planting disturbed areas with native wetland vegetation. In addition, 0.56 acres of wetland would be enhanced. The proposed mitigation would meet the City of Seattle's guideline of providing 1:1 wetland creation /re- establishment in addition to a 4:1 ratio of wetland enhancement to meet the City's mitigation requirements. Enhancement activities would include noxious weeds removal, and replanting with native species to enhance the ecological integrity of the wetland and its buffer. Mitigation for wetland impacts from Project 2 – Stormwater Treatment Improvements would be provided off -site, by removing 5,572 cubic yards of fill material from 0.38 acres of former wetland, regrading the site to reconnect the wetland contours located adjacent to the fill, and planting disturbed areas with native wetland vegetation. In addition, 1.44 acres of existing wetland area at the Puget Creek site would be enhanced. Enhancement activities would include noxious weed removal and replanting with native species. In addition, 2.37 acres of wetland buffer located at the Puget Creek Natural Area would be enhanced through noxious weed removal and native species plantings to compensate for 2.37 acres of buffer impacts from the proposed stormwater treatment pond and the access road. This proposed mitigation would meet the City of Seattle's guideline of providing a 1:1 ratio of wetland creation /re- establishment and a 4:1 ratio of wetland enhancement for impacts on Wetland S; a 2:1 ratio of wetland creation/re- establishment for impacts on Wetland A; and a 1:1 ratio of buffer enhancement for impacts on wetlands A and S buffers. All enhanced wetlands within Puget Creek Natural Area would have restored buffers of a minimum of 85 feet as required by the City of Seattle (Seattle Municipal Code [SMC] 25.09.160). These enhancement activities would increase the structural diversity of the Puget Creek Natural Area, improve bird and small mammal habitat, improve organic export by increasing tree density, increase sediment removal and nutrient/toxicant removal through increased species richness, and overall, increase the ecological integrity of the Puget Creek Natural area for future generations. In addition to the total mitigation required for wetland and buffer impacts, the remainder of the Puget Creek Natural Area will be similarly enhanced by removing noxious weeds and replanting with native species as appropriate to prevent the spread of noxious weeds and non - native species from adjacent areas on the site. This will result in a surplus of wetland re- establishment and wetland and buffer enhancement at the Puget Creek Natural Area. An additional 0.04 acres of wetland re- establishment, 1.53 acres of wetland enhancement, 0.17 acres of buffer enhancement, and 1.0 acres of habitat enhancement would occur at the Puget Creek Natural Area beyond that required by mitigation. A summary of mitigation activities at the Puget Creek Natural Area is shown in Table 3. vii Wetland Mitigation Plan— Norfolk -Martin Luther King Jr. Way Subbasin Table 3. Summary of Puget Creek Natural Area mitigation activities. Puget Creek Natural Area Mitigation Activity Wetland Wetland Buffer Habitat Re- establishment Enhancement Enhancement Enhancement (acres) (acres) (acres) (acres) Available Mitigation Area at 0.56 3.53 2.54 1.0 Puget Creek Total Mitigation Requirement 0.14 0.56 0 0 Project I Total Mitigation Requirement 0.383 1.44 2.37 0 Project 2 Total Mitigation Requirements 0.52 2.0 2.37 0 for Projects 1 and 2 Additional Mitigation Provided 0.04 1.53 0.17 1.0 Temporary impacts on the buffers of Wetland A and Wetland S resulting from Project 2 construction activities will be provided on -site. All temporary impacts on the buffers of Wetland A and Wetland S will be mitigated on -site by replanting disturbed areas with native upland species and controlling the spread of noxious and aggressive weed species after construction activities are completed. In addition, SPU is applying for a sensitive area ordinance deviation under the City of Tukwila's Special Permission Director Permit to reduce the required buffer width for Wetland B to 50 feet. A reduction of the width of the buffer of Wetland B to 50 feet under this permit would require enhancement of the remaining 50 -foot buffer. The buffer of Wetland B would be enhanced on- site as required by the Special Permission Director Permit by planting native upland species and removing non - native and weed species. viii Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Introduction This mitigation plan was prepared by Herrera Environmental Consultants (Herrera) as a consultant to Seattle Public Utilities (SPU). This mitigation plan describes mitigation for wetland and buffer impacts resulting from two projects proposed by SPU to improve storm drainage conveyance problems and degraded water quality in the Norfolk and MLK Way subbasins. The Norfolk and MLK Way subbasins are two of the eight subbasins that make up the Norfolk drainage basin which extends from Boeing Field to Beacon Avenue South. Portions of the drainage areas served by this system are owned by the cities of Tukwila and Seattle. The Norfolk -MLK Way subbasin stormwater improvements include two functionally independent projects, constructed in different years, and funded separately. The two projects are: • Project 1 – Conveyance Improvements: replacement of a 36 -inch CMP storm drainage line, and regrading of a WSDOT ditch east of I -5 • Project 2 – Stormwater Treatment Improvements: construction of a stormwater treatment facility to treat runoff before it is discharged to the Duwamish Waterway WRIA 9. Each project will be constructed and fully operational, even if the other is not constructed. This plan describes the offsite and on -site wetland mitigation that would be provided as compensation for temporary and permanent wetland impacts stemming from the Norfolk -MLK Way subbasin stormwater improvements. This plan will assist with agency review of permit applications that require a wetland mitigation plan. The following sections describe the project location, explain the purpose of and need for the project, summarize the proposed actions and impacted wetlands, and describe proposed mitigation for project impacts on wetlands. Detailed information on the ecological condition, classifications and functions and values of the wetlands and buffers that would be adversely affected by the two Norfolk – MLK Way subbasin stormwater improvement projects are provided in the wetland delineation reports (Tetra Tech/KCM and Herrera 2007; Herrera 2007c; Herrera 2007d). Project Location The Norfolk basin drainage and water quality improvements project sites are located within Sections 3 and 10, Township 23 North, Range 4 East. The project site for Project 1 – Conveyance Improvements is located on the west side of I -5 between South 113th Street (approximately 2,000 feet south of South Boeing Access Road) and South Norfolk Street (approximately 2,000 feet north of South Boeing Access Road) in the cities of Seattle and Tukwila, King County, Washington. The project area encompasses 340 feet of the existing ditch on the east side of I -5. The project site for Project 2 – Stormwater Treatment Improvements is located on the east side of I -5 between South 113th Street (approximately 2,000 feet south of ab ro6- 03354- 100,vetland mitigation plan February 11, 2008 1 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin South Boeing Access Road) and South Norfolk Street (approximately 2,000 feet north of South Boeing Access Road) in the cities of Seattle and Tukwila, King County, Washington. Construction of Project 2 would include the restoration of temporarily disturbed wetland buffers. A vicinity map of showing the locations of the Project 1 and Project 2 sites are shown in Figure 1. Mitigation for permanent wetland and wetland buffer impacts would be provided at the Puget Creek Natural area which is outside the boundaries of the Project 1 and Project 2 sites (Figure 1). The Puget Creek Natural area is between 18th and 21st Avenues NW and between SW Brandon and SW Juneau Avenues. A wetland is located in a swale between the east and west ridges centered along the undeveloped 19th Avenue SW right -of -way. Elevation ranges between 195 feet and 200 feet above sea level for the west and east ridges respectively. The wetland trough is about 45 feet below the ridge tops. The legal description is Township 24, Range 3, Section 24, Block 14. Responsible Parties SPU is the project proponent and applicant for Project 1 — Conveyance Improvements and Project 2 — Stormwater Treatment Improvements. Herrera Environmental Consultants, Inc. prepared this plan as a consultant to SPU. The applicant's address is: Arnel Valmonte Seattle Public Utilities Seattle Municipal Tower 700 Fifth Avenue Seattle, Washington 98124 -4018 Project Descriptions SPU proposes two projects to improve the stormwater conveyance and treatment system in the Norfolk -MLK Way subbasin to reduce frequent overflow of stormwater to the sanitary sewer system, restore the conveyance capacity of the system, reduce flooding on Martin Luther King Jr. Way, and reduce pollutant loading to the lower Duwamish Waterway WRIA 9. Storm drainage conveyance problems and degraded water quality have been identified by SPU as prevalent concerns in the Norfolk -MLK Way drainage subbasin. The drainage system does not function properly due to significant pipe degradation and sediment accumulation. The two projects are: • Project 1 — Conveyance Improvements • Project 2 — Stormwater Treatment Improvements. at) /06- 03354.100 wetland mitigation plain Herrera Environmental Consultants 2 February 11, 2008 d D D O d D ISIS d D D 0 0 D Project 2 Stormwater Treatment Improvements Figure 1. Vicinity map for the Norfolk — Martin Luther King Jr. Way subbasin stormwater improvement projects sites and the Puget Creek Natural Area proposed mitigation site, Seattle and Tukwila, Washington. Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin Each project meets the U.S. Army Corps of Engineers definition of "independent utility" in that each project can be constructed and considered fully operational if the others are not constructed. Project 1— Conveyance: Improvements Purpose and Description A portion of the piped drainage system between Martin Luther King, Jr. Way S. (MLK Way) and I -5 is damaged, causing stormwater to back up into an adjacent sanitary sewer system. King County has notified SPU that it will no longer allow stormwater to be discharged to the sanitary sewer system. The proposed project involves replacing the damaged and undersized drain line (36 -inch CMP) and regrading a section of the WSDOT ditch that has become clogged with sediment to restore the hydraulic capacity of the existing system. Although privately - owned, the damaged pipe is a key component of the Norfolk -MLK Way drainage system. In addition to restoring hydraulic capacity, the project will also eliminate overflows of stormwater from the Norfolk -MLK Way drainage system to the sanitary sewer system and reduce flooding on MLK Way. The damaged line will be replaced with a 64 -inch, ductile -iron pipe to provide the necessary conveyance capacity. The new 64 -inch pipe would be 480 feet long, with an upstream invert elevation of 11.12 feet NAVD88 and a downstream invert elevation of 10.75 feet NAVD88. A small sediment trap and spill control structure will be installed at the downstream end of the new 64 -inch pipe to facilitate future maintenance of the ditch as well as to protect the WSDOT ditch from spills that may occur in the drainage basin. Low flows will be routed to the spill control structure via a 4 -foot by 6 -foot concrete flow diversion structure. Higher flows will be discharged directly to the sediment trap. The sediment trap will be constructed by excavating a 33 -foot by 5 -foot depression along the east side of the WSDOT ditch. The spill control structure will consist of a 12 -foot diameter manhole equipped with a baffle to retain oil, grease, and other floatable materials, and will discharged to the sediment trap. SPU has been conducting source control activities (e.g., business inspections and source tracing) in the Norfolk -MLK Way subbasin since 2001. Several illicit connections /discharges were discovered and have been eliminated. A spill control structure has been included in the project design as a precaution to protect the downstream WSDOT ditch, given the industrial nature of the businesses operating in the basin. The WSDOT ditch is located within Wetland D, a regulated wetland. Regrading of the ditch and construction of the sediment trap will involve work in this regulated wetland (Figure 2). Mitigation for impacts to Wetland D will include wetland re- establishment and enhancement activities at the Puget Creek Natural Area, owned by the City of Seattle Parks Department. Replacement of the existing storm drain and construction of the flow diversion and spill control structures will not involve work in waters of the U.S. This activity is being proposed under USACE Nationwide Permit 41 — Reshaping Existing Drainage Ditches. ab /0603354-100 wctlandmitigation pion February 11, 2008 5 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Project 2 – Stormwater Treatment Improvements Purpose and Description SPU proposes to construct a water quality treatment pond in the Norfolk -MLK Way Subbasin. The purpose of the project is to reduce pollutant loading to the lower Duwamish Waterway. The stormwater treatment pond will capture total suspended solids (TSS), thereby reducing total pollutant loading to the Duwamish Waterway. The proposed stormwater pond would be a 2 -cell deep wet pond (8 feet deep) in the southern portion of the City of Seattle owned property. The pond would have a dead storage volume of approximately 393,000 cubic feet (9.05 acre - feet). This pond would displace the existing WSDOT wetland constructed as mitigation to improve water quality treatment (Westland S). Norfolk -MLK Subbasin runoff would enter the new pond through the existing parallel culverts under 1 -5. In addition, runoff from a WSDOT wet pond to the north would enter the pond through an existing pipe. Outflows from the proposed pond would typically be directed to the wetland west of the pond (Wetland A) through an outflow structure and 30- inch - diameter discharge pipe. During large storm events outflow would be directed into the 60 -inch diameter WSDOT trunk storm drain line that discharges to the Duwamish Waterway at the Ryan Street outfall. A 36- inch - diameter pipe would be installed to make this high -flow connection into the trunk line. This activity is being proposed under USACE Nationwide Permit 43 – Stormwater Management Facilities. This wet pond would be designed as an on -line facility, meaning all flows from the Norfolk - MLK Way subbasin would enter the pond without an upstream bypass for larger storm events. The pond would be constructed entirely on City of Seattle owned property and would not extend into the WSDOT right -of -way. The pond would be constructed with two cells. The northern cell would be used to trap the majority of the sediment load, and therefore would be the focus of sediment removal maintenance activity. A 15 -foot wide maintenance access road would be constructed on the western pond embankment. One pair of utility poles would be moved. The proposed maintenance access road would provide access to both the utility poles and the wet pond inlet and outlet structure. The area south of the proposed pond would be used for staging during pond construction and for long -term pond sediment dewatering. The pond would be created entirely by excavation. Approximately 2,157 cubic yards would be excavated within Wetland S. Approximately 163 cubic yards of fill would be placed within Wetland S across the swale outlet to maintain a consistent elevation for the maintenance access roadway. This crossing would double as the location of an emergency pond overflow spillway. On -site excavated material would be used for this fill. The proposed excavation would result in 0.32 acres of direct impacts to Wetland S and 0.06 acres of indirect impact to Wetland S. Wetland area indirectly impacted would not be excavated or filled, but would no longer function appropriately as a result of excavation of the rest of the wetland. The base of the northern pond cell would be lined with a 6 -inch layer of crushed rock overlying a construction geotextile. Six inches of crushed rock, covered with topsoil, would be applied to the maintenance access road and the sediment management area to the south, and these areas would be seeded with grass and allowed to re- vegetate. Revegetation of the pond and sediment management area is not addressed in this mitigation plan. ab Ma-033544W wrdand maiparion plan Herrera Environmental Consultants 6 February 11, 2008 ui Figure 2. Wetlands within the Norfolk—Martin Luther King Jr. Way subbasin stormwater improvement projects sites, Seattle and Tukwila, Washington. Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin One pair of utility poles would be moved to accommodate the proposed pond and a 15 -foot wide maintenance road on the western pond embankment would be constructed to provide access to both the utility poles and the wet pond inlet cell and outlet structure. A sediment management area would be located on a parcel of land south of the treatment pond in the City of Tukwila. This area would provide a staging area for periodic maintenance activities. Annual and periodic operation and maintenance activities for the stormwater treatment pond will include the following: ■ Maintain landscaping in the pond as needed during the first 3 years following construction to ensure vegetation establishment. This activity is a part of the pond construction and not included in this mitigation plan. • Annually inspect the pond area for the following: nuisance vegetation, pests, trash, outlet structure debris accumulation, needed fencing repairs, erosion at inlet, and settlement of embankment height • Dredge the first cell of the pond when sediment exceeds 1 foot and clean inlet/outlet (assumed every 10 years) ▪ Dredge the second cell of the pond when sediment exceeds 1 foot (assumed every 25 years) ▪ Monitoring to evaluate the amount of sediment and associated pollutants that are removed. Sediment monitoring will occur annually and chemical analysis will be performed every 2 years. Monitoring is anticipated to continue for 8 to 10 years. Description of Impacted Wetlands Wetland delineations conducted in 2006 show five wetlands within the boundaries of the Norfolk -MLK Way subbasin improvement projects (Figure 2). Wetland D is located in the WSDOT ditch, east of I -5 within the Project 1 — Conveyance Improvements site. The City of Seattle uses the Washington State Wetland Rating System for Western Washington (Ecology 2004b) to rate wetland functions. Wetland D is an approximately 1.4 acre palustrine scrub -shrub wetland rated as a Category III wetland. Its most important function is stormwater quality improvement as a result of the filtration of sediment by reed canarygrass and shrubs. Wetland A, Wetland B, Wetland C, and Wetland S (WSDOT bio- filtration swale) are located within the Project 2 — Stormwater Treatment Improvement site between I -5 and the BNSF railroad tracks. Wetland A is rated by the Washington state rating system as a Category II wetland. Wetland B is a 0.97 acre wetland that was probably connected to Wetland A in the past ah /06- 03356401 wetland miagaian plan February 11, 2008 9 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin and is now separated by the stormwater pipeline. It contains three wetland classes, scrub- shrub, open-water and emergent, and is rated as a Category I wetland by the City of Tukwila. Wetland C is a small ditch wetland of 0.02 acres located north of Wetland A. This is rated as a Category III wetland. Wetland S (just east of Wetland A) is a 0.36 -acre bio- filtration swale which is also rated as a Category III wetland. Wetland delineations have been conducted for each of the wetlands within the Project 1 and Project 2 sites. Detailed information on the ecological condition, classifications and functions and values of the wetlands and buffers that would be adversely affected by the two Norfolk — MLK Way subbasin stormwater improvement projects are provided in the wetland delineation reports (Tetra Tech/KCM and Herrera 2007; Herrera 2007c; Herrera 2007d). ah /06 -03354 -100 wetland mitigation plan Herrera Environmental Consultants 10 February 11, 2008 Wetland Mitigation Plan— Norfolk -Martin Luther King Jr. Way Subbasin Regulatory Framework The proposed project is subject to a variety of federal, state, and local regulations affecting wetlands and aquatic environments. These regulations are described in this section. Federal Regulations Federal laws regulating wetlands include the National Environmental Policy Act and Sections 401 and 404 of the Clean Water Act (33 U.S. Code 1344). Section 404 of the Clean Water Act regulates all waters of the United States (including wetlands) and is administered by the U.S. Army Corps of Engineers. Construction of the Norfolk -MLK Way subbasin stormwater improvement is expected to qualify for a Section 404 Nationwide Permit. Section 401 of the Clean Water Act ensures that federally permitted projects are consistent with state water quality standards. The Section 401 water quality certification is administered by the Washington State Department of Ecology. The application for the Section 404 Nationwide Permit and the Section 401 Water Quality Certification will require preparation of a joint aquatic resource permit application (JARPA). Compliance with Section 7 of the Endangered Species Act is also required. State Regulations The primary state laws and regulations that regulate activities in wetlands and streams include the Hydraulic Code rules (Chapter 222 -110 of the Washington Administrative Code [WAC 222 - 110]), the Water Pollution Control Act, and the Shoreline Management Act (Ecology 1994). Other Washington state laws and programs designed to control the loss of wetland acreage include the State Environmental Policy Act of 1971 (SEPA). The wetland mitigation proposed exceeds state guidelines for mitigating wetland losses (Ecology 1992). The purpose of the state Water Pollution Control Act is to protect water quality for the benefit of public health and for fish and wildlife. The Water Pollution Control Act is implemented through rules established by the Department of Ecology (WAC 173 -201A) that define water quality, sedimentation management, and discharge standards. The rules also implement provisions of Section 401 of the Clean Water Act and the National Pollutant Discharge Elimination System (NPDES). An NPDES permit will be obtained for this project. Local Regulations Seattle Municipal Code, Section 25.05.908, identifies environmentally critical areas such as landslide -prone areas, riparian corridors, wetlands, and fish and wildlife conservation areas (Seattle 2007). The Directors Rule 6 -2003 issued by the City of Seattle Department of Planning ab /05-13354 -HX1 wetland mi,igmion plan February 11, 2008 11 Herrera Environmental Consultants Wetland Mitigation Plan— Norfolk - Martin Luther King Jr. Way Subbasin and Development requires wetlands to be rated according to the Washington state wetlands rating system (Ecology 2004). According to the Seattle Municipal Code, Section 25.09.160, Category I and II wetlands greater than 100 square feet in area must have a 100 -foot standard buffer zone. Category III wetlands must have 85 foot buffers (Seattle 2007). If a project requires altering or eliminating any wetland area, Section 25.09.160 of the Seattle Municipal Code provides applicable guidelines for replacing or enhancing the functions and values of the wetland. To mitigate for permanent impacts on wetlands greater than 100 square feet, the City of Seattle allows for wetland re- establishment and wetland enhancement. For Category III wetland impacts, a 2:1 wetland replacement ratio for re- establishment or 1:1 wetland replacement ratio for re- establishment along with a 4:1 ratio for enhancement is allowed. The municipal code also prescribes that any re- establishment or creation of a wetland be of a similar type, should take place before alteration of the existing wetland, and that the restored or substituted wetland shall provide comparable water - quality benefits and be of at least equal habitat and hydrologic value. Temporary impacts on wetlands are required to be restored to the original or better condition. For permanent impacts to wetland buffers, buffer enhancement or replacement is required at a 1:1 ratio. Temporary impacts on wetland buffers are required to be restored to the original or better condition. Tukwila Municipal Code, Section 18.45 protects environmentally sensitive areas such as regulated wetlands and watercourses and geologically hazardous areas and to protect these areas and their functions and values, while also allowing for reasonable use of public and private property. According to Section 18.45.080, wetlands shall be designated Type 1, Type 2 or Type 3. Type 1 wetlands require a 100 -foot buffer. ab N6-03354 -100 .,'land minpmion plan Herrera Environmental Consultants 12 February 11, 2008 Wetland Mitigation Plan— Norfolk -Martin Luther King Jr. Way Subbasin Mitigation The activities associated with the proposed Project 1 are expected to result in a total of 0.14 acres of permanent impacts on wetlands (Figure 3) and Project 2 activities are expected to result in 0.37 acres of permanent impacts on wetlands, 0.32 acres of direct impacts on Wetland S, 0.06 acres of indirect impact on Wetland S, and 0.01 acres of direct impact on Wetland A (Figure 4). This will result in a total of 0.52 acres of permanent impacts on wetlands as a result of the Norfolk -MLK Way stormwater subbasin improvements. Project 2 would also result in 2.37 acres of permanent impacts to wetland buffers. The 0.52 acres of permanent wetland impacts and the 2.37 acres of permanent buffer impacts resulting from both Project 1 and Project 2 Norfolk -MLK Way stormwater subbasin improvements would be mitigated by a wetland re- establishment, wetland enhancement and buffer enhancement project located at Puget Creek Natural Area, outside the boundaries of the project sites. The proposed offsite mitigation would restore former wetlands by excavating fill and replanting the new wetland area. It would also enhance degraded wetlands by restoring native plant communities. SPU is also applying buffer averaging to the project as prescribed in SMC 25.09.160 D Buffer Averaging and Buffer Reductions. A 40 -foot buffer for this wetland in addition to a 15 -foot setback from the Puget Creek Natural Area property boundary will be enhanced to the east of the restored wetland and 0.41 acres of buffer will be added on the northwest corner of the Puget Creek Natural Area property to compensate for the narrow buffer. Project 2 construction activities will occur within a 100 feet of Wetland B in the City of Tukwila. Wetland B is rated as a Category I wetland by the City of Tukwila. Category I wetlands have a 100 -foot standard buffer zone. SPU is applying for a sensitive area ordinance deviation under a Special Permission Director Permit to reduce the Wetland B buffer width to 50 feet. A reduction of width of the buffer of Wetland B to 50 feet under this permit would avoid all impacts to the buffer associated with the access road and sediment management area; however, the Special Permission Director Permit would require enhancement of the remaining 50 -foot buffer. As such, approximately 0.15 acres of the buffer of Wetland B will be enhanced on -site as required by the Special Permission Director Permit (Figure 5). There will also be temporary impacts on the buffers of Wetland A and Wetland S resulting from Project 2 activities. Disturbed on -site buffer areas would be restored by replanting disturbed areas with native upland species and controlling the spread of noxious and aggressive weed species after construction activities are completed (Figure 5). Impact Minimization The wetland impacts resulting from Project 1 and Project 2 are unavoidable. The Project 1 — Stormwater Conveyance Improvements must be completed to reduce pollutant loading to the Lower Duwamish Waterway, and reduce flooding on Martin Luther King Jr. Way and in the business park area. Regrading the entire 900 -foot length of Wetland D (WSDOT ditch) to the original profile would provide greater conveyance and treatment benefits. However, doing so oh /06-03354 -100 wetland mm}atian plan February 11, 2008 13 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin would result in substantially more disturbance of Wetland D. The regrading footprint was minimized to the extent possible to minimize wetland impacts while still achieving the project's purpose. Potential adverse impacts on wetlands during construction were minimized to the extent possible by means of the engineering design. The Project 2 — Stormwater Treatment Improvements must be completed to reduce pollutant loading to the Lower Duwamish Waterway. Stormwater treatment alternatives were evaluated in terms of construction cost, constructability, operation and maintenance accessibility, and ability to meet performance criteria. Three stormwater treatment options were developed: • Treatment Pond Option A: construct a shallow wet pond on City -owned property west of I -5 • Treatment Pond Option B: construct a deep wet pond on City -owned property west of I -5 • Treatment Pond Option C: construct a deep wet pond on City property and property to be acquired located to the south. The proposed Project 2 is a modified version of Treatment Pond Option B which was chosen because it reduces pollutant loading in stormwater runoff discharged to the Duwamish Waterway compared to existing conditions, and compared to Treatment Pond Option A, while not exceeding the available funding for the project. Potential adverse impacts on wetlands during construction were minimized to the extent possible by means of the engineering design. Mitigation Goals On -site wetland buffers that are affected by temporary impacts due to land clearing and other disturbances would be restored by regrading to the natural site contours, removing invasive species, and planting native plant species appropriate to the habitat types. Compensation for permanent wetland and wetland buffer impacts would be provided by restoring and enhancing wetlands and wetland buffers within the Puget Creek Natural area. Implementation of the mitigation plan would accomplish the following: • Remove invasive species and plant native species in disturbed on -site wetland buffers at the Project 2 Water Quality Treatment site • Re- establish 0.56 acres of former wetland by excavating fill to restore wetland hydrology and restoring native wetland vegetation within the Puget Creek Natural Area • Enhance 3.53 acres of wetland by removing invasive plant species and replanting with native species within the Puget Creek Natural Area • Enhance 2.54 acres of wetland buffer by removing invasive plant species and replanting with native plant species within the Puget Creek Natural Area. ah /0643354 -100 wetland miiiRalmn plan Herrera Environmental Consultants 14 February 11, 2008 Figure 3. Wetland impacts for Project 1 of the Norfolk- Martin Luther King Jr. Way subbasin stormwater improvement projects, Seattle and Tukwila, Washington ■ 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 S NORFOLK STREET ' 100' BUFFER FOR WETLAND A INDIRECT IMPACTS 9.0t BOUNDARY TREATMENT t: POND S.) \ Ti ACCESS ROAD 5 NORFOLK ST 100' BUFFE FOR WETLAND B ?WETLAND SEDIMENT MANAGEMENT AREA 1 Figure 4.Wetland and buffer impacts for Project 2 of the Norfolk - Martin Luther King Jr. Way subbasin stormwater improvement projects, Seattle and Tukwila, Washington. LEGEND: MIMIMI -- DIRECT WETLAND IMPACT BUFFER IMPACT INDIRECT WETLAND IMPACT WETLAND 100' WETLAND BUFFER TREATMENT POND BOUNDARY 'o 9, TREATMENT POND BOUNDARY -o BUFFER RESTORATION FOR WETLAND A \ \ ACCESS ROAD JETLAND 1,1:10' BUFF R FOR ETLAN B SEDIMENT MANAGEMENT \ AREA 50' BUFFER ENHANCEMENT AREA FOR WETLAND B \ • •0 Figure 5. Location of on -site mitigation for impacts of Project 2 to buffers on the Norfolk - Martin Luther King Jr. Way subbasin stormwater improvement projects, Seattle and Tukwila. 100 0 100 200 HOR. SCALE: 1' = 200' LEGEND: ON -SITE BUFFER MITIGATION :: ;-• WETLAND _m®� 100' WETLAND BUFFER TREATMENT POND BOUNDARY HERRERA CONSULTANTS. Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin • Enhance 1.0 acres of adjacent habitat by removing invasive plant species and replanting with native plant species within the Puget Creek Natural Area • Improve the following wetland functions in the Puget Creek Natural Area: ❑ Production of organic matter and its export ❑ General habitat suitability ❑ Habitat for wetland- associated mammals ❑ Habitat for wetland - associated birds • Native plant richness. Mitigation Objectives The objective of the proposed Project 2 – Water Quality Treatment Project on -site buffer enhancement is to improve the functions of the temporarily affected on -site buffers and enhance the buffer of Wetland B to the maximum extent possible. The objective of the proposed mitigation for permanent wetland and buffer impacts is to restore wetlands impacted by fill, and improve the native plant communities within the freshwater wetland and buffers within the Puget Creek Natural Area, a highly valued semi - natural habitat area. Puget Creek Natural Area contributes runoff to Puget Sound as do the Norfolk -Martin Luther King, Jr. Way subbasin stormwater improvements project sites. On -site Mitigation — Norfolk Stormwater Treatment Improvements Site Site Description On -site mitigation will be located on the west side of I -5 between South 113th Street (approximately 2,000 feet south of South Boeing Access Road) and South Norfolk Street (approximately 2,000 feet north of South Boeing Access Road) in the cities of Seattle and Tukwila, King County, Washington. The site has three wetlands located on it, including a wetland created by WSDOT for wetland mitigation (Figure 2). The site has rolling topography and is generally highly disturbed. Mitigation Site Ownership Seattle Public Utilities Seattle Municipal Tower 700 5th Avenue Seattle, Washington 98124 -4018 an /On -03354 -100 wetland mitigation plan February 11, 2008 21 Herrera Environmental Consultants \' allo \`‘ Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin Site Restoration Plan Following construction of the proposed Project 2 — Stormwater Treatment Improvements, all temporarily disturbed areas of the buffers of Wetland A and Wetland S will be seeded with native grasses (Figure 5). In addition, a 50 -foot wide portion of the buffer adjacent to Wetland B will be enhanced to include native tree and shrub plantings and native grasses (Figure 5). General Planting Specifications All temporarily disturbed areas of the buffers of Wetland A and Wetland S (approximately 0.65 acres) will be restored by seeding the areas with native grasses. Approximately 0.15 acres of the buffer of Wetland B will be enhanced by planting native trees and shrubs within 50 feet of the wetlands. Planting containerized trees and shrubs grown in deep pots (minimum of 10 inches) will reduce the shock of planting and provide for the best adaptation to localized soil and moisture conditions. Containerized plants will be installed between November and February, while dormant, to reduce stress on the plants and encourage the best possible survival. Trees will be planted with an average spacing of 10 feet on center to provide a final density of 400 trees per acre. Shrub species will be planted in natural- appearing clusters of three to seven plants. Placement of the plants within the clusters will vary between 3 feet on center and 6 feet on center. Shrubs will be planted at 1,000 shrubs per acre. Each tree and shrub will have a fertilizer pack placed in the bottom of the planting hole prior to backfilling. Fertilizers will be slow release products that will not result in nutrient runoff into aquatic systems. Mulch (3 inches deep) will be placed in an 18- inch - diameter ring around each plant to prevent invasive species or native grasses from out - competing the plant and to help maintain soil moisture. Seeding of grasses will be conducted in disturbed areas or where enhancement is needed. Seed may be applied by broadcasting and raking or with a hydroseeder then hydro - mulching over the seeded areas. Tackifier can be detrimental to aquatic organisms and will be excluded from the seed application process. Two seed mixes will be provided for the buffer areas; an upland buffer mix and a transitional mix. Regreen (a sterile wheatgrass cover crop) will be used in both mixes to provide cover and prevent erosion during the first year. In successive years, it will die out, allowing the native species to finish colonizing the site. Construction documents have been prepared to communicate the requirements of the site restoration plan to the contractor installing the on -site buffer restoration. The construction document for on -site mitigation is available on Sheet 13 of Appendix A and graphically communicates the design specifications and special provisions to construct the plan. Zone 1— Upland Shrub Buffer Enhancement Area Approximately 0.15 acres of on -site upland shrub buffer enhancement will occur on the Project 2 site. Upland shrub buffer enhancement in the buffer of Wetland B will occur as required by the City of Tukwila Special Permission Director Permit. The buffer of Wetland B is generally dry throughout most of the year. Tree and shrub species to be planted and planting densities in the upland shrub zone are listed in Table 4. The seed mix and application rates identified for use in the upland shrub zone are listed in Table 5. No tree species will be planted within 20 feet of the overhead power lines located at the site. ab /06-03354.100 wcilonammRmion plan Herrera Environmental Consultants 22 February 11, 2008 Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Table 4. Zone 1 tree and shrub plantings for on -site upland shrub buffer restoration. Species Density per Acre Total Plants Needed Pseudotsuga menziesii 200 28 Populus balsamifera ssp. trichocarpa 200 28 Acer circinatum 100 15 Amelanchier alnifolia 100 15 Crataegus douglasii 100 15 Rosa gymnocarpa 300 45 Sambucus racemosa var. arborsecens 100 15 Symphoricarpos albus 300 45 Table 5. Zone 1 grass seed mix and application rate for on -site upland shrub buffer restoration. Percent of Mix PLS e Total PLS a for Site Species ( %) (lbs. /acre) (lbs.) Elymus glaucus (blue wild rye) 33 14.2 2.1 Bromus sitchensis (Alaska brome) 32 29.6 4.4 Festuca rubra (creeping red fescue) 32 3.8 0.8 Triticum aestivum (Regreen hybrid) 3 16.2 2.4 PLS = Pure Live Seed Note: Assuming approximately 0.15 acres of disturbance. Zone 2 – Shrub Transitional Buffer Restoration Area Approximately 0.65 acres of transitional buffer restoration will occur on the Project 2 site. This area includes the temporarily disturbed portions of the buffers of Wetland A and Wetland S. This area is very moist to saturated most of the winter and some areas are dry to moist during summer. The seed mix and application rates identified for use in the transitional buffer zone are listed in Table 6. Table 6. Zone 2 grass seed mix and application rate for on -site transitional buffer restoration. Percent of Mix PLS a Total PLS Species ( %) (lbs /acre) for Site (lbs) Camagrostis canadensis (blue joint) 33 0.6 0.4 Deschampisa cespitosa (tufted hairgrass) 32 10.4 6.3 Glyceria elata (fowl mannagrass) 32 0.8 0.5 Triticum aestivum ( Regreen hybrid) 3 16.2 9.9 PLS = Pure Live Seed Note: Assuming approximately 0.65 acres of disturbance. aA /Oh -03354 -)O1) wetland mitigation plan February 11, 2008 23 Herrera Environmental Consultants Wetland Mitigation Plan— Norfolk- Martin Luther King Jr. Way Subbasin Site Preparation Site preparation for the new plantings will include soil testing to determine whether the nutrient content of the soil is adequate for native plantings. If amendments are needed they will be organic, slow release type that will not contribute to nutrient run -off to aquatic systems. Invasive weeds on the mitigation site will be eradicated using a combination of mechanical removal and treatment with a nonresidual herbicide. Only those herbicides approved by the Department of Ecology for use in aquatic areas will be used for site preparation. All herbicides will be applied as authorized by law and at the application rates and conditions specified by the manufacturer of the product. A licensed herbicide applicator will apply all herbicides. Site Protection Adequate site protection is essential for the success of restoration and enhancement activities. Steps will be taken to protect the existing soil structure and biota, the seed bank, and the areas of native vegetation to be retained. During construction, these steps will include the installation of protective fencing around the vegetation to remain and the preparation of an access plan that limits the routes to be used by construction equipment. It may be necessary to protect new plantings from herbivores during the early part of the plant establishment period. Predatory herbivores that likely inhabit the area include voles (Microtus spp.), mountain beavers (Aplodontia rufa), and Canada geese (Branta canadensis). Should there be significant predation, strategies that will be used to protect plants may include mesh goose - exclusion fencing or plastic protection tubes around individual plants. Maintenance SPU or its contractor will be responsible for maintaining the mitigation site for 1 year after the buffer enhancement is completed. After that time, SPU will assume complete responsibility for maintenance of the site. Maintenance activities will include weeding, watering, replacing dead or distressed plants, repairing damage due to herbivores or vandals, and removing trash. All nonnative materials or materials that are not biodegradable, such as protective fencing, will be removed from the site at the end of the 1 year maintenance period or when no longer needed. Monitoring Plan Monitoring will be conducted by SPU or its contractor during years 1, 2, 3, and 5 after buffer enhancement to confirm that the site restoration performance standards, as defined below, are being met by the enhanced buffer areas. Vegetation success will be monitored and photo points will be established to visually document the observed conditions. Incidental observations of wildlife will be made during each monitoring visit. These data will be documented by SPU in annual monitoring reports and presented to the City of Seattle for each year of monitoring. ah /P1-03354-100 wetland miriganon plan Herrera Environmental Consultants 24 February 11, 2008 W\cYia 1,v\o\vokt■E 5 7 wc2 J ;Ls — \ct \tfickd c t vo@v) Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin If the monitoring results indicate that the buffers are not meeting the goals and objectives as defined in the site enhancement performance standards, then contingency measures will be implemented by SPU. Contingency measures that may be necessary include removing invasive species, increasing the frequency of watering, adjusting planting mixes to reflect hydrological changes, replanting as needed to meet the performance standards, and installing or removing protective fencing. Site Restoration Performance Standards The following performance standards will be used to measure the success of the enhancement during monitoring visits and to identify and guide any adaptive management measures that may be required to address problem situations. Performance Standard 1 During the first -year monitoring event, no more than 2 percent of the woody plant materials planted in the wetland buffer plant communities will have died or become stressed to the point that the survival of the plant is in question. Performance Standard 2 During the first -year monitoring event, no area of bare soils measuring more than 2 feet by 2 feet will be visible. Stem densities in these areas, including those of herbaceous plants, will exceed 10 stems per square foot. Areas of mulch surrounding planted native species will not be considered areas of bare soil. Performance Standard 3 During the first -, second -, third -, and fifth -year monitoring events, no more than 20 percent of the total plant coverage in the buffer plant communities will consist of invasive species. Invasive species may include, but are not limited to, Scot's broom, reed canarygrass, nonnative blackberry, holly, birdsfoot trefoil, cherry laurel, and English ivy. No percent coverage of Japanese knotweed will be allowed on the site. Performance Standard 4 During the second -, third -, and fifth -year monitoring events, the wetland buffer plant communities will achieve a density of 15 percent coverage by the second year, 40 to 50 percent coverage by the third year, and 60 to 80 percent coverage by the fifth year. Native volunteer species may contribute up to 20 percent of the contribution. Performance Standard 5 During the fifth -year monitoring event, habitat for birds and small mammals will be mature enough to support these species. The presence of these animals or indications of their presence will be documented through incidental observations of wildlife or indicators such as nests or scat. a6 /06- 03354400 wetland mitigation plon February 11, 2008 25 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Offsite Mitigation — Puget Creek Natural Area All permanent wetland impacts and permanent impacts to the buffers of Wetland A and Wetland S will be mitigated by re- establishing 0.56 acres of wetlands, enhancing 3.53 acres of wetlands, enhancing 2.54 acres of wetland buffer, and enhancing 1.0 acres of adjacent habitat located in the Puget Creek Natural Area. Activities covered in the mitigation plan include excavation and removal of fill on former wetlands and re- establishment of wetland vegetation on that site, invasive species removal, revegetation of disturbed areas with native plant species, supplemental planting to increase conifer tree densities, garbage removal, monitoring, and adaptive management. These activities will occur annually over 3 years. Site Description The Puget Creek Natural Area is located between 18th and 21st Avenues NW and between SW Brandon and SW Juneau avenues. The area is a wooded trough between 18th and 21st Avenues with Puget Creek running north through the center of the natural area along the undeveloped 19th Avenue right -of -way. The Puget Creek Natural Area is a large contiguous property that is a series of undeveloped rights -of -way and undeveloped residential parcels owned by City of Seattle Parks and Recreation (Figure 6). The property is comprised of 7.85 acres, within which is a forested wetland (approximately 3.6 acres in size). After leaving the site, Puget Creek flows through the West Duwamish Greenbelt and drains into the Duwamish River across from Kellogg Island. A wetland delineation completed by SPU's Environment, Science and Technology Section (SPU 2007), describes in detail the wetland locations and conditions within the property. The canopy is comprised primarily of native deciduous species, black cottonwood (Populus trichocarpa), and red alder (Alnus rubra) with Douglas fir (Psuedotsuga menziesii) in the uplands and several western red cedar groves (Thuja plicata) in the transition areas. The understory is a mixture of intact native vegetation communities and patches of invasive species, particularly along the adjacent roadways and private properties. According to Seattle Parks and Recreation, the wetland area dries up in the summer, and the upland edges are infested with noxious weed species and blackberry. Several areas on the property provide habitat enhancement opportunities (Bonoff 2007). Mitigation Site Ownership Land within Puget Creek Natural Area is owned by the City of Seattle and managed by Seattle Parks and Recreation: Seattle Parks and Recreation 100 Dexter Avenue N. Seattle, WA 98109 aA /0643354 -100 wetland mitigation plan Herrera Environmental Consultants 26 February 11, 2008 21ST AVE SW IVI .1%•-•• LEGEND: BUFFER REDUCED BUFFER AVERAGED AVERAGED BUFFER ADDED .10-w-1■74wpwir 4q:AFN■p....0.-.0.400 4h-q-Nown-tw- + + ÷ + + + + + . 0 4q,. 04 % qp 4 p■ ■%%0100 pew-or-PP+ + 0 40, 0 AW 44- — • 4%0%0% 0 4 • 4 40. 0 • 40 0 40 40 4 40 AiP 4 40 • 0 -.4i■• 4 0 -- 4W 0 %0 %10,- %0 40 & t40 W!4 0 40 • 4,10 11. • 4'0"'" 40 410 4IP-''41 • 1 I• ■ -4i■ 40 4 0 O'.,.%i■ 'O■ Alro -0V 4" 1 4■Ik - ig ■ A dt 0 40 • .,..--=---,-::.1t,':-1:-Fik O• 4%.-40„ 0 '..:14,'-<- 1.11,111 4hb.- 44■40.-- • 40 # —0 :---A0::141 Aki--4;*-- ■--- 11114.4V 11"` ■ ' Ili.' l■ • ' - 4 Ii-0.1■41tw_4 iHABITAT ENHANCEMENT 43,438 SQ. FT. 1.00 ACRE 50 0 50 100 SCALE IN FEET N + + + + + + + + + + + + + + + + + + + + + + + + BUFFER ENHANCEMENT 96,817 SQ. FT. 2.22 ACRES -0 0-0 0-0 G77-01-7-TZL-C-C19 ZONE 1 WETLAND RE-ESTABLISHMENT AREA ZONE 2 WETLAND ENHANCEMENT AREA ZONE 3 BUFFER ENHANCMENT AREA ZONE 4 HABITAT ENHANCEMENT AREA WETLAND BUFFER BOUNDARY PROPERTY LINE BOUNDARY CREEK AVERAGED BUFFER ADDED 11,787 SQ. FT. 0.27 ACRES Q0000_Lt0000SF WETLAND RE-ESTABLISHMENT AREA 22901.6 SQ. FT. .56 ACRES PUGET CREEK BUFFER ENHANCEMENT 1818 SQ. FT. 0.04 ACRE ENHANCEMEN ANcEmEN 0 665 SQ. FT. 0.01 ACRE 15' PROPERTY LINE SETBACK 40' BUFFER BOUNDARY 181}1 AVE SW BUFFER AVERAGED (45 FT. WIDE) 11,787 SQ. FT. 0.27 ACRES EXISTING 85' BUFFER BOUNDARY 40' BUFFER BOUNDARY 15' PROPERTY SETBACK HERRERA CONSULTANTS Figure 6. Puget Creek Natural Area Wetland Mitigation Strategy, Seattle, Washington. Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Rationale for Selection of Mitigation Site Several options for offsite wetland mitigation were identified for the two projects included in the Norfolk -MLK Way subbasin stormwater improvements from which the Puget Creek Natural Area was selected as the best option for mitigation. During the site selection process several requirements were identified for a site to be considered. Site requirements included the following: an in -city location, a location within the Green Duwamish WRIA 9 basin, conditions conducive to providing wetland functions and hydrology, and availability for mitigation. Puget Creek Natural Area satisfied all of these requirements. In addition, the site was large enough to satisfy all portions of the mitigation requirements without requiring additional property acquisition, and maintenance of the site could be provided by entities already involved. Puget Creek Natural Area has the potential to provide an urban wildlife preserve but is currently limited in this capacity by the loss of wetlands from illegal filling and encroachment of nonnative invasive plant communities that provide little high - quality wildlife habitat or sources of food for native birds and mammals. The aggressive growth of invasive species in specific locations within the area has reduced the diversity of native wetland and upland plants and diminished sediment removal capacity by shading out ground covers and native herbaceous species that would ordinarily provide this function. The extent of invasive coverage is threatening the survival of existing trees and is limiting the regeneration of replacement trees within the mostly forested area. The existing forest consists primarily of deciduous species whereas the historic forest canopy was dominated by conifers. The proposed wetland re- establishment and enhancements would enlarge the total acreage of wetlands, increase the structural diversity of habitat within the Puget Creek Natural Area and benefit small mammals, amphibians, and birds. Increased plant diversity would provide more species and reduce the area of bare ground, which in turn is expected to improve organic export. An increase in conifer density would begin the process of restoring the historic make up of the existing forest. The proposed wetland re- establishment and enhancements would significantly advance the City of Seattle's plan to preserve the ecological integrity of Puget Creek Natural Area for future generations. Enhancement potential at the Puget Creek Natural Area is high due to an intact native vegetation canopy. Western red cedar enhancement potential is high due to an intact deciduous native vegetation canopy providing shade. The site's potential is enhanced by its location within a very large and relatively undisturbed greenbelt. Other portions of the greenbelt and Puget Creek have already been funded for enhancement and improvements by the City of Seattle. Enhancing this wetland site would contribute to that ongoing effort. Enhancement and mitigation of the Puget Creek Natural Area would be beneficial ecologically and socially for the neighborhood and the city and was selected for these reasons. Site Constraints The Puget Creek Natural Area has some steep slopes, a large amount of recent windfall, and many areas are choked with hazardous noxious weeds. These situations will require ah /06-03354 -100 wetland mingaaan plan February 11, 2008 29 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin professionally trained workers to safely navigate them. Volunteer labor should not be used for invasive species removal in many areas of the ravine. Ecological Assessment of Proposed Mitigation Site Wetland vegetation in the Puget Creek Natural Area is characterized by an overstory of black cottonwood and red alder with some red cedar. Himalayan blackberry (Rubus discolor) and hardhack spirea (Spirea douglasii) dominate the shrub layer with some willow (Salix spp), red -osier dogwood (Cornus stolonifera) and salmonberry (Rubus spectabilis) present. In the herbaceous layer, reed canarygrass (Pharalus arindinacea), common cattail (Typha latifolia), watercress (Rorippa nasturtium - aquaticum), creeping buttercup (Ranunculus repens), slough sedge (Carex obnupta), and lady -fern (Athyrium ftlix femina) are found. The upland vegetation is dominated by cottonwood, bigleaf maple (Acer macrophyllum), red cedar (Thuja plicata), Douglas fir, and Pacific madrone (Arbutus menziesii) in the overstory. Blackberry dominates the shrub layer; however, there is occasional Indian plum (Oemelaria cerasiformis) present. The herbaceous layer contains swordfern (Polystichum munitum), tall fescue (Festuca arundinacea), and orchardgrass (Dactylis glomerata). The Puget Creek Natural Area is a Conifer - Deciduous Mixed Forest containing predominately a 5- to 15 -inch diameter class with Himalayan blackberry covering 25 to 49 percent of the site, and bindweed covering greater than 5 percent of the site (Seattle Urban Nature Project 2000). Other weed species present include English holly (Ilex aquifolium), Japanese knot weed (Polygonum cuspidatum), Scot's broom (Cytisus scoparius), English laurel (Prunus laurocerasus), and some non - native Prunus, Crataegus, and Solanum species. The Seattle Parks Department (1995) has identified band - tailed pigeons and pileated woodpeckers in the park which triggers a Washington State "Priority Area" 1 or 2 habitat designation. The following song birds were identified on the reconnaissance group trip on November 30, 2006: black capped chickadee, song sparrow, Bewick's wren and bushtit SPU 2007). Beaver have also been observed at the site. The wetland within the Puget Creek Natural Area ranks as a Category III under the Washington State Rating System. The hydrogeomorphic class assigned to the wetland is depressional based on the wetland being ponded or saturated to the surface at some time of year. The wetland area within the Puget Creek Natural Area provides moderate hydrologic and water quality functions. The wetland also has high potential to provide habitat because it has a varied vegetative structure, a visible hydroperiod, high plant richness, and habitat features with moderate interspersion. However, despite the wetland at the Puget Creek Natural Area having a wide buffer for more than half its circumference and containing two priority habitats, it has limited connectivity to open space and limited proximity to other wetlands. Wetland Re- establishment and Wetland and Upland Enhancement Plan Wetland re- establishment and wetland and upland enhancement within the Puget Creek Natural Area would promote and enhance the ecological integrity of 3.53 acres of wetlands, enhance the 4-A /06- 03354-100 wetland minga;nn plan Herrera Environmental Consultants 30 February 11, 2008 Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin 85 -foot buffers of these wetlands, and improve wildlife habitat in the adjacent uplands. Site re- establishment and enhancement activities include the excavation and removal of fill in a former wetland area and re- establishment of wetland vegetation, invasive species removal, revegetation of disturbed areas with native plant species, supplemental planting to increase conifer tree densities and fill gaps in the canopy, garbage removal, monitoring, and adaptive management as needed. Excavating fill from former wetlands and re- establishing the wetland vegetation will provide mitigation for the 0.52 acres of permanent wetland loss as a result of the Norfolk -MLK Way subbasin stormwater improvements projects. The amount of fill to be excavated is approximately 5,572 cubic yards. The proposed mitigation meets the Washington State Department of Ecology guidelines of providing either 2:1 wetland re- establishment or 1:1 wetland re- establishment plus 4:1 enhancement in Category III wetlands (Ecology 2004). Re- established and enhanced wetland areas within Puget Creek Natural Area would also have enhanced buffers at least 85 feet wide for the majority of the wetland as required by the City of Seattle (SMC 25.09.160) for Category III wetlands. The exception to this is the area of wetland re- established by the removal of fill. The removal of fill will adjust the 85 -foot wetland buffer to the east onto the developed properties adjacent to the Puget Creek Natural Area. The extension of the buffer onto the private property would require that property owners apply for an exception to the CAO if they ever applied for a DPD permit. To alleviate this burden, SPU is applying buffer averaging to the project as prescribed in SMC 25.09.160 D Buffer Averaging and Buffer Reductions. A 40 -foot buffer for this wetland in addition to a 15 -foot setback from the Puget Creek Natural Area property boundary will be enhanced to the east of the restored wetland and 0.41 acres of buffer will be added on the northwest comer of the Puget Creek Natural Area property to compensate for the narrow buffer. Figure 6 graphically displays how the buffer averaging will occur. To apply buffer averaging the project must meet the following requirements. • It will not reduce the wetlands functions or values. The project will not reduce the function or value of the wetland at Puget Creek Natural Area. The focus of this project is to increase wetlands functions or values by re- establishment of 0.56 acres of wetland and enhance 3.53 acres of wetland and 2.54 acres of buffers. In addition, as currently configured, the development to the east of the Puget Creek Natural Area is within the 85 -foot buffer. • The total area contained in the buffer area after averaging is no less than that which would be contained within the buffer required in subsection C of 125.09.160. Section C of 125.09.160 requires that a Category III wetland receive an 85 -foot buffer. After re- establishment of the wetland and enhancement of the buffer, the buffer will contain the same area that the standard buffer configuration. ab N6.o33.50 -100 wetland mitigation plan February 11, 2008 31 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin • The buffer width is not reduced to less than 40 feet for all Category III wetlands that do not have a high level of function for habitat. The wetland, after re- establishment, will continue to be a Category III wetland and the project will maintain a 40 -foot buffer on the east side of the wetland per 25.09.160. Mitigation at the Puget Creek Natural Area is divided into four zones based on the type of activity that will occur in each area: Zone 1 — Wetland Re- establishment Area, Zone 2 — Wetland Enhancement Area, Zone 3 — Wetland Buffer Enhancement Area, and Zone 4 — Adjacent Habitat Enhancement Area (Figure 6). The construction documents for the Puget Creek Natural Area are available in Appendix A on sheets 2 through 12 and graphically communicate the design specifications and special provisions to construct the on -site mitigation plan. Zone 1— Wetland Re- establishment Area On the northeast corner of the Puget Creek Natural Area property there are two areas of historic wetland that have been filled, thus eliminating wetland hydrology and vegetation. Wetland re- establishment will consist of excavating these two areas, to restore original wetland grades and improve hydrology, and subsequently replanting with native wetland plants. Wetland re- establishment will result in 0.56 acres of restored wetlands. As only 0.52 acres of wetland re- establishment are required as mitigation for project impacts, a surplus of 0.04 acres of wetland re- establishment will occur at the Puget Creek Natural Area under this mitigation plan. Zone 2 — Wetland Enhancement Area Wetland enhancement will occur on approximately 3.53 acres of the Puget Creek Natural Area. Weeds and exotic vegetation will be removed from the wetland and the area will be planted with native trees and shrubs. In addition, there are several remnant western red cedar groves with scattered cedar regeneration on nurse logs and hummocks throughout the existing wetland at the Puget Creek Natural Area. Wetland enhancement will occur in these areas by utilizing natural hummocks and constructing 2 foot by 6 foot raised planting areas, using cottonwood downfall, to plant additional cedars. The planting beds would be constructed in the dry season and cedar trees would planted during the approved planting window. A sewer easement on the south east side of the property where trees and shrubs have been removed will also be planted with native wetland shrubs as part of the wetland enhancement. The margin of the clearing will also be planted with trees to within 15 feet of the centerline of the sewer easement. The described wetland enhancement will result in a total of 3.53 acres of enhanced wetlands at the Puget Creek Natural Area. As only 2.0 acres of wetland enhancement are required as mitigation for project impacts, a surplus of 1.53 acres of wetland enhancement will occur at the Puget Creek Natural Area under this mitigation plan. ah /01103334 -100 wiland miaRmion Man Herrera Environmental Consultants 32 February 11, 2008 Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Zone 3 — Wetland Buffer Enhancement Area Wetland buffer enhancement will occur on approximately 2.54 acres of the Puget Creek Natural Area. Noxious weeds and exotic vegetation will be removed from the wetland buffer and the area will be planted with native trees and shrubs. In addition, several discrete buffer areas on the property will be enhanced. There is an existing cherry laurel hedge along an old fence on the west side of the property. This hedge is approximately 100 feet long with cherry laurel about 20 feet in height. The fence and cherry laurel will be removed and the area will be replanted with native vegetation. The cherry laurel may be composted on -site if conditions warrant. Other identified laurel patches will be treated in a similar manner. Noxious weeds will be removed and the area will be planted with Douglas fir, western hemlock, and native shrubs. Buffer enhancement will also be performed along the western portion of the property by removing exotic vegetation and planting native shrubs and Douglas fir and as part of the wetland re- establishment described above. The described wetland buffer enhancement activities will result in of 2.54 acres of wetland buffer enhancement at the Puget Creek Natural Area. As only 2.37 acres of wetland buffer enhancement are required as mitigation for project impacts, a surplus of 0.17 acres of buffer enhancement will occur at the Puget Creek Natural Area under this mitigation plan. Zone 4 — Adjacent Habitat Enhancement Area In addition to the wetland and wetland buffer enhancement, adjacent habitat enhancement will occur on approximately 1.0 acre of the Puget Creek Natural Area. Exotic vegetation will be removed and native shrubs and trees will be planted. Removal of weeds and exotic vegetation in the adjacent habitat area will protect the integrity of the wetland and wetland buffer and other improvements made as part of this project. This habitat enhancement is not required mitigation for project impacts. General Planting Specifications Trees will be planted among existing conifers to achieve an average conifer spacing of 10 feet on center to provide a final density of 400 conifers per acre. Shrub planting will be conducted to achieve a density of 1,000 shrubs per acre. Shrub species will be planted in natural- appearing clusters of three to seven plants. Placement of shrubs within the clusters will vary between 3 feet on center and 6 feet on center. These clusters will be placed in existing openings and areas disturbed by excavation and weed control activities. Each tree and shrub will have a fertilizer pack placed in the bottom of the planting hole prior to backfilling. Fertilizers will be slow release products that will not result in nutrient runoff into aquatic systems. Mulch (3 inches deep) will be placed in an 18 -inch diameter ring around each plant to prevent invasive species or native grasses from out - competing the plant and to help maintain soil moisture. Planting plan sheets for the Puget Creek Natural Area are included in Appendix A. Herbaceous and emergent species will be planted in natural appearing groups in the re- established wetlands. These species will be spaced at 18 inches on center in areas of suitable hydrology. Plants will be container grown and from seed sources from west of the Cascades and from a similar elevation. ah X06- 03354 -100 wetland mMRanon plan February 11, 2008 33 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Seeding of grasses will be conducted in disturbed areas or where enhancement is needed. Seed may be applied by broadcasting and raking or with a hydroseeder then hydro - mulching over the seeded areas. Tackifier can be detrimental to aquatic organisms and will be excluded from the seed application process. Separate seed mixes for each zone are identified. Regreen (a sterile wheatgrass cover crop) will be used in the seed mix for Zone 1 – Wetland Re- establishment Area to provide cover and prevent erosion during the first year. In successive years, it will die out, allowing the native species to finish colonizing the site. Zone 1– Wetland Re- establishment Area Re- establishment will consist of excavating these two areas to restore original wetland hydrology then replanting native wetland plants and seeding of disturbed areas. Tree and shrub species to be planted and planting density in the wetland re- establishment area are listed in Table 7. The seed mix and application rates for grasses in the wetland re- establishment area are listed in Table 8. Table 7. Zone 1 tree, shrub and herbaceous plantings in the Puget Creek Natural Area wetland re- establishment area. Species Density per Acre Total Plants Needed Thuja plicata (western red cedar) 100 56 Tsuga heterophylla (western 200 112 hemlock) Rosa gymnocarpa (bald hip rose) 200 112 Cornus sericea (red osier dogwood) 200 112 Rubus parvorus (thimble berry) 200 112 Salix sitchensis (Sitka willow) 200 112 Sorbus sitchensis (Sitka mountain 200 112 ash) Carex obnupta (slough sedge) 400 224 Athyrium filix femina (lady fern) 100 56 Polystichum munitum ( sword fern) 100 56 Table 8. Zone 1 grass seed mix and application rate in the Puget Creek Natural Area wetland re- establishment area. Species Percent of Mix ( %) PLS a Total PLS a for Site (lbs /acre) (lbs) Camagrostis canadensis (blue joint) 33 0.6 0.3 Deschampisa cespitosa (tufted 32 10.4 5.8 hairgrass) Glyceria elata (fowl mannagrass) 32 0.8 0.4 Triticum aestivum (Regreen hybrid) 3 16.2 9.0 PLS = Pure Live Seed Note: Assuming approximately 0.8 acres of disturbance. oh /06-03354-100 wetland mingaion plan Herrera Environmental Consultants 34 February 11, 2008 Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin Zone 2 — Wetland Enhancement Area Enhancement of this area will include both weed removal and native plant establishment. In areas disturbed by weed removal, shrubs will be planted and a grass mix will be applied. Because existing native vegetation is dense over much of the area and plantings will be concentrated in disturbed areas, planting densities will be much lower than in Zone 1 — Wetland Re- establishment Area. Tree and shrub species to be planted and planting densities in the wetland enhancement area are listed in Table 9. The grass seed mix and application rates for use in the wetland enhancement area are listed in Table 10. Table 9. Zone 2 tree and shrub plantings in the Puget Creek Natural Area wetland enhancement area. Species Density per Acre Total Plants Needed Thuja plicata (western red cedar) 25 88 Cornus sericea (red osier dogwood) 100 352 Spiraea douglasii (hard hack) 50 176 Rubus parviflorus (thimble berry) 50 176 Salix sitchensis (Sitka willow) 100 352 Sorbus sitchensis (Sitka mountain ash) 50 176 Athyrium filix femina (lady fern) 25 88 Polystichum munitum (sword fern) 25 88 Table 10. Zone 2 grass seed mix and application rate in the Puget Creek Natural Area wetland enhancement area. Species Percent of Mix PLS ° Total PLS a for Site ( %) (lbs /acre) (lbs) Camagrostis canadensis (blue joint) 33 0.6 0.5 Deschampisa cespitosa (tufted hairgrass) 33 10.4 8.3 Glviceria elata (fowl mannagrass) 34 0.8 0.6 a PLS = Pure Live Seed Note: Assuming approximately 0.8 acres of disturbance. Zone 3 — Wetland Buffer Enhancement Area Buffer enhancement will be performed by removing exotic vegetation and noxious weeds and planting native shrubs and Douglas fir. Because existing native vegetation is dense over much of the area, shrub plantings will be concentrated in areas of weed removal. To restore a more historic conifer component to the site, Douglas fir seedlings will be planted throughout the buffer enhancement area at an approximate spacing of 15 feet. An upland grass mix will be applied by hand broadcasting all disturbed sites following planting. Tree and shrub species to be planted and planting densities in the wetland buffer enhancement area are listed in Table 11. The grass seed mix and application rates for use in the wetland buffer enhancement area are listed in Table 12. aA /06 -03354 -100 wetland mitigation plan February 11, 2008 35 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin Table 11. Zone 3 tree and shrub plantings in the Puget Creek Natural Area wetland buffer enhancement area. Species Density per Acre Total Plants Needed Pseudotsuga menziesii (Douglas fir) 100 254 Tsuga heterophylla (western hemlock) 100 254 Acer macrophyllum (big leaf maple) 25 64 Berberis nervosa (dull Oregon grape) 75 190 Holodiscus discolor (ocean spray) 50 127 Sambucus racemosa (red elderberry) 50 127 Amelanchier alnifolia (service berry) 50 127 Acer circinatum (vine maple) 50 127 Table 12. Zone 3 grass seed mix and application rate in the Puget Creek Natural Area wetland buffer enhancement area. Percent of Mix PLS a Total PLS a for Site Species ( %) (lbs /acre) (lbs) Elymus glaucus (blue wild rye) 33 14.2 8.5 Bromus sitchensis (Alaska brome) 33 29.6 17.8 Festuca rubra (creeping red fescue) 34 3.8 2.3 PLS = Pure Live Seed Note: Assuming approximately 0.6 acres of disturbance. Zone 4 – Adjacent Habitat Enhancement Area Noxious weeds and exotic vegetation will be removed and native shrubs and trees will be planted within the habitat areas adjacent to the wetland and buffer boundaries at the Puget Creek Natural Area. To restore a more historic conifer component to the site, Douglas fir seedlings will be planted throughout the buffer enhancement area at an approximate spacing of 15 feet. Native shrubs will be planted and an upland grass mix will be applied by hand broadcasting all sites disturbed by weed removal. Tree and shrub species to be planted and planting densities in the adjacent habitat enhancement area are listed in Table 13. The seed mix and application rates for use in the adjacent habitat enhancement area are listed in Table 14. Table 13. Zone 4 tree and shrub plantings in the Puget Creek Natural Area habitat enhancement area. Species Density per Acre Total Plants Needed Pseudotsuga menziesii (Douglas fir) 100 100 Tsuga heterophylla (western hemlock) 100 100 Holodiscus discolor (ocean spray) 50 50 Sambucus racemosa (red elderberry) 50 50 Amelanchier alnifolia (service berry) 50 50 Acer circinatum (vine maple) 50 50 al, /06-03334400 wetland muepa0mr plan Herrera Environmental Consultants 36 February 11, 2008 Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Table 14. Zone 4 grass seed mix and application rate in the Puget Creek Natural Area habitat enhancement area. Percent of Mix PLS a Total PLS a for Site Species ( %) (lbs /acre) (lbs) Elymus glaucus (blue wild rye) 33 14.2 4.3 Bromus sitchensis (Alaska brome) 33 29.6 8.9 Festuca rubra (creeping red fescue) 34 3.8 1.2 PLS = Pure Live Seed Note: Assumes approximately 0.3 acres of disturbance. Site Protection It may be necessary to protect new plantings from herbivores during the early part of the plant establishment period. Predatory herbivores that use the ravine include voles (Microtus spp.) and mountain beavers (Aplodontia rufa). Should there be significant predation, strategies for protecting plants could include, using repellants, installing exclusion fencing, or inserting plastic protection tubes around individual plants. Maintenance SPU or its contractor will be required to maintain the mitigation site for 5 years after the Puget Creek Natural Area mitigation site plan is completed. After that time, Seattle Parks and Recreation, will assume responsibility for maintenance of the site. Maintenance activities during the first 5 years will include weeding, replacing dead or distressed plants, repairing damage due to herbivores or vandals, and removing trash. All remaining nonnative or non - biodegradable materials, such as protective fencing, will be removed from the site at the end of the maintenance period or when no longer needed. Worker pathways not needed for site maintenance will be restored after monitoring is completed. Monitoring Plan Seattle Public Utilities or its contractor will be responsible for monitoring the re- established and enhanced sites within Puget Creek Natural Area for a 5 -year period. Activities performed each year will include removing invasive species, revegetating disturbed areas with native plant species, stabilizing slopes where needed, removing garbage, monitoring and adaptive management. The first year of monitoring will represent the most intensive effort followed by thorough site surveys in successive years to remove remaining noxious weeds and to replant as needed. ah /06-03354 -100 weilandmitigaimn plan February 11, 2008 37 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin Site Enhancement Performance Standards The performance standards for invasive species removal are Listed below. Performance Standard 1 The hydrology of the restored wetland, created by excavating fill material, will resemble the hydrology of the original delineated wetland. Performance Standard 2 During the first -year monitoring event, no more than 2 percent of the woody plant materials planted in the wetland and buffer plant communities will have died or become stressed to the point that the survival of the plant is in question. Performance Standard 3 During the first -, second -, third -, and fifth- year monitoring events, no more than 20 percent of the total plant coverage in the wetland and buffer plant communities will consist of invasive species. Invasive species may include, but are not limited to, Scot's broom, reed canarygrass, nonnative blackberry, holly, birdsfoot trefoil, cherry laurel, and English ivy. No percent coverage of Japanese knotweed will be allowed on the site. Performance Standard 4 During the second -, third -, and fifth -year monitoring events, the wetland and buffer plant communities (in the excavated area and where weed eradication resulted in open areas and native plantings replaced the weeds) will achieve a density of 15 percent coverage by the second year, 40 to 50 percent coverage by the third year, and 60 to 80 percent coverage by the fifth year. Native volunteer species may contribute up to 20 percent of the contribution. Performance Standard 5 By the fifth year of monitoring, the tree species will be dominated by conifers and native plant richness will have increased overall from existing conditions. oh /0603334 400 wetland mitigation plan Herrera Environmental Consultants 38 February 11, 2008 Wetland Mitigation Plan — Norfolk- Martin Luther King Jr. Way Subbasin Implementation Schedule On -site mitigation will be initiated immediately after the construction activities within the Project 2 — Stormwater Treatment Improvements site have been completed. This is expected to occur in the late summer and early fall of 2009. Offsite wetland and buffer enhancement activities at the Puget Creek Natural Area are scheduled to occur in summer to fall of 2008. ab /06.03354 -100 wetland mitigation plan February 11, 2008 39 Herrera Environmental Consultants Wetland Mitigation Plan— Norfolk- Martin Luther King Jr. Way Subbasin References Bonoff, Mike. 2007. Personal communication (telephone conversation with Len Ballek, Herrera Environmental Consultants, Inc., Missoula, Montana, regarding Puget Creek Natural Area). Wetland Biologist, City of Seattle. May 15, 2007. Ecology. 1992. Wetland Mitigation Replacement Ratios: Defming Equivalency. Publication No. 92 -08. Prepared for Washington Department of Ecology, Shorelands and Coastal Zone Management Program, Olympia, Washington, by A.J. Castelle, C. Conolly, M. Emers, E.D. Metz, S. Meyer, M. Witter, S. Mauermann, M. Bentley, D. Sheldon, and D. Dole of Adolfson Associates, Inc. Ecology. 1994. Permit Handbook — Commonly Required Environmental Permits for Washington State. Ecology Publication No. 90 -29. Washington State Department of Ecology, Olympia, Washington. Ecology. 1997. Washington State Wetlands Identification and Delineation Manual. Publication No. 96 -94. Washington State Department of Ecology, Olympia, Washington. Ecology. 2004. Washington State Wetlands Rating System for Western Washington. Publication No. 04 -06 -025. Washington State Department of Ecology, Olympia, Washington. Herrera. 2007a. Evaluation of Potential offsite Wetland Mitigation Areas: Norfolk -Martin Luther King Jr. Way Subbasin Stormwater Improvements. Prepared for Seattle Public Utilities by Herrera Environmental Consultants, Inc., Seattle, Washington. February 2007. Herrera. 2007b. Summary of Field Meeting Related to Off -site Wetland Mitigation Sites for the Norfolk -Martin Luther King Jr. Way Subbasin Stormwater Improvements Project. Prepared for Seattle Public Utilities by Herrera Environmental Consultants, Inc., Seattle, Washington. February 2007. Herrera. 2007c. Wetland Delineation; Norfolk Basin Drainage and Water Quality Improvements, Seattle and Tukwila, Washington. Prepared for Seattle Public Utilities by Herrera Environmental Consultants, Inc., Seattle, Washington. February 2007. Herrera. 2007d. Wetland Delineation; Norfolk –MLK Way Subbasin Stormwater Improvements Project. Prepared for Seattle Public Utilities by Herrera Environmental Consultants, Inc., Seattle, Washington. August 2007. Reed, Porter B. 1993. National List of Plant Species That Occur in Wetlands (Region 9). U.S. Fish and Wildlife Biological Report 88 (26.9) and Supplemental Report. December 1993. Seattle Parks Department. 1995. Puget Creek Natural Area Land Acquisition – Application to the Washington Interagency Committee on Outdoor Recreation. July 1, 1995. al, X06- 03351 -100 wetland mitigation plan February 11, 2008 41 Herrera Environmental Consultants Wetland Mitigation Plan — Norfolk -Martin Luther King Jr. Way Subbasin Seattle Urban Nature Project. 2000. Habitats on Seattle Public Lands, Invasive Species Distribution Map for Camp Long and Longfellow Creek and Vicinity. 1st Edition. September 30, 2002. Seattle. 2007. Seattle Municipal Code, Chapter 25. City of Seattle, Department of Planning and Development, Seattle, Washington. Obtained May 31, 2007, from agency website: <http://clerk.ci.seattle.wa.us>. SPU. 2007. Puget Creek Natural Area Wetland Delineation Report. Prepared for Seattle Public Utilities Engineering Division by Seattle Public Utilities, Science, Environment and Technologies Section. April 2007. Tetra Tech/KCM and Herrera. 2007. Norfolk -MLK Way Subbasin Stormwater Improvements Project: Preliminary Engineering Report. Prepared for Seattle Public Utilities by Tetra Tech/KCM in association with Herrera Environmental Consultants, Inc., Seattle, Washington. February 2007. USFWS. 1996. National List of Vascular Plant Species that Occur in Wetlands: 1996 National Summary. U.S. Department of Interior, Fish and Wildlife Service. Obtained January 26, 2004, from agency website: <http: / /www.nwi.fws.gov/bha/>. aA /06-03353 -100 wrrland mitigation plan Herrera Environmental Consultants 42 February 11, 2008 APPENDIX A Project Plan Sheets 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 PUGET CREEK NATURAL AREA WETLAND - MITIGATION SITE LOCATION MAP A SCALE: 1' = 1000' NORFOLK ON SITE WETLAND BUFFER ENHANCEMENT SITE H: NAD 83/98 (GPS) V: NAVD -88 SURVEY PERFORMED BY SPU VICINITY MAP NOT TO SCALE BASIS OF BEARING: WASHINGTON STATE PLANE (NORTH ZONE) CITY DATUM /NAVD88 DIFFERENCE; COS DATUM IS 9.42 FEET LOWER THAN NAVD -88 PROJECT FIELD BOOK; # 3676 PROJECT SCALE FACTOR; 0.999990727 CONVERGENCE ANGLE —1° 08' 07.87275' PROJECT COMBINED GRID FACTOR- 0.999983398 SCALE FACTOR BASIS. NORTHING: 205040 EASTING: 1263810 LOCATION MAP B SCALE: 1' = 1000' HERRERA 2200 Shah Avenue Suite 1100 Seattle. Washington 98121-1820 206441 -9080 206 -441 -9108 FAX CONSULTANTS lexitorectaffurWnexam APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 ar: DIRECTOR CONTRACTING SERVICES NAME OR INITWS AND DATE DESIGNED A 8DONE 02/06 /2008 a0!CIO71 A A20US 02/06 /2008 INITIALS AND DATE REVIEWED: DES. SOOT CONST. PROM. MGR. DRAWN L 1UW0.GE 02/06 /2008 CHECKED IE EWBANK 02/06/2008 • RECEIVED REV6ED AS BUILT ILL AMA ONE M IOLp0. MI NC ON R =TILE MANN) MANS NO MCP, CAMS NO 01101 000AE= O41E0 NNI N =MN 0-00.3 6 11E IIOECT MAN- SHEET INDEX SHT NO. DWG NO. SHEET DESCRIPTION 1 G1 TITLE SHEET, VICINITY MAPS, AND SHEET INDEX 2 G2 GENERAL NOTES, ABBREVIATIONS, AND LEGEND 3 C1 PUGET CREEK NATURAL AREA SITE SURVEY AND EXISTING CONDITIONS 4 C2 PUGET CREEK NATURAL AREA GRADING PLAN 5 C3 PUGET CREEK NATURAL AREA GRADING SECTIONS AND DETAIL 6 C4 PUGET CREEK NATURAL AREA TESC PLAN 7 C5 PUGET CREEK NATURAL AREA TESC NOTES AND DETAIL 8 C6 PUGET CREEK NATURAL AREA TESC DETAILS 9 P1 PUGET CREEK NATURAL AREA PLANTING PLAN 10 P2 PUGET CREEK NATURAL AREA PLANTING UST 11 P3 PUGET CREEK NATURAL AREA WEED CONTROL PLAN 12 P4 PLANTING DETAILS 13 P5 NORFOLK ON —SITE BUFFER MITIGATION PLAN DETAIL AND SECTION REFERENCING DETAIL REFERENCE NUMBER `� DRAWING NO. ON WHICH DETAIL APPEARS (TITLE) (SCALE) C1 DETAIL REFERENCE NUMBER DRAWING NO. FROM WHICH DETAIL WAS TAKEN (' TYP' SPECIFIES THAT DETAIL IS UNIFORMLY TYPICAL THROUGHOUT PROJECT EXCEPT WHERE OTHERWISE NOTED.) ('VAR' SPECIFIES THAT DETAIL WAS TAKEN FROM SEVERAL DRAWINGS.) A C1 SECTION A —A IS SHOWN ON DRAWING NO. C1. SECTION A -A C1 -- SECTION A —A IS TAKEN FROM DRAWING NO. C1. 0 up G1 TITLE SHEET, VICINITY MAPS, AND SHEET INDEX Public Utilities ORDNANCE NO. FIND: SCALE AS NOTED City of Seattle Chuck Clarke, Director APPROVED INSPECTORS BOOK NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN z 0 PC C333205 R/W co VAULT PLAN NO. SHEET 1 OF 13 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 GENERAL NOTES: 1. 2. 3. 4. 5. ALL WORK SHALL CONFORM TO THE 2008 CITY OF SEATTLE (cos) STANDARD SPECIFICATIONS FOR ROAD, BRIDGE, AND MUNICIPAL CONSTRUCTION, THE 2008 CITY OF SEATTLE STANDARD PLANS, AND SEATTLE DEPARTMENT OF TRANSPORTATION (SDOT) DIRECTORS RULE 2004 -02 FOR STREET AND SIDEWALK PAVEMENT OPENING AND RESTORATION (LATEST VERSION). A COPY OF THESE DOCUMENTS SHALL BE ON SITE AT ALL TIMES DURING CONSTRUCTION. A COPY OF THE APPROVED PLANS AND PERMITS MUST BE ON SITE WHENEVER CONSTRUCTION IS IN PROGRESS. THE CONTRACTOR SHALL OBTAIN ALL PERMITS REQUIRED FOR WORK WITHIN THE PUBLIC RIGHT —OF —WAY. PRIOR TO ANY CONSTRUCTION ACTIVITY, THE CONTRACTOR SHALL ATTEND A PRE — CONSTRUCTION CONFERENCE WITH THE CITY OF SEATTLE. RESIDENT ENGINEER SHALL NOTIFY THE CONTRACTOR OF THE PRE — CONSTRUCTION MEETING TIME AND LOCATION. PAVED SURFACES INCLUDING ROADWAYS, SIDEWALKS, AND CURBS THAT ARE DAMAGED BY NEW CONSTRUCTION SHALL BE REPAIRED AS REQUIRED BY SDOT STREET USE INSPECTOR. ALL SURVEYING AND STAKING OF IMPROVEMENTS AND GENERATION OF AS —BUILT PLANS IS TO BE PROVIDED BY THE CONTRACTOR AT THE CONTRACTOR'S EXPENSE, IN ACCORDANCE WITH COS STANDARDS. 6. THE LOCATIONS OF EXISTING FEATURES, UTJITTIES, AND TOPOGRAPHY ARE EITHER NOTED AS "EXISTING' OR 'EXIST' , AND /OR ARE SHOWN IN LIGHT LINE WEIGHTS, OR AS SCREENED BACKGROUND. WORK TO BE PERFORMED UNDER THIS CONTRACT OR NEW FEATURES ARE SHOWN WITH HEAVY OR DARK LINE WEIGHTS. 7. ALL UTILITIES MAY NOT BE SHOWN ON THE DRAWINGS. THE CONTRACTOR IS RESPONSIBLE FOR DETERMINING THE EXTENT OF AND HAZARD CREATED BY OVERHEAD POWER AND OTHER UTILITIES. THE CONTRACTOR SHALL MEET WITH UTILITY OWNERS PRIOR TO CONSTRUCTION AND SHALL TAKE WHATEVER PRECAUTIONS ARE REQUIRED BY LAW AND REGULATIONS, UTILITY OWNERS, SAFE CONSTRUCTION PRACTICES, OR AS DIRECTED BY THE ENGINEER. 8. ALL LOCATIONS OF EXISTING UTILITIES SHOWN HEREON HAVE BEEN ESTABLISHED BY COS ENGINEERING RECORDS SEARCH SUPPLEMENTED BY LIMITED FIELD SURVEY AND SHOULD THEREFORE BE CONSIDERED APPROXIMATE ONLY AND NOT NECESSARILY COMPLETE. IT IS THE RESPONSIBILITY OF THE CONTRACTOR TO INDEPENDENTLY VERIFY THE ACCURACY OF ALL UTILITY LOCATIONS SHOWN AND TO FURTHER DISCOVER AND AVOID ANY OTHER UTILITIES NOT SHOWN HEREON WHICH MAY BE AFFECTED BY THE IMPLEMENTATION OF THIS PLAN. 9. THE CONTRACTOR SHALL LOCATE AND PROTECT ALL UTILITIES DURING CONSTRUCTION AND SHALL CONTACT THE UNDERGROUND UTILITIES LOCATOR SERVICE (1 -800- 424 -5555) AT LEAST 48 HOURS PRIOR TO CONSTRUCTION. 10. THE COS MATERIALS LAB SHALL PROVIDE FOR ALL COMPACTION TESTS AS REQUIRED. 11. BACKFILL MATERIAL USED SHALL MEET COS STANDARD SPECIFICATIONS AND PASS INSPECTIONS PERFORMED BY GEOTECHNICAL ENGINEER. 12. INSPECTION AND ACCEPTANCE OF ALL WORK WILL BE ACCOMPLISHED BY REPRESENTATIVES OF THE CITY OF SEATTLE. IT SHALL BE THE CONTRACTOR'S RESPONSIBILITY TO COORDINATE AND SCHEDULE APPROPRIATE INSPECTIONS, ALLOWING PROPER ADVANCE NOTICE. THE INSPECTOR MAY REQUIRE RECONSTRUCTION OF ITEMS THAT DO NOT MEET CITY STANDARDS OR THAT WERE CONSTRUCTED WITHOUT INSPECTION AT CONTRACTOR'S EXPENSE. 13. THE CONTRACTOR SHALL KEEP OFFSITE PAVED STREETS CLEAN AT ALL TIMES BY SWEEPING. WASHING OF THESE STREETS WILL NOT BE ALLOWED WITHOUT PRIOR WRITTEN APPROVAL BY THE RESIDENT ENGINEER OR REPRESENTATIVE OF THE CITY OF SEATTLE.. 14. TRAFFIC CONTROL SHALL BE IN ACCORDANCE WITH THE PERMITTED TRAFFIC CONTROL MANUAL THE CONTRACTOR TRAFFIC CONTROL PLAN SHALL BE APPROVED BY THE REPRESENTATIVE OF THE CITY OF SEATTLE PRIOR TO IMPLEMENTATION. 15. REMOVE AND RESET HIGH VISIBILITY FENCE AS NECESSARY TO COMPLETE DEMOLITION, GRADING AND OTHER WORK. 16. PERFORM SURFACE CLEARING AND DEMOLITION AS REQUIRED TO INSTALL IMPROVEMENTS AS INDICATED ON PLANS. 17. THE REQUIREMENTS OF THIS PLAN ARE THE MINIMUM REQUIREMENTS. THEY DO NOT REPLACE, REPEAL, ABROGATE, SUPERSEDE, OR AFFECT ANY OTHER MORE STRINGENT REQUIREMENTS, RULES, REGULATIONS, STANDARDS, OR RESTRICTIONS. 18. THE REFUSE RESULTING FROM CLEARING AND GRUBBING SHALL BE DISPOSED OF BY THE CONTRACTOR PER THE SPECIFICATIONS. IN NO CASE SHALL REFUSE MATERIAL BE LEFT ON THE PROJECT PROPERTY, PLACED ON ABUTTING PROPERTIES, OR BURIED IN EMBANKMENTS OR TRENCHES. MAINTAIN HAULING ROUTES CLEAN AND FREE OF ANY DEBRIS RESULTING FROM THE PROJECT. 19. CONTRACTOR SHALL PROTECT POWER POLES NEAR EXCAVATIONS PER WAC 296 - 155- 655(9)(a). 20. SOILS TEST BORING LOCATIONS ARE INDICATED ON THE PLANS. BORING DATA IS INCLUDED IN THE PROJECT MANUAL. 21. UTILITIES ENCOUNTERED DURING CONSTRUCTION SHALL BE SUPPORTED OR PROTECTED. WATERMAINS MAY BE SUPPORTED WITH STRAPS BUT CHAINS AND CABLES WILL NOT BE ALLOWED. RESTORATION OF BEDDING AND BACKFILL SHALL BE SELECTED NATIVE MATERIAL IF APPROVED BY THE REPRESENTATIVE OF THE CITY OF SEATTLE. 22. CONTRACTOR VEHICLE AND WORK LIMITS SHOWN ON THE DRAWINGS DO NOT HAVE COORDINATES. CONTRACTOR AND THE REPRESENTATIVE OF THE CITY OF SEATTLE WILL ESTABLISH WORK LIMITS SHOWN ON DRAWINGS IN THE FIELD PRIOR TO STARTING CONSTRUCTION USING EXISTING SITE FEATURES. VEHICLE AND WORK LIMITS SHALL BE MARKED WITH TRAFFIC BARRIERS SUCH AS CONES OR STANDARDS. CONTRACTOR SHALL MAINTAIN MARKERS AT ALL TIMES. SEE SPECIFICATIONS FOR ADDTTIONAL GUIDANCE. 23. TRUCK TRAFFIC SHALL BE MINIMIZED THROUGH NEIGHBORHOODS. TRUCK TRAFFIC SHALL OCCUR ON ARTERIAL ROUTES WHERE POSSIBLE. 24. CONTRACTOR TO PERFORM WORK ONLY DURING APPROVED HOURS AS DETERMINED BY COS. HERRERA 2200 Sixth Avenue Suite 1100 Seattle, Washington 98121 -1820 206441 -9080 206 -441 -9108 FAX COMMLO nS Mplio rnAr,a✓wmn APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 Br: DIRECTOR, CONTRACTDIG SERVICES NAME OR INITIALS AND DATE DESIGNED A BEHNtE 02/08/2008 OtE.CKED A A20US 02/06/2008 INITIALS AND DATE REVIEWED: DES SOOT CONST. PRQK. MGR: DRAWN L TURNIDGE 02/08/2008 CHECKED IL EWBANK 02/06 /2008 RECEIVED REVISED AS BUILT ML WM mE aNam,¢WMTEarrsSEATTLEMM.)RMOMOvOW- OM= MO 000 00aAEMS MID FOR M =MN 0—.1 OF DE ROST WMML EGEND: 210 • • HVF PROPOSED MAJOR CONTOUR PROPOSED MINOR CONTOUR GRADING LIMITS CLEARING AND GRUBBING LIMITS WETLAND BOUNDARY EXISTING CONTOUR EXISTING DRAINAGE PUGET CREEK CHANNEL COMPOST SOCK WATTLES HIGH VISIBILITY FENCE WETLAND MAT STABILIZED CONSTRUCTION ENTRANCE TEMPORARY BRIDGE ABBREVIATIONS: COS DWG EL ESC EX FAC FACU FACW FT IPM MAX MIN NI OBL ROW SDOT SPU TESC TYP CITY OF SEATTLE DRAWING ELEVATION EROSION AND SEDIMENT CONTROL. EXISTING FACULTATIVE FACULTATIVE UPLAND FACULTATIVE WETLAND FEET INTEGRATED PEST MANAGEMENT MAXIMUM MINIMUM NOT INDICATED OBLIGATE RIGHT OF WAY SEATTLE DEPARTMENT OF TRANSPORTATION SEATTLE PUBLIC UTILITIES TEMPORARY EROSION AND SEDIMENT CONTROL TYPICAL *REFER TO 2008 CITY OF SEATTLE STANDARD PLANS FOR CONSTRUCTION FOR A COMPLETE LIST OF ABBREVIATIONS STANDARD SYMBOLS. MUNICIPAL AND z w co 0 G2 GENERAL NOTES, ABBREVIATIONS, AND LEGEND Pale Public Utilities ORDDUNCE N0. F1R/D: SCALE AS NOTED City of Seattle Chuck Clarke, Director APPROVED OSPECTORS BOOK NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN i 0 Pc C333205 R/W co VAULT PLAN NO. SHEET 2 OF 13 1 1 1 1 1 1 1 1 1 1 1 1 50 0 50 100. HORIZ. 1°=50' LEGEND: 205 — EXISTING CONTOURS EXISTING DRAINAGE • • . • PUGET CREEK CHANNEL PROPERTY LINE STREET CENTERLINE WETLAND BOUNDARY PARK BOUNDARY SEWER EASEMENT H: NAD 83/98 (GPS) V: NAVD -88 SURVEY PERFORMED BY SPU BASIS OF BEARING; WASHINGTON STATE PLANE (NORTH ZONE) CITY DATUM /NAVDBB DIFFERENCE; COS DATUM IS 9.42 FEET LOWER THAN NAVD -88 PROJECT FIELD BOOK; A 3676 PROJECT SCALE FACTOR- 0.999990727 CONVERGENCE ANGLE. —1° 08' 07.87275' PROJECT COMBINED GRID FACTOR; 0.999983398 SCALE FACTOR BASIS- NORTHING: 205040 EASING: 1263810 PUGET CREEK NATURAL AREA SITE SURVEY AND EXISTING 982 Sixth AVenue Sotto 1100 Seattle, Washington 98121-1820 206-441 -9080 HERRERA 206441 -9106 FAX E HIRROW9NTAL CCNSULTAHnt IIOPIhwNilwnr•I excel APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 UT: OFIECTOR. CONTRACTNC 806810 S NAME OR INMALS AND DATE DESIRIED L BAUD( 02/06/2008 CHECKED A AZOUS 02/06 /2008 INITIALS AND DATE REVIEWED: DES. CONST. SOOT PRO1. MDR. DRAWN L TURKU:ME 02 /06/2008 CHECKED 8. EWBANK 02/06/2008 RECEIVED REV6ED AS BUILT El. TANK ODE N w06 WIN TIC CM D' EATOL =IOW NNC OIO Wan- 2E3313 NO OIIF11 OOD•OCC CALM FOR 01 SECTION 0-023 OF TIE NOECT WHIM rzr1�. !v�l W' 0 co 01 CONDITIONS ttle Public Utilities ORDINANCE N0. FUND: SCALE AS NOTED City of Seattle Chuck Clarke, Director APPROVED INSPECTORS BOOK NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN z m PC C333205 R/W GO VAULT PLAN NO. SHEET 3 OF 1 3 NOTES: 1. SEE PLANTING PLAN (DWG P1) FOR PLANTING DETAILS. PLANT DISTURBED AREAS AS INDICATED ON PLANTING PLAN. 2. EARTHWORK SHALL CONFORM TO 2008 CITY OF SEATTLE STANDARD SPECIFICATIONS. 3. SEE CITY OF SEATTLE STANDARD PLAN NO. 003 FOR STANDARD SYMBOLS. 4. CLEARING, GRUBBING, AND ROADSIDE CLEANUP SHALL CONFORM TO 2008 CITY OF SEATTLE SPECIFICATION 2 -01.2. 5. CONTRACTOR TO PROTECT ADJACENT PROPERTIES. 6. CLEAR AND GRUB AS NECESSARY FOR ACCESS AND GRADING. 1 `.\ �r. 6 7. PROTECT ALL EXISTING UTILITIES. 8. DO NOT DISTURB SOIL WITHIN 3 FEET OF PROPERTY LINES. 9. REMOVE TREES AS INDICATED BY THE CITY OF SEATTLE REPRESENTATIVE. 10. COORDINATE CROSSING WITH THE CITY OF SEATTLE REPRESENTATIVE. r. 9T , AvE _ ;h PUGET CREEK — / SEE TESC PLAN FOR ACCESS (NOTE 6). LIMITS ARE APPROXIMATE PROTECT EXISTING SANITARY SEWER (NOTE 7) cP — '–nPSS — DRAINAGE CROSSING. SEE TESC PLAN (NOTE 10) — ao Co 20 0 HORIZ. 1' =20' r CO Co - Co - Co CO CO CO CO USE WETLAND MATS FOR ACCESS, SEE NOTE 9 /% i -° N .// .�1\ 1, Ik l ' EXISTING DRAINAGE (TYP) Q APPROX GRADING LIMITS (TYP) PROPERTY LINE (TYP) C-I HERRERA 2200 Sbt h Avenue Suite 1100 Seattle. Washington 98121 -1820 206441 -9080 206441.9108 FAX COOLI LrANI0 OtcdOw .A.nrrsmn APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 BY: DIRECTOR. 00R AC1ING SERVICES NAME OR INITIALS AND DATE DESIGNED A mom 02/08 /2008 DECKED A AZOUS 02/08/2008 ORAWN L TUR1®CE 02 /08/2008 CHECKED U. EWBANK 02/08/2008 INITIALS AND DATE REVIEWED: DES SOOT PRDJ. NCR. RECEIVED REVISED AS MALT MiMU COME NA ®OM¢ n TIE OT O EATUZ ■OIIOIO MAO NO 11.0011- MUM MO 00EA =OEM 011LD 10 N =OM 0$3 6 11E OD= NOM- DO NOT DISTURB EXISTING DRAINAGE (TYP) C 3' MIN (NOTE 8) LEGEND: SSS X215 EXISTING CONTOURS DUSTING DRAINAGE PUGET CREEK CHANNEL PROPERTY LINE PROPOSED CONTOURS GRADING LIMITS CO CLEARING AND GRUBBING LIMITS C2 PUGET CREEK NATURAL AREA GRADING PLAN DESIGN SUBMITTAL lea We City of Seattle Public Chuck Clarke, Director Utilities ORDINANCE N0. FUND: SCALE AS NO1E0 APPROVED INSPECTORS 900K NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN z 0 PC C333205 R/W co VAULT PLAN NO. SHEET 4 OF 13 220 215 210 205 200 0 3' MIN BEGIN GRADING, SEE© 3 EXISTING GRADE / \//\///\ NATIVE SOIL 7 1 JUTE MATTING SEE NOTE 1 .......3... 2' MIN FINISHED GRADE SEE PLANTING PLAN (NOTE 2) ROUNDING, SEE END GRADING ± w z 215 210 205 200 0 3' MIN SECTION SCALE: 1' =5' A —A C2 NOTES: 1. JUTE MATTING PER 2008 CITY OF SEATTLE 220 SPECIFICATION 9- 14.5(1)8. SEED GRASSES PRIOR TO INSTALLING JUTE MATING. SEE DWG P2 PLANTING PLAN FOR PLANTING DETAILS AND PLANT AS INDICATED. JUTE MATTING TO BE USED UP SLOPE OF BUFFER ENHANCEMENT. 2. PLANT TREES AND SHRUBS IN JUTE MATTING AS DIRECTED IN NOTE 11, DWG P2. 3. GRADE SLOPE PER CITY OF SEATTLE STANDARD PLAN NO. 140. SEE DETAIL 1. 215 210 205 200 BEGIN GRADING, SEE 3• • \'.:; 1 JUTE MATTING SEE NOTE 1 • EXISTING GRADE 2' . MIN - LNATNE SOIL 7 "' >—I 1 SEE PLANTING PLAN (NOTE 2) ROUNDING, SEE FINISHED GRADE /: // 7/' •' '/. 7 // END GRADING ± /'7/\r. // SECTION SCALE: 1' =5' EXISTING OR NEW GRADE (VARIABLE) 1' -0' MIN APR 2' -0' DESIRABLE • ER C2 EXISTING OR NEW GRADE (VARIABLE) 1' -0' MIN 2' -0' DESIRABLE SLOPE ROUNDING DETAIL SCALE: NOT TO SCALE — ;\ /.\/i< HERRERA 2200 Sixth Avenue Suite 1100 Seattle, Washington 96121 -1820 206-441 -9080 206- 441 -9108 FAX CONSIA.TAMIS ImbADIDIa INS .0n APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 By DIRECTOR CONTRACTING SEANCES NAME OR INITIALS AND DATE DE 0NED A. BEI*I11E 02/08 /2008 CHEMED A AZOIA 02/06 /2008 INITIALS AND DATE REVERED: DES. 500T C0 ST. PROD. MGR. DRAWN L. TURA®CE 02 /06/2008 CHECKED 1L MBANK 02/06 /2008 RECEIVED REVISED AS BUILT ML IOW COE 11 IAIDYMICE 00 TIE CR 6 GATOE MONO MAD MD iPlaF MUDS MD 011404 DOME= MILD MN ISM. 0-@J ID THE N0801 MIMIC 220 215 210 205 200 PUGET CREEK NATURAL AREA GRADING C3 SECTIONS AND DETAIL in cn z W 0 co Pale Public Utilities ORDINANCE NO. FUND: SCALE AS NOTED City of Seattle Chuck Clarke, Director APPROVED INSPECTORS BOO( NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN z PC C333205 R/W CO VAULT PLAN NO. SHEET 5 OF 13 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 8 t §8 I .2 °ME 2E2 JL SW JUNEAU ST > , '1— ! ,"\ 19TH AVE ‘o-1 ) , !p, , • r_ 21ST AVE SW .• - dw---,.___ .--_-_-------T=7:,:.- ----_-.-.-.. ,-___------..-.---.. ,,,..-:---,- - ----------•- -----2---...-r----„:•------- --5.::-. •--_,,,......... __----.1.727-,---- .470--s------ - --=-',-;,-----:--Z-,1-;:- ',-=--'-'-' -2- -.----------:::--Zr--------:--------------------- ---i-- 7::-_7:--- 27.--. .. - -------"---- ...."--...'`-' -..... .....,_;>:',/,,,*-----.-.,:---:-7---1-------,..›.■ . .. rj;rt - ------.-"----.=.'-:.-''-- ' //./---- --------.--"-------- 44VE -' ' -., -HVF-14,-- -,--- ___ _ . _ SEE • 25 WET1AND BOUNDARY . — - 20 ---- ) f \ — , S...? SW R/W ! __,__,.___ „ SPU 50' ..=---Hyr , i- -L05-----,&=2,715.:, ,...)-,*,..-.,..t.--4.------pe----4,-- RIGHT,OF WAY ± — - ---71-- --- — TEMPORARY BRIDGE - .... ----..... ._, \\\_ \ ---- - :i V.. ii ) ..... ,.... /-..A4.----L c '-',''',,.:--^----.----- 5-7- PUGET CREEK \----7---- 1 ' - , ---r, ---, , •- - ‘ W 'IV- ------- - ------=---.-.7.- / __....-i,,---'--,,,,, N. ii' --' ' .,..-■ `-----.\41—t--\ t,.- 1 ..-.----.---' -- ( ...-- VII W " -14vr. -4.iy# 50 LEGEND: 1=/332133 —HVF- • • 111111111111111111 1111111111111111111111111111111 WETLAND MAT COMPOST SOCK WATRES, SEE 18TH AVE SW VF-,--HVFJ HERRERA 2200 SbOh Avenue Stake 1100 Seattle, Washington 98121-U320 206-441-0080 2013-441-9108 FAX CCOISLILTAIRS Rejr-fravol=11•MhC-CCOI APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTNE ADMINISTRATION SEATTLE. WASHINGTON 20 BY: DIRECTOR. CONTRACTPC SERVB:ES NAME OR INMALS AND DATE DESIGNED J. *MANN 02/08/20:111 CHECKED A. AZOUS 02/06/2008 DRAWN L TURN= 02/002008 CHECKED M. (V/BANK 02/06/2008 INITIALS AND DATE REVIEVAID: DES. SOOT CONST. PRCU. MG RECEIVED REVISED AS BUILT AL WM 00 ROMMACE 00 De CFA Or MAME MORO RAG MO 08S 000 NO MCC COMAIDAS MAW 00 0 SCRIM 0-027 W TE RDECT RAM- SW BRANDON ST HORIZ. 1"=50' COMPOST SOCK WATTLES HIGH MEEMITY FENCE PUGET CREEK CHANNEL WETLAND BOUNDARY WETLAND MAT STABILIZED CONSTRUCTION ENTRANCE TEMPORARY BRIDGE STABILIZED CONSTRUCTION ENTRANCE, SEE PUGET CREEK NATURAL AREA TESC C4 PLAN (Seattle Public Utilities ORDDIANCE NO FUND. SCALE: AS NOTED City of Seattle Chuck Clarke, Director APPROVED INSPECTOR'S BOOK NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN ci z CO PC C333205 R/W 0 co VAULT PLAN NO. SHEET 6 Or 13 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 GENERAL EROSION CONTROL NOTES: 1. VEGETATION PREVENTING PLACEMENT OF WETLAND MAT SHALL BE REMOVED. 2. RESTORE AND REVEGETATE AREA DISTURBED BY WETLAND MAT AT CONCLUSION OF CONSTRUCTION AS SHOWN ON DWG P1 PLANTING PLAN. 3. TEMPORARY BRIDGE SHALL BE PROVIDED, PLACED, MAINTAINED, AND REMOVED AT COMPLETION OF CONSTRUCTION BY CONTRACTOR. TEMPORARY BRIDGE MUST NOT IMPACT FLOW OF PUGET CREEK. 4. STORM WATER INLETS IN VICINITY OF CONSTRUCTION EQUIPMENT MOBILIZATION AND STAGING SHALL HAVE INLET PROTECTION PROVIDED BY THE CONTRACTOR. SEE WSDOT STANDARD PLAN 1- 40.20 -00. 5. NONCOMPLIANCE WITH EROSION CONTROL REQUIREMENTS, WATER QUALITY REQUIREMENTS, AND INDICATED CLEARING LIMITS MAY RESULT IN REVOCATION OF PROJECT PERMITS, PLAN APPROVAL, AND BOND FORECLOSURES. 6. PRIOR TO ANY WORK, INCLUDING GROUND DISTURBANCE, THE CONTRACTOR SHALL CONTACT COS TO SCHEDULE A PRE — CONSTRUCTION MEETING. SEE DWG G2, GENERAL NOTE 3. 7. PRIOR TO ANY SITE CONSTRUCTION (WHICH INCLUDES CLEARING /LOGGING OR GRADING THE SITE), CONTRACTOR SHALL LOCATE AND MARK CLEARING LIMITS. THE CONTRACTOR SHALL COORDINATE WITH COS AS REQUIRED. 8. AFTER THE TEMPORARY EROSION AND SEDIMENT CONTROL (TESL) FACILITIES ARE CONSTRUCTED BY CONTRACTOR, CONTRACTOR SHALL SCHEDULE AN INSPECTION BY COS DEPARTMENT OF PLANNING AND DEVELOPMENT (DPD) SITE DEVELOPMENT INSPECTOR PRIOR TO ANY GRADING, DEMOLITION, OR EXTENSIVE LAND CLEARING. CONTRACTOR SHALL OBTAIN APPROVAL OF INSTALLED TESC MEASURES IN ACCORDANCE WITH THE APPROVED TEMPORARY EROSION AND SEDIMENT CONTROL PUN. CALL (206) 684 -8950 TO SCHEDULE AN INSPECTION. 9. LOCATE STOCKPILES IN DESIGNATED AREAS AND PROTECT WITH PLASTIC SHEETING, PERIMETER FILTER FABRIC FENCING AND OTHER TESC MEASURES. PROTECT STOCKPILES FROM EROSION AND WET WEATHER AND PROVIDE FUGITIVE DUST CONTROL SEE SPECIFICATIONS FOR ADDITIONAL REQUIREMENTS. STOCKPILES SHALL NOT BE HIGHER THAN 10 —FT OR EXCEED A MAXIMUM SIDE SLOPE OF 1:1. STOCKPILES THAT BECOME UNSUITABLE DUE TO LACK OF PROTECTION MEASURES SHALL BE PROPERLY DISPOSED OF AND REPLACED WITH SUITABLE MATERIAL AT NO ADDITIONAL EXPENSE TO THE OWNER. 10. CONSTRUCT THE TESC FACILITIES SHOWN ON THE PLAN IN CONJUNCTION WITH ALL CLEARING AND GRADING ACTIVITIES AND IN SUCH A MANNER AS TO PREVENT SEDIMENT —LADEN WATER FROM LEAVING THE SITE AND ENTERING PUGET CREEK OR THE EXISTING PUBLIC STORM DRAW SYSTEM. 11. THE TESC FACILITIES SHOWN ON THE PLAN ARE THE MINIMUM REQUIREMENTS FOR ANTICIPATED SITE CONDITIONS. DURING THE CONSTRUCTION PERIOD, CONTRACTOR SHALL UPGRADE THESE TESC FACILITES AS NEEDED FOR UNEXPECTED STORM EVENTS. 12. THE TESC FACILITIES SHALL BE INSPECTED DAILY BY THE CONTRACTOR'S ESC LEAD AND MAINTAINED AS NECESSARY TO ENSURE THEIR CONTINUED FUNCTIONING. 13. NO EXPOSED EARTH SHALL REMAIN UNSTABILIZED FOR MORE THAN 7 DAYS FROM MAY 1ST TO SEPTEMBER 30TH. FROM OCTOBER 1ST TO APRIL 30TH NO EXPOSED EARTH SHALL REMAIN UNSTABRIZED FOR MORE THAN 2 DAYS. STABILIZATION OF EXPOSED EARTH SHALL BE WITH APPROVED TESC METHODS (I.E., MULCHING, NETTING, EROSION BLANKETS, COVERING, ETC.). SEE COS STANDARD PLANS FOR STABILIZATION METHODS. 14. THE TESC FACILITIES IN INACTIVE AREAS SHALL BE INSPECTED AND MAINTAINED ONCE A DAY, OR WITHIN 24 HOURS FOLLOWING A STORM EVENT. 15. NO SEDIMENT OR SOIL SHALL BE TRACKED INTO THE PAVED STREET OR ONTO OTHER PAVED SURFACES. SEDIMENT AND SOIL SHALL BE REMOVED FROM TRUCK AND EQUIPMENT SURFACES PRIOR TO LEAVING THE SITE. IN THE EVENT OF FAILURE OF THE TESC SYSTEM RESULTING IN SEDIMENT BONG TRACKED ONTO PAVED SURFACES, THE CONTRACTOR SHALL IMMEDIATELY IMPLEMENT MEASURES TO CORRECT THE SITUATION, AND STREET SWEEPING SHALL BE EMPLOYED ON AN EMERGENCY BASIS. IF STREET SWEEPING VEHICLES ARE UTILIZED, THEY SHALL BE OF THE TYPE THAT REMOVES THE SEDIMENT FROM THE PAVEMENT. 16. WHERE STRAW MULCH OR COMPOST MULCH FOR TEMPORARY EROSION CONTROL IS REQUIRED, IT SHALL BE APPLIED AT A MINIMUM THICKNESS OF TWO INCHES. 17. THE CONTRACTOR SHALL BE RESPONSIBLE TO PREVENT EROSION AND CONTROL SEDIMENTATION. THE CONTRACTOR IS PROHIBITED FROM DISCHARGING SEDIMENT —LADEN RUN —OFF BEYOND WORK LIMITS EXCEPT AT PERMIT SPECIFIED DISCHARGE POINTS AND ONLY AFTER TREATMENT TO MEET DISCHARGE REQUIREMENTS. DRAINAGE GRATE 5' MAX. GRATE FRAME SEDIMENT AND DEBRIS OVERFLOW BYPASS 1. SIZE THE BELOW INLET GRATE DEVICE (BIGD) FOR THE STORM WATER STRUCTURE IT WILL SERVICE. 2. THE BIGD SHALL HAVE A BUILT —IN HIGH —FLOW RELIEF SYSTEM (OVERFLOW BYPASS). 3. THE RETRIEVAL SYSTEM MUST ALLOW REMOVAL OF THE BIGD WITHOUT SPILLING THE COLLECTED MATERIAL. 4. PERFORM MAINTENANCE IN ACCORDANCE WITH STANDARD SPECIFICATION 8- 01.3(15). DRAINAGE GRATE RECTANGULAR GRATE SHOWN BELOW INLET GRATE DEVICE RETRIEVAL SYSTEM TYP ) BELOW INLET GRATE DEVICE DETAIL — STORM DRAIN INLET PROTECTION HERRERA 2200 Shith Avenue Suite 1100 Seattle. Washington 98121-1820 208441-8080 208 - 441 -9108 FAX ENVnasa3nu CCMSA.TANB hltrlhowarhertemincsom APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 BY: CRECTOR. CONTRACTING SIOWICES NAME OR INITIALS AND DATE DESIGNED J. RAID! 02/08/2008 CHECKED A AMOS 02/06/2008 INITIALS AND DATE REVIEWED: DES SDOT PROJ. MGR. DRAWN L IUR1®GE 02/06 /2008 CHECKED N. EMBANK 02/08 /2008 RECEIVED REWSED AS WJILT AL Oa ODIC N AQaIONICE 010 ne CT 6 SWILL MOOD MAO YD OMNI- nIDe MD ODEN MOM= 1110 FOR N OCIOI 0-aJ Cr Of WT WORM, NOT TO SCALE _ OVERFLOW BYPASS (TOP) O \. co C5 PUGET CREEK NATURAL AREA TESC NOTES AND DETAIL (Seattle Public Utilities °ROMANCE NO. FUND: SCALE AS NOTED City of Seattle Chuck Clarke, Director APPROVED INSPECTOR'S BOOK NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN 0 PC C333205 R/W CO VAULT PLAN NO. SHEET 7 of 13 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 SPACING VARIES DISTURBED (rep) - SEE NOTE 4 AREA 10' - 0' 0 30° ANGLE EACH END TO PREVENT FLOW AROUND (TYP) EXCESS SOCK MATERIAL DRAWN IN AND TIED OFF AT STAKE (TYP) ,,,%t 2x2x3' -0' WOODEN STAKE COMPOST SOCK « SEE NOTE 1 PLAN VIEW EROSION CONTROL BLANKET « SEE NOTE 3 COMPOST SOCK DETAIL CONTOUR LINE (TYP) 2x2x3' - 0' WOODEN STAKE, SPACED EVERY 3' - 0' 0.C. (TYP) 1. COMPOST SOCK SHALL BE IN ACCORDANCE WITH STANDARD SPECIFICATION 9- 14.5(6). COMPOST SOCK SHALL BE A MINIMUM OF 8' IN DIAMETER OR SIZED TO SUIT CONDITIONS AS SPECIFIED BY THE ENGINEER OR CONTRACT. 2. COMPOST MATERIAL TO BE DISPERSED ON SITE, AS DETERMINED BY THE ENGINEER. 3. WHEN PLACING COMPOST SOCK ON SLOPES, USE EROSION CONTROL BLANKET IF SPECIFIED BY THE ENGINEER AND IN ACCORDANCE WITH STANDARD SPECIFICATION 9- 14.5(2). SEE STANDARD PLAN I- 60.10. 4. ALWAYS INSTALL COMPOST SOCK PERPENDICULAR TO DIRECTION OF RUNOFF FLOW ON SLOPE AND ALONG CONTOUR LINES. 5. REMOVE SEDIMENT FROM THE UP SLOPE SIDE OF THE COMPOST SOCK WHEN ACCUMULATION HAS REACHED 1/2 OF THE EFFECTIVE HEIGHT OF THE COMPOST SOCK. 6. LIVE PLANT STAKES CAN BE USED IN ADDITION TO WOODEN STAKES TO ANCHOR COMPOST SOCK AND SHALL BE IN ACCORDANCE WITH STANDARD SPECIFICATION 9- 14.6(1). SEE PLANTING PLANS FOR SPECIES SELECTION AND SPACING. DETAIL — COMPOST SOCK WATTLES (1h NOT TO SCALE C4 EROSION CONTROL BLANKET SEE NOTE 3 2x2 WOOD POST FENCING MATERIAL SECTION COMPOST SOCK ■ SEE DETAIL PROTECTED EA STAPLE TOP TIE SELF - LOCKING TIE • NYLON 6/6, 50# MIN TENSILE STRENGTH, UV STABILIZED EXISTING ROAD 25' - 0' R MIN (TYP) « 8' QUARRY SPALLS GEOCTEXTILESFORCSOIL STABILIZATION AND A MINIMUM OF 0.15' CRUSHED ROCK UNDER THE SPACES, FROM THE EDGE OF THE EXISTING ROADWAY TO THE RADIUS RETURNS, OR AS DIRECTED BY THE ENGINEER. STEEL T -BAR POST AS REQUIRED « 100' MIN, EXCEPT MAY BE REDUCED TO 50' MIN FOR SITES WITH LESS THAN ONE ACRE OF EXPOSED SOIL PROVIDE FULL WIDTH OF INGRESS / EGRESS AREA 15' -0' MIN DETAIL — STABILIZED CONSTRUCTION ENTRANCE NOT TO SCALE \4 SELF - LOCKING TIE - NYLON 6/6, 50# MIN TENSILE STRENGTH, UV STABILIZED FENCING MATERIAL ENVIRONMENTALLY • SENSMVE AREA • BOUNDARY (DESIRABLE) 1' - 0' MIN HIGH DENSITY POLYETHYLENE FABRIC WITH OPEN MESH, UV RESISTANT, ORANGE COLOR 2x2 WOOD OR STEEL T -BAR POST TYPICAL SECTION DETAIL — HIGH VISIBILITY NOT TO SCALE C-I HERRERA 2200 Sixth Avenue Suite 1100 Seattle. Washington 98121.1620 20B- 441.9000 208441 -9108 FAX COVISLILMMTS mron...nrl.Irmmn APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE, WASHINGTON 20 BT: DRECTOR. CONTRACTING SERVICES NAME OR INITIALS AND GATE DESIGNED J. AMANN 02/08/2008 DECKED A AZOUS 02/06 /2008 INITIALS AND DATE REVIEWED: DES SOOT CONST. PROA. MGR. DRAWN L 'rum= 02/06/2008 CHECKED N. 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LEGEND: + + + +, ZONE 1 WETLAND RE- ESTABLISHMENT AREA ZONE 2 WETLAND ENHANCEMENT AREA ZONE 3 BUFFER ENHANCEMENT AREA ZONE 4 HABITAT ENHANCEMENT AREA WETLAND BUFFER BOUNDARY WETLAND BOUNDARY — — EXISTING DRAINAGE PUGET CREEK CHANNEL EXISTING CONTOURS PROPOSED CONTOURS BUFFER ENHANCEMENT 8.072 SQ FT 0.19 ACRE 15' PROPERTY' SETBACK 40' BUFFER BO GI HERRERA 2200 Shah Avenue Suite 1100 Seattle, Washington 88121 -1020 206- 441 -9080 206 -441 -9108 FAX CONSULTANTS 1Am' %Aom slowal — APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATRE. WASHINGTON 20 Br: DDiEOTOR. CONTRACTING SERVICES NAME OR INRALS AND DATE D ESIGNED L BALLDC 02/06/2008 CHFT.10'D A AZOU5 02/06/2006 INITWLS AND DATE REVRM4D: DES. SOOT cONST. �. NCR DRAWN L TUR800S 02/06/2006 CHECKED 8. EWBANK 02/06/2008 RECENED REVISED AS BABLT ALL WIN I0t •I OCCONNQ .M M env 6 DAT11L FUNGI NAM NO Gal. DOS= MD 000 OOQAEN11 CMIW F N =COON 0-0J 6 11E NORT 11AI1S. WETLAND RE- ESTABLISHMENT AREA 1 c, 0.56 ACRES BUFFER ENHANCEMENT 4,818 SQ FT 0.111 ACRE oe EXISTING 85' BUFFER BOUNDARY 4Q BUFFER BOUNDARY I, 15' PROPERTY SETBACK PUGET CREEK NATURAL AREA PLANTING 100 Public Ut/Iities ORDINANCE NO. EUND•. SCALE: AS NOTED City of Seattle Chuck Clarke, Director APPROVED INSPECTOR'S BOOK NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN 0 PC C333205 R/W co VAULT PLAN NO. SHEET 9 OF 13 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 J 0 PLANT MATERIAL SCHEDULE WETLAND INDICATOR SPECIES SCIENTIFIC NAME (COMMON NAME) ROOT CONDITION SPACING ON CENTER (FEET) ZONE 1 WETLAND RE- ESTABLISHMENT AREA ZONE 2 WETLAND ENHANCEMENT AREA ZONE 3 BUFFER ENHANCEMENT AREA ZONE 4 HABITAT ENHANCEMENT AREA FAC+ ACER CIRCINATUM (VINE MAPLE) CONT. AT LEAST 10 INCH DEEP 10 FT CENTERS IN CLUMPS 32% 10.4 LBS 148 50 FACU ACER MACROPHYLLUM (BIG LEAF MAPLE) CONT. AT LEAST 10 INCH DEEP 10 FT CENTERS IN CLUMPS TRITICUM AESTNUM (REGREEN HYBRID) 3% 64 9.0 LBS FACU- AMELANCHIER ALNIFOUA (SERVICE BERRY) CONT. AT LEAST 10 INCH DEEP 6 FT CENTERS IN CLUMPS 0.6 LBS 0.5 LBS 148 50 FACU ATHYRIUM FILIX- FEMINA (LADY FERN) ONE GAL CONT 3 FT CENTERS IN CLUMPS 56 88 ZONE 3 (ASSUMING APPROX 0.6 ACRES OF DISTURBANCE) OS*0 WS •••S••• ,/,,,, / .0/S, See. OS 10.0001.1 Otel.tt UPLAND BERBER'S NERVOSA (DULL OREGON GRAPE) CONT. AT LEAST 10 INCH DEEP 3 FT CENTERS IN CLUMPS BROMUS SITCHENSIS (ALASKA BROME) 33% 221 20.7 LBS OBL CARER OBNUPTA (SLOUGH SEDGE) TUBLING OR LARGER 2 FT CENTERS IN CLUMPS 224 WILD E(BLUE LYMUS GLAUCRYE) U) 33% FACW CORN US SERICEA (RED OSIER DOGWOOD) CONT. AT LEAST 10 INCH DEEP 6 FT CENTERS IN CLUMPS 112 352 FESTG R RUBRA A (CREEPING RED FESCUE) 34% UPLAND HOLODISCUS DISCOLOR (OCEAN SPRAY) CONT. AT LEAST 10 INCH DEEP 6 FT CENTERS IN CLUMPS 148 50 FACU POLYSTICHUM MUNITUM (SWORD FERN) ONE GAL CONT 3 FT CENTERS IN CLUMPS 56 88 UPLAND PSEUDOTSUGA MENZIESII (DOUGLAS FIR) CONT. AT LEAST 10 INCH DEEP 10 FT CENTERS IN CLUMPS 592 200 FACU ROSA GYMNOCARPA (BALD HIP ROSE) CONT. AT LEAST 10 INCH DEEP 6 FT CENTERS IN CLUMPS 112 FAC- RUBUS PARVIFLORUS (THIMBLE BERRY) CONT. AT LEAST 10 INCH DEEP 3 FT CENTERS IN CLUMPS 112 176 FACW SALIX SITCHENSIS (SITKA WILLOW) CONT. AT LEAST 10 INCH DEEP 6 FT CENTERS IN CLUMPS 112 352 FACU SAMBUCUS RACEMOSA (RED ELDERBERRY) CONT. AT LEAST 10 INCH DEEP 6 FT CENTERS IN CLUMPS 148 50 NI SORBUS SITCHENSIS (SITKA MOUNTAIN ASH) CONT. AT LEAST 10 INCH DEEP 6 FT CENTERS IN CLUMPS 112 176 FACW SPIRAEA DOUGLASII (HARD HACK) CONT. AT LEAST 10 INCH DEEP 6 FT CENTERS IN CLUMPS 176 FAC THUJA PUCATA (WESTERN RED CEDAR) ONE GAL. CONT 2 PER PLANTING BED 56 88 FACU- TSUGA HETEROPHYLLA (WESTERN HEMLOCK) CONT. AT LEAST 10 INCH DEEP 10 FT 112 GENERAL PLANTING NOTES: 1. PLANTS SHALL BE CONTAINER GROWN AND FROM SEED SOURCES FROM WEST OF THE CASCADES AND FROM A SIMILAR ELEVATION AS PER CITY OF SEATTLE SPECIFICATION 9 -14.6 SPECIFICATION FOR PLANT MATERIALS. 2. TREES AND SHRUBS EXCEPT FOR THE THUJA PUCATA (WESTERN RED CEDAR) SHALL BE PROVIDED IN CONTAINERS AT LEAST 10 INCHES DEEP OR DEEPER SIMILAR TO THOSE PROVIDED BY STUEWE & SONS OF CORVALLIS, OREGON. THIS WILL ENSURE GOOD SURVIVAL WITHOUT SUPPLEMENTAL IRRIGATION BEYOND THE FIRST YEAR. 3. PLACEMENT OF SHRUBS WITHIN THE CLUSTERS SHALL VARY BETWEEN 3 FEET ON CENTER AND 6 FEET ON CENTER. THESE CLUSTERS SHALL BE PLACED IN EXISTING OPENINGS AND AREAS DISTURBED BY EXCAVATION AND WEED CONTROL ACTIVITIES. 4. EACH TREE AND SHRUB SHALL HAVE A FERTILIZER PACK PLACED IN THE BOTTOM OF THE PLANTING HOLE PRIOR TO BACKFILLING. FERTILIZERS SHALL BE SLOW RELEASE PRODUCTS THAT WILL NOT RESULT IN NUTRIENT RUNOFF INTO AQUATIC SYSTEMS. 5. MULCH 3 INCHES DEEP SHALL BE PLACED IN AN 18 INCH DIAMETER RING AROUND EACH PLANT TO PREVENT INVASIVE SPECIES OR NATIVE GRASSES FROM OUT - COMPETING THE PLANT AND TO HELP MAINTAIN SOIL MOISTURE AS PER CITY OF SEATTLE SPECIFICATION 9- 14.4(5) SPECIFICATION FOR DECOMPOSED ORGANIC MULCH AMENDMENT. 6. HERBACEOUS AND EMERGENT SPECIES SHALL BE PLANTED IN NATURAL APPEARING GROUPS IN THE RE- ESTABLISHED WETLANDS. THESE SPECIES SHALL BE SPACED AT 2 FT TO 3 FT IN AREAS OF SUITABLE HYDROLOGY. 7. CEDAR SHALL BE PLANTED IN TWO FOOT BY SIX FOOT RAISED PLANTING AREAS CREATED BY USING COTTONWOOD DOWNFALL FOR THE SIDES AND ENDS. SOIL FOR PLANTING BEDS SHALL BE TOP SOIL TYPE A AS SPECIFIED BY CITY OF SEATTLE SPECIFICATION 9- 14.1(1) TOP SOIL TYPE A. THE PLANTING BEDS SHALL BE CONSTRUCTED IN THE DRY SEASON AND TWO CEDAR TREES SHALL BE PLANTED IN EACH BED DURING THE APPROVED PLANTING WINDOW. SEE DETAIL 1/P4. 8. ENHANCEMENT IN ZONE 3 AND ZONE 4 SHALL BE PERFORMED BY REMOVING EXOTIC VEGETATION AND PLANTING NATIVE SHRUBS AND DOUGLAS FIR. BECAUSE EXISTING NATIVE VEGETATION IS DENSE OVER MUCH OF THE AREA, SHRUB PLANTINGS SHALL BE CONCENTRATED IN AREAS OF WEED REMOVAL 9. SEEDING OF GRASSES SHALL BE CONDUCTED ON THE ENTIRE AREA OF ZONE 1 AND IN DISTURBED AREAS OR WHERE ENHANCEMENT IS NEEDED IN ZONE 2, ZONE 3 AND ZONE 4. SEED MAY BE APPLIED BY BROADCASTING AND RAKING OR WITH A HYDROSEEDER FOLLOWED BY HYDRO- MULCHING OVER THE SEEDED AREAS. TACKIFIER CAN BE DETRIMENTAL TO AQUATIC ORGANISMS AND SHALL BE EXCLUDED FROM THE SEED APPLICATION PROCESS. SEED MIXES FOR EACH ZONE ARE IDENTIFIED IN THE SEED MIXES AND APPLICATION RATES TABLE ON THIS SHEET. ALL GRASS MIXES MUST MEET CITY OF SEATTLE SPECIFICATION 9- 14.2(1) FOR GRASS MIXES. 10. REGREEN (A STERILE WHEATGRASS COVER CROP) SHALL BE USED IN THE SEED MIX FOR ZONE 1 - WETLAND RE- ESTABLISHMENT AREA TO PROVIDE COVER AND PREVENT EROSION DURING THE FIRST YEAR. IT IS INTENDED THAT THIS SPECIES WILL DIE OUT IN SUCCESSIVE YEARS, ALLOWING THE NATIVE SPECIES TO FULLY COLONIZE THE SITE. 11. TREES AND SHRUBS FROM THE ZONE 1 MIX SHOULD BE PLANTED THROUGH THE EROSION MAT ON THE SLOPE IMMEDIATELY ABOVE THE RE- ESTABLISHED WETLAND AREA. THIS CAN BE DONE BY MAKING AN X- SHAPED CUT IN THE FABRIC, FOLDING THE FLAPS BACK, PLANTING THE PLANT, FOLDING BACK THE FLAPS AND FASTENING THE FLAPS WITH GROUND STAPLES. HERRERA 2200 SbOh Avenue Suite 1100 Seattle, Washington 98121 -1820 206441 -9080 206- 441 -9108 FAX CONSULTANTS MO erma S„nine.com APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 BY: DIRECTOR. CONTRACTING SERVICES NAME OR INITIALS AND DATE DEEMED L BA 1EK 02/06/2008 CHECKED A AZOUS 02 /06/2008 IRTIAL.S AND DATE REVIEWED: DES. CONTE SOOT PROD. MGR DRAWN L IURN6OE 02/06/2008 CHECKED M. EMBANK 02 /06/2008 RECEIVED REVD AS BUILT AL WO ONE N AZOIOYQ Wm 11E ON OF SUCK SWOON nAe NO NUM- MOO AO MICR WGYZNIS MOM WI H EMMA 0-0L.1 OF no 0*OT um. SEED MIXES AND APPLICATION RATES Q co cn La 0 CD P2 PUGET CREEK NATURAL AREA PLANTING UST the Public Utilities ORDINANCE N0. FUND: SCALE AS NITER City of Seattle Chuck Clarke, Director APPROVED INSPECTOR'S 8001 NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN z 0 PC C333205 R/W co VAULT PLAN NO. SHEET 10 OF 13 SPECIES PERCENT OF MIX PLS (PURE LIVE SEED) (POUNDS /ACRE) TOTAL PLS (POUNDS) ZONE 1 • , / ♦1111♦ ♦����� CAMAGROSTIS CANADENSIS (BLUE JOINT) % 0.6 LBS 0.3 LBS DESCHAMPISA CESPITOSA (TUFTED HAIRGRASS) 32% 10.4 LBS 5.8 LBS ♦����♦ 1 ������1 GLYCERIA ELATA (FOWL MANNAGRASS) 32% 0.8 LBS 0.4 LBS TRITICUM AESTNUM (REGREEN HYBRID) 3% 16.2 LBS 9.0 LBS ZONE 2 (ASSUMING APPROX 0.8 ACRES OF DISTURBANCE) • T + T + T + T + + + + • + + + • + + + + + + + + + + + • + + + CAMAGROSTIS (BLUE JOINT) 33% 0.6 LBS 0.5 LBS DESCHAMPISA CESPITOSA (TUFTED HAIRGRASS) 33% 10.4 LBS 8.3 LBS GLYCERIA ELATA (FOWL MANNAGRASS) 34% 0.8 LBS 0.6 LBS ZONE 3 (ASSUMING APPROX 0.6 ACRES OF DISTURBANCE) OS*0 WS •••S••• ,/,,,, / .0/S, See. OS 10.0001.1 Otel.tt ELYMUS GLAUCUS (BLUE WILD RYE) 33% 14.2 LBS 9.9 LBS BROMUS SITCHENSIS (ALASKA BROME) 33% 29.6 LBS 20.7 LBS FESTUCA RUBRA (CREEPING RED FESCUE) 34% 3.8 LBS 2.7 LBS ZONE 4 (ASSUMING APPROX 0.3 ACRES OF DISTURBANCE) WILD E(BLUE LYMUS GLAUCRYE) U) 33% 14.2 LBS 4.3 LBS BROMUS SITCHENSIS (ALASKA BROME) 33% 29.6 LBS 8.9 LETS FESTG R RUBRA A (CREEPING RED FESCUE) 34% 3.8 LBS 1.2 LBS Q co cn La 0 CD P2 PUGET CREEK NATURAL AREA PLANTING UST the Public Utilities ORDINANCE N0. FUND: SCALE AS NITER City of Seattle Chuck Clarke, Director APPROVED INSPECTOR'S 8001 NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN z 0 PC C333205 R/W co VAULT PLAN NO. SHEET 10 OF 13 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 GENERAL SPECIFICATION: A WEED CONTROL PLAN SHALL BE PREPARED INCORPORATES THE FOLLOWING PROVISIONS: 1. INVASIVE WEEDS ON THE MITIGATION SITE A NON- RESIDUAL HERBICIDE. 2. AN INTEGRATED PEST MANAGEMENT (IPM) POSSIBLE. 3. AN APPLICATION MUST BE SUBMITTED TO BY THE CONTRACTOR AND SUBMITTED TO THE SPU PROJECT ENGINEER FOR APPROVAL THAT SHALL BE ERADICATED USING A COMBINATION OF MECHANICAL REMOVAL AND TREATMENT WITH APPROACH SHALL BE TAKEN THAT WILL USE PHYSICAL METHODS OF CONTROL WHENEVER SEATTLE PUBLIC UTILITIES FOR APPROVAL OF ANY HERBICIDE USE. 4. ALL HERBICIDES WILL BE APPLIED AS AUTHORIZED BY LAW AND AT THE APPLICATION RATES AND CONDITIONS SPECIFIED BY THE MANUFACTURER OF THE PRODUCT. 5. A LICENSED HERBICIDE APPLICATOR SHALL BE HIRED TO APPLY ALL HERBICIDES. 6. ORGANIC MATERIAL GENERATED BY WEED REMOVAL SHALL BE DISPOSED OF AS SPECIFIED BY THE CITY OF SEATTLE. SPECIFIC TREATMENTS: SPECIES SCIENTIFIC NAME (COMMON NAME) DEGREE OF INFESTATION CONTROL METHOD HERBICIDE APPLICATION FOLLOW -UP TREATMENTS RUBUS ARMENTACUS (HIMALAYAN BLACKBERRY) 25% TO 49% OF THE SITE CUT PRIOR TO SEED SET AND HERBICIDE APPLICATION TO RESPROUTS. APPLY GLYPHOSATE WITH A DYE FOR MARKING TREATED PLANTS. APPLY TO RESPROUTTNG INDIVIDUALS IN LATE SUMMER OR FALL WHEN RE- GROWTH IS AT LEAST 2 FT TALL. FOLLOW UP CUTTING AND TREATMENT OF SPROUTS YEARLY FOR THREE YEARS. CONVOLVULUS ARVENIS (BINDWEED) 5 % OF THE SITE CUTTING AND PULLING IS NOT EFFECTIVE USE OF GLYPHOSATE IS RECOMMENDED BY KING COUNTY. APPLY GLYPHOSATE WITH WICK APPLICATOR. AVOID CONTACT WITH NATIVE VEGETATION. RE -APPLY ONCE MORE THE FIRST YEAR AFTER FOLIAGE HAS RE- APPEARED THEN YEARLY FOR THREE YEARS. POLYGONUM CUSPIDATUM (JAPANESE KNOTWEED) 5% OF THE SITE STEM INJECTION FOLLOWED BY REMOVAL OF DEAD CANES. USE STEM INJECTION GUN, MARKER PAINT AND CORK FOR THE NEEDLE. FOR STEM INJECTION USE 'AQUAMASTER'AND CONDUCT FROM MID JUNE TO END OF SEPTEMBER. INJECT 3 TO 5 ML INTO STEM BETWEEN FIRST AND SECOND NODES OR HIGHER F LOWER STEM IS TOO WOODY. FOLLOW UP CUTTING (OR RE- INJECTION) OF RESPROUTS SPRING, SUMMER, AND FALL FOR 3 YEARS. CYTISUS SCOPARIUS (SCOTS BROOM) 5% OF SITE, MOSTLY IN WETLAND BUFFERS CUT NEAR GROUND LEVEL WHEN PLANTS BEGIN TO FLOWER. NONE FOLLOW UP CUTTING OF RESPROUTS YEARLY FOR 3 YEARS. ILEX AQUIFOLIUM (ENGLISH NY) LESS THAN 5% HAND PULL TO REMOVE AS MUCH ROOT AS POSSIBLE. WORK SYSTEMATICALLY TO AVOID MISSING ROOT MATERIAL NONE FOLLOW UP PULLING YEARLY FOR 3 YEARS. PRUNUS LAUROCERASUS (CHERRY LAUREL) TWO DISTINCT PATCHES AND SCATTERED INDIVIDUALS CUTTING AT GROUND LEVEL AND REMOVAL OF MATERIAL APPLY GLYPHOSATE WITH A DYE FOR MARKING TREATED PLANTS. APPLY TO RESPROUTING INDIVIDUALS IN LATE SUMMER OR FALL WHEN RE- GROWTH IS AT LEAST 2 FT TALL SOLANUM DULCAMARA (BITTERSWEET NIGHT SHADE) SCATTERED OCCURRENCE PULLING TO GET AS MUCH ROOT AS POSSIBLE AND REMOVAL OF ALL MATERIAL FROM SITE. NONE FOLLOW UP PULLING YEARLY FOR 3 YEARS. CRATAEGUS MONOGYNA (ENGLISH HAWTHORNE) SCATTERED OCCURRENCE CUTTING AT GROUND LEVEL TREATMENT WITH AND REMOVAL OF MATERIAL BECAUSE CUT MATERIAL CAN RE- SPROUT. APPLY GLYPHOSATE WITH A DYE FOR MARKING TREATED PLANTS. APPLY TO RESPROUTTNG INDIVIDUALS IN LATE SUMMER OR FALL WHEN RE- GROWTH IS AT LEAST 2 FT TALL Gi HERRERA 2200 Sixth Avenue Suite 1100 Sea01e. Washington 98121 -1820 206- 441 -9080 200- 441 -9108 FAX BIVFONFENTAL C0161ATAMTS I0W,Mw"OMmilo APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 BY DIRECTOR, CONTRACTING SEFMCtS NAME OR I01NLS AND DATE DESIGNED L BMLEX 02/08/2008 PECKED k AZDUS 02/08/2008 DJITWS AND DATE REVIEWED: DES. SOOT CONST. PRQI. MGR. DRAWN L TURNOIGE 02/06/2008 D4EEC D U EWBANN 02/06/2008 KLEMM RESEED AS BUILT ILL WOK DOE 11 ACI»eN12 riM OE UTY OF MAME /W WIO nNe MO SEM- WTDB MO OMR COMMITS OWED FOR M =MI 0-023 OF M AMER mom_ Z 0 LLI 0 0 W P3 PUGET CREEK NATURAL AREA WEED CONTROL PLAN the City of Seattle PubIIC Chuck Clarke, Director Utilities ORODUNCE N0. FUND: SCALE: AS NOTED APPROVED INSPECTOR'S BOOK NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN 0 PC C333205 R/W CO VAULT PLAN NO. SHEET 11 OF 13 1 1 1 1 1 a 1 1 1 1 1 1 1 1 1 1 1 1 1 CEDAR SEEDLINGS — 8' MIN NOTES: A. CONSTRUCT BOXES DURING THE DRY SEASON: 1. CUT EXISTING DOWN COTTONWOOD LOGS IN 3 FT LENGTHS AND 6 FT LENGTHS. 2. PLACE TWO 6 FT LOGS APPROXIMATELY 2 FT APART. 3. PLACE TWO 3 FT LOGS PERPENDICULAR TO THE LONG LOGS TO FORM A BOX. 4. DRIVE TWO 2 INCH BY 2 INCH BY 3 FT STAKES ON THE OUT SIDE OF THE PLANTING BOX ONE FOOT FROM EACH END OF THE 6 FOOT LOGS AND 6 INCHES FROM EACH END OF THE 3 FOOT LOG. 5. FILL THE PLANTING BOX WITH MAX 12' SOIL OF TYPE A TOP SOIL AS SPECIFIED BY CITY OF SEATTLE SPECIFICATION 9- 14.1(1) TOP SOIL TYPE A. 6. LOCATION OF PLANTING BOXES WILL BE STAKED BY A WETLAND BIOLOGIST. B. PLANT CEDARS IN BOXES DURING THE PLANTING WINDOW WHEN MOISTURE CONDITIONS ARE OPTIMUM: 1. EXCAVATE TWO PLANTING HOLES ONE FOOT IN FROM EACH END OF THE BOX. 2. PLACE A FERTILIZER PACK IN THE BOTTOM OF EACH HOLE. 3. PLACE THE PLANTS AND BACKFILL TO THE LEVEL OF THE PLANT IN THE CONTAINER. 4. DO NOT LEAVE AIR POCKETS OR DAMAGE ROOTS DURING PLANTING OPERATION. ELEVATION 2' x2' x3' WOODEN STAKE FILL WITH MAX 12' SOIL FROM COTTONWOOD ROOT WADS 3' IJ 6' PLAN CEDAR PLANTING DETAIL — PUGET CREEK SITE (1\ SCALE: 1' =1' — 3' BARK MULCH, KEEP 1' AWAY FROM TRUNK. APPLY MULCH AT 18' DIA FOR SHRUBS AND TREES FINISH GRADE PLANT AT SAME LEVEL AS GROWN 7 6' GREATER THAN ROOTBALL OR CONTAINER DEPTH EXISTWG NATIVE SOIL f7 EXCAVATE SOIL FOR PLANTING TO DIMENSIONS SHOWN. FIRM SOIL AROUND ROOTBALL DO NOT LEAVE AIR POCKETS. DO NOT DAMAGE ROOTS DURING PLANTING OPERATIONS GI HERRERA 2200 Sixth Avenue Suite 1100 Seems. Washington 98121 -1820 208- 441 -9080 208. 441 -9108 FAX CONSULTANTS lezdkranchetnnlinC.COM APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION SEATTLE. WASHINGTON 20 BY: DIRECTOR. CONTRACTING SERVICES NAME OR INITIALS AND DATE 0080802 L BAUD( 02/06/2008 CHECKED A. AZOUS 02/06 /2006 INITIALS AND DATE REVIEWED: SOOT COST. PROJ. NGR. DRAWN L IURNI00E 02/06/2008 CHECKED Y. MAW 02/06 /2008 RECEIVED REVISED AS WALT XL MK 00ML W AL@mWCE WM T• CM 6 RFATTLE SWAMI RAM MO 0aI CM= No OVER 006011) 06106 10O N 0006 0-6J 6 TE MELT WMa PLANTING HOLE\EXCAVATION 2x GREATER THAN ROOTBALL OR CONTAINER WIDTH CONTAINER SHRUB AND TREE PLANTING DETAIL NOT TO SCALE — PLANTING cn z. IH ( w co P4 DETAILS Me Public Utilities ORDINANCE NO. FUND: SCALE AS NOTED City of Seattle Chuck Clarke, Director APPROJED 8SPECTOR'S BOOK NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN Z 0 PC C333205 R/W Co VAULT PLAN NO. SHEr r 12 or 13 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ■ r gE E 100 0 100 200 HORIZ. 1"=100' LEGEND: It. • ♦ +� ♦ a + + + ZONE 1 WETLAND B BUFFER ENHANCEMENT AREA ZONE 2 WETLAND A BUFFER SEEDING AREA WETLAND WETLAND B 50' BUFFER WETLAND B 100' BUFFER TREATMENT POND BOUNDARY WETLAND A TREATMENT POND BOUNDARY' WETLAND S ZONE 2 WETLAND A BUFFER SEEDING A APPROX 0.65 ACRES REA GENERAL PLANTING NOTES: 1. SEE DWG P4 FOR PLANTING DETAILS. 2. PLANTS SHALL BE CONTAINER GROWN AND FROM SEED SOURCES FROM WEST OF THE CASCADES AND FROM A SIMILAR, ELEVATION. 3. TREES AND SHRUBS SHALL BE PROVIDED IN CONTAINERS AT LEAST 10 INCHES DEEP OR DEEPER SIMILAR TO THOSE PROVIDED BY STUEWE & SONS OF CORVALLIS, OREGON. THIS WILL ENSURE GOOD SURVIVAL WITHOUT SUPPLEMENTAL IRRIGATION BEYOND THE FIRST YEAR. PLANTS WILL MEET CITY OF SEATTLE SPECIFICATION 9 -14.6. 4. PLACEMENT OF SHRUBS WITHIN THE CLUSTERS SHALL VARY BETWEEN 3 FEET ON CENTER AND 6 FEET ON CENTER. 5. EACH TREE AND SHRUB SHALL HAVE A FERTILIZER PACK PLACED IN THE BOTTOM OF THE PLANTING HOLE PRIOR TO BACKFILUNG. FERTILIZERS SHALL BE SLOW RELEASE PRODUCTS THAT WILL NOT RESULT IN NUTRIENT RUNOFF INTO AQUATIC SYSTEMS. 6. MULCH 3 INCHES DEEP SHALL BE PLACED IN AN 1B INCH DIAMETER RING AROUND EACH PLANT TO PREVENT INVASIVE SPECIES OR NATIVE GRASSES FROM OUT - COMPETING THE PLANT AND TO HELP MAINTAIN SOIL MOISTURE. MULCH MUST MEET CITY OF SEATTLE SPECIFICATION 9- 14.4(5) DECOMPOSED ORGANIC MULCH AMENDMENT. 7. SEEDING OF GRASSES SHALL BE CONDUCTED ON THE ENTIRE AREA OF ZONE 1 AND ZONE 2. SEED MAY BE APPLIED BY BROADCASTING AND RAKING OR WITH A HYDROSEEDER FOLLOWED BY HYDRO- MULCHING OVER THE SEEDED AREAS. TACKI IER CAN BE DETRIMENTAL TO AQUATIC ORGANISMS AND WILL BE EXCLUDED FROM THE SEED APPLICATION PROCESS. SEED MIXES FOR EACH ZONE SHALL BE IDENTIFIED. GRASS MIXES MUST MEET CITY OF SEATTLE SPECIFICATION 9- 14.2(1). 8. REGREEN (A STERILE WHEATGRASS COVER CROP) SHALL BE USED IN THE SEED MIX FOR ZONE 1 - WETLAND B BUFFER AND ZONE 2 - WETLAND A BUFFER TO PROVIDE COVER AND PREVENT EROSION DURING THE FIRST YEAR. IT IS INTENDED THAT THIS SPECIES WILL DIE OUT IN SUCCESSIVE YEARS, ALLOWING THE NATIVE SPECIES TO FULLY COLONIZE THE SITE. 9. NO TREES OR SHRUBS SHALL BE PLANTED IN ZONE 2. \ C- i icy. / 1 il;v . ' .' L. y • ACCESS . ROAD ZONE 1 WETLAND B BUrrLk ENHANCEMENT AREA APPROX 0.15 ACRES r\ t` t\ t;\ \ t\ C•\ t•. WETLAND B ■ • • � � • :::fit \ t= :•:•: \ t 1:::•t • ti tr._.t 1' tie �,T ♦ -i SEDIMENT MANAGEMENT AREA GI HERRERA 2200 SOON Avenue Suite 1100 Seattle. Washington 98121_1820 206.441 -9080 208.441 -9108 FAX CONSULTARa ROMMAmM,tl1YERmD APPROVED FOR ADVERTISING FRED PODESTA DEPARTMENT OF EXECUTIVE ADMINISTRATION 1 SEATTLE. WASHINGTON 20 er: DIRECTOR. CONTRACTING SERVICES NAME OR WITIALS AND DATE DES&NE) L. MUSK 02/06 /2006 acco D A. AMOUS 02/06 /2006 INIIULLS AND DATE REVIEWED: DES. SOOT CONST. PROD. MCI DRAWN L 1U08 E 02 /08/2006 QIEOCED I EWBANK 02/06/2008 RECEIVED REVISED AS BUILT ALL AIMO DOW P$ 1rCOMOC 81, 1,E COT Di MOIL EpONO RAO MO F COMM MO OMER DOAEERIS OILED RAM =AO 0-02i 6 08 MEM MANUAL ZONE 1 PLANT MATERIAL SCHEDULE WETLAND INDICATOR SPECIES SCIENTIFIC NAME (COMMON NAME) ROOT CONDITION SPACING ON CENTER (FEET) ZONE 1 WETLAND B (0.15 ENHANCEMENT (0.15 ACRES) FAC+ AC ER CIRCINATUM (VINE MAPLE) CONT. AT LEAST 10 INCH DEEP 6 FT. CENTERS IN CLUMPS 15 FACU- AMELANCHIER ALNIFOLIA (SERVICE BERRY) CONT. AT LEAST 10 INCH DEEP 6 FT. CENTERS IN CLUMPS 15 FAC CRATAEGUS DOUGLASII (BLACK HAWTHORNE) CONT. AT LEAST 10 INCH DEEP 6 FT. CENTERS IN CLUMPS 15 UPLAND PSEUDOTSUGA MENZIESII (DOUGLAS FIR) CONT. AT LEAST 10 INCH DEEP 10 FT CENTERS 28 FACU ROSA GYMNOCARPA (BALD HIP ROSE) CONT. AT LEAST 10 INCH DEEP 3 FT CENTERS IN CLUMPS 45 FACU SAMBUCUS RACEMOSA (RED ELDERBERRY) CONT. AT LEAST 10 INCH DEEP 3 FT CENTERS IN CLUMPS 15, FACU SYMPHORICARPOS ALBUS (SNOWBERRY) CONT. AT LEAST 10 INCH DEEP 3 FT CENTERS IN CLUMPS' 45, SEED MIXES AND APPLICATION RATES P5 UFFER MITIGATION PLAN 11911the City of Seattle 1UbliC Chuck Clarke, Director Utilities ORDINANCE NO. SCALE AS NOTED APPROVED INSPECTORS 8008 NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN z m 'PC: C333205 R/W co VAULT PLAN NO. ,SHEET 13 OF 13 SPECIES PERCENT OF MIX PLS (PURE LIVE SEED) (POUNDS /ACRE) TOTAL PLS (POUNDS) ZONE 1 WETLAND B BUFFER SEED MIX • •• ♦������ • ��II ELYMUS GLAUCUS (BLUE WILD RYE) 33% 14.2 LBS 2.1 LBS BROMUS SITCHENSIS (ALASKA BROME) 32% 29.6 LBS 4.4 LBS ♦����♦ •�����4 •���j •����•j FESTUCA RUBRA (CREEPING RED FESCUE) 32% 3:8 LBS 1 0.6 LBS TRIIICUM AESTNUM ( REGREEN HYBRID) 3% 16.2 LBS 2.4 CBS. ZONE 2 WETLAND A BUFFER SEED MIX +T +T +T 4. ♦ + + + +++ + * + + +4' + *+ ++ + + + ♦ ♦ CAMAGROSTIS CANADENSIS (BLUE JOINT) 33% 0.6 LBS 0.4 LBS DESCHAMPISA CESPITOSA (TUFTED HAIRGRASS) 32% 10.4 LBS 6.3 LBS ** ** M + + + + + ♦ * ♦ + + a 4' * • * + ++ *+ *+ *++ + + + + 4 GLYCERIA ELATA (FOWL MANNAGRASS) 32% 0.8 LBS 0.5 LBS TRIRCUM AESTNUM ( REGREEN HYBRID) 3% 16.2 LBS 9.9 LBS P5 UFFER MITIGATION PLAN 11911the City of Seattle 1UbliC Chuck Clarke, Director Utilities ORDINANCE NO. SCALE AS NOTED APPROVED INSPECTORS 8008 NORFOLK WATER QUALITY IMPROVEMENTS MITIGATION PLAN z m 'PC: C333205 R/W co VAULT PLAN NO. ,SHEET 13 OF 13 r ATTACHMENT C Wetland Delineation Report Puget Creek Natural Area PUGET CREEK NATURAL AREA VET SAND DELINEATION REP( RT May 30, 2007 Prepared for Arnel Valmonte, Project Manager Seattle Public Utilities, Erigineering Division Prepared by Michael Bonoff, Wetland Biologist SPU Environment, Science and Technology. Section TABLE OF CONTENTS INTRODUCTION 1 METHODOLOGY 1 Literature Review 1 Delineation Approach 2 Reconnaissance 2 RESULTS 3 Literature Review History and. Land Use 3 Hydrology 3 Soils 4 Vegetation 4 Wetlands Identified • 5 Wildlife and Birds 5 Field Results Soils 5 Hydrology 6 Vegetation 6 Wetland Delineation 7 Invasive Plants 7 Man Made Changes 7 Wildlife Observations 8 WETLAND FUNTIONS AND RATING 8 FOREST STAND ASSESSMENT 8 REFERENCES 10 FIGURES Map #1 - Vicinity Map Map #2 - Wetland Delineation Map ATTACHMENTS 1 Photos of Soil Pits 2 Data Forms 3 Observed Birds, Mammals and Amphibians 4 Photos of Special. Features 5 Plant List 6 Wetland Rating Form SUMMARY A Depressional Palustrine Forested wetland (PFOd) was delineated of 3.6 acres during the week of March 10, 2007. The wetland is contained within the 6+ acre Puget Creek Natural Area, a wooded trough between 18th and 212 Avenues in West Seattle. Puget Creek runs north along the undeveloped 19th Avenue right -of -way. The western wetland edge is a gradual wide transition in an undeveloped area. The east wetland edge is .abrupt due to decades old fill and recent residential clearing. Varied vegetative structure such as mature cedar and cottonwood stands, old growth stumps and many downed trees, provides good wildlife habitat with enhancement opportunities. The wetland ranks as a Category 1I1 state rated wetland with a Seattle CAO buffer requirement of 85 feet. INTRODUCTION Purpose of the Study The Norfolk — MLK Way Sub -Basin Stormwater Improvement Project team has selected this site for the required off site mitigation. The wetland delineation and characterization will enable the project team to develop appropriate mitigation measures to be implemented in the near future. Acknowledgements SPU employees Bob Spencer and Melissa Campbell assisted in the wetland delineation. Sheryl Shapiro and Chris Woefehl provided background information and community contacts. Joe Starstead provided base maps and stream survey information. Seattle Parks Department employees Bob Blair and Lise Ward provided real estate and other background records. Study Area Description The project area is between 18th and 21st Avenues NW and between SW Brandon and SW Juneau Avenues (See Vicinity Map #I). The trough between the east and west ridges is centered along the undeveloped 19`h Avenue SW right -of -way. Elevation ranges between 195 and 200 feet above sea level for the west and east ridges respectively. The wetland trough is about 45 feet below the ridge tops. The legal description is Township 24, Range 3, Section 24. Block 14. METHODS Literature Review Pertinent wetland reports, environmental site assessments, real estate appraisals, Seattle Parks Department grant applications and other Parks records were examined. Air photos available through the City's GIS were reviewed. SPU and Parks Department employees with knowledge of the site were contacted. Delineation Approach The routine onsite determination method described in the Washington Department of Ecology Washington State Wetlands Identification and Delineation Manual methodology was used to delineate wetlands. The Ecology manual requires the use of the three - wetland parameter methodology when determining the presence or absence of wetlands. With few exceptions, all three parameters including wetland hydrology, hydric soils and hydrophytic vegetation must be present for an area under normal circumstances to meet the wetland criteria. Michael Bonoff, an SPU biologist and Wetland Scientist performed the delineation between March 10 and 13, 2007. An auger was used to sample soils in and around the wetlands. Then the representative soil pits were dug to a depth of 18 inches using a sharpshooter shovel. The south face of each pit was used for the soil observations and photos. A squeeze water bottle was used to moisten dry soils and determine their color using a Munsell Color Chart. Each hole was marked with blue wire flagging to show the wetland number and the upland or wetland location. Photos were taken of the soil pits and surrounding area (See Attachment 1). Vegetative sampling was conducted at each soil pit and dominant plant species and its percent cover was recorded. Ten meter circular plots were established with the soil pit as the most southerly point. Data forms were compiled for each location (See Attachment 2). Orange `wetland delineation boundary' ribbons ( #s A, B, 1 -40 on the west side S to N and #s 41 -60 N to S on the east side) are shown on the project base map — not part of this report. Since the Park property does not abut platted streets on all borders, labeled blue flagging was used to provide an access path for surveyors and others from the street edges. Reconnaissance An interdisciplinary group of SPU and consultant staff visited the north end of the site on November 30, 2006. The inspection was part of a search for an appropriate mitigation site for the Norfolk — MLK Way Sub -Basin Stormwater Improvements Project impacts. The group assessed the nature of the wetland and its potential to benefit from enhancements measures. 2 RESULTS LITERATURE REVIEW History and Land Use Earliest records indicated that Pope and Talbot owned the low area and surrounding property until sale to private interests after 1920 (Geo Group 1997). No evidence of logging exists in the swale since the old growth stumps have irregular features. Some stumps bear evidence (fire scars) of burning that was associated with early logging. The adjacent properties were sparsely developed with single family houses and farms during this period (Sound Environmental 2003). Rural uses persisted through the 1940s. Although the area was platted in the 1920s, it was underdeveloped until the 1940's when houses were built along 18`h and 21s1 Avenues. By the 1950s, Kroll maps and aerial photos show about a 50% build out without any clearing of the trough containing today's park. By 1969, 95% of the residential lots along the avenues were occupied by single family homes. In 1970 one or more of the lots in the southwest comer of the trough were cleared and graded along with parts of 19`h Avenue, the latter to accommodate the installation of the sanitary sewer in the right -of -way (Geo Group 1997). The Puget Creek Natural Area is designated by Seattle Parks as a "Greenspace" for preservation of special environmental resources such as wildlife habitat and wildlife corridors. The Park is part of a larger Seattle DPD Critical Area designation running from SW Brandon Street south, beyond SW Juneau Street. Hydrology The site is located in the middle of the drainage basin with the lower third of the historic creek channel piped across the Duwamish industrial zone. About 140 acres of the basin is upgradient of the wetland. However, most of the surface flow is now collected by the city stormwater system and diverted away from the creek. The inflow to the creek is then composed of surface water runoff within the topographic trough and the occasional residential or street drain discharging into the creek hillsides. Puget Creek enters the park from the south and flows northward along the eastern edge of the trough. The creek is described (Shapiro 1995) as braided and meandering in the south and less sinuous and more incised in the northern portions of the wetland. During this February visit, the southern portion of the stream channel was 10 to 15 feet wide with 8 to 10 inch water depths. The northern creek portion was 5 to 6 feet wide and 18 to 24 inches deep. Soil saturation or inundation was observed through most of the trough bottom. 3 Soils Geo Group (1995) noted that the property is underlain by the Vashon till, a dense, glacially compacted, heterogeneous, unsorted silt, sand and gravel. The unit is characterized by low infiltration rates and low vertical permeabilities. Shapiro (1995) noted gray to dark gray distinctly mottle silt loams in the trough bottom. Hillslope soils were predominately dark brown to dark yellow brown loams lacking hydric indicators, SPU (2004) soil pits noted black peaty soil in the wetland pit and dark brown silty clay in the upland pit. Vegetation Vegetation in thc southeast park quadrant was characterized in 1995 (Shapiro). A black cottonwood (Populus trichocarpa) and red alder (Alnus rubra) dominated wetland forest canopy was over Himalayan blackberry (Rubus discolor) and hardhack spirea (Spirea douglasii) dominiated shrub layer. Creeping buttercup (Ranunculus repens), slough sedge (Carex obnupta) and lady -fern (Athyriumflix femina) was found in the herbaceous layer. The upland in this quadrant was dominated by a cottonwood and cedar (Thuja plicata) overstory with Indian plum (Oemelaria cerasiformis) and blackberry dominants in the shrub layer. The herbaceous layer contained swordfern (Polystichum munitum), tall fescue (Festuca arundinacea) and orchardgrass (Dactylis glomerata). Wetland vegetation in the southeast quadrant included willow (Salix spp), red -osier dogwood (Cornus stolonifera) and salmonberry (Rubus spectabilis). In the herbaceous layer, reed canarygrass (Pharalus arindinacea), common cattail (Typha latifolia) and watercress (Rorippa nasturtium - aquaticum) were found. The upland slope contained Douglas fir (Psuedotsuga menziesii), Pacific madronas (Arbutus menziesii) and blackberry thickets. (Reader note: these observations may have been made south of the park boundaries on this east side). The northwest park quadrant and wetland boundary were characterized in 2005 (SPU). The upland slopes contained a variety of native plant species with only a minor component of invasive plants, Mature bigleaf maple (Acer macrophyllum) and red alder trees covered 30% of the hill slope while mature oceanspray (Holodiscus discolor), peafruit rose (Rosa pisocarpa), and snowberry (Symphoricarpos alba) dominated the shrub layer with sword fern dominant in the herbaceous layer. The wetland overstory was dominated by even age, pole size cottonwood, 25 to 35 years of age. The shrub layer was dominated by red stem dogwood and Himalayan blackberry with little herbaceous coverage apparent during this dormant season. The Seattle Urban Nature Map (2000) shows a Conifer- Deciduous Mixed Forest containing predominately a 5 -15 inch diameter class in the park. Invasive species are listed as Himalayan blackberry as 25 -49% cover and bindweed <5% cover. No holly, ivy or Scot's broom are mapped as being present. 4 Wetlands Identified In 1995, a wetland was identified on a reconnaissance survey on 18 adjacent undeveloped parcels that today comprise the park. (Shapiro 1995). It was characterized as a Palustrine forest, broad - leaved deciduous (PFOd), seasonally flooded wetland system. in 2004, a PFOd wetland was identified along a single lot in the northwest park quadrant (SPU 2004). Wildlife and Birds Other open spaces in this predominately single family area is Puget Park '/ mile to the north and South Seattle Community College, less than '/ mile to the east. The proximity to other wildlife habitats is illustrated on Map 1. The Seattle Parks Department (1995) has identified band- tailed pigeons and pileated woodpeckers in the park which triggers a Washington State "Priority Area" 1 or 2 habitat designation. The following song birds were identified on the reconnaissance group trip, November 30, 2006 (Deb Heiden, SPU Habitat Specfier): black capped chickadee, song sparrow, Bewick's wren and bushtit. A list of previously observed birds, amphibians, reptiles and mammals is in Attachment 3. FIELD RESUL'T'S Soils Three pairs of soils pits (S.P.s #s 1, 9, 26) were established along approximately 1100 linear feet of the west wetland boundary and another pair (SP # 48) along 550 feet of the eastern boundary. The soils pit locations are shown on Map #2 and individual photos are in Attachment 1. The wetland pits along the west wetland boundary included S.P. # 1; a 10YR 3/2 loamy sand with 50% yellowish brown organic streaking (10YR 5/6). S. P. # 9 is a very dark grayish brown (10YR 3/2) silty clay loam with abundant dark yellowish brown redoximorphic features (10YR 4/6). S.P.# 26 is a black (10YR 2/1) loam. These soil features are different than the 2004 SPU wetland pit of peaty soil. The wetland pit along the east boundary, S.P. # 48 is a black (10YR 2/1) silt loam with abundant brownish yellow and yellow redox features (10YR 6/8 and 10YR 7/6) beginning at 8 inches of depth. These soil features are consistent with the 1997 (Shapiro) recorded soil features in the vicinity of dark gray, distinctly mottled silt loamy. The upland pits along the west boundary included S.P. #1 as a very dark grayish brown (10YR) 3/2 silt loam to 12 inches and a dark yellowish brown (10YR 4/6) silty clay loam (with pebbles sized up to V2 inch) to 16 inches deep. S.P. #9 is a yellowish brown (10YR 5/4) clay loam to 16 inches. S.P. # 26 is a very dark grayish brown (10YR 3/2) silt loam to 5 inches and a dark brown (7.5YR 3/3) silt loam with abundant reddish yellow (7.5 YR 6/8) redox to 16 inches deep. These soil features are consistent with the 2004 SPU 5 upland pit of dark brown silty clay. The upland pit along the east boundary, S.P. # 48, is a yellowish brown (10 YR 5/4) loamy sand (with pebbles sized up to % inch) to 16 inches. These soil features are consistent with the 1997 (Shapiro) recorded soil features in the vicinity of dark brown to dark yellowish brown loams. Hydrology Wetland soil pits had standing water between 3 and 9 inches deep and soils were saturated to the surface. Upland S.P.s had no free water and saturated soil was no closer to the surface than 11 inches depth. Within the wetland, there was weakly running water in the stream channels and ponded water throughout (Photo 415). There was no surface water flow off the west side although a drainage swale feature was noted near Wetland Flag 9. On the east side there are two swales discharging water into the wetland near Flags #t14 -45, 56 (Photos #s 6, 7, 8), 56. An isolated pond of 20' by 25' in size and about 30 inches deep is located near Wetland Flag # 29 (Photo 9). It has recently been enlarged by the winter blowdown of a mature tree on its edge. See Attachment 4 - Photos of Special Features, Vegetation The four wetland plots are dominated by alder and black cottonwood in the overstory, dogwood, hawthorne (Crataegus spp), blackberry and salmonberry ( Rubus spectabilis) in the shrub layer and sword fern and big leaf avens (Geum macrophyllum) in the herb layer. Indian plum, red cedar, black locust (Robinia psuedoacacia), beaked hazelnut (Corvlus cornuta), English laurel ( Prunus laurocerasus) and English holly (Ilex aquilifolium) were less dominant. Slough sedge was recorded in one plot. The recorded dominants are consistent with the previous wetland reconnaissance and wetland delineation (Shapiro 1995, SPU 2004). The 4 upland plots are dominated by Western red cedar, red alder, bitter cherry (Prunus emarginata), and black cottonwood. The shrub layer is dominated by blackberry, Indian plum, beaked hazelnut, snowbenry and laurel, with sword fern the herbaceous dominant. Also less dominant are holly, black locust, trailing blackberry (Rubus uranus). Present are dogwood, domestic cherry, salmonberry, bleeding heart (Maianthenum dilatatum) and western trillium (Trillium ovatum). A complete plant list is in Attachment 5 and is a compilation of this delineation as well as previous work (Shapiro 1997, SPU 2004). Wetland Delineation A Palustrine Forested wetland (PFOd) was delineated of 3.6 acres. Invasive Plants The Park contains plants listed on the King County Noxious Weed List as Non - designated Noxious Weeds where control is recommended but not required. Japanese 6 1 1 i 1 1 1 1 1 1 1 1 1 knotweed (Polygonum cuspiatum) is the largest threat to the native plants here (See Map#2). It is east of the creek channel, 150 feet south of SW Brandon Street. Holly and laurel are widespread on the west upland side with blackberry being a codominant on the slopes and into the wetland. A mature laurel hedge straddles the property line to the wetland edge near Flag #' 14. Ivy is a major understory component found over the wetland soil, hillslope and on trees on the east side, Herb Robert (Geranium robertiium) is present with fess frequency of holly and laurel. Reed canarygrass is a minor component in the wetland. Manmade Changes The major wetland disturbance was the installation of the sewer line and the associated creek ditches in the 1970s period. The construction must have resulted in the removal of some mature deciduous trees, created a fill berm the length of the right -of -way and altered hydrology. Site photos (Attachment 4) illustrate other manmade changes to the east buffer and the wetland. Map #2 indicates their location. A four rail wood fence (between Flag #s 14- 15) and fragments of metal fencing nearby is the only sign of recent disturbance along the west boundary. The east buffer has been disturbed recently and in the past. Fairly new house construction on "back lots" (Flag #s 56 -60, Photos #s 1, 2) has required clearing and grading to the wetland edge. The side sewer connection for these 2two homes has necessitated removal of _woody vegetation in a 20 -foot wide swath (Flag # 58, Photo #3). This work was preceded by a 1995 wetland delineation report by B -12 Associates, Job # 94 -124 (Jacobsen 2007). To the north, the flat areas on the top of the slopes are being used for active residential uses (Flag #s 42, 43, Photo #4). As for decades old disturbances, existing slopes were over steepened by the addition of fill in the upland bordering Flag #s 41 to 44 (Photo #5). Here along slope margins concrete, metal and tires (Flag #40) are exposed as well as miscellaneous discarded items such as a steel tank (Flag #40), an oil drum and cast iron tub. Also in a previous decade, fill was added to create a roadbed leading into to the wetland (Flag #s 51 -52). In this vicinity a shallow ditch (2 feet wide and 6 inches deep) runs along the base of the fill slope (Flag #s 49 -50). Rusty water is discharged from a buried pipe in one of two swales contributing surface water flow to the wetland. (Flag #56, Photo #6). The SPU March. 2007 survey will reveal whether any trespass issues exist along the east park boundary. Wildlife Observations Signs of beaver activity were observed in the wetland center. A 20 inch diameter cottonwood was girdled and several blowdown deciduous tops were severed at about 6 inches in diameter. There was no sign of damming although there was ponding throughout the wetland. No small sapling cuts were seen. Several mid day bird observations were made. A pair of red - shafted Northern flickers was observed on a mature cottonwood along SW Juneau Street. A hawk perching on a 7 mature cottonwood along SW Brandon Street was observed. Several common crows were seen and 5 scattered crow nests were noted. A mallard duck was seen in the ponded water. WETLAND FUNCTIONS AND RATING The wetland ranks as a Category III under the Washington State Rating System. It was classified as a Depressional HGM Class based on the entire wetland being ponded or saturated to the surface at some time of year. See Attachment 6 for the Wetland Rating Form. The total score is 44 within the 30 -50 point range fora Category Ill wetland. The wetland provides moderate hydrologic functions since between 2 and 3 feet of water storage exists and the watershed drainage is between 10 and 100 times the size of the wetland. The wetland provides moderate water quality functions primarily because it has persistent, ungrazed vegetation over 95% of its area. The wetland has high potential to provide habitat because it has a varied vegetative structure, hydroperiods, and habitat features, plant richness with moderate interspersion. The wetland has moderate opportunity to provide habitat because of a wide buffer for more than half its circumference and it contains two priority habitats. It does have limited connectivity to open space and limited proximity to other wetlands, however. Category I.II wetlands with Moderate or greater habitat value require a 85 foot buffer according to the City of Seattle, Critical Areas Ordinance. Moderate habitat value is between 20 and 28 points for this Seattle category; this wetland scored 24 points. FOREST STAND ASSESSMENT Deciduous tree cover dominates the wetland trough and adjacent slopes. Black cottonwood is the most common species in the wetland with 3 age classes present. Mature cottonwood up to 4 feet in diameter is found along the wetland edges, mostly in the Southeast quadrant. There is an abundance of vigorously growing trees in the 12 -18 inch and 1 -3 inch diameter age classes throughout the wetland. Pacific willow regeneration and a few mature trees are also scattered throughout the wetland. Sitka mountain ash, hawthorne and black locust are found along both sides of the west boundary. Dogwood is along all boundaries with densities that exclude other shrubs in parts of the southeast quadrant. Blowdown from the December 2006 windstorm is extensive, reducing wetland canopy cover by an estimated 10 -20% overall. Greater losses were sustained in the northwest wetland and buffer quadrant. The downed timber has created varied micro sites for plant establishment and increased biomass available for insect colonization. The blowdown will also make the wetland more insular from human intrusion since the downed logs and increased shrub growth from more direct sunlight will restrict physical access. 8 The buffer characteristics differ on each side. The east buffer, constrained by backyard clearing and house construction noted above, consists of 20 -30 year old alder with a few maples in a narrow to non existent buffer. Due to fill slopes, the transition between wetland and upland in other areas is abrupt. There is close to 100% crown closure. No conifer was seen on this side with the exception of a property line of Douglas fir leading to the park's southeast corner. The transition zone from wetland to upland is broad on the west side due to a more gentle topographic change and the absence of fill. Alder, especially in the northwest quadrant, dominates the west buffer. Scattered fir and cedar, greater than 18 inches in diameter, are found on the hillside. Black locust, hawthorne and Sitka mountain ash join cedar and the occasional fir along the wetland edge of the west boundary. Micro habitats of note are: • Grove of 1.5 cedar including one species with 4'h foot diameter (and other old growth form). All others are between 13 and 22 inches in diameter) from Flag #s 8 -11 (Photo #s 10, 11) • Twin mature cedar with one broken top 30 feet high ( Flag #1 8, Photos # 12) • Old growth stumps 5 to 15 feet high and logs greater than 4 feet in diameter (Flag #s 1, 3, 22 -25, 28 (Photo #s 13, 14) • Cedar regeneration patch (Flag #22). • Two grand .firs greater than 20 inches in diameter (Flag # 6) FIGURES Map #1 - Vicinity Map Map #2 - Wetland Delineation Map Map #3 - Proximity to Open Space ATTACHMENTS 1 Photos of Soil Pits 2 Data Forms 3 Observed Birds, Mammals and. Amphibians 4 Photos of Special Features 5 Plant List 6 Wetland Rating Form 9 REFERENCES Geo Group Northwest Inc 1997. Level 1 Environmental Site Assessment for Gutschmidt property, #E 0865. Prepared for the Seattle Parks Department, November 26, 1997. Jacobson, Bryon 2007. Neighbor at 5469 18th Ave SW, near wetland flag #59. Personal communication March 23 and 30, 2007. Seattle Parks Department 1995. Puget Creek Natural Area Land Acquisition - Application to the Washington Interagency Committee for Outdoor Recreation, July 1, 1995. Seattle Public Utility 2004. Wetland Delineation of Ekshtut Property, 5400 Block of 19th Avenue SW. Prepared for Seattle for Seattle Parks Department, December 12, 2004. Seattle Urban Nature Project 2000. Habitats on Seattle Public Lands, Invasive Species 'Distribution Map for Camp Long, Longfellow Creek and Vicinity, 1st edition, September 30, 2000. Shapiro and Associates 1995. Wetland reconnaissance of the Puget Creek Parcels ( #6955006). Prepared for Lamb Hanson Lamb, Appraisal Associates, February 16, 1995. Sound Environmental Strategies 2003. Phase One Environmental Site Assessment for Ekshtut Property. Prepared for Seattle Parks Department, August 18, 2003. Washington Department of Ecology, 2004. Washington State Wetland. Rating System for Western Washington. Pub #04 -06 -025 Washington Department of Ecology, 1997. Washington State Wetland Identification and Delineation Manual. Pub. #96 -94. Munsell Color, 1988. Munsell Soil Color charts. Kollmorgen Instruments Corp., Baltimore, MD. USDA Natural Resources Conservation District, 1996, Key to Field Indicators of Hydric Soils, Version 3.2, July 1996. 10 Camp Long, Longfellow Creek & Vicinity 1 Invasive Species Distribution Map Key 06,00‘ "6•11.% tow. 1 1 towi SO. PAM ie.., 0 0•C0 Hite% caw fl 62 DPI cowl WattSwasla Ornli,k" L_L Longfellow Creek Greenspace • W „A Camp Long • P le. r Delridge Playfield LI (!) JI- 1 1 --, -1"1----1* -I— _LI 1 _..0__J__0 . 1. _ MAP #1 Er Duwamish Public Access -- Park Nadi. Wand Greg Davis Park Puget q, :1 Creek ?..1.Natural A • ,Y• tAkn\i Kellogg Island Longfellow Creek Greenspace 543de Ude. rera eleeerseuemem.“ lea teed., 000 401 FOREST TYPES Cant,. awes, atattann Forest CrAitaiiDemiduous Miami FaNtst Deektionut Tome" • Rlotmm Tot. 011111111.10.141.1. ern 00010a 0001. 110.4.,0 00‘ 01■1011 titan* our. iNtittAt. PI_. Ate OW Peen. Pee 1.1■2011 .0 maim natal. eavol 1.4•1apnel Habitats on Seattle Public Lands - ist Edition FOREST SOIL CLASSES [2.1 e S. ittintier M6 Or Warn.. M10 20' dlammei 0 20 30. Moo. 30' ilatitto Kest, .01101100 010.71 NM. 11.01010 mune,. 010■04.0 0.0,00100.111. ICValnellay {1.1.1 .00 4.1.0 it 0.90 el01110111111.17.01101.., OPEN CANOPY LI Batch arAl Molt r_D SatowN Vegetated F-1 Grasslano Shrub Savannah C...1 &valeta." EaSTAAmmt ma* ...miion ea Italy ▪ Gold elloiroc... ▪ 001101000 0 4000 01/00 1101004 ina0 010.* 1i4 0d0201. 3*Pleedbee 30, 2000 WEILAND TYPES Fwatied Wefiand Scnte-Strub INttisnd Emmotat Wetland ralOw. Was Vegetated Wetland Donn Want V40.14 L. 1. Shawn with Std &Awn with tholual Bad - bidluanced Sues, RN. DEVELOPED LANDSCAPE Li Otandoommo Atedlum Deeelem Newt Owelopenent Lant10.0300 Goaa11.001 landwitosd E10u0t.0 Liindsto011ToNNI landscaped Ix Swat.. Ntibacto. Row C., Orttiard of linty.," OTHEA deck end Rem 1.1 010.00111 Kea ISO opt Foliancs * Community Feat.. tr. Seattle Map Number 43 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 18TH AVE SW PUGET CREEK NATURAL AREA WETLAND DELINEATION MAP#2 March 2007 Seattle Public Utilities 100 50 0 100 200 SCALE IN FEET WETLAND PARKS OM N MI N MN M M • • IIIIIII • • • IIIIIII I • • ATTACHMENT 1 Soil Pit #1-Wet Soil Pit #1-Upland Soil Pit #9-Wet Soil Pit #9-Upland ATTACHMENT 1 Soil Pit #26 -Wet Soil Pit #26- Upland Soil Pit #48 -Wet Soil Pit #48- Upland EPA E=F4 "et M NW MIN IMO MI MIN MR 411111 NM MI MO Projes~tUSite: p tsi Applicant/owner; % 1. `'. Investigator(s).. r . Do Normal air stance eist on ,the ft& Is the si' e significantly disturbed (atypical sit ton)'. s`theaarea *potential Paoblem Area?` Explanation ofatypical;orprobleta.area DAB FORM 1 01 Routine Wetla*d Determin*dOn (WA State Wetiatrd Deiins atmi aln**l ur 1987 Corjet WeilturdDeihreationletiunnik VEGETATION (Forstrata, indicate' = tt HYDROPEIVIIC VEGETATION INDICATORS.• % of dominants OBL, FACW, & FAC Check all indicators that apply& explain below: Visual observation of plant species grower an areas of prolonged inundation/saturation Morphological adaptations Technical Literature P tysio1pgicalfreprod nctive.adaPtations Wetland plant database Personal knowledge of regional plant. communities Other (explain Hydrophytle vegetation present? Rationale for decision/Remarks: no IIYDROLOGY Is it the growing season? Based; on: soil temp record temp other (explain) Dept of inundation Depth to free water in pit: Depth to saturated soil: inches inches inches Cheek all that apply & explain b Steam, Lake or gage data: Aerial l: hotograpbs:: Wetland hydrology present? Raaar alt, for decision/Remarks: Water yes,, ' not: on Drift Lilies:_ Drainage Pis: Oxidized Root (live roots) Channels <12 in. yes no FAC Neutral:: yes ISO Local Soil. Survey: yes no Water - stained T Other (explain) Map Unit Name (Series :& Phase) Taxonomy (subgroup) Profile Description Depth Horizon. (inches) age Class Field observations confirm Yes 1! c d Matrix can (Mansell moist) zell moist) Mettle abundance size ,&'connate Textgz^e", concretions, ltructure, ems. Drawing of soil profile (Igaticscrit�tion) .Hydr e Sell Indicate= (cl►eck all that apply) Histosol Epipedm Sulfidic Odor Aquic Moisture Regime Reducing Conditions Gleyed or Low- Cl►rarna ( -1) matrix Hydric sends: present? Rationale for decision/Rem u ehroma 2 witlx mottles or Fe Concretions fi Organic Content in Surface Layer of Sandy Soils St ang in Sandy Sails Llstcct;onNation al Hydric Soils List Other: (explain in remarks) Wetland Determination (circle) Hydrophytic.vegetation present? Hydric soils present? Wetland hydrology present? RationaleiRemaritsz no the sampling point, wiithins wetland? NOTES. Projec t/Site: pc Applitan tf owner: SP Investigator(s): DATA FARM 1 (71te Routine Wetland DebermIfl On (WA StaterWetiudDelinottion :lltsnuaia 1937 Corps 'Wetland Dellimstion ManuuaI) Do Normal Circumstances exist on is the site significantly disttub d (atypical Con)? the. area a potential Prubler Area? Explanation t (atypical or proble nt area: VEGETATION (Far strata, indicate T Date: : -1,:5 State Ste: l Transeet ID: PIotMD: a6i s Dominant. Plant :Species -At Y Stratum %: S herb; V = vine{). Dominant Pmt' Seel FA HYDROPHYTIC VEGETATION INDICATORS % of FACW,> . FAG Check all indicators that apply .& explain below Visual observation of plant species growing in areas of prolonged inundation/saturation Morphological adaptations Technical Lite ature Physiological/reproductive adapted on Wetland plant database Personal knowledge afregional plant' Other (explain)' Hydro pie vegetation payment? Rationale for decision/Remarks: HYDROLOGY Is it the growing seas Based on soil temp (record telnp other (explain) Dept, of inundation: Depth to free water in pit: Depth to saturated soil: inks inches inches Water Marks ern Drift tines; t)nc`d ed Root (live roots) Channels <12 in. yes no Deposits: yes (`iiu` l Soil Survey: : t Check all that apply & explain below: Stream, Lake .orgage data: Aerial photographs: Other: Other (explain): Water-stained Leaves yes uo Wetland hydrology present? Rationale for dexision/Reanarks: no Map Unit Name: Sories & Phase) Taxonomy (subgroup) p -t Horizon Matrix cam (Munson mgt) Mottle (Nitrogen Class Field observations'coni`am Ves No Pffliel Toonstre, moons, structure, etc. Drawing of soil profile on dkat ►: (cheek tit supply }. ilistosoi HisicE Sulfid c Odor AK Moisture Regime Reducing Cons Gieyed or.Low- Chroma (=1) matrix Hydro soils present? ?s'+ r no Rationale for decision/Remarks: Matrix chrome .2 :with: des Mg arP'e Concretions i :t tic Content in Surface 1 afsa "moils "S in Sandy Soils Listed: on National/Local Hydrie Soils List __ Other' (ein remarks Wetland Determination (circle) Rydruphytic vegetation: present? Hydric soils present? Wetland 'hydrology 'i en Rationale/ReinerkE no no no Is the same within a wetland? NOTES: DATA FORM 3 alevisegO Routine Wetland Dete ntion (WA :SW etland Dellustionidastualor 19/1/ Corps Wetland Debsestkut 'M sst Inve Do Normal Circumstances exist cm the site Is the: site sat"ficaatIy (atypicsl,sitttation)7 Is dm area a pal Problem Ares? Ex1lanationofatbpical orproblem.area: VEGETATION (for strata, indicate T is tree: S .shmb;. H`= herb, 3omitt Plant Species Stratum goer Indicator WA C. vase): Date: ,5 County: lei Stec: r,,e SfT1 Comnumityllk Transom ID: Pict ID:,* Wet Do rtinmt Plant Species Stratitto % c over Indicator HYDROPRYTlC VEGETATION INDICATORS: 7p. of dominants OBE , FA R,& FAC Cheek all indicators that apply & explain. below: Visual abseava Lion ofplant species pawing .m areas of pampa intutdation/ssituration;. Morphological adaptations Technical Litette Physiologicalhepmductive adaptations Wetland plant database Personal knowledge of regional plant:crnnrnitie Othm (explain) vegetation present? Rationale fcr: amnarks: 00 BYDROLOGX Is it the growing season? Based an: soil temp ,(record temp (e p1+ ) Dept. of inundation: Depth to ffree water is pit: Depth to saturated sail: inches,. inches nch Oxidized Root (live Channels <12 in. PAC Neutratl Sediment Deposits: yes Drainage Patterns: yes on Local Soil Survey: yes ,,hu) Water4tained Leaves Check all that apply & explain below: Stream, Lake or gage data: Aerial . Wetland hydrology present? Rationale for decision/Remarks: Other (explain): 20 Maplirdt Name (Series Thasc) Taton y (subgroup) Cl ons confirm maimed tyre? PreilleDesedpfien .. Depth (inches) Horizon 'Matrix, color (Munseil Mottle cokes (Mown moist) Mottle abtaiduice Texture, co ifs. strateltet etc. Drava** of soil nd Hss Sulfidic:Odor Aquic 'Moisture Regirne Reducing: Conditions Gerd, or Low +nrna. ( i) m ydric present, yes Rationale fordecisiaadReurarks rmo:2 vrieh tootles Esc Content n Surface Layer of Sandy Sys. ,at xy n rema> ) "Wettsnd Determin t on (circle) Hydraphytic vegetation present? yes Hydric soils present ? yes no Wetlasai hydrology pry? no tionalearks. NOTES: is thesamplirtg point. within a wetland? DATA FORM 1 Rte' Routine Wethuld Deteerudniton Wetland "De nes inn.' tdor 'Coma Wetland De atfoa'.IMsnttall) Projasaisite: lei A Applicant/owner Se :4. Investigatot(a)s _A& Do Nonni' .+Cie nnstanoes eat on the Is the site signiftcz tly bed'(stypicsl situation)? Is dte::arras poteMiat Problem Areal Explanation of atypical o prabkm area: VEGETATION (For strata, indicate T tree: S =:shrub; H herb; V vine) Dominant Plant Species Strait Indicator Date: 7( frk State; IA/A S/T/R: Ccuranunity 1D . Tnusect 1D Plot ID: z Punt Species`_ Stratum Indicator AC 5 F4 K. t T AC U' HVDRtlPHYTICVEGE TToi:Ii�t i cATC %. aide:nimbi ABEL, FACW, & FAG: Check all indicators that apply & explain Visual Sian of plant species growing in areas of prolonged itiout$aturati0n Morphological adaptations Technical Literature Physiologicaltrepluductive adaptations Wetland plant database P e r s o n a l knowledge ofr giona pla t so mines Other (eoliths) Hydrnphytic intuition present" Rationale for cisiont temarks HYDROLOGY Is it the growing season? yes' no Based on: anti (record temp otherlexplain Dept. of inundation: uu ileac Depth to:froe Avatar in pit: 21a_ inches' Depth to saturated d soil; inches Check all thaf apply at explain ,below: Strom,. Lake or gage data: Aerial plsotetttahs: :h relea present? innate for decision/Remarks Water "Marks: yes on Draft I it : Oxidized (live roots) Channels <12 in. yes ra3 Sediment yea {'no Drainage Patterns:- yea .no Local Soil Survey: yes ao AC Neutral: yes no- Water -stained Leis v Oth • Other (explain): Yes MAP- Unit` MIMIC (SSene $;Pia* Taxonomy (aubgnmil ) NO: Project/Site: Applicanttowner :' investigates) :: i Do Normal Crt<i Is the-site significantly ti stW Is the arena potential Problem At?` Explanation of atypical or prnbletn area: DATA FORM .1 Routine Wetland .Deteroinaiion. (WAStaieWntiand Delineation Manua or I987-Corps Wetland Delineation Manttai) � Date; I :,•; TfR: Communfty ID Trot ID Plot,lD• -` 442 VEGETATION (for strata, indicate T true; S Dominant Plant Species Stratum shrub; H ='herb; V = vine) Indicator Dortttnattt Plant Specie. IIVDROPHYTIC VEGETATION INDICATORS. % of dominants OBL, FACW, -& FAC ck all indicators tisuut apply & explain below: Visual observation of plant species growing in areas of prolonged inundation/saturation Morphological-adaptations Technical Literature Physiological/ petive adaptations Wettand°plant database Pe monat knowledge : of regional plant: amities Other (explain) Rydr phytic vegetation present? Rationale for decision/Remarks J1YDR©LOG Is it The growing season? Based on nc 5011 temp (,record temp Wier (explain) Dept. of inundation: Depth to free water in pit: Depth to saturated soil: no Water Marks: on Sediment Deposits: Drift Lines: yes ' no' Drainage Patterns:: itIPtIcs inches inches Oxidized Root (live roots)s Channels <12 in. yes .:nD FAC Neutral: yes no 1 eater.stain Leaves `ye no Check all that apply & explain below: Stream, Lake or gage data:._... Aerial photographs: Other (explain): Other: 'Wetland' hydrology present? yes no Rationale for decision/Remarks: nit Name (Series' & Phase) Taxonomy (subgroup Field observations confirm Yes . mapped t Mottle colors (Monsen. ntaist) Texture, con ntnucttmee elk 11ydric Soil Indicate (check all that apply) ) Th� on Sulfidic Odor Aquic =Moisuae.lteg nae Reducing Conditions GI ed or Low -t hrame (= l rii vclric soils present ?' ationale for de isios arnartks: Matrix chrorna .3 with mottles Mg OT Fe Concretions . :High Cargattio Content to Surface tart orSandY 'Ss is 'Organic Streaking in Sandy Soils; Lister on Nation Nationalitcical liydric Soils List Other :.. iabrin remarks Wennd Determinations (cis Hydropbytic vegetation present? Hydric sods present? Wetland hydrology present? Rationaleatesrarks£ NOTES: DATA FORM .1 (Revis Routine' Wetland Determination <WA State Wetland Delineation Manual or 1937 Coips Vgetland.Delineation Manual) s. Applicant/owner ves(igator(s): NomatiCircurastances exist on the site? Is the site significantly tbs. tutbed:-(atypical situation)?" Is the area a potential Problem Area? Explanation of atypical or problem :area: Community Transact ID: Plata): V GETA O I (For strata, <indicate = tree; nirratrt Plant Species shrub;; ; V = vane) % cower Indicator Dominant Plant Species 1; Ac 5 f ti YDR:OPH%I1C VEGETATION IN fiCATt i % of dominants . QBi FACW, &' FAC k all indicators that apply & explain below: Visual observation of plant species growing in areas of prolonged Mundationtsaturation Morphological adaptations Technical lateral Physiologicai/repradtrctiue_ adaptati Wetland plant database Personal knowledge c f regional- plant communities .. ; ;er (explain) Hydrophytic vegetation p:n Rationale for decision/Remarks.: no HYDROLOGY. Is it the growing. season? Based on: soil temp (record temp other (explain) Dept. of inrurdation: inches Depth to free water in pit: Depth to saturated soil: Check all that apply & explain below; Stream, Lake or gage data: Aerial photographs: ouches inches Water Marks; yes < it on meet ;L psrts::yes Li Yes Drainage Patterns: yes no Oxidized Root (live roots) Channels <12 in.. yes Soil'Si y: yes 'Ito . FAC Nediral: v n Water - stained Leaves yes Other (explain): Oth WW etIatid: hydrology ;present? yes Rationale for decision/Remarks: SOILS Map Unit Name (Series & Phase) Taxonomy (subgroup). Proflle:pdon Depth (inches) Matrix color Mottle colors (Mtmsell (Mutiseil moist) moist) Drainage Class F cld observations non#'rrm Nc maPPed tYPe` tiie almmdance • ' Texture, conch, size & Fast strutting, etc. Drawing of'<suil profile (etc +il) Hydrie Soil Indinters., (eh cck all that apply) Histosol; Hisiic. Epipedon Suifidic Odor Aquic Moisture Regime Reducing Conditions Gleyed or Low- Chroma ( =1) rnatriix. Bydrlc soils present? yes Rationale for decision/Remarks: 5 with mottles Concretions High organic Contest in Surface Layer of Sm l ir„ganlc Su i s (Sandy Soils Listed on Na tional/Lo Cai Hydric Soilss`List: Other (explain in remarks) Wetland Determination (circle) Hydraphytic vegetation present? Hydric soils present? Wetland hydrology present? Rationale/Remarks: NOTES; Yes yes Yes, Is the sampling point nt. within a weed? • no 1 1 1 1 1 Project/Site i Applicantiowner A DATA FORM 1(R Routine WetlaudDeternibuttkin 4WA a Westland PikneatiosiManualor • 1,87 Cans W °flelitaestiOi Man Tani Do'Noonal Circumstances es exist. >Is the.site signiikanly mod.. (styp situation)? Is the wets peal Problem rArc a? lantaion of'eical erwohiew area: VEGE'TATTON (For strata indicate ;T _ ; S = shr :•t3' *I ► Vi"' r►f damireogs f FAGS,.& FAC all indicators that apprly & expo ►isuei >obsa atioa of plait species growing in •sress.ofprolonged inundationitaturation Motphological adaptations Teolnhicd Literature Phy iologjad/rep eductive adaptations Wetland plies database: PersoaatknOWlesfge ofregional plant communities Other ( ►l*in) vegetation present/ for.. VDROLOGY h the stowing season. Based: soil temp (record` ather(expiaah of inundation: inches Depth to free water in pit; 61 inches mortis %o nun to d soli; C inches Check all that apply & explain below: Stream, Lake or sue dew �Ajcrri�ai,,�a ♦ ear:(„ 7Rail p t? Rationale for decision/Remarks: lWa#er es Mars t Deposits; Yes tom; on Drift Lines; Oxidized Root chatntels <12 in FACNeutral: Other (explain) Drainer, Patterns: Locai'Soil S Leaves 110 Profile ; feec Ofl Depth Homo • ) ottle colors Mottle ,abuntlance (Mtmsell sleek COMMA moist Textq*.c' structure, profile 'rnitfl} q $ydric t i'eatery (check all Histosol Histic Epipeden Sulfidic Odor Agsic Moisture Regime Rig Conditions. Gleyed or Low - anima (=l Bydri+c soils present? Rationale for decision/Remarks : Matrix aroma atienal Hydrie • is 1 A DATA F:t ' (Reykreog Routine Wetland Determination (WA State Wetland Delisead= okol'sl or 1987 'W d D aline atio llgt out° Applicant/owner' Investig itot(s): Do Normal Ciro is the site significantly (a Is the area it potential Problem .Arett? Explanation of atypical or problem arena: Yes Yes Dew Sfi ' yv Community ID: Transact ID: VEGETATION .(pm strata, indicateT = tree; S shrub ;:H Dort Pant Specie Plan;�Spa Indicato e F4 C 0 RYDRO A IONIND CATORS: % of dominants OBL, FACW,& PAC Check all indicators that' apply & explain below; Viand observation ofplant,species growing in areas:ofprolonged inundation/sanitation Morphological adaptations Technical Litexatnure P yaiolog calimpet ctivc adaptations Wetland plant dstitb se Other ie t communities Hydroptytie'vegetation present? Rationale for decision/Remarks: HYD Is it the wowing '.season? Based OM soil temp (record temp other (explain) ater Manna Deposits: yes Drift Unes: Drainage Patters yeS , ,11,9„." Dept. of inundation: Depth to free water in pit: Depth to saturated soil: taciaes inches+ t)x + ed Root (live roots) Channels X12 in. yes P F.ACNeutral; yes no Local :Soil Survey yes W!nteputained Leaves yes no Check all that apply &explain below: Stream, Lake or gage data: Aerial photographs: Other (explain): Other Wetland hydrology present? Rationale for decisicnt/itemarlks: yez MLE Map Unit Name. (Series & Phase) Taxonomy`(subgronp) Drainage Clan Field abservatimut confirm ` tYpe? No :POW orizon co ore (Mansell z ) T L%wing dsoil, l escrinti soil Iadtcato rm (check up. Hisineol TC Epipedon Sulfidic Odor Aquic Moisture Regime Reducing Conditions Gleyead or Low (*.1) matrix ydtic per' y Rationale for decisionfiemarkK ISO, • s -.z des: -.Mg or pa Cosmetic= Mgt Organic Content in St face'I. rer ofSan Suakin Organic ` Listed <on onal/Local Rydric ttts List Other °tearnlain iu° Wetiand emanation (calk) Hydrophytic vegetation present? Hydrie soils present? Wetted bydmio2Y per?, It ale/Remarii s: Yes no Is the sampling point within a w ? NOTES: u iii NM M E M MIR M WM I I I I N MIN . MI M MIN UM PUGET CREEK WETLANDS (riparian/wetland area between 18th and 21st Ave. SW) BIRDS mallard sharp - shinned hawk Cooper's hawk red - tailed hawk: * band - tailed pigeon: criterion 2, game, regular small concentrations mourning dove screech owl rufous hummingbird northern flicker downy woodpecker hairy woodpecker * pileated woodpecker: criteria 1 and 3, state candidate, regular foraging area western wood -pewee violet -green swallow barn swallow Steller's jay American crow black- capped chickadee chestnut - backed chickadee bushtit brown creeper winter wren Bewick's wren golden - crowned kinglet ruby - crowned kinglet Swainson's thrush varied thrush American robin cedar waxwing European starling orange - crowned warbler yellow - romped warbler yellow warbler Wilson's warbler black - headed grosbeak rufous -sided towhee song sparrow dark -eyed junco white - crowned sparrow house sparrow pine siskin American goldfinch house finch AMEHIMAISLAND-REEDIES western redback salamander ensatina garter snake sp. MAMMALS red fox raccoon opossum eastern gray squirrel shrew sp. mole sp. vole sp. deer mouse mouse sp. rat sp. Al; ►11 F 1 additional birds seen only in/near Duwamish Greenbelt and Puget Park BIRDS great blue heron killdeer bald eagle California quail common barn -owl belted kingfisher willow flycatcher black - throated gray warbler savannah sparrow golden- crowned sparrow fox sparrow western tanager AMP IRTANS AND REPTILES long -toed salamander red - legged frog (Duwamisb Greenbelt only) northern alligator lizard common garter snake northwestern garter snake Prepared by Noelle Congdon, 762 -7069 (Naturalist at The Seattle Aquarium) a D e e D e D e D e Q e = = e Attachment 4 Special Features #1 Back Lot Development from Clearing Looking East #2 Back Lot Development to Wetland Boundary #3 Sewer Connection/Wetland Clearing Looking West #4 Active Backyard Use in Cleared Buffer - Looking N. near Flags 42 & 43 #5 Upland Slopes over Steepened with Fill Concrete exposed Looking North near Flag #s 41-49 #6 Rusty Discharge from Broken Drain Pipe Near Flag #56 in 2"d Swale #7 Northerly of 2 Swales Looking East near Flag # 45 #8 Northerly of 2 Swales Looking East near Flag #44 N9 Isolated Pond near Flag #29 Looking East #10 Cedar Grove Looking West near Flags #8-11 #11 Old - Growth Cedar West Edge of Grove near Flags #5 -7 #12 Twin Cedars with 1 Top Broken Near Flag #18 - cet I .■ ■•■V , •■•• #13 Old-Growth Stump Near Flag #22 Looking East #14 Old-Growth Stump with Cavity Near Flag #25 #15 Areas of Inundation North- Central Wetland Looking East ATTACHMENT .5 INN NM ON OM NW SIM =IS 111116 PM ale MO OM NM MR On 011•1 1 11 1 1 t 1 1 1 11 ti t 11 1 1 t ATTACHMENT 5 - PUGET CREEK NATURAL AREA PLANTS SCIENTIFIC NAME TREES Abies concolor Acer macrophyllum Alnus rubra Arbutus menziesii` Crataegus spp Populus balsam ifera Prunus emarginata Psuedotsuga menziesii Robinia psuedoacacia Salix Iasiandra Sorphus sitchensis Thuja plicata SHRUBS COMMON NAME WIS LOCATIONS W. Buffer Wetland E. Buffer grand fir FACU X big leaf maple FACU X X red alder FAC X X X Pacific madrona X hawthome FAC X X black cottonwood FAC X X bitter cherry FACU X X Douglas fir FACU X black locust FAC X X X Pacific willow FACW+ X Sitka mountain ash FAC X X western red -cedar FAC X X Acer circinatum vine maple FAC- X X Cornus stolonifera redstem dogwood FAC X X Corylus cornuta var. beaked hazelnut FACU X X Gaultheria shailon salal FACU X Holodiscus discolor oceanspray FACU X Ilex aquilifolium english holly NL X X X Mahonia nervosa Oregon grape FACU X Oemlaria cerasiformus Indian plum FACU X Prunus Iaurocerasus English laurel X Rosa gymnocarpa baldhip rose FACU X X Rubus discolor) Himalaya blackberry FACU X X X Rubus spectabilis salmonberry FAC+ X X Rubus ursinus trailing blackberry FACU X X Sambucus racemosa red elderberry FACU X Spirea douglasii hard hack FACW X Symphoricarpos albus snowberry FACU X Vaccinium parvifolium red huckleberry NL X HERBS Dicentra formosa bleeding heart X Geum macrophyllum large -leaf avens FACW- X Hedera helix English ivy FACU+ X X X Maianthenum dilatatum false lily of the valley FAC X Ranunculus repens creeping buttercup FACW X X Rorippa nast. -aquat watercress* X Trillium ovatum Western trillium X Typha Iatifolia common cattail` OBL X Urtica dioica stinging nettle FAC+ X GRASSES, RUSHES AND SEDGES Carex obnupta slough sedge OBL Dactylis glomerata orchard -grass FACU Festuca arundinacea tall fescue FAC - Phalaris arundinacea reed canary grass FACW Polygonum Japanese Knotweed UPL FERNS X X X X X Athyrium filix-fem ina Equisteum telmateia Polystichum munitum lady fern FAC giant horsetail FACC+ sword fem FACU * Shapiro 1995: may only exist south of park boundary X ATTACHMENT 6 11 SOS OM I= AVM i=t 1=1. INN Mt MS NM MD Mr ININ Me M 11 it I 11 s 1 1 1 1 ti 11 1 1 1 1 t Wetland name or number _if:4 \\� WETLAND RATING FORM — WESTERN WASHINGTON Version 2 - Updated July 2006 to increase accuracy and reproducibility among users Name of wetland (if known): Date of site visit: .34 '7 Rated by t \I `C Trained by Ecology? Yes No_ Date of training 2, j SEC: TWNSHP: _ RNGE: Is SfT/R in Appendix 1)? Yes No Map of wetland unit: Figure Estimated size SUMMARY OF RATING Category based on FUNCTIONS provided by wetland 1 II III IV Category t = Score > =70 Category I1= Score 51-69 Category Ili = Score 30 -50 Category IV = Score < 30 ;core for Water Quality Functions Score for Hydrologic Functions Score for Habitat Functions TOTAL score for Functions Category based on SPECIAL CHARACTERISTICS of wetland 1 II_ Does not Apply Final Category (choose the "highest" category from above) Summary of basic information about the wetland unit "Vlzetlagtifeu itiia Sliecial Characteristics -dCs: used for Rating .. _ . . Estuarine Depressional Natural Heritage Wetland Riverine Bog Lake- fringe Mature Forest Slope Old Growth Forest Flats Coastal Lagoon Freshwater Tidal Interdunal None of the above / Check if unit has multiple, HGM classes present Wetland Rating Form — western Washington version:, August 2004 Wetland name or number Does the wetland unit being rated meet any of the criteria below? If you answer YES to any of the questions below you will need to protect the wetland according to the regulations regarding the special characteristics found in the wetland. { +•. i a?&;,`.`r r.�-s s ,�F' ,. dad v .. ,-.,,or. ° 4,-- v+. i te k� a�for� ,„ ,,, uai a ldecd a�l 't :tee o .. -: (04 adil onto the p ro eCtiontrecommen ed,for ca egc►r;ar M7� , 1.i✓, t' .. ' . . SP1. Has the wetland unit been documented as a habitat for any Federally listed Threatened or Endangered animal or plant species (TJE species)? For the purposes of this rating system, "documented" means the wetland is on the appropriate state or federal database. SP2. Has the wetland unit been documented as habitat for any State listed Threatened or Endangered animal species? For the purposes of this rating system, "documented" means the wetland is on the appropriate state database. Note: Wetlands with State listed plant species are categorized as Category I Natural Heritage Wetlands (see p. 19 of data form). SP3. Does the wetland unit contain individuals of Priority species listed by the WDFW for the state? SP4. Does the .wetland unit have a local significance in addition to its functions? For example, the wetland has been identified in the Shoreline Master Program, the Critical Areas Ordinance, or in a local management plan as having special significance. To complete the next part of the data sheet you will need to determine the Hydrogeomorphic Class of the wetland being rated. The hydrogeomorphic classification groups wetlands into those that function in similar ways. This simplifies the questions needed to answer how well the wetland functions. The Hydrogeomorphic Class of a wetland can be determined using the key below. See p. 24 for more detailed instructions on classifying wetlands. Wetland Rating Form — western Washington version 2 2 August 2004 Wetland name or number Classification of Wetland Units in Western Washington if the hydrologic criteria fisted iu each •question do u, t hpply� to ithe entire unit beutg 'ate, you p ob bly hav ti t a#t t it j n ii j io uc�1�3 Cases °Sn tits c e 4Fieutff Which h"}fldrolog ci me to in que iotts l ,7app p,aitid ga-to`"Question S. 1.. Arc.the water levels in the entire unit usually controlled by tides (i.e. except during floods)? NO - go to 2 YES — the wetland class is Tidal Fringe If yes, is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)? YES — Freshwater Tidal Fringe NO — Saltwater Tidal Fringe (Estuarine) !f your wetland can be classified as a Freshwater Tidal Fringe use the forms for Riverine wetlands. !fit is Saltwater Tidal Fringe it is rated as an Estuarine wetland Wetlands that were called estuarine in the first and second editions of the rating system are called Salt Water Tidal Fringe in the Hydrogeomorphic Classification. Estuarine wetlands were categorized separately in the earlier editions, and this separation is being kept in this revision. To maintain consistency between editions, the term "Estuarine" wetland is kept. Please note, however, that the characteristics that define Category I and II estuarine wetlands have changed (see p. ). 2. The entire wetland unit is flat and precipitation is the only source ( >90 %) of water to it. Groundwater and surface water runoff are NOT sources of water to the unit. NO — go to 3 YES — The wetland class is Flats If wetland can be classified as a "Flats" wetland, use the form for Depressional wetlands. 3. Does the entire wetland unit meet both of the following criteria? The vegetated part of the wetland is an the shores of a body of permanent open water (without any vegetation on the surface) at least 20 acres (8 ha) in size; "^ At least 30% of the open water area is deeper than 6.6 ft (2 m)? • NO — go to .4 YES — The wetland class is Lake -fringe (Lacustrine Fringe) 4. Does the entire wetland unit meet all of the following criteria? The wetland is on a slope (slope can be very gradual), The water flows through the wetland in one direction (unidirectional) and usually comes from seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks. The water leaves the wetland without being impounded? NOTE: Surface water does not pond in these type of wetlands except occasionally in very small and shallow depressions or behind hummocks (depressions are usually <3ft diameter and less than I foot deep). NO - go to 5 YES — The wetland class is Slope Wetland Rating Form — western Washington version 2 3 August 2004 Wetland name or number 5. Does the entire wetland unit meet•all of the following criteria? _ The unit is in a valley, or stream channel, where it gets inundated by overbank flooding from that stream or river The overbank flooding occurs at least once every two years. NOTE: The riverine unit can contain depressions that are filled with water when the river is not flooding. NO - go to 6 YES — The wetland class is Riverine 6. Is the entire wetland unit in a topographic depression in which water ponds, or is saturated to the surface, atsome time during the year. This means that any outlet. if present, is higher than the interior of the wetlanu NO — go to 7 , YES — The wetland class is Depressional 7. Is the entire wetland unit located in a very flat area with no obvious depression and no overbank flooding. The unit.does not pond surface water more than a few inches. The unit seems to be maintained by high groundwater in the area, The wetland may be ditched, but has no obvious natural outlet. NO — go to 8 • YES — The wetland class is Depressional 8. Your wetland unit seems to be difficult to classify and probably contains several different HGM clases. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small stream within a depressional wetland has a zone of flooding along its sides. GO BACK AND IDENTIFY WHICH OF THE HYDROLOGIC REGIMES DESCRIBED IN QUESTIONS 1 -7 APPLY TO DIFFERENT AREAS IN THE UNIT (make a rough sketch to help you decide). Use the following table to identify the appropriate class to use for the rating system if you have several HGM classes present within your wetland. NOTE: Use this table only if the class that is recommended in the second column represents 10% or more of the total area of the wetland unit being rated. lithe area of the class Iisted in column 2 is less than 10% of the unit; classify the wetland using the class that represents more than 90% of the total area. , EMM Clasges within to wi?tairr{u eltdiir, crated; i% aN Wit lass 1o"'fi se: in.Rating: Slope + Riverine Riverine Slope + Depressional Depressional Slope + Lake -fringe Lake - fringe Depressional + Riverine along stream within boundary Depressional Depressions( + Lake - fringe Depressional Salt Water Tidal Fringe and any other class of freshwater wetland Treat as ESTUARINE under wetlands with special characteristics If you are unable still to determine which of the above criteria apply to your wetland, or if you have more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the rating. Wetland Rating Form — western Washington 4 version 2 August 2004 11 11 1 1 1 1 11 11 11 1 Wetland name or number ' tra,lrr'25kn- a�X: i> n Yl A`'�`:. R t & S ' bw. ! t; 9 aio ��an Fla t�It�n+�s., "��� ''�- ��� ��� � }�£: -.)lea a ?� ` aj1U 0151 • tftet+c'fi1anfitncftd `+" 3 s, oin s (see p.38) D D D D D D D 1. Does the wetland unit have the potential to improve water quality? 1)1,1 Characteristics of surface water flows out of the wetland: Unit is a depression with no surface.water leaving it (no outlet) points = 3 Unit has an intermittently flowing, OR highly constricted pemranently flowing outlet points- 2 Unit has an unconstricted, or slightly constricted, surface outlet (permanentlyJlawing) points Unit is a "flat" depression (Q. 7 on key), or in the Flats class, with permanent surface outflow and no obvious natural outlet and /or outlet is a man -made ditch points = l (lf ditch is not permanently flawing treat unit as "Intermittently f mving ") Provide photo or drawing Figure ) S 1.2 The soil 2 inches below the surface (or duff layer) is clay or organic (use NRCS definitions) A points - 4 1. •c points = 0 r ; D 1.3 Characteristics of persistent vegetation (emergent, shrub, and/or forest Cowardin class) Wetland has persistent, ungrazed, vegetation > = 95% of area points Wetland has persistent, ungrazed. vegetation > =1/2 of area points =3 Wetland has persistent, ungrazed vegetation > = 1/10 of area points = I Wetland has persistent. ungrazed vegetation <1 /10 of area points = 0 Map of Cowardin vegetation classes Figure _ �. D 1.4 Characteristics of seasonal ponding or inundation. This is the area of the wetland unit that is ponded for at least 2 months, but dries out sometime during the year. 1)o not count the area that is permanently ponded. Estimate area as the average condition .5 out of 10 yrs. Area seasonally ponded is> 4 total area of wetland points = 4 Area seasonally ponded is> %. total area of wetland points = 2 Area seasonally ponded is <'1 total area of'wetland points Map of Hydroperiods Figure _ (-) Total for D I Add the points in the boxes above I 42 1 D D D 2. Does the wetland unit have the opportunity to improve water quality? (see p. 44) multiplier e... Answer YES if you know or believe there are pollutants in groundwater or surface water coming into the wetland that would otherwise reduce water quality in streams, lakes or groundwater downgradient from the wetland. Note which of the following conditions provide the sources of pollutants. it unit may have pollutants coming from several sources, but any single source would qua* as opportunity. — Grazing in the wetland or within 150 ft — Untreated stormwater discharges to wetland a — Tilled fields or orchards within 150 ft of wetland .4 A stream or culvert discharges into wetland that drains developed areas, residential areas, farmed fields, roads, or clear -cut logging - Residential, urban areas, golf-courses are within 150 R of wetland — Wetland is fed by groundwater high in phosphorus or nitrogen ,. Other i ITS multiplier is 2 NO multiplier is 1 TOTAL - Water Quality Functions Multiply the score from DI by D2 Add score to table on 1 Wetland Rating Form - western Washington version 2 5 August 2004 Wetland name or number D Depressional an `�lats.0 hands `s, - Y ,�€ r e HYD DLO IC* GAO e'.nt icatot 'that�the ttarsd unit functions o > g��r *r %u k der rr �;as • c t'i .net u a #laodutg attc.stseatn riegradation t-.I � . = , eo ; , , , _ `i Peiints .4: t aRJ . (seep.46) D D D D D 3. Does the wetland unit have the potential to reduce flooding and erosion? D 3.1 Characteristics of surface water (lows out of the wetland unit Unit is a depression with no surface water leaving it (no outlet) points =-4 Unit has an intermittently flowing, OR highly constricted permanently flowing outlet points = 2 Unit is a "flat" depression (Q. 7 on key), or in the Flats class, with permanent surface outflow and no obvious natural outlet and/or outlet is a man -made ditch points = 1 (If ditch is not permanentlyftowtng treat unit as "intermittently flawing") Unit has an unconstricted, or slightly constricted, surface outlet (permanently flowing) points 41)\; D 3.2 Depth of storage during wet periods .Estimate the height of ponding above the bottom of the outlet. For units with no outlet measure from the surface of pennanent water or deepest part (if dry). Marks of ponding are 3 ft or more above the surface or bottom of outlet points = 7 The wetland is a "headwater" wetland" points = 5 Marks of pending between 2 ft to <3 ft from surface or bottom of outlet points =,,5 Marks are at least 0.5 ft to < 2 ft from surface or bottom of outlet points = 3 Unit is flat (yes to Q. 2 or Q. 7 on key) but has small depressions on the surface that trap water points = 1 Marks ofponding less than 0.5 ft points = 0 .... D 3.3 Contribution of wetland unit to storage in the watershed Estimate the ratio of the area of upstream basin contributing surface water to the wetland to the area of the wetland unit itself. The area of the basin is less than 10 times the area of unit points = 5 The area of the basin is 10 to 100 times the area of the unit points =D The area of the basin is more than 100 times the area of the unit points = 0 Entire unit is in the FLATS class points = 5 Total for D 3 Add the points in the boxes above 0=1, - D D D 4. Does the wetland unit. have the opportunity to reduce flooding and erosion? (see p. 49) multiplier Answer YES if the unit is.in.a location in the watershed where the flood storage, or reduction in water velocity, it provides helps protect downstream property and aquatic resources from flooding or excessive and/or erosive flows. Answer NO if the water coming into the wetland is controlled by a structure such as flood gate, tide gate, flap valve, reservoir etc. OR you estimate that more than 90% of the water in the wetland is from groundwater in areas where damaging groundwater flooding does not occur. Note which of the following indicators of opportunity apply. — Wetland is in a headwater of a river or stream that has flooding problems — Wetland drains to a river or stream that has flooding problems — Wetland has no outlet and impounds surface runoff water that might otherwise flow into a river or stream that has flooding problems — Other _ YES multiplier is 2 NO ) multiplier is I TOTAL - Hydrologic Functions Multiply the score from D 3 by D 4 Add score to table on p. I Wetland Rating Form - western Washington 6 version 2 August 2004 111 t t 11 1 11 11 1 it 11 1 1 11 11 11 1 Wetland name or number CS Y ?.KvE, a'C± k.t '"'e fza r� S `tc *. -ta-a 91 aSJ S f LF. Y 5 Tfiespquesaans applytD weiYat ds r� `ailIHG' cusses L� hY 4 ! a . HABITAT FUNCTIQNS -Ind-I'm-tor iha �unit funettons{.to provtde�intpotfiati halaitaty ti. rtt *; H .1. Does the wetland unit have the potential to provide habitat for many species? 1-1 1.1 Vegetation structure (see p. 72) Figure r`? 1 Check the types of vegetation classes present (as defined by Cowardin)- See threshold for each class is Y, acre or more than 10% oldie area f unit is smaller than 2.5 acres. Aquatic bed . )q' Emergent plants ; Scrub /shrub (areas where shrubs have >30% cover) Forested (areas where trees have >30% cover) If the unit has•a forested class check if: _.'The forested class has 3 out of 5 strata (canopy, sub - canopy, shrubs, herbaceous, moss/ground- cover) that each cover 20% within the forested polygon Add the number of vegetation structures that quay. If you have: 4 structures or more points= 4 Map of Cowardin vegetation dosses 3 structures points = 2 2 structures points = 1 1 structure points = 0 H 1.2. Hvdroperiods (seep. 73) Figure Check the types of water regimes ( hydroperiods) present within the wetland. The water regime has to cover more than 10% of the wetland or 14 acre to count. (see text for descriptions of hydroperiods) Permanently flooded or inundated 4 or more types present points = 3 VSeasonally flooded or inundated 3 types present points = 2 Occasionally flooded or inundated 2 types present point = 1 .V. . Saturated only 1 type present points = 0 X Permanently flowing stream or river in, or adjacent to, the wetland Seasonally flowing stream in, or adjacent to, the wetland _ __ Lake- fringe wetland = 2 points _Freshwater tidal wetland = 2 points Map of hydroperiods H 1.3. Richness of Plant Species (seep. 75) Count the number of plant species in the wetland that cover at least 10 ft . (different patches of the same species can be combined to meet the size threshold) You do not have to name the species. Do not include. Eurasian Milfoil, reed canarygrass. purple loosestrife. Canadian Thistle If you counted: > 19 species points = 2 List species below if you want to: 5 - 19 species points = 1 < 5 species points = 0 Wetland Rating Form - western Washington version.? 13 Total for page August 2004 Wetland name or number H 1.4. Interspersion of habitats (see p. 76) Figure — Decide from the diagrams below whether interspersion between Cowardin vegetation classes (described in H 1.1), or the classes and unvegetated areas (can include open water or mudflats) is high, medium, low, or none. n None = 0 points Low = 1 point Moderate = 2 points ale ,.,.� y [riparian braided channels] High = 3 points NOTE: If you have four or more classes or three vegetation-classes and open water the ratting is always "high ". Use map of Cowardin vegetation classes H 1.5. Special Habitat Features: (see p. 77) Check the habitat features that are present in the wetland The number of checks is the number of points you put into the next column. ,' Large. downed, woody debris within the wetland (>4in. diameter and 6 ft long). Standing snags (diameter at the bottom > 4 inches) in the wetland banks are present for at least 6.6 ft (2m) and/or overhanging vegetation extends at _Undercut least 3.3 ft (1m) over a stream (or ditch) in, or contiguous with the unit, for at feast 33 ft (1Om) .."' Stable steep banks of fine material that might be used by beaver or muskrat for cleaning ( >30degree slope) OR signs of recent beaver activity are present (cut shrubs or trees that have not yet turned grey /brown) At least' V1 acre of thin- stemmed persistent vegetation or woody branches are present in areas that are permanently or seasonally inundated. (structures for egg- laying by amphibians) Invasive plants cover less than 25% of the wetland area in each stratum of plants _ NOTE: The 20% stated in early printings of the manual on page 78 is an error. H 1. TOTAL Score - potential for providing habitat r-, - 1 Add the scores from HI. l, 111.2, /11.3, 1114, 111.5 IL' • j Comments Wetland Rating Form — western Washington 14 version 2 August 2004 t 1 1 11 11 11 11 1 11 11 11 11 1 Wetland name or number H 2. Does the wetland unit have the opportunity to provide habitat for many species? H 2.1 Buffers (seep. 80) - Figure Choose the description that best represents condition of buffer of wetland unit. The highest scoring criterion that applies to the wetland is to be used in the rating. See text for definition of "undisturbed" — 100 m (330ft) of relatively undisturbed vegetated areas, rocky areas, or open water >95% of circumference. No structures are within the undisturbed part of buffer. (relatively undisturbed.also means no- grazing, no landscaping, no daily human use) Points = 5 — 100 m (330 ft) of relatively undisturbed vegetated areas, rocky areas, or open water > 50% circumference. Points = 4 — 50 m (17013) of relatively undisturbed vegetated areas. rocky areas, or open water >95% circumference. Points = 4 — 100 m (330ft) of relatively undisturbed vegetated areas, rocky areas, or open water > 25% ,, circumference, . Points = 3 r 50 m (170ft) of relatively undisturbed vegetated areas, rocky areas, or open water for > .--a 50% circumference. Points = 3 - .-' If buffer does not meet any of the criteria above — No paved areas (except paved trails) or buildings within 25 m (80ft) of wetland > 95% circumference. Light to moderate grazing, or lawns are OK. Points = 2 — No paved areas or buildings within 50m of wetland for >50% circumference. Light to moderate grazing, or lawn are OK. Points = 2 — Heavy grazing in buffer. Points = 1 — Vegetated buffers are <2m wide (6.6ft) for more than 95% of the circumference (e.g. tilled fields, paving, basalt bedrock extend to edge of wetland Points = 0. — Buffer does not meet any of the criteria above. Points = 1 Aerial photo showing buffers H 2.2 Corridors and Connections (seep. 81) H.2.2.1 Is the wetland part of a relatively undisturbed and unbroken vegetated corridor (either riparian or upland) that is at least 150 if wide, has at least 30% cover of shrubs, forest or native undisturbed prairie, that connects to estuaries, other wetlands or undisturbed uplands that are at least 250 acres in size? (dams in riparian corridors, heavily used gravel roads, paved roads, are considered breaks in the corridor). YES = 4 points (go to 112.3) NO = go to 11 2.2.2 H 2.2.2 Is the wetland part of a relatively undisturbed and unbroken vegetated corridor (either riparian or upland) that is at least 50ft wide, has at least 30% cover ofshrubs or forest, and connects to estuaries, other wetlands or undisturbed uplands that are at least 25 acres in size? OR a Lake -fringe wetland, if it does not have an undisturbed corridor as in the question above? YES =2 points (go to11 2.3) NO= H2.2.3 H 2.23 is the wetland: within 5 mi (8km) of a brackish or salt water estuary OR within 3 mi of a large field or pasture ( >40 acres) OR within -1=1nI of a lake greater than 20 acres? \YESy 1 point NO = 0 points Wetland Rating Form – western Washington 15 version 2 Total for page August 2004 Wetland name or number H 2.3 Near or adiacentto other priority habitats listed by WDFW (see p. 82) Which of the following priority habitats are within 330ft (100m) of the wetland unit? NOTE: the connections do not have to be relatively undisturbed. These are DFW definitions. Check with your local DFW biologist if there are any questions. \. Riparian: The area adjacent to aquatic systems with flowing water that contains elements of both aquatic and terrestrial ecosystems which mutually influence each other. _Aspen Stands: Pure or mixed stands of aspen greater than 0.8 ha (2 acres). _Cliffs: Greater than 7.6 m (25 ft) high and occurring below 5000 ft. _Old-growth forests: (Old -growth west of Cascade crest) Stands of at least 2 tree species, forming a multi - layered canopy with occasional small openings; with at least 20 trees/ha (8 trees/acre) > 81 cm (32 in) dbh or > 200 years of age. Mature forests: Stands with average diameters exceeding 53 cm (21 in) dbh; crown cover may be less that 100%; crown cover may be less that 100%; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that found in old - growth; 80 - 200 years old west of the Cascade crest. _Prairies: Relatively undisturbed areas (as indicated by dominance of native plants) where grasses and/or forbs form the natural climax plant community. _ Talus: Homogenous areas of rock rubble ranging in average size 0.15 - 2.0 m (0.5 - 6.5 ft), composed of basalt, andesite, and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs. _Caves: A naturally occurring cavity, recess, void, or system of interconnected passages _Oregon white Oak: Woodlands Stands of pure oak or oak/conifer associations where canopy coverage ofthe oak component of the stand is 25 %. . _Urban Natural Open Space: A priority species resides within or is adjacent to the open space and uses it for breeding and/or regular feeding; and/or the.open space functions as a corridor connecting other priority habitats, especially those that would otherwise be isolated; and/or the open space is an isolated remnant of natural habitat larger than 4 ha (10 acres) and is surrounded by urban development. Estuary/Estuary-like: Deepwater tidal habitats and adjacent tidal wetlands. usually semi - enclosed by land but with open, partly obstructed or sporadic access to the open ocean. and in which ocean water is at least occasionally diluted by freshwater runoff from the land. The salinity may be periodically increased above that of the open ocean by evaporation. Along some low- energy coastlines there is appreciable dilution of sea water. Estuarine habitat extends upstream and landward to where ocean - derived salts measure less than 0.5ppt. during the period of average annual low flow. Includes both estuaries and lagoons. Marine/Estuarine Shorelines: Shorelines include the intertidal and subtidal zones of beaches, and may also include the backshore and adjacent components of the terrestrial landscape (e.g., cliffs, snags, mature trees, dunes, meadows) that are important to shoreline associated fish and wildlife and that contribute to shoreline function (e.g., sand/rock/log recruitment, nutrient contribution, erosion control). If wetland has 3 or more priority habitats = 4 points If wetland has 2 priority habitats = 3 points If wetland has 1 priority habitat = 1 point No habitats = 0 points Note: All vegetated wetlands are by definition a priority habitat but are not included in this list. Nearby wetlands are addressed in question H 2.4) Wetland Rating Forth — western Washington 16 version 2 August 2004 11 11 1 11 1 11 t 1 Wetland name or number Fi 2A Wetland Landscape (choose the one description of the landscape around the wetland that best fits) (seep. 84) There are at least 3 other wetlands within !: mile, and the connections between them are relatively undisturbed (light grazing between wetlands OK, as is lake shore with some boating, but connections should NOT be bisected by paved roads, fill, fields, or other development. points = 5 The wetland is Lake - fringe on a lake with little disturbance and thereare 3 other lake- fringe wetlands within 'A mile points = 5 There are at least 3 other wetlands within 'A mile, BUT the connections between them are disturbed points = 3 The wetland is Lake - fringe on a lake with disturbance and there are 3 other lake- fringe wetland within 'A mile 119,41t, ss 3, There is at feast 1 wetland within 'A mile. i i = ...j There are no'wetlands within 'A mile. points = 0 11 2. TOTAL Score - opportunity for providing habitat Add the scores om H2.1.112.2, H2.3, H2.4 s 1 TOTAL for H 1 from page 14 -- -- Total Score for Habitat Functions — add the points for H I, H 2 and record the result on P.1 / Wetland Rating Form — western Washington version 2 17 August 2004 Wetland name or number CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS Please determine if the wetland meets the attributes described below and circle the appropriate answers and Category. Wetland Type Check off any<eritera that apply to the wetla %Circle, the. Category when the ..„ appropriate: criteria are met, Category SC 1.0 Estuarine wetlands (seep. 86) Does the wetland unit meet the following criteria for Estuarine wetlands? — The dominant water regime is tidal, — Vegetated, and — With a salinity greater than 0.5 ppt. I ./ YES = Go to SC 1.1 NO/ SC 1.1 is the,wettand unit within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area Preserve, State Park or Educational, Environmental, or Scientific Reserve designated under WAC 332 -30 -151? YES = Category I NO go to SCI 2 Cat. I . SC 1.2 Is the wetland unit at least 1 acre in size and meets at least two of the following three conditions? YES = Category 1 NO = Category I1 — The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has less than 10% cover of non- native plant species. I the non - native Spartina spp. are the only species that cover more than 10% of the wetland, then the wetland should be given a dual rating (1/11). The area of Spartina would be rated a Category I1 while the relatively undisturbed upper marsh with native species would be a Category 1. Do not, however, exclude the area of Spartina in determining the size threshold of I acre. — At least'/, of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un- grazed or un -mowed grassland. — The wetland has at least 2 of the following features: tidal channels, depressions with open water, or contiguous freshwater wetlands. Cat. I Cat. I1 Dual rating 1/11 Wetland Rating Form — western Washington 18 version 2 August 200d 1 1 1 i 1 1 1 1 1 1 i 1 1 11 it 11 11 11 11 Wetland name or number SC 2.0 Natural Heritage Wetlands (see p. 87) Natural Heritage wetlands have been identified by the Washington Natural Heritage Program/DNRas either high quality undisturbed wetlands or wetlands that support state Threatened, Endangered, or Sensitive plant species. SC 2.1 Is the wetland unit being rated in a Section/Township/Range that contains a Natural Heritage wetland? (this question is used to screen out most sites before you need to contact WNHP /DNR) St DR information from Appendix D or accessed from WNHP/DNR web site _ Cat. 1 YES — contact WNHP/DNR (see p. 79) and go to SC 2.2 NO SC 2.2 Has DNR identified the wetland as a high quality undisturbed wetland or as or as a site with state threatened or endangered plant species? YES = Category 1 NO not a Heritage Wetland SC 3.0 Bogs (see p. 87) Does the wetland unit (or any part of the unit) meet both the criteria for soils and vegetation in bogs? Use the key below to identify if the wetland is a bog. If you answer yes you will still need to rate the wetland based on its functions. 1. Does the unit have organic soil horizons (i.e. layers of organic soil), either peats or mucks, that compose 16 inches or more of the first 32 inches of the soil profile? (See Appendix 13 for a field key to identify organic soils)? Yes - notoQ.3 No -go to Q.2 2. Does the unit have organic soils. either peats or mucks that are less than 16 inches deep aver bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on a lake or pond? Yes - go to Q. 3 No - Is not a bog fir purpose of rating 3. Does the unit have more than 70% cover of mosses at ground level, AND other plants, if present, consist of the "bog" species listed in Table 3 as a significant component of the vegetation (more than 30% of the total shrub and herbaceous cover consists of species in Table 3)? Yes — Is a bog for purpose of rating No - go to Q. 4 NOTE: If you are uncertain about the extent of mosses in the understory you may substitute that criterion by measuring the pH of the water that seeps into a hole dug at least 16" deep. If the pH is less than 5.0 and the "bog" plant species in Table 3 are present, the wetland is a bog. 1. Is the unit forested (> 30% cover) with sitka spruce, subalpine fir, western red cedar, western hemlock, lodgepole pine, quaking aspen, Englemann's spruce, or western white pine, WITH any of the species (or combination of species) on the bog species plant list in Table 3 as a significant component of the ground cover (> 30% coverage of the total .shrub /herbaceous cover)? 2. YES = Category I No >e is not a bog for purpose of rating Cat I Wetland Rating Form — western Washington version 2 19 August 2004 Wetland name or number Wetland Rating Form — western Washington 20 version 2 August 2004 v 11 11 11 0 e a 1 0 1 SC 4.0 Forested Wetlands (seep. 90) Does the wetland unit have at least 1 acre of forest that meet one of these criteria for the Department of Fish and Wildlife's forests as priority habitats? Ifyou answer yes you will still need to rate the wetland based on its functions. — Old- growth forests: (west of Cascade crest) Stands of at least two tree species, forming a multi- layered canopy with occasional small openings; with at least 8 trees/acre (20 trees/hectare) that are at least 200 years of age OR have a diameter at breast height (dbh) of 32 inches (81 cm) or more. NOTE: The criterion for dbh is based on measurements for upland forests. Two - hundred year old trees in wetlands will often have a smaller dbh because their growth rates are often slower. The DFW criterion is and "OR" so old- growth forests do not necessarily have to have trees of this diameter. — Mature forests: (west of the Cascade Crest) Stands where the largest trees are 80 – 200 years old OR have average diameters (dbh) exceeding 21 inches (53cm); crown cover may be less that 100 %; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that found in old- growth. YES = Category 1 NO not .a forested wetland with special characteristics Cat. 1 SC 5.0 Wetlands.in Coastal Lagoons (see p. 91) Does the wetland meet all of the following criteria of a wetland in a coastal lagoon? — The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from marine waters by sandbanks, gravel banks, shingle, or, Tess frequently, rocks — The lagoon in which the wetland is located contains surface water that is saline or brackish (> 0.5 ppt) during most of the year in at least a portion of the lagoon (needs to be measured near the bottom) YES = Go to SC 5.1 NO not a wetland in a coastal lagoon SC 5.1 Does the wetland meets all of the following three conditions? — The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing), and has less than 20% cover of invasive plant species (see list of invasive species on p. 74). — At least % of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un- grazed or un -mowed grassland. Cat. 1 — The wetland is larger than 1/10 acre (4350 square feet) YES = Category 1 NO – Category 11 Cat. 11 Wetland Rating Form — western Washington 20 version 2 August 2004 v 11 11 11 0 e a 1 0 1 1 1 1 1 11 ti 1 1 1 1 Wetland name or number SC 6.0 Interdunal Wetlands (see p. 93) Is the wetland unit west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? YES - go to SC 6.1 NO _ not an interdunal wetland for rating If you answer yes you will still need to rate the wetland based on its functions. In practical terms that means the following geographic areas: • Long Beach Peninsula- lands west of SR 103 • Grayland- Westport- lands west of SR 105 • Ocean Shores - Copalis- lands west of SR 115 and. SR 109 SC 6.1 Is the wetland one acre or larger. or is it in a mosaic of wetlands that is once acre or larger? YES = Category II Nf1 go to SC 6.2 Cat. 11 SC 6.2 Is the unit between 0.1 and 1 acre, or is it in a mosaic of wetlands that is between 0.1 and 1 acre? YES = Category III Cat. III Cate, gory. of. wetlandbaseit:bn,SpevialKCharacteristics ''., Chooseihe "highest' rafrng`rf wetland falls int several categories,, and record oir If.y''ou answered NO,for all types enter "Not Applicable" on p. t Wetland Rating Form — western Washington version 2 21 August 2404 ATTACHMENT D SEPA Checklist and DNS ENVIRONMENTAL CHECKLIST Norfolk -MLK Way Subbasin Stormwater Conveyance Improvements Project Prepared for Seattle Public Utilities January 2008 ENVIRONMENTAL CHECKLIST Norfolk -MLK Way Subbasin Stormwater Conveyance Improvements Proj ect Prepared for Seattle Public Utilities Engineering Services Branch Seattle Municipal Tower, Suite 4900 P.O. Box 34018 Seattle, Washington 98124-4018 Prepared by Herrera Environmental Consultants, Inc. 2200 Sixth Avenue, Suite 1100 Seattle, Washington 98121 Telephone: 206/441 -9080 January 24, 2008 Contents Environmental Checklist 1 A. Background 1 A 1. Name of Proposed Project 1 A2. Name of Applicant 1 A3. Address and Phone Number of Applicant 1 A4. Date Checklist Prepared 1 A5. Agency Requesting Checklist 1 A.6. Proposed Timing or Schedule 1 A7. Plans for Future Additions or Further Activity 1 A8. Environmental Information Related to Proposal 2 A9. Pending Permit Applications 2 A10. Approvals or Permits Needed for Proposal 2 A 11. Description of Proposal 3 Al2. Location of Proposed Project 4 B. Environmental Elements 9 B I. Earth 9 B2. Air 10 133. Water 11 B4. Plants 13 B5. Animals 14 B6. Energy and Natural Resources 14 B7. Environmental. Health 15 B8. Land and Shoreline Use 16 B9. Housing 17 B10. Aesthetics ..18 811.. Light and. Glare 18 B 12. Recreation 18 B13. Historic and Cultural Preservation 19 B14. Transportation 19 B15. Public Services 20 B16. Utilities 20 C. Signature 21. References ab 06-03354-100 saps checklist ?3 Figures Sheet 1 of 4. Vicinity map 5 Sheet 2 of 4. Proposed conveyance improvements 6 Sheet 3 of 4. Wetland impacts 7 Sheet 4 of 4, Wetland impacts 8 ab 06-0354400 seue cneckcsf t.i SEATTLE PUBLIC UTILITIES ENVIRONMENTAL CHECKLIST A. BACKGROUND Al. Name of proposed project, if applicable: Norfolk -MLK Way Subbasin Stormwater Conveyance improvements Project A2. Name of applicant: Seattle Public Utilities A3. Address and phone number of applicant and contact person: Amel Valmonte, Project Manager Seattle Public Utilities Engineering Services Branch Seattle Municipal Tower, Suite 4900 PO Box 34018 Seattle, WA 98124 -4018 206 -615 -1438 A4. Date checklist prepared: December 18, 2007 A5. Agency requesting checklist: Seattle Public Utilities A6. Proposed timing or schedule (including phasing, if applicable): The Norfolk -MLK Way Subbasin Stormwater Conveyance Improvements Project is scheduled to be completed in the fall and winter of 2008, over a period of 12 to 16 weeks. Temporary improvements were installed in summer 2007. A7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? A stormwater treatment facility is. planned to be constructed on the west side of 1 -5 sometim.e in the future depending on available funding. These two projects are functionally independent and the conveyance project can function with, or without, the future stormwater treatment facility. ab 06- 03354-00 sopa checklist A8. List any environmental.information you know about that has been prepared, or will be prepared, directly related to this proposal. The following reports are available at Seattle Public Utilities (SPU). To obtain a copy, please contact Amel Valmonte, Project Manager at phone: 206- 615 -1438, cell: 206 -291 -5167, e -mail: amel.valmonte@seattle.gov Geotechnical .Report - February 2007. Evaluation of surface and subsurface geology on the project site. Included in Appendix A of the Norfolk -MLK Way Subbasin Stormwater improvements Project Preliminary Engineering Report (SPU 2007a) Geotechnical Memorandum - September, 2007. Environmental investigation and data report for Pape property NorfolkfMLK. Way Drainage Improvements (SPU 2007b) XP -SWMM Model Documentation - February 2007. Update to the initial Norfolk Basin Comprehensive Drainage Plan containing computation of runoff from the land surface and peak flow rates and stages at multiple points in the conveyance system. Included as Appendix B of the Norfolk - MLK Way Subbasin Stormwater Improvements Project Preliminary Engineering Report (SPU 2007a) Wetland Delineation - May 2006. Delineation of wetland area in the WSDOT ditch, conducted by SPU. Included in Appendix C of the Norfolk -MLK Way Subbasin Stormwater improvements Project Preliminary Engineering Report (SPU 2007a) Evaluation of Potential Offsite Wetland Mitigation Areas - February 2007. Evaluation of potential wetland mitigation sites, and recommendations. Included as Appendix D in the Norfolk -.MLK Way Subbasin Stormwater Improvements Project Preliminary Engineering Report (SPU 2007a) Wetland Mitigation Plan - November 2007. Description of wetland mitigation to be provided at the Puget Creek Natural Area. To be submitted along with permit applications for this project (HEC 2007). A9. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. None known. A10. List any government approvals or permits that will be needed for your proposal, if known. City of Seattle, Exception to the .Environmentally Critical. Areas Ordinance. City of Seattle, Stormwater, Grading and Drainage Permit City of Tukwila. Building, Mechanical, Plumbing/Gas Piping and Public Works Permit City of Tukwila, Special Permission Director .Permit US Army Corps of Engineers, Section 404 Nationwide Permit Coastal Zone Consistency Certification Endangered Species Act Review, No Effect Letter Washington Department of Ecology, Section 401 Water Quality Certification Washington Department of Ecology, National Pollutant Discharge Elimination System (NPDES) Washington Department of Transportation, General Permit aA 06- 03354.100 sepa checklist 7 All. Give brief, complete description of your proposal, including the proposed.uses and the site of the project. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You do not need to repeat those answers on this page. (Lead agencies may modify this form to include additional specific information on project description.) SPU proposes to repair a damaged drainage system in the Norfolk -MLK Way subbasin. The project area is located in the vicinity of the South Boeing Access road interchange on I -5 (Sheet 1). Stormwater runoff from the subbasin is conveyed through a series of pipes to an existing ditch on the east side of I-5 that is owned by WSDOT (Sheet 2). A portion of the piped drainage system between Martin Luther King, Jr. Way S (MLK Way) and 1 -5 is damaged. causing stormwater to back up into an adjacent sanitary sewer system. King County has notified SPU that it will no longer allow stormwater to be discharged to the sanitary sewer system. The proposed project involves replacing the damaged and undersized drain line (36 -inch CMP) and regrading a section of the WSDOT ditch that has become clogged with sediment to restore the hydraulic capacity of the existing system. Although privately- owned, the damaged pipe is a key component of the Norfolk-MLK Way drainage system. In addition to restoring hydraulic capacity, the project also would eliminate overflows of stormwater from the Norfolk -MLK Way drainage system to the sanitary sewer system and reduce flooding on Martin Luther King Jr. Way S. Prior to replacing the damaged drain line, the proposed project would temporarily bypass stormwater around the non-functioning 36 -inch CMP, through an above- ground pipeline to an above - ground stilling well and rock pad energy dissipater using a portable pump system. The purpose of the temporary pumping is to substantially reduce the overflow volume of stormwater into the King County sanitary system until the permanent pipeline is installed to replace the non - functioning pipe. This portion of the proposed project consists of two portable skid - mounted 900 gpm pumps, installed on the southwest corner of the Steeler property (10023 Martin- Luther King Jr. Way South) and powered by a self - contained diesel motor. An 8 -inch- diameter suction pipe would connect to the existing storm drain maintenance hole that connects the 60 -inch- diameter storm dram line with the non - functioning 36- inch - diameter CMP. The above - ground pipeline and stilling well and rock pad energy dissipater were installed in summer 2007. During the pumping, the damaged line would be replaced with a 64 -inch, ductile -iron pipe to provide the necessary conveyance capacity. The new 64 -inch pipe would be 480 feet long, with an upstream invert elevation of 11.12 feet NAVD88 and a downstream invert elevation of 10.75 feet NAVD88. A small sediment trap and spill control structure would be installed at the downstream end of the new 64 -inch pipe to facilitate future maintenance of the ditch as well as to protect the WSDOT ditch from spills that might occur in the drainage basin. Low flows would be routed to the spill control structure via a 4 -foot by 6 -foot concrete flow diversion structure. Higher flows would be discharged directly to the sediment trap. The sediment trap would be constructed by excavating a 33 -foot by 5 -foot depression along the east side of the ditch. The spill control structure would consist of a 12 -foot diameter manhole equipped with a baffle to retain oil. grease, and other floatable materials, and would discharged to the sediment trap. SPU has been conducting source control activities (e.g., business inspections and source tracing) in the Norfolk -MLK Way subbasin since 2001. Several illicit connections /discharges were discovered and have been eliminated. A spill control structure has been included in the project design as a precaution to protect the downstream WSDOT ditch, given the industrial nature of the businesses operating in the basin. Regrading of the ditch and construction of the sediment trap would involve work in a regulated wetland (Wetland 0, see Sheets 3 and 4). The WSDOT ditch is located within Wetland D. Mitigation ab 06- 03354. f Q0 sepo chocktis? 3 for impacts to Wetland D would include wetland .re- establishment and enhancement activities at the Puget Creek Natural Area, owned by the City of Seattle Parks Department (see Sheet 1, Vicinity Map). Temporary pumping, replacement of the existing storm drain, and construction of the flow diversion and spill control structures would not involve work in waters of the U.S. Al2. Location of the proposal. Give sufficient information for a person to understand the precise location of, your proposed project, including a street. address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range .or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available. While you should submit any plans required by-the agency, you are not required to duplicate maps or detailedplans submitted with any permit applications related to this .checklist. The project site is located within Sections 3 and 10, Township 23 North, Range 4 East, on the east side of 1. -5 in the vicinity of the South Boeing Access Road in the cities of Seattle and Tukwila, Icing County, Washington (Sheet 1). The temporary pumping, pipe removal and installation, and ditch regrading would occur in the City of Seattle (and would require a City of Seattle, Exception to the Environmentally Critical Areas Ordinance, and a City of Seattle, Stormwater, Grading and Drainage Permit). Only ditch regrading would occur in the City of Tukwila and would require a City of Tukwila, Building, Mechanical, Plumbing /Gas. Piping and Public Works Permit, and a City of Tukwila, Special Perrnission Director Permit. A site plan showing topography is available in Sheets 3 and 4. ab 06- 03354 -tW sepe cnec*Ns' 4 1 it 1 1 1 1 1 1 1 1 1 1 3 1 1 ",t .! 3 -I-N,,,1 1 1.1 , , ) I r.--LHI '[. .., 7* I \.41 i ,,,„ ; ;.„, , • : 1 •,. 1....._..-i'' i i'-''' I. 1 1 i I ,....-'5: ''' ...,•..,„,. 5/ • si, , ,-, , 1.1-11 r l'f-• --;•—•• •I " ‘• 5 i i i • ..1 7 ; , .., t 1„! , ..•,- I \ )`.-1: \-!..-4-4 ----1 ! I . Atads T , ! :: • t'' ' • .• "-aa•—•••i :` '•-• 1 ! • 1 .: . PUGET CREEK NATURAL AREA i MITIGATION SITE 3000 0 3000 6000 SCALE 1- 3000' • • • I • : • • • `, , • is 1-; • 4 • 1 -3.•_ ‘0. • 't-•• 1••-••• ‘5,_•V -• !-- • I ' I I sy, r--ltiymtairr; r ; 01 ,i .., , .. \..._,_ ! , ,i0,4,,E,,-- -, , • - 1 vossirahe $411,-7----,•-• • 8.47' a • . . : • ! • , , ! : , , • , ; , , „ 1 1, 1 1 _.,L, 1 ' : : i,,.------; . , 1,,,, • i . ...1... 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H_ -1- —I ! • I r---.-,- •,.i. * t•[-..--r•-•--1..-- ‘‘• el • __Hs_ ....,L,..4.ii8,‘,, 1- tt•--i- ..._1I,..__I_ ! 5 WM61\ \ • — 4- • ; / •-4 ). 11 1_2\ , I r \ • 7 : c•-•-•• s*Egthu 01. 1 a , • ,•,..-• • 1- ! • • 3 \ , I A rti---"-•-t-"•;""i I PROJECT LOCATION • a, \ ;‘, 21` -1-sr-/ -,--, . • " • , ! 1 I • I . ; • svi -----171X174 11r : 5' ,51" ,„. 5 !; s , ,„....<„,,,,,!,, \ 1 ! 1 ! 1 1 1 •,'. .„.:7 s'. 5. s 1 Ism or „ i , '••• ; , a. • • j ■ !. . . . , -1 Il. ,4.3...!..T.,,t ,.......... .2„, Sil • , , s' i Dam, ' • '' / \ •--1 i t 4 • ” 1 • • I •5, ! • 1$1 • ' I ! • I , g • : • 1 ! • • - • •K• .E1 ; • • I r--- PROJECT SITE COORDINATES: r SECTIONS 3 AND 10, TOWNSHIP 23 NORTH, RANGE 4 EAST --"! : LAT. 47°3035%, LONG. 12r1645Erw , ! MITIGATION SITE COORDINATES: g t. LAT. 473313"N, LONG. 122°21'30W t Ili DATUM: NAVD-88 I HERRERA INVIRCIMISTRA1 CONERATAWS 2200 Sixth Avenue Suite 1100 Seattle, Washington 1#7121-51320 200-441-9000 2004414108 FAX h10.4....1.1.10sInesclen Date: DECEMBER 18, 2007 VICINITY MAP lApplicant SEATTLE PUBLIC UTILITIES Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Project Location: SEATTLE AND TUKWILA, i KING COUNTY, WASHINGTON I SCALE AS NOTED SHEET 1 of 4 EriAr L CORf'U TU CiAtil. CORPORATF LI 17 Match, 3 LEGEIND ! 1 Proposed improvement Wetland Ditch Storm drain 1-toot topographic contour 5-foot topographic contour * Section line Propertyieasement boundary City limit e Cliannet 52 ^;PSD oil °Oiltilmi;SizustUre`, E4 PSD Alum Diversion 5truttu re`�.,,..i.. 3iment;Trap Abandoriln.r -taci' Existing '3C.r..',chiP 3/ 0 50' 100 ApQm01l S0all0.'. 16e iRu kbill; 'Fiappiic 10'141.1 41► Abatufnli iii%P,iaae Existing S Manhole ," TETRA TECH wrowdetreteauXtrn 1420 FMR MINIM, Sued 503 Swim, Wasto» 98101 Pmmrw: 208-saa,s3W Fax 2n0.8113-12301 Date: DECEMBER 1.8, 2007 PROPOSED CONVEYANCE IMPROVEMENTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 2 of 4 3 E ----START PROJECT WETLAND/ D 7' \ \ \ \ 15 0 15 30 SCALE IN FEET \ ". \\\\\ \ \ \ \ \ \ \ DITCH CENTER64E.' • \ \ \ \ \\ \ ' CONSTRUCTION UMITV\ 0 1- — ADJACENT PROPERTY OWNERS: 0 PAPE MATERIAL HANDLING NOTE: WETLAND AREA TEMPORARILY DISTURBED: TOTAL PROJECT SEDIMENT EXCAVATION VOLUME: TOTAL PROJECT FILL VOLUME: EXCAVATION WITHIN WETLAND D: FILL WITHIN WETLAND D: DATUM: NAVD-88 \\\ \\\ \\• \ \ \ \ \ \ 6,234 SO FT (0.14 ACRES) 334 CU YDS 105 CU YDS FOR OUTLET PROTECTION 133 CU YDS 6 CU YDS PAD LEGEND: — — — PROJECT LIMITS CONSTRUCTION LIMITS FENCE —11— PROPOSED CONTOURS ---12 - EXISTING CONTOURS 1 EXISTING WETLAND HERRERA 2200 614/1 Avenue Suite 1100 Seatti, Wastengtee 03121-1020 200441-9000 200-441-0108 FAX EXVIROmosirli. COMMET.VerS Date: DECEMBER 18, 2007 WETLAND IMPACTS Application for: PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 3 of 4 WETLANb D 12.PS0 39LF. OIL CONTROL STRUCTURE 15 0 11 15 30 11 SCALE IN I-LL I SEDIMENT TRAP WITH 3H1V SIDE SLOPES EXTEND EXISTING CONCRETE BLOCK RETOUNO WALL 12P3 29LF, S.41.30% PLOW DIVERSION STRUCTURE 0 .-•••■••••■•■■■■••■••■••••■■■■•••■■••■•■• 7j1c,v4LA LEGEND- PROJECT umns CONSTRUCTION UMITS FENCE ----11---- PROPOSED CONTOURS 2 ---- EXISTING CONTOURS • 1 EXISTING WETLAND \ • .„ 11, \ „;;;,; •\,\ ADJACENT PROPERTY OWNERS: 0 PAPE MATERIAL HANDLING 0 UNDAHL CEDAR HOMES NOTE: WETLAND AREA TEMPORARILY DISTURBED: TOTAL PROJECT SEDIMENT EXCAVATION VOLUME: TOTAL PROJECT FILL VOLUME: EXCAVATION WITHIN WETLAND D: FILL WITHIN WETLAND 0: DATUM: NAVD-88 2CMP 8Y SURVEY PROTECTION PAD _1 V CONSTRUCTION LIMIT `• \ • `• s•:\ 6,234 S4 FT (0,14 ACRES) 334 CU YDS 105 CU YDS FOR OUTLET PROTECTION 133 CU YDS 6 CU YDS PAD END PROJECT CMMMI HERRERA ==7:W7 2200 Sixth Avon= Sono 1100 Seattle, Washington 08121-1020 200-4414080 2004414108 FAX oitommoatenior.o. Date: DECEMBER 18, 2007 WETLAND IMPACTS Application for PROPOSED STORMWATER CONVEYANCE IMPROVEMENTS Purpose: REPLACE PIPELINE AND REGRADE WSDOT DITCH (WETLAND D) Applicant: SEATTLE PUBLIC UTILITIES Project Location: SEATTLE AND TUKWILA, KING COUNTY, WASHINGTON SCALE AS NOTED SHEET 4 of 4 B. ENVIRONMENTAL ELEMENTS B1. Earth a. General description of the site: CO Flat ❑ Rolling ❑ Hilly ❑ Steep Slopes E Mountains ❑ Other: b. What is the steepest slope on the site (approximate percent slope)? The project area is relatively flat with the exception of the engineered slopes that define the boundaries of Wetland D. c. What general types of soils are found on the site (for example, clay sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them and note any prime farmland. Soil maps from the Natural Resources Conservation Service and King County do not contain any soil information for the project site. This area is considered urban, where soils have not been mapped. A geological map of the area indicates that the surficial deposits of the surrounding area are mainly recent alluvium and peat deposits. The geotechnical report produced for this project indicated that subsurface soils encountered included fill, non - glacial fluvial (river) soils, non - glaciat lacustrine (lake) soils, and peat. d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe: There is a Potential Liquefaction Area documented in the City of Seattle Environmentally Critical Areas Map Folios within the. project area. The Geotechnical report for this project indicated that structures located in Potential Liquefaction Areas but situated above groundwater levels would incur minimal earthquake risk. All structural components of this project would be located above the groundwater table. e. Describe the - purpose, Wa,.and approximate quantities of any filling or grading proposed. Indicate source of fill. The purpose of the stonnwater improvement project is to reduce frequent overflows of stormwater to the sanitary sewer system, restore the conveyance capacity of the system, and reduce flooding on Martin Luther King Jr. Way. The 36 -inch CMP would be removed and replaced with a 500- foot -long 64 -inch ductile -iron pipe. Following excavation, geotextile would be placed on the undisturbed su.bgrade, followed by approximately 6 inches of compacted crushed rock, followed by the pipe bedding and the pipe. About 2,200 cubic yards of material would be excavated from the pipeline trench. Approximately 1,800 cubic yards of fill would be placed in the trench with the installation of the pipe. Approximately 40 cubic yards of rock would be placed at the pipe outfall. No material from the pipe excavation would be used on- site; Regrading the WSDOT ditch would require clearing and regrading a 340 -foot long section of the ditch extending from 100 feet upstream of the new 64 -inch pipe to 240 feet downstream of the new pipe. The regraded section would have a trapezoidal shape with a 5 -foot bottom and 3:1 side slopes. The upstream and downstream invert of the regraded ditch would match existing eb 06.03354-WO 00 sopo checklist grade. Excavated material would be taken to an SPU approved storage facility. Total excavation volume for this part of the project would be 334 cubic yards including 94 cubic yards of sediment in Wetland D. A new sediment trap would be constructed at the outran of the new 64 -inch conveyance pipe. The sediment trap would be approximately 33 feet long with a 5 -foot base width and 3:1 side slopes. Six cubic yards of rock would he used to construct an outlet protection pad. f. Could erosion occur as a result of clearing, construction, or .use? If so, generally describe: No significant erosion is anticipated. Clearing and grading for construction of the proposed project would follow an approved temporary erosion and sedimentation control (TESC) plan as a condition of its NPDES permit, the City of Seattle's Stormwater, Grading and Drainage Permit and the City of Tukwila's, Building, Mechanical, Plumbing/Gas Piping and Public Works Permit. Therefore any erosion that might occur during construction would be effectively Managed. g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? The proposed project would not result in new impervious surfaces. Areas currently impervious, such as roads or parking lots, would be resurfaced and would remain impervious. h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any. A TESC plan would be prepared prior to construction. The project would comply with Seattle's Grading and Drainage Control Ordinance, and the City of Tukwila's, Building, Mechanical, .Plumbing/Gas Piping and. Public Works Permit. B2. Air a. What types of emissionsto the air would result from the proposal (i.e., dust, automobile, odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known. Emissions during construction would include normal amounts of dust from grading activities and exhaust (carbon monoxide, sulfur, particulates) from construction equipment. The completed project would not produce any emissions. b. Are there any off -site sources of emissions or odor that may affect your proposal? If so, generally describe. There are no known off -site sources of emissions or odor that would affect this proposal. c. Proposed measures to reduce or control emissions or other impacts to air, if any: During construction, impacts to air quality would be reduced and controlled through implementation of standard federal, state and local emission control criteria and City of Seattle construction practices. These could include: spraying areas of exposed. soil with water for dust control, regular street cleaning, and reducing exhaust emissions by minimizing vehicle and equipment idling. eb 06-03354 100 sapa cnecxtist 10 B3. Water a. Surface: (1) Is there any surface water body on or in the immediate vicinity of the site (including year -round and seasonal streams, saltwater, lakes, ponds, wetlands)? If so, describe fie and provide names. If appropriate, state what stream or river or water body it flows: into. The project proposes improvement to the storm drainage system serving the Norfolk Street and MLK Way drainage subbasins. This storm drain system discharges to the. Lower Duwam.ish Waterway. The Duwamish Waterway is approximately 3,000 feet west of the project site. There are no streams in the project area. The project area has one wetland. The WSDOT ditch that would be regraded is located within Wetland D, a regulated wetland, and is located in both the City of Seattle (rated a Category III) and the City of Tukwila (rated a Type 3), along the east side of northbound 1 -5. Water from the WSDOT ditch flows west into two parallel culverts located under 1 -5. Once reaching the west side of I -5, flow passes through two other regulated wetlands and then enters a piped system before discharging to the Duwamish Waterway. (2) Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If so, please describe and attach available plans. The above - ground stilling well and rock pad energy dissipater was installed on the edge of the WSDOT ditch in sumrner 2007 however the location was subsequently modified in consultation with the U.S. Army Corps of Engineers to avoid wetlands impacts. Regrading of th.e WSDOT ditch (located in W etland D) would result in impacts on approximately 0.14 acres of wetland. The area of wetland that would be impacted by the project is shown in Sheets 3 and 4 and totals 6234 112(0.14 acre), including 4979 ft` (0.11 acre) within the City of Seattle and 1255 fie (0.03 acre) within the City of Tukwila. (3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. Approximately 91 cubic yards of deposited sediment would be removed from Wetland D. Six cubic yards of quarry spans (obtained from a SPU approved facility) would be used to construct an outfall protection pad (4) Will the proposal .require surface water withdrawals or diversions? If so, give general description, purpose, and approximate quantities if known. No surface water withdrawals or diversions would be required. During the replacement of the damaged pipeline and installation of the check valve, a temporary pumping system, installed in the fall of 2007 to reduce stormwater overflow to the sanitary system, would bypass stormwater flows less than 5 cfs around the construction site and discharge them into the WSDOT ditch through an energy dissipating structure. atr 06-03354-100 seas .:hetidts! 11 (5) Stormwater flow greater than 5 cfs would be diverted to the City of Seattle's sanitary system. Does the proposal Iie within a 100 -year floodplain? If so, note location on the site.plan. The proposal does not lie within a 100 -year floodplain. (6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. The project would not produce or discharge waste materials to surface waters. b. Ground: (1) Will ground water be withdrawn, or will water be discharged to ground water? If so, give general description, purpose, and approximate quantities if known. No ground water would be withdrawn. (2) Describe waste material that will be discharged into the. ground from septic tanks or other sources, if any (for example: domestic sewage; industrial, agricultural, etc.). Describe the general size of such systems, the number of houses to be served (if applicable), orthe number of animals or humans the system(s) are expected to serve. No waste material would be discharged. c. Water Runoff (including storm water): (1) et, 0(43354 -100 sem checklist Describe the source of runoff (including storm water) and method of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe. The source of water to the project site is rainfall occurring as stormwater runoff. Stormwater runoff during project construction would be routed as described in section B.3.a.4. After the project is constructed, runoff from the Norfolk -MLK. Way subbasin would flow through the new 64 -inch storm drain pipe to the WSDOT ditch that parallels the east side of '1 -5. Two existing parallel culverts would convey runoff from the east side of the highway to the west side of 1 -5. From there runoff would discharge to two wetlands located between I- 5 and the BNSF Railway right -of -way to the west, then to the Duwamish Waterway through the City of Seattle's combined seweristorm drain at the Norfolk outfall. Under high flow conditions stormwater would flow through the 60 -inch Ryan Street outfall owned by WSDOT that is located approximately 1400 feet south (upriver) of the Norfolk outfall. The runoff quantity for the area would not change, but .flooding at Martin Luther King Jr. Way would decrease by approximately 2 feet for the 25 year design storm event. 12 1 1 1 1 1 1 l 1 1 t 1 1 t 1 1 1 1 (2) Could waste materials enter ground or surface waters? If so, generally describe. There would be no waste materials from this project that could enter ground or surface waters. d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any: No surface, ground, or runoff water impacts are anticipated. Best management practices (BMPs) would be used to limit erosion and sediment transport during construction. Following construction the conveyance improvements would result in additional water quality treatment capacity within the system to treat future stormwater runoff. B4. Plants a. Check tunes of vegetation found on the site: b. What kind and amount of vegetation will be removed or altered? Regrading the WSDOT ditch would require clearing of wetland and adjacent upland vegetation including reed canarygrass, nightshade, hardhack, Sitka willow and black cottonwood in the wetland portion and blackberry, Scot's broom and Nootka rose in the adjacent upland. ab 0643354 -WO sex? checklist 1 3 Deciduous trees (check types): ❑ alder E maple ❑ aspen Ei other: Sitka willow and black cottonwood ❑ Evergreen trees (check types): ❑ fir ❑ cedar ❑ pine ❑ other: Ed Shrubs Q Grass ❑ Pasture E Crop or grain Q Wet soil plants (check types): Ei cattail ❑ buttercup Er bullrush ❑ skunk cabbage Q Other: canarygrass, nightshade, hardhack (NOTE: wet soil plants are located in ditches). • Water plants (check types): E water lily E. eelgrass ❑ milfoil ❑ Other: E 1Other types of vegetation: blackberry, Scot's broom and Nootka rose b. What kind and amount of vegetation will be removed or altered? Regrading the WSDOT ditch would require clearing of wetland and adjacent upland vegetation including reed canarygrass, nightshade, hardhack, Sitka willow and black cottonwood in the wetland portion and blackberry, Scot's broom and Nootka rose in the adjacent upland. ab 0643354 -WO sex? checklist 1 3 c. List threatened or endangered species known to be on or near the site. According to the Washington Natural Heritage Program data base retrieval, dated August 21, 2007, there are no known threatened or endangered plant species on or near the site. d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: The wetland ditch would be replanted with native species and all upland areas with disturbed exposed soils would be seeded with grass. B5. Animals a. Checkmark any birds and animals that have been observed on or near the site or.are known to be on or near the site: Birds: M.ammals: . Fish: ❑ hawk ❑ heron eagle El songbirds ❑ other: C deer 0 bear ❑ elk ❑ beaver Eother: E bass C salmon ❑ trout ❑ herring C shellfish C other: b. List any threatened or endangered species known-to be on or near the site: According to the Washington Natural Heritage "Program data base retrieval, dated August 21, 2007, there are no known threatened or endangered wildlife species on or near the site. c. Is the site part of a migration route? If so, explain. The site is not located in a known migration .corridor. d. Proposed measures to preserve or enhance wildlife, if any: Best management practices and minimization measures would be implemented during the design and construction phases of the project in order to minimize the potential impacts on fish and aquatic life. A TESC plan and a spill prevention, control, and countermeasures (SPCC) plan is being prepared and would be implemented prior to the start of construction. Clearing limits would be marked to avoid impacts on sensitive areas and all equipment to be used for construction activities would be cleaned and inspected before it arrives at the project site to minimize potential fuel or lubricant Teaks. B6 Energy and Natural Resources a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. The completed project would not require any supplementary energy to operate. b. Would your project affect the potential use of solar energy by adjacent properties? if so, generally describe. The project does not involve building structures or planting vegetation that would block access to the sun for adjacent properties. ab 6. 3354 -1 DC saps dleckilsi 14 c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any: Not applicable (see item. B6a. above) B7. Environmental Health a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe: Environmental sampling was performed in the project area on September 14, 2007, in accordance with the procedures outlined in ASTM .D -4700 Standard Guide for Soil Sampling from the Vadose Zone and ASTM D -5088 Standard Practices for Decontamination of Field Equipment Used at Waste Sites, to determine whether petroleum - related contaminants were present in the soil at the study area. The results indicated that the soils in the project area did not meet hazardous waste criteria. Small amounts of substances that may be present during construction include gasoline and diesel fuels, hydraulic fluids, oils, lubricants, solvents, and other chemical products. Although a spill of one of these chemicals could potentially occur during construction as a result of either equipment failure or worker error, a SPCC plan would be in place to address any emergency spill situations. (1) Describe special emergency services that might be required. Possible fire or medic services could be required during construction. (2) Proposed measures to reduce or control environmental health hazards, if any: A I- Iealth and Safety Plan would be submitted by the contractor before work commences. A SPCC plan would be implemented to control spills on site. b. Noise (l) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? Noises that exist in the area would not affect the project. (2) What types and levels of noise would-be created by or associated with the project on a short -term or a .long -term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site. Noise levels in the project vicinity would temporarily increase during pumping and construction activities. The pump motors would be housed in sound - attenuating enclosures with a noise level of 60 dbA at 23 feet (60 dbA is equivalent to normal conversation levels). Pumping would occur as needed over a period of between 12 and 18 months prior to construction of the conveyance pipeline. The average annual pump run time is expected to be about 1200 hours and would vary daily based on storm events. Short-term noise from construction equipment would be limited to the allowable maximum levels of City of ab 06 -03354 -100 sepa char -Mist 15 (3) Seattle's Noise Control Ordinance (SMC Chapter 25.08. After completion of the project, occasional noise from equipment used for on -going routine maintenance and repair would occur, but would be limited to lam to 9pm weekdays and 9am to 9pm weekends. Proposed measures to reduce or control noise impacts, if any: Construction and pumping equipment would be muffled as needed to comply with applicable laws. SMC Chapter 25.08, which prescribes limits to noise and construction activities, would be fully enforced while the project is under. construction. B8. Land and Shoreline Use , a. What is the current use of the site and adjacent properties? The site is currently used as a drainage facility, parking lot, and driveway. Private property owners in the project area include: Pape M.aterial Handling and Steeler, .Inc. The area surrounding the project is highly industrialized, with 61 percent of the subbasin in industrial use, 14 percent in single family residential, 10 percent in highway right -of -way, 9 percent in open space or vacant lots, and 5 percent in commercial use. b. Has the site been used for agriculture? If so, describe. The site has not been used for agriculture in recent history. c. Describe any:structures on the site. The existing structures in the project area include buildings, parking lots and driveways on Pape Material Handling, Lindahl Cedar Homes, and Steeler, Inc. properties. d. Will any structures be demolished? Ii so, what? The Pape washhouse would be partially demolished to facilitate installation of the pipeline. The washhouse would be reconstructed after construction is complete. e. What is the current zoning classification of the site? The section of the project within the City of Seattle limits is zoned General Industrial 2 (City of Seattle 2006). In the City of Tukwila, the area north east of the I -5 / S. Boeing Access Road interchange is zoned Light Industrial. The portion of the site within WSDOT right -of -way is exempt from zoning. 1. What is the current comprehensive plan designation of the site? The site is currently designated as "Industrial" in the City of Seattle comprehensive plan (City of Seattle 2005). In the City of Tukwila the area north east of the I -5 / S. Boeing Access Road intersection is designed Light Industrial in the current comprehensive plan. g. If applicable, what is the current shoreline master program designation of the site? The proposed site is not designated shoreline or within 200 feet of a designated shoreline. 80 06-03304-100 sops :heck liar 16 h. Has any part of the site been classified as an "environmentally sensitive" area? If so, specify. Yes. One wetland occurs in the project area (Wetland D). It is classified as an "environmentally critical area" according to the City of Seattle (City of Seattle 2006 and City of Seattle 2007). The northern portion of the site (north from the alignment of the proposed 36 -inch pipe replacement is mapped as Potential Liquefaction Area in the City of Seattle Environmentally Critical Areas Map Folios (City of Seattle 2006 and City of Seattle 2007). Activities occurring in Wetland D are detailed in item B.3.a.1. Compensation for permanent wetland impacts would be provided by restoring and enhancing freshwater wetlands and wetland buffers in the Puget Creek Natural Area (Sheet .I). This 7.85 acre property is located approximately 4.5 miles northwest of the project site. It contains a headwater forested wetland 'that Puget Creek, which drains to the Duwamish River. Compensation for permanent wetland impacts would be provided by restoring and enhancing wetlands and wetland buffers within the Puget Creek Natural Area. i. Approximately how many people would reside or work in the completed project? No people would reside or work in the completed project. j• Approximately how many people would the completed project displace? No people would be displaced by the project. k. Proposed measures to avoid or reduce displacement impacts, if any: Not applicable (see item B.8 j. above) 1. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: The proposed project would: be consistent with current land uses and plans. B9. Housing a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low- income housing. This project does not involve the construction of any housing units. b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or law= income housing. No housing units would be eliminated. c. Describe proposed measures to reduce or control housing impacts, if any: This project does not have any housing impacts. ab 06.03354 -100 sepa chatbdist 17 B10. Aesthetics a. What is the tallest height of any proposed structure(s), not including antennas? What is the principal exterior building material(s) proposed? No structures are proposed. b. What views in the immediate vicinity would be altered or obstructed? No views would be altered by this project. c. Proposed measures to reduce or control aesthetic, impacts, if any: There would be no aesthetic impacts as a result of this project. B11. Light and Glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur? The completed project would not produce any light or glare. b. Could light or glare from the finished project be a safety hazard or interfere with views? Not applicable (see item B.1 1.a. above) c. What existing off -site sources of light or glare may affect your proposal? There are : no existing off -site sources of light and glare that would affect the proposal. d. Proposed measures to reduce or control light and glare impacts, if any: Not applicable (see item B.1 La. above) B12. Recreation a. What designated and informal recreational opportunities are in the immediate vicinity? There are no designated or informal recreation opportunities in the area. b. Would the proposed project displace any existing recreational uses? If so, describe. No recreational uses would be displaced. c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: There are no impacts on recreation so no measures are proposed to reduce or control impacts on recreation. at) 06- 03354-1o( seue the ,thst 18 B13. Historic and Cultural Preservation a. Are there any places or objects listed on, or proposed for, national, state, or local preservation 'registers known to be on or next to the site? If so, generally. describe. The project location was checked using the Washington Department of Archaeology and Historical Preservation. website (DAHP 2007) for properties listed on the Washington Heritage Register and the National Register of Historic Places and the Seattle Department of Planning and Development website (City of Seattle 2007) for City of Seattle landmarks on December 3, 2007. In addition the location was checked using the King County .Historic Preservation archaeological and ethnographic database on January 10, 2008. No landmarks or evidence of historic, archaeological, scientific, or cultural importance are known to be on the project site. Archaeological surveys have been conducted in the immediate area for road projects, with no recorded archaeological material. b. Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site. No landmarks or evidence of historic, archaeological, scientific, or cultural importance are known to be on or adjacent to the project site. The project area is an urban industrial area and the entire area is indicated to have been modified by grading activities (SPU 2007). c. Proposed measures to reduce or control impacts, if any: Should evidence of cultural remains, either historic or prehistoric, be encountered during excavation, work in that immediate area would be suspended, and the find would be examined and documented by a professional archaeologist. Decisions regarding appropriate mitigation. and further action would be made at that time. B14. Transportation a. Identify public streets and highways serving the site, and describe proposed access to the existing street system. Show on site plans, if any. Access to the project site is from Martin Luther King Jr. Way S. and through private property. b. Is site currently served by public transit? If not, what is the approximate distance to the nearest transit stop? The nearest transit stop is located at Martin Luther King Jr. Way S. and S. Norfolk Street and is approximately 1,500 feet from the project area. Bus stop use would not he affected by this project during construction or following project completion. c. How many parking spaces would the completed project have? How many would the project eliminate? The completed project would have no effect on the number of parking spaces in the area. Local parking availability could be temporarily disrupted during construction but is expected to be accommodated elsewhere on -site. ab 0643354-100 sepa checklist 19 d. Will the proposal require any new roads or streets, or improvements to existing roads or streets, not including driveways? If so, generally describe (indicate whether public or private). No, the proposed project would not require any new roads, streets, or-improvements to existing roads. e. Will the-project use (or occur in the immediate vicinity of) water, rail, or atr transportation? If so, generally describe. The proposed project would not use water, rail or air transportation; however, the project does occur in the vicinity of these types of transportation. Boeing Field/ King County International Airport is located approximately 0.5 miles northwest of the project area. The BNSF railroad tracks are located west of l -5. g. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would occur. This project would not generate any new vehicular trips and peak volumes would not change as a result of this project. Constnictioa.is expected to generate approximately 300 trips over the course of the 12 to 16-week project due to removal of some of the excavated material and collapsed pipe from the site and. importing of base rock and new pipe sections to the site. Proposed measures to reduce or control transportation impacts, if any: Construction traffic would be accommodated by the surrounding street system. This completed project would not affect traffic, therefore no measures are proposed. B15. Public Services a. Would the project result in an increased need for public services (for example: -fire protection, police protection, health care, schools, other)? If so, generally describe. The project would have no impact on the need for public services. b. Proposed measures to reduce or control direct impacts on public services, if any. Not applicable (see B15a. above) B16. Utilities a. Check utilities currently available at the site, if any: ❑ None electricity IEI natural gas ❑ water ❑ refuse service CJ( telephone RI sanitary sewer ❑septic system [].other: b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed. ❑ None Other than the stormwater system improvements described previously, no new utilities are proposed. ab Cb- 03354- 1 aC Sops checkti51 20 C. SIGNATURE The above answers are true and complete to the best of my knowledge. I understand that the lead agency is relying on them to make its decision. Signature: ; �`` _.` �/ ,��v [•H , {f` Date: '274/ o8 Arne'. Valmonte, I Project Manager ab 06-03354-100 seas check t 1 2 l References City of Seattle. 2005. City of Seattle Comprehensive Plan. City of Seattle, Department of Planning and Development, Seattle Washington. Obtained on May 14, 2007 from website: <http: / /www.seattle. gov/ DPD/ PlanningiSeattle _s_Comprehensive_ Plan/ ComprehensivePlan/default.asp >. City of Seattle, 2006. Zoning Maps. Department of Planning and Development, Seattle, Washington. Obtained on May 28, 2007 from agency website: <http: / /www.seattle. gov /dpd/Research/Zoning,Maps/ and http://www.seattle.govidpillReseareh/gisiwebplots/k305w.pdf>. City of Seattle. 2007. DPD GIS Map Builder. Department of Planning and Development, Seattle, Washington. Obtained on May 28, 2007 from agency website: <http: /. /web.l .seattle. gov /dpd/dpdgisv2/mapviewer.aspx >. City of Tukwila. W95. City of Tukwila Comprehensive Plan Map ( dated. December 4, 1995). Tukwila Planning Division, Tukwila, Washington. Obtained on May 28, 2007 from agency website: <http://www.ci.tukwila.wa.usitme/title18.pdf>. City of Tukwila. 2007. Zoning Code, Chapter 18 (dated January 2007). City of Tukwila, Tukwila Planning Division, Tukwila, Washington. Obtained on May 28, 2007 from agency website: .chttp://www.ci.tuicwila.wa.usitmc/title18.pdf>. City of Tukwila. 2007b. City of Tukwila Critical Areas Map. Unpublished snap provided to Herrera Environmental Consultants by Sharron Dibble, Community Development, Graphic Specialist. City of Tukwila, Washington. DAHP 2007. Department of Archaeology and Historic Preservation. WISAARD map tool. Obtained November 30, 2007 from agency website: http: / /www.dahp.wa.gov /. H.EC. 2007. Wetland mitigation plan - Norfolk- Martin Luther King Jr. Way Subbasin Stormwater Improvements . Prepared for Seattle Public Utilities by Herrera Environmental Consultants, Inc.,, Seattle, Washington. Ruby, Marie. 2008. Personal communication (email regarding results of King County Historic Preservation database search). Cultural Resources Advisor, Seattle Public Utilities, Seattle, Washington. January 10, 2008. SPU. 2007a. Norfolk -MLK. Way Subbasin Stormwater Irnpmvements Project Preliminary Engineering Report Final. Prepared for Seattle Public Utilities by TetraTech/KCM, Seattle, Washington. SPU. 2007b. Environmental investigation and data report for Pape property. MLK Way/Norfolk Drainage Improvements. Prepared for SPU Engineering Division by Cody Nelson. Seattle Public Utilities Materials Laboratory, Seattle, Washington. eC G6-03354-100 soaa checklist 23 Seattle Public Utilities Norfolk -MLK Way Subbasin Stormwater Conveyance Improvements Project SEPA Determination of Nonsi2nificance (DNS) Description of Proposal: SPU proposes to repair a damaged drainage system in the Norfolk -MLK Way subbasin. A portion of the piped drainage system between Martin Luther King, Jr. Way S (MLK Way) and 1 -5 is damaged, causing stormwater to back up into an adjacent sanitary sewer system. The proposed project involves temporary pumping to bypass and replace the damaged and undersized drain line (36 -inch CMP) and regrading a section of the WSDOT ditch that has become clogged with sediment to restore the hydraulic capacity of the existing system. In addition to restoring hydraulic capacity, the project also would eliminate overflows of stormwater from the Norfolk -MLK Way drainage system to the sanitary sewer system and reduce flooding on Martin Luther King Jr. Way S. The damaged line would be replaced with a 480 -foot long, 64 -inch diameter, ductile -iron pipe to provide the necessary conveyance capacity. A small sediment trap and spill control structure would be installed at the downstream end of the new 64 -inch pipe to facilitate future maintenance of the ditch as well as to protect the WSDOT ditch from spills that might occur in the drainage basin. The sediment trap would be constructed by excavating a 33 -foot by 5 -foot depression along the east side of the ditch. The spill control structure would consist of a 12 -ft diameter manhole equipped with a baffle to retain oil, grease, and other floatable materials, and would discharge to the ditch immediately downstream of the sediment trap. Regrading of the ditch and construction of the sediment trap would involve work in a regulated wetland. Compensation for wetland impacts would include wetland re- establishment and enhancement activities at the Puget Creek Natural Area, owned by the City of Seattle Parks Department. The proposed mitigation at Puget Creek Natural Area meets all City of Seattle, Washington State Department of Ecology, and U. S. Army Corps of Engineers regulatory requirements for protecting aquatic resources. Proponent: Seattle Public Utilities Seattle Municipal Tower, Suite 4900 PO Box 34018 Seattle, WA 98124-4018 Attn: Arnel Valmonte, Project Manager; Phone: 206 -615 -1438 Location of Proposal, including street address, if any: The project site is located within Sections 3 and 10, Township 23 North, Range 4 East, on the east side of 1 -5 in the vicinity of the South Boeing Access Road in the cities of Seattle and Tukwila, King County, Washington SEPA Dehrnr:no( ion of Nonsignificaace (DNS) Page 2 Lead Agency: Seattle Public Utilities (SPU), the lead agency for this proposal, has determined that it does not have a probable significant adverse impact on the environment. An environmental impact statement (EIS) is not required under RCW 43.21C.030(2)(c). This decision was made after review of a completed environmental checklist and other related documents on file with the lead agency. This information may be examined at Seattle Public Utilities offices by contacting the Project Manager listed above. This DNS is issued under 197 -11- 340(2); the lead agency will not act on this proposal for 14 days from the publication date below. Comments must be submitted by 31 ID , 200$ Responsible Official: Joy Keniston - Longrie Major Interagency Projects Director Seattle Public Utilities Seattle Municipal Tower, Suite 4900 PO Box 34018 Seattle, WA 98124 -4018 (206) 684-5972 Signature: Date of Publicati Seattl Daily Jo . Date: Fe l.os'?-tc .,c-c f ,' cx; 8 ce: You may appeal this determination, in writing, no later than Z1111103% 1 to: City Hearing Examiner PO Box 94729 Seattle, WA 98124 -4729 1 There is a $50 filing fee for the appeal. You should be prepared to make specific factual objections. Contact the Hearing Examiner at (206) 684 -0521 to ask about or to make arrangements to read the procedures for SEPA appeals. ATTACHMENT E Coastal Zone Consistency Analysis 1 1 1 1 1 1 t 1 1 i 1 1 1 t COASTAL ZONE MANAGEMENT ACT CONSISTENCY ANALYSIS AND DETERMINATION Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements Project Prepared for Seattle Public Utilities February 2008 t 1 1 COASTAL ZONE MANAGEMENT ACT CONSISTENCY ANALYSIS AND DETERMINATION Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements Project Prepared for Seattle Public Utilities Seattle Municipal Tower 700 Fifth Avenue Seattle, WA 98124 -4018 Prepared by Herrera Environmental Consultants, Inc. 2200 Sixth Avenue, Suite 1100 Seattle, Washington 98121 Telephone: 206 - 441 -9080 February 11, 2008 1 1 1 Contents Introduction 1 Project Description 3 Replacement of 36 -inch CMP Storm Drainage Line 3 WSDOT Ditch Regrade and Sediment Trap 3 Mitigation 4 Consistency Analysis 5 The Shoreline Management Act 5 The Clean Water Act 6 The Clean Air Act 6 State Environmental Policy Act 7 Energy Facility Site Evaluation Council Law 7 Ocean Resources Management Act 8 Statement of Consistency 9 References 11 CZMA — Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements Project Introduction The Coastal Zone Management Act (CZMA) was enacted on October 27, 1972, to encourage coastal states to develop comprehensive programs to manage and balance competing uses of and impacts to coastal resources. CZMA requires that activities requiring federal agency permits, licenses, or funding, that have reasonably foreseeable effects on any land or water use or natural resource of the coastal zone must be consistent to the maximum extent practicable with the enforceable policies of a coastal state's federally approved coastal management program. The CZMA gives states the primary role in managing coastal zones under the act. The Washington State Department of Ecology is responsible for implementing Washington's program. The Norfolk — MLK Way Subbasin Conveyance Improvements project must comply with the federal CZMA because the project is located in King County, Washington, which is in the Washington Coastal Zone, and the project is an activity that requires federal permitting. AB /06-03354 -100 norfolk csma analysis comevance February 11, 2008 1 Herrera Environmental Consultants CZMA — Norfolk – MLK Way Subbasin Stormwater Conveyance Improvements Project Project Description Seattle Public Utilities (SPU) proposes improvements to the conveyance system in the Norfolk -MLK Way subbasin (Sheet 1). The proposed project involves replacing the damaged and undersized drain line (36 -inch CMP) and regrading a section of the WSDOT ditch that has become clogged with sediment to restore the hydraulic capacity of the existing system. Although privately - owned, the damaged pipe is a key component of the Norfolk -MLK Way drainage system. In addition to restoring hydraulic capacity, the project will also eliminate overflows of stormwater from the Norfolk -MLK Way drainage system to the sanitary sewer system and reduce flooding on Martin Luther King Jr. Way S. These proposed improvements are described in detail below. Replacement of 36 -inch CMP Storm Drainage Line The damaged line will be replaced with a 64 -inch, ductile -iron pipe to provide the necessary conveyance capacity (Sheet 2). The new 64 -inch pipe would be 480 feet long, with an upstream invert elevation of 11.12 feet NAVD88 and a downstream invert elevation of 10.75 feet NAVD88. A small sediment trap and spill control structure will be installed at the downstream end of the new 64 -inch pipe to facilitate future maintenance of the ditch as well as to protect the WSDOT ditch from spills that may occur in the drainage basin. Low flows will be routed to the spill control structure via a 4 -foot by 6 -foot concrete flow diversion structure. Higher flows will be discharged directly to the sediment trap. The sediment trap will be constructed by excavating a 33 -foot by 5 -foot depression along the east side of the ditch. The spill control structure will consist of a 12 -ft diameter manhole equipped with a baffle to retain oil, grease, and other floatable materials, and will discharge to the sediment trap. SPU has been conducting source control activities (e.g., business inspections and source tracing) in the Norfolk -MLK Way subbasin since 2001. Several illicit connections and discharges were discovered and have been eliminated. A spill control structure has been included in the project design as a precaution to protect the downstream WSDOT ditch, given the industrial nature of the businesses operating in the basin. WSDOT Ditch Regrade and Sediment Trap The WSDOT ditch would be cleaned and regraded in a 340 -foot section extending from 100 feet upstream of the outfall from the piped drainage system to 240 feet downstream. A backhoe would be used to reshape the ditch to a trapezoidal shape with 5 -foot bottom width and 3:1 side - slopes. The upstream and downstream invert of the regraded ditch would match the existing grade. The depth of cut along the ditch would vary from about 2.5 feet at the pipe outfall to zero AR /06- 03354 -100 narfalk czma analysis conveyance February 11, 2008 3 Herrera Environmental Consultants CZMA — Norfolk - MLK Way Subbasin Stormwater Conveyance Improvements Project at the downstream end of the project area. The grading would start approximately 100 feet upstream of the 64 -inch pipe to provide a transition between the existing and regraded sections of the ditch. Regrading the ditch would disturb approximately 0.14 acres of wetland area (sheets 3 and 4) therefore wetland mitigation is proposed. Mitigation All permanent wetland impacts will be mitigated by restoring and enhancing wetlands and their buffers located in the Puget Creek Natural Area (see Sheet 1). Restoration and enhancement will include invasive species removal, revegetation of disturbed areas with native plant species, slope stabilization where needed, garbage removal, monitoring, and adaptive management. These activities will occur over 3 years. A complete description of the proposed mitigation is provided in the document Final Draft Norfolk- Martin Luther King Jr. Way Subbasin Stormwater Improvements Wetland Mitigation Plan. This document can be obtained by request from Arnel Valmonte Project Manager, Engineering Division- Seattle Public Utilities, telephone: 206 - 615 -1438, e-mail: arnel.valmonte @seattle.gov. AB /06- 03354-100 norfol0 czma analysis conveyance Herrera Environmental Consultants 4 February 11, 2008 CZMA — Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements Project Consistency Analysis This analysis examines the policies and regulations that apply to the Norfolk - MLK Way Subbasin Stormwater Conveyance Improvements project. The enforceable policies identified in Washington State's Coastal Program are as follows: • Shoreline Management Act • Clean Water Act • Clean Air Act • State Environmental Policy Act • Energy Facility Site Evaluation Council law • Ocean Resources Management Act. The Shoreline Management Act The Washington State Shoreline Management Act was enacted in 1971 to manage and protect the shorelines of the state by regulating development in the shoreline area. A major goal of this act is "to prevent the inherent harm in an uncoordinated and piecemeal development of the state's shorelines." Its jurisdiction includes the Pacific Ocean shoreline and the shorelines of Puget Sound, the Strait of Juan de Fuca, rivers, and streams and lakes larger than a certain size. It also regulates "wetlands" associated with these shorelines (Revised Code of Washington, Chapter 90.58 [RCW 90.58]). The Shoreline Management Act is the core authority of Washington's Coastal Zone Management Program. RCW 90.58.020 stipulates that the state is responsible for the following: • Managing the shorelines of the state by planning for and fostering all reasonable and appropriate uses • Ensuring the development of shorelines in a manner that promotes and enhances the public interest while allowing only limited reduction of the rights of the public in navigable waters • Protecting against adverse effects on public health, the land and its vegetation and wildlife, and waters of the state and their aquatic life, while generally protecting the public rights of navigation and corollary rights. At the local jurisdiction level, the Shoreline Management Act is implemented through Shoreline Master Programs (SMPs). As the Shoreline Management Act changes, cities and counties must update their SMPs to remain consistent with the new guidelines. Local master programs regulate new development and the use of shorelines along rivers and larger streams, lakes covering more than 20 acres, and marine waterfronts within their jurisdictions. Therefore, consistency with the AB /06 -03354 -100 norfolk cnna analysis conveyance February 11, 2008 5 Herrera Environmental Consultants CZMA — Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements Project adopted SMPs for the affected jurisdictions, the City of Seattle and the City of Tukwila in the case of the Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements project, indicates consistency with the Shoreline Management Act. The Norfolk — MLK Way Subbasin Stormwater Improvements project area is approximately 3000 feet (914 meters) from the Duwamish River, which is outside of the 200 foot shoreline management zone designated in both the City of Seattle and City of Tukwila Shoreline Management Master Programs. Therefore, the Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements project would conform to the purpose and intent of the Washington State Shoreline Management Act. The Clean Water Act The project would require a National Pollutant Discharge Elimination System (NPDES) permit. Best management practices (BMPs) will be used to limit erosion and sediment transport during construction (e.g., limiting the extent of site disturbance at any point in time, and providing erosion control for all disturbed ground). Best management practices would conform to the 2005 Stormwater Management Manual for Western Washington (Ecology 2005). The Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements project therefore would conform to the purpose and intent of the Clean Water Act. The project will require a Section 404 Nationwide 41 permit for regrading existing stormwater facilities to restore historical capacity. A mitigation plan is proposed that will meet federal, state and local wetlands protection requirements and mitigation ratios and is in accordance with the Clean Water Act. The Clean Air Act The 1990 Clean Air Act is a federal law administered by the U.S. Environmental Protection Agency (U.S. EPA), which sets limits on the amount and types of pollutants that can be discharged into the nation's air. While the Clean Air Act regulates clean air on a federal level, local and state agencies have established their own standards. The Washington State Department of Ecology and the Northwest Air Pollution Authority have adopted state and local ambient air quality standards that are equivalent to the national standards. Air emissions in the project area would have to comply with these standards. The use of heavy equipment use during construction of this project would emit exhaust and create dust that would contribute to ambient concentrations of suspended particulate matter during project construction. However, these emissions and resulting concentrations typically would be exceeded by emissions from normal traffic in the project vicinity. The contractor will A13 /06-03334 -100 norfolk czma analysis conveyance Herrera Environmental Consultants 6 February 11, 2008 CZMA — Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements Project be required to adhere to all applicable federal, state, and local air quality regulations. Best management practices for the control of windborne construction dust (such as applying water to the roadway) will be used, if needed. Construction equipment will be properly maintained to minimize emissions. The Puget Sound Region, including King County, has been in attainment for all criteria air pollutants for almost a decade (PSCAA 2006). With the exception of fine particulate matter (PM2.5) and ozone, criteria air pollutant concentrations have fallen well below levels of concern (PSCAA 2006). The Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements project therefore would conform to the purpose and intent of the Clean Air Act. State Environmental Policy Act A SEPA checklist was prepared by SPU for the Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements project on February 1, 2008 and received a determination of non - significance. Energy Facility Site Evaluation Council Law The Energy Facility Site Evaluation Council (EFSEC) is a Washington state agency that has the regulatory authority to enforce compliance with state laws through fines or by ceasing construction or operation of a project (WAC 463). The EFSEC oversees a variety of energy projects: • Non - hydroelectric power plants • Energy facilities of any size that exclusively use alternative energy resources • Floating thermal power plants • Crude or refined petroleum or liquid petroleum product pipelines • Crude or refined petroleum or liquefied petroleum facilities • Natural gas, synthetic fuel, gas, or liquefied petroleum gas pipelines • Liquid natural gas facilities AB /06- 03354 -100 norfolk czma analysis conveyance February 11, 2008 7 Herrera Environmental Consultants CZMA — Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements Project • Any underground natural gas storage reservoir • Refineries. The Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements project does not involve the use of, construction of, or operation of any of the above described facilities. Therefore, the EFSEC law does not apply to this project. Ocean Resources Management Act The Ocean Resources Management Act prohibits leasing of certain tidal and submerged lands for purposes of oil or gas exploration, development, or production (RCW 43.143.010). The Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements project does not involve any of these activities, therefore, the Ocean Resources Management Act does not apply. AB /06-03334 -100 no folk czma analysis comrvance Herrera Environmental Consultants 8 February 11, 2008 CZMA — Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements Project Statement of Consistency Based on the above evaluation, Seattle Public Utilities has determined that the actions proposed for the Norfolk — MLK Way Subbasin Stormwater Conveyance Improvements project will be consistent with the enforceable policies of the approved Coastal Zone Management Program of Washington, including the enforceable policies as specified in the local planning documents for the affected jurisdictions that are incorporated in the approved programs. AN /06- 03354 - 100 norfolk czma analysis conveyance February 11, 2008 9 Herrera Environmental Consultants CZMA — Norfolk – MLK Way Subbasin Stormwater Conveyance Improvements Project References Ecology. 2005. Stormwater Management Manual for Western Washington. Publication Numbers 05 -10 -029 through 05 -10 -033. Washington State Department of Ecology, Seattle, Washington. Obtained on May 30, 2007 from agency website: < http: / /www.ecy .wa.gov/biblio /0510029.html >. PSCAA. 2006. 2005 Air Quality Data Summary. Puget Sound Clean Air Agency. Seattle, Washington. Obtained on May 30, 2007 from website: <http: / /www.pscleanair.org/ news / library /reports /2005AQDSFinal.pdf -. Tetra Tech and Herrera. 2007. Norfolk – MLK Way Subbasin Stormwater Improvements Project Preliminary Engineering Report. Prepared for Seattle Public Utilities, by Tetra Tech/KCM, Seattle, Washington and Herrera Environmental Consultants, Seattle, Washington. AB /06 -03354 -100 norfolk czma analysis conveyance February 11, 2008 11 Herrera Environmental Consultants