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SEPA E04-008 - CITY OF TUKWILA / PUBLIC WORKS - 2004 COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN
2004 COMPREHENSIVE SURFACE WATER MGMT PLAN E04 -008 • • City of Tukwila Steven M. Mullet, Mayor Department of Community Development Steve Lancaster, Director July 23, 2004 NOTICE OF DECISION To: Tukwila Department of Public Works Department of Fish and Wildlife, Attn Larry Fisher State Department of Ecology, SEPA Division PROJECT: Update of Tukwila Comprehensive Surface Water Management Plan FILE NUMBERS: E04 -008 ASSOCIATED FILES: E04 -009 APPLICANT: City of Tukwila Department of Public Works REQUEST: Adoption of updated Surface Water Management Plan LOCATION: City -wide This notice is to confirm the decision reached by Tukwila's SEPA Official to issue a Determination of Non - significance (DNS) for the above project based on the environmental checklist. Project materials including the application, any staff reports, and other studies related to the permits are available for inspection at: Tukwila. Department of Community Development 6300 Southcenter Blvd., Suite 100 Tukwila, WA 98188 Monday through Friday 8:30 a.m. - 5:00 p.m. The project planner is Carol Lumb, who may be contacted at (206) 431 -3661 for further information. The decision is appealable to King County Superior Court pursuant to the Judicial Review of Land Use Decisions, Revised Code of Washington (RCW 36.70C). q: \2004 Surface Water Comp Plan \E04 -008 NotDec.doc 6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • Phone: 206 - 431 -3670 • Fax: 206 - 431 -3665 • City of Tukwila Department of Community Development / 6300 Southcenter BI, Suite 100 / Tukwila, WA 98188 / (206)431 -3670 DETERMINATION OF NON - SIGNIFICANCE (DNS) File Number: [04 -008 Applied: 05/18/2004 Issue Date: 07/22/2004 Status: ISSUED Applicant: CITY OF TUKWILA PUBLIC WORKS Lead Agency: City of Tukwila Description of Proposal: ADOPT COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN UPDATING 1993 PLAN. PLAN INCLUDES IDENTIFICATION OF PROBLEM AREAS, RANKS CAPITAL IMPROVEMENT PROJECTS AND REQUIRES USE OF BEST MANAGEMENT PRACTICES TO REDUCE WATER QUANTITY AND IMPROVE WATER QUALITY. Location of Proposal: Address: Parcel Number: Section/Township/Range: CITY WIDE The City has determined that the proposal 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 information on file with the lead agency. This information is available to the public on request. This DNS is issued under WAC 197 -11- 340(2). Comments must be submitted by The lead agency, will not act on this proposal for 14 days from the date below. Steve Lancaster, Responsible Official City of Tukwila 6300 Southcenter Blvd Tukwila, WA 98188 (206)431 -3670 Date Any appeal shall be linked to a specific governmental action. The State Environmental Policy Act is not intended to create a cause of action unrelated to a specific governmental action. Appeals of environmental determinations shall be commenced within the time period to appeal the governmental action that is subject to environmental review. (RCW 43.21C.075) doc: DNS E04 -008 Printed: 07 -21 -2004 Dept. Of Community Development City of Tukwila AFFIDAVIT OF DISTRIBUTION /, girrpct___ HEREBY DECLARE THAT: Notice of Public Hearing Determination of Non - Significance Notice of Public. Meeting Mitigated Determination of Non -. Significance s ' itflt1 S ' Board of Adjustment Agenda Pkt ovl S 'TVA. t.l , Project Number:. — p'tb4 2 - 0L/ -oO.7 Determination of Significance & Scoping Notice _ Board of Appeals Agenda Pkt g riaC4 ` Notice of Action Person requesting mailing: Planning Commission Agenda Pkt 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 a �,( c� A Cs∎ o.--rTh Was mailed to each of the addresses listed on this year 20_ day 9L) d y in the P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM Project Name: I/1 0a s ' itflt1 S ' I Li u 4 I...I .',/# ovl S 'TVA. t.l , Project Number:. — p'tb4 2 - 0L/ -oO.7 mot_ --k/' ,'-e w - _ Mailer's Signature: g riaC4 ` • Person requesting mailing: (1162kg tke,//) P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM Goy -008 CI LIST: ENVIRONMENTAL REVIEW /SHORELINE PI" MAILINGS ED!" _ 009 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 STATE AGENCIES ( ) OFFICE OF ARCHAEOLOGY ( ) TRANSPORTATION DEPARTMENT () DEPT NATURAL RESOURCES ( ) OFFICE OF THE GOVERNOR j>)iiii)EPT OF COMM. TRADE & ECONOMIC EPT OF FISHERIES & WILDLIFE ( ) DEPT OF SOCIAL & HEALTH SERV. () DEPT OF ECOLOGY, SHORELAND DIV pf.QEPT OF ECOLOGY, SEPA DIVISION' . ( ) OFFICE OF ATTORNEY GENERAL DEV. 1SEND CH LIST W/ DETERMINATIONS R+F SION KING COUNTY AGENCIES () BOUNDARY REVIEW BOARD () FIRE DISTRICT #11 ( ) FIRE DISTRICT #2 ( ) K.C. WASTEWATER TREATMENT DIVISION () K.C. DEPT OF PARKS & REC () K.C. ASSESSOR'S OFFICE ( ) TUKWILA SCHOOL DISTRICT >UKWILA LIBRARY () RENTON LIBRARY () KENT LIBRARY ( ) CITY OF SEATTLE LIBRARY () QWEST ( ) SEATTLE CITY LIGHT () PUGET SOUND ENERGY ( ) HIGHLINE WATER DISTRICT () SEATTLE WATER DEPARTMENT ( ) AT &T CABLE SERVICES SCHOOLS /LIBRARIES UTILITIES CITY AGENCIES KENT PLANNING DEPT ( ) TUK I A Q Cfl PARTMENTS: I PU RR$ () FIRE 6' \,N ( ) POLICE ( ) FINANCE ( ) PLANNING () BUILDING ( ) PARKS & REC. () MAYOR ( ) CITY CLERK () HEALTH DEPT PORT OF SEATTLE ( .C. DEV & ENV!R SERVICES -SEPA INFO CNTR C.C. TRANSIT DIVISION - SEPA OFFICIAL KC.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 )C 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. OTHER LOCAL AGENCIES () PUGET SOUND REGIONAL COUNCIL ( ) SW K C CHAMBER OF COMMERCE MUCKLESHOOT INDIAN TRIBE CULTURAL RESOURCES PROGRAM .FISHERIES PROGRAM WILDLIFE PROGRAM MEDIA ( ) SEATTLE TIMES () SOUTH COUNTY JOURNAL P: \ADMINISTRATIVE \FORMS \CHKLIST.DOC $. UWAMISH INDIAN TRIBE ( ) P.S. AIR POLLUTION CLEAN AGENCY ( ) SOUND TRANSIT ( ) DUWAMISH RIVER CLEAN -UP COALITION *SEND NOTICE OF ALL APPUCATIONS ON DUWAMISH RIVER ( ) HIGHLINE TIMES ( ) CLTUKWILA.WA.US.WWW City of Tukwila Steven M. Mullet, Mayor Department of Community Development Steve Lancaster, Director MEMORANDUM July 26, 2004 TO: Interested Parties FM: Carol Lumb, Senior Planner RE: Extension of Comment Period on Determination of Nonsignficance for E04 -008 and E04 -009 On July 23, 2004, the City issued a Determination of Nonsignificance on E04 -008, the adoption of a Comprehensive Surface Water Management Plan updating the City's 1993 Plan and E04 -009, adoption of a surface water management ordinance updating the City's surface water regulations to comply with state and federal requirements. Due to a publishing error, the comment period on these two Determinations of Nonsignificance has been extended to August 10, 2004. Any comments on these two determinations must be received by 5:00 p.m. Wednesday, August 10, 2004 at the Department of Community Development, 6300 Southcenter Blvd., Suite 100, Tukwila, WA, 98188. If you have any questions, please call me at 206 - 431 -3661. 6300 Southcenter Boulevard, Suite #100 0 Tukwila, Washington 98188 0 Phone: 206 - 431 -3670 0 Fax: 206 - 431 -3665 Dept. Of Community Development City of Tukwila AFFIDAVIT OF DISTRIBUTION I. 1LJtpWtfrHEREBY DECLARE THAT: Notice of Public Hearing Project Number : .,04-"•00/ Determination of Non - Significance Person requesting mailing: Ltfrptb Notice of Public Meeting Mitigated Determination of Non- Significance Board of Adjustment Agenda Pkt Determination of Significance & Scoping Notice Board of Appeals Agenda Pkt Notice of Action Planning Commission Agenda Pkt 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 X Other 1 k41 Q1)'' etryytmnim, � D ,t. '1 77 Eat -o08' Z42- Was mailednto each of the addresses listed on this A2 day. of in the year 200 P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM Project Name: t4.44f-C pla,frt Project Number : .,04-"•00/ Mailer's Signature: ,C ii/_ 6Za€ �(jj,f Person requesting mailing: Ltfrptb P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM Eoy-008 COKLIST: ENVIRONMENTAL REVIEW/SHORELINEO MIT MAILINGS E LI MCI 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 STATE AGENCIES ( ) OFFICE OF ARCHAEOLOGY ( ) TRANSPORTATION DEPARTMENT O DEPT NATURAL RESOURCES ( ) OFFICE OF THE GOVERNOR DEPT OF COMM. TRADE & ECONOMIC DEV. • SEND CHK EPT OF FISHERIES & WILDLIFE i N 1 fA }4n Tlsdle✓ KING COUNTY AGENCIES () DEPT OF SOCIAL & HEALTH SERV. () DEPT OF ECOLOGY, SHORELAND DIV 1QEPT OF ECOLOGY, SEPA DIVISION• ( ) OFFICE OF ATTORNEY GENERAL LIST W/ DETERMINATIONS () BOUNDARY REVIEW BOARD () FIRE DISTRICT #11 ( ) FIRE DISTRICT #2 ( ) K.C. WASTEWATER TREATMENT DIVISION () K.C. DEPT OF PARKS & REC ( ) K.C. ASSESSORS OFFICE ( ) TUKWILA SCHOOL DISTRICT fUKWILA LIBRARY () RENTON LIBRARY ( ) KENT LIBRARY ( ) CITY OF SEATTLE LIBRARY () QWEST ( ) SEATTLE CITY LIGHT () PUGET SOUND ENERGY ( ) HIGHLINE WATER DISTRICT ( ) SEATTLE WATER DEPARTMENT ( ) AT &T CABLE SERVICES KENT PLANNING 5■11� PUs If \ () POLICE ( ) PLANNING () PARKS & REC. ( ) CITY CLERK DEPT PARTMENTS: ( ) FIRE ( ) FINANCE ( ) BUILDING ( ) MAYOR SCHOOLS /LIBRARIES UTILITIES CITY AGENCIES () HEALTH DEPT PORT OF SEATTLE .C. DEV & ENV!R SERVICES-SEPA INFO CNTR '<.C. TRANSIT DIVISION - SEPA OFFICIAL )'1<.C. LAND & WATER RESOURCES q.kFOSTER 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 SEWER/WATER 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. OTHER LOCAL AGENCIES () PUGET SOUND REGIONAL COUNCIL ( ) SW K C CHAMBER OF COMMERCE MUCKLESHOOT INDIAN TRIBE CULTURAL RESOURCES PROGRAM ).FISHERIES PROGRAM WILDLIFE PkOGRAM MEDIA ( ) SEATTLE TIMES () SOUTH COUNTY JOURNAL P: WD M IN ISTRATIV E \FORMS \CHKLIST. DOC XZUWAMISH 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 ( ) C1.TUKWILA.WA.US.WWW • Cty of Tull Steven M. Mullet, Mayor Department of Community Development Steve Lancaster, Director MEMORANDUM July 21, 2004 To: Steve Lancaster, Director Fm: Carol Lumb, Senior Planner Re: Project File No. E04 -008: Comprehensive Surface Water Management Plan Project Description: This is a nonproject action to adopt a new Comprehensive Surface Water Management Plan for the City of Tukwila. The Plan applies to all areas within the City limits. Proponent: Tukwila Department of Public Works Location: City -wide Date Checklist prepared: May 18, 2004 Lead Agency: City of Tukwila, Department of Community Development Challenges to Document: None Other Agencies of Jurisdiction: Department of Ecology Department of Fish and Wildlife 6300 Southcenter Boulevard, Suite #100 0 Tukwila, Washington 98188 0 Phone: 206 - 431 -3670 0 Fax: 206 -431 -3665 SEPA Review — E04 -008 Comprehensive Surface Water Management Plan July 21, 2004 • • Recommendation: Determination of Non - Significance (DNS) Existing Environmental Information: 2004 Comprehensive Surface Water Management Plan Background: The City's current Comprehensive Surface Water Management Plan was approved by the City Council in 1993. Since then, the built environment and the amount of impervious surface have continued to increase in the City. Regulations governing the management of surface water have also changed at the state and federal level since the last Plan was prepared. During the past two years, the Department of Public Works has taken several actions to update and improve its surface water management practices: completed an application to the Washington State Department of Ecology for a National Pollutant Discharge Elimination Permit (NPDES) Phase II; completed a new Comprehensive Surface Water Management Plan; and updated the surface water element of the Tukwila Comprehensive Land Use Plan. The updates are to ensure the City complies with current regulations including the Growth Management Act, the Clean Water Act, and the Endangered Species Act. The update also allows for the use of the innovative surface water design technique of Low Impact Development. Summary of Proposed Surface Water Comprehensive Plan: The City limits contain Gilliam, Southgate, and Riverton Creeks, wetlands and seasonal drainage courses. Nearly all surface water in the City drains to the Green/Duwamish River. The new Comprehensive Plan includes: • Background on the existing conditions in the City and the regulatory environment; • Identification of flooding, fish habitat and water quality problem areas and drainage basin maps with these problem areas located; • Use of best management practices for outdoor operation and maintenance activities for all City departments, including Public Works, Parks and Fire; • Ranking of capital improvement projects based on benefits versus cost; • Recommendation on regulations and policies, surface water management issues, operations and maintenance and consideration of innovative storm water techniques such as Low Impact Development to control water quantity and improve water quality. 2 q:\2004 Surface Water Comp Plan & Ordinance \E -04- 008 -SEPA staffrpt.doc SEPA Review — E04 -008 Comprehensive Surface Water Management Plan July 21, 2004 • 1 Summary of Major Impacts The Comprehensive Surface Water Management Plan provides background information and a surface water management framework to protect the public health, safety and welfare and comply with local, state and federal regulations. The major impact of the adoption of this Plan will be to further control the quantity and quality of surface water runoff in the City and its impact on the natural environment. Recommendation Determination of Nonsignificance 3 q:\2004 Surface Water Comp Plan & Ordinance \E -04- 008 -SEPA staffrpt.doc CITY OF T. UKWILA. NOTICE OF APPLICATION PROJECT INFORMATION The City of Tukwila Department of Public Works has filed applications for environmental review of a new Comprehensive Surface Water Management Plan and a draft ordinance revising Chapter 14.30, Storm Water Management of the Tukwila Municipal Code. This ordinance and the Comprehensive Surface Water Management Plan apply city -wide. FILES AVAILABLE FOR PUBLIC REVIEW The project files are available at the City of Tukwila. To view the files, you may request them at the counter at the Department of Community Development (DCD), located at 6300 Southcenter Boulevard #100. Project Files include: E04 -008: Environmental Review for Comprehensive Surface Water Management Plan and E04 -009: Environmental Review for Storm Water Management Ordinance. Environmental checklists have been submitted for each of these projects. ..':-OPPORTUNITY:FOFCPUBLIC!.:COMMENTir "`. 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., Thursday, June 24,.2004. Opportunity for additional oral and written public comments will be provided at a public hearing before the Tukwila City Council when it considers the proposed ordinance adopting the revisions to the City's storm water regulations. The date of this hearing has not been set as yet. To confirm the date call Jill Mosqueda, Development Engineer, Department of Public Works at 206 - 433 -0179. APPEALS' You may request a copy of any decision, information on hearings, and your appeal rights by calling DCD at (206) 431 -3670. The environmental determinations for the Storm Water Comprehensive Plan and the Ordinance adopting revised storm water regulations may be appealed to King County Superior Court. For further information on these proposals, contact Carol Lumb at (206) 431 -3661 or visit our offices at 6300 Southcenter Boulevard, Suite #100, Monday through Friday, 8:30 a.m. to 5:00 p.m. Applications Filed:. Notice of Completeness Issued: Notice of Application Issued: May 18, 2004 and June 4, 2004 June 8, 2004 June 10, 2004 • Dept. Of Community Development • City of Tukwila AFFIDAVIT OF DISTRIBUTION HEREBY DECLARE THAT: Notice of Pub is Hearing Determination of Non - Significance g k 04 -Do 1 Notice of Public Meeting Project Number: N / aLa ,t k / ;. 1A Mitigated Determination of Non - Significance Mailer's Signature: ,,4 i ,;,,,,k IA 1 `06_ Board of Adjustment Agenda Pkt Person requesting mailing: Cjovre La/J...4 Determination of•Significance & Scoping Notice Board of Appeals Agenda Pkt Notice of Action Planning Commission Agenda Pkt Official Notice Short Subdivision Agenda • Notice of Application Shoreline Mgmt Permit Notice of Application for Shoreline Mgmt Permit _ _ FAX To Seattle Times Classifieds Mali:' Gail Muller Classifieds :P0 Box 70 - Seattle WA 98111 Other Was mailed to each of the addresses listed on this tu day of year 20b L( in the P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM Project Name: , 0 (- g k 04 -Do 1 Project Number: N / aLa ,t k / ;. 1A c2 ` l/0- A Mailer's Signature: ,,4 i ,;,,,,k IA 1 `06_ s Person requesting mailing: Cjovre La/J...4 P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM CHEIRIST: ENVIRONMENTAL REVIEW /SHORELINE POT MAILINGS FEDERAL AGENCIES )(U.S. ARMY CORPS OF ENGINEERS () FEDERAL HIGHWAY ADMINISTRATION eEPT OF FISH & WILDLIFE O U.S. ENVIRONMENTAL PROTECTION AGENCY ( ) U.S. DEPT OF H.U.D. poKNATIONAL MARINE FISHERIES SERVICE WASHINGTON STATE AGENCIES O OFFICE OF ARCHAEOLOGY f�6TRANSPORTATION DEPARTMENT () DEPT NATURAL RESOURCES ( ) OFFICE OF THE GOVERNOR ?(DEPT OF COMM. TRADE & ECONOMIC DEV. ('DEPT OF FISHERIES & WILDLIFE ( ) DEPT OF SOCIAL & HEALTH SERV. *DEPT OF ECOLOGY, SHORELAND DIV DEPT OF ECOLOGY, SEPA DIVISION' ( ) OFFICE OF ATTORNEY GENERAL SEND CHKLIST W/ DETERMINATIONS SEND SITE MAPS WITH DECISION KING COUNTY AGENCIES () BOUNDARY REVIEW BOARD ( ) FIRE DISTRICT #11 O FIRE DISTRICT #2 ( ) K.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 W QEST SEATTLE CITY LIGHT PUGET SOUND ENERGY HIGHLINE WATER DISTRICT el SEATTLE WATER DEPARTMENT AT &T CABLE SERVICES ENT PLANNING DEPT ( ) TUKWILA CITY DEPARTMENTS: () PUBLIC WORKS ( ) FIRE ( ) FINANCE ( ) BUILDING ()MAYOR () POLICE ( ) PLANNING ( ) PARKS & REC. ( ) CITY CLERK SCHOOLS /LIBRARIES UTILITIES CITY AGENCIES O HEALTH DEPT () PORT OF SEATTLE j71QC.C. DEV & ENVIR SERVICES -SEPA INFO CNTR ( ) K.C. TRANSIT DIVISION - SEPA OFFICIAL ( ) K.C. LAND & WATER RESOURCES 1OSTER LIBRARY C PUBLIC LIBRARY ()HIGHLINE SCHOOL DISTRICT ( ) SEATTLE SCHOOL DISTRICT () RENTON SCHOOL DISTRICT OLYMPIC PIPELINE AL- VUESEWER DISTRICT ATER DISTRICT #20 04.WATER DISTRICT #125 f'CITY OF RENTON PUBLIC WORKS c*BRYN MAWR- LAKERIDGE SEWERNVATER DISTRICT ^ RENTON PLANNING DEPT IQ CITY OF SEA -TAC '( )_CITY OF BURIEN ( ) TUKWILA PLANNING COMMISSION MEMBERS ( ) TUKWILA CITY COUNCIL MEMBERS *rCITY OF SEATTLE - SEPA INFO CENTER - DCLU () STRATEGIC PLANNING OFFICE* NOTICE OF ALL SEATTLE RELATED PLNG PROJ. OTHER LOCAL AGENCIES UGET SOUND REGIONAL COUNCIL SW K C CHAMBER OF COMMERCE b4MUCKLESHOOT INDIAN TRIBE f ( ) CULTURAL RESOURCES PROGRAM () FISHERIES PROGRAM ( ) WILDLIFE PROGRAM MEDIA () SEATTLE TIMES SOUTH COUNTY JOURNAL P:WDMINISTRATIV E\FORMS \CHKLIST.DOC MDUWAMISH INDIAN TRIBE ( ) P.S. AIR POLLUTION CLEAN AGENCY <SOUND TRANSIT (' DUWAMISH RIVER CLEAN -UP COALITION SEND NOTICE OF ALL APPLICATIONS ON DUWAMISH RIVER ,1IGHLINE•TIMES ( ) CI.TUKWILA.WA.US.WVVW PSIC NOTICE MAILINGS FOR P TS 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. 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 State Attorney General *Applicant *Indian Tribes *Other agencies as necessary (checked off on attached list). *Any 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:W DMINISTRATIVE \FORMS \CHKLIST.DOC June 8, 2004 • City of Tukwila Steven M. Mullet, Mayor Department of Community Development Steve Lancaster, Director MEMORANDUM TO: Jill Mosqueda, Development Engineer FM: Carol Lumb, Senior Planner RE: SEPA Applications for Surface Water Management Ordinance (E04 -009) and Comprehensive Surface Water Management Plan (E04 -008) Your applications for SEPA review of the draft Surface Water Management Ordinance and Comprehensive Surface Water Management Plan have been found to be complete on June 8, 2004 for the purposes of meeting state mandated time requirements. J Notice of Application will be mailed to agencies of interest and published in the Seattle Times on June 10, 2004 as well. The comment deadline is close of business Thursday, June 24, 2004. This determination of complete application does not preclude the City from requesting additional plans or information, if in our estimation such information is necessary to ensure the project meets the substantive requirements of the City or to complete the review process. I will be in touch with you if I have any questions. If you have any questions or concerns, please call me at 431 -3661. q: \mydocs\Surface Water Plan - Ordinance \Complete.doc 6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • Phone: 206 - 431 -3670 • Fax: 206- 431 -3665 Control No. Epic File No. E O .41— 00 8 Fee: 0 Receipt No. 0 ENVIRONMENTAL CHECKLIST A. BACKGROUND 1. Name of proposed project, if applicable: New Comprehensive Surface Water Management Plan. 2. Name of applicant: City of Tukwila, Public Works Department. 3. Address and phone number of applicant and contact person: Jill Mosqueda P.E. 6300 Southcenter Blvd. Suite 100 Tukwila, WA 98188 4. Date checklist prepared: May 17, 2004. 5. Agency requesting checklist: City of Tukwila. 6. Proposed timing or schedule (including phasing, if applicable): New Comprehensive Surface Water Management Plan approved by November 30, 2004. 7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. No 8. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. None known. Page 1 • • ENVIRONMENTAL CHECKLIST 9. 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. 10. List any government approvals or permits that will be needed for your proposal. None. 11. Give brief, complete description of your proposal, including the proposed uses and the size of the project and site. 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. Section E requires a complete description of the objectives and alternates of your proposal and should not be summarized here. Update City's Comprehensive Surface Water Management Plan. 12. 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 detailed plans submitted with any permit applications related to this checklist. The comprehensive plan applies to all areas within the City limits. 13. Does the proposal lie within an area designated on the City's Comprehensive Land Use Policy Plan Map as environmentally sensitive? Yes. B. ENVIRONMENTAL ELEMENTS 1. Earth a. General description of the site (circle one): Flat, rolling, hilly, steep slopes, mountainous, other: b. What is the steepest slope on the site (approximate percent slope)? 1V:1H Page 2 • ENVIRONMENTAL CHECKLIST 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. All types. d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. Yes. The City limits contain some areas of unstable slopes. e. Describe the purpose, type, and approximate quantities of any filling or grading proposed. Indicate source of fill. None. f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. NA — non - project SEPA. g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? NA — non - project SEPA. h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: Require development project assessment for impacts and require Best Management Practices. 2. Air a. What types of emissions to 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. Not Applicable b. Are there any off -site sources of emissions or odor that may affect your proposal? If so, generally describe. Not Applicable c. Proposed measures to reduce or control emissions or other impacts to air, if any: Not Applicable Page 3 ENVIRONMENTAL CHECKLIST 3. 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 yes, describe type and provide names. If appropriate, state what stream or river it flows into. The City limits contain Gilliam Creek, Southgate Creek, Riverton Creek, wetlands, and seasonal drainage courses. Nearly all surface water drains to the Green/Duwamish River. 2) Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. NA — non - project SEPA. 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. NA — non - project SEPA. 4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities, if known. No. 5) Does the proposal lie within a 100 year floodplain? If so, note location on the site plan. The City limits contain FEMA designated 100 -year flood plains mostly along the Green/Duwamish River. 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. No. b. Ground: 1) Will ground water be withdrawn, or will water be discharged to ground water? Give general description, purpose, and approximate quantities, if known. No. 2) Describe waste materials that will be discharged into the ground from septic tanks or other sources, if any (for example: Domestic sewage; industrial, containing the following chemicals...; agricultural; etc.) Describe the general size of the system, Page 4' • ENVIRONMENTAL CHECKLIST the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve. Not applicable. c. Water Runoff (including storm water): 1) 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 plan and the ordinance apply to storm -water generated surface water runoff within the City limits. 2) Could waste materials enter ground or surface waters? If so, generally describe. No. d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any: Assess each development for possible impacts and require Best Management Practices to prevent or lessen the impacts. 4. Plants a. Check or circle types of vegetation found on the site: .Ni deciduous tree: alder, maple, aspen, other I evergreen tree: fir, cedar, pine, other .4 shrubs .NI grass pasture crop or grain II wet soil plants: cattail, buttercup, bulrush, skunk cabbage, other 'I water plants: water lily, eel grass, milfoil, other -\I other types of vegetation b. What kind and amount of vegetation will be removed or altered? NA — non - project SEPA. c. List threatened or endangered species known to be on or near the site. None. d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: None. Page 5 ENVIRONMENTAL CHECCIST • 5. Animals a. Circle any birds or animals which have been observed on or near the site or are known to be on or near the site: Birds:. Hawk, heron, eagle, songbirds, other: Mammals: Deer, bear, elk, beaver, other: Fish: Bass, salmon, trout, herring, shellfish, other: Other: b. List any threatened or endangered species known to be on or near the site. Chinook salmon, bald eagle. c. Is the site part of a migration route? If so, explain. Yes. Pacific flyway. d. Proposed measures to preserve or enhance wildlife, if any: Control quantity and quality of surface water runoff. 6. 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. Not applicable. b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. No. 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. 7. 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. No. Page 6 • • ENVIRONMENTAL CHECKLIST 1) Describe special emergency services that might be required. None. 2) Proposed measures to reduce or control environmental health hazards, if any: Require water quality treatment for activities that might pollute surface water runoff. b. Noise 1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? Not applicable. 2) What types and levels of noise would be created by or associated with the project on a short -term or long -term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site. Not applicable. 3) Proposed measures to reduce or control noise impacts, if any: Not applicable. 8. Land and Shoreline Use a. What is the current use of the site and adjacent properties? Uses vary throughout the City. b. Has the site been used for agriculture? If so, describe. No current agricultural activities. Historically, some areas were agricultural. c. Describe any structures on the site. Single - family residences, commercial, and manufacturing. d. Will any structures be demolished? If so, what? No. e. What is the current zoning classification of the site? Varies and matches the City's zoning districts. f What is the current comprehensive plan designation of the site? Varies and matches the City's zoning districts. Page 7 ENVIRONMENTAL CHECCIST • g. If applicable, what is the current shoreline master program designation of the site? Not applicable. h. Has any part of the site been classified as an "environmentally sensitive" area? If so, specify. The City limits contain flood zones, geologically hazardous areas, wetlands, watercourses, and abandoned coal mines. i. Approximately how many people would reside or work in the completed project? NA — non - project SEPA. Approximately how many people would the completed project displace? None. J• k. Proposed measures to avoid or reduce displacement impacts, if any: Not applicable. L Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: Coordinate adoption of the Comprehensive Surface Water Management Plan with the City's Department of Community Development. . Housing a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low - income housing? Not applicable. b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low - income housing. Not applicable. c. Proposed measures to reduce or control housing impacts, if any: Not applicable. 10. 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 proposed. Page 8 ENVIRONMENTAL CHECKL T b. What views in the immediate vicinity would be altered or obstructed? None. c. Proposed measures to reduce or control aesthetic impacts, if any: Not applicable. 11. Light and Glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur? None. b. Could light or glare from the finished project be a safety hazard or interfere with views? No. c. What existing off -site sources of light or glare may affect your proposal? None. d. Proposed measures to reduce or control light and glare impacts, if any: Not applicable. 12. Recreation a. What designed and informal recreational opportunities are in the immediate vicinity? Varies throughout the City and includes trails, parks, sports fields. b. Would the proposed project displace any existing recreational uses? If so, describe. No. c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: None. 13. 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. None. b. Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site. Page 9 ENVIRONMENTAL CHECCIST • None. c. Proposed measures to reduce or control impacts, if any: The plan aims to reduce damage from surface water runoff. 14. 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. NA — nonproject SEPA b. Is the site currently served by public transit? If not, what is the approximate distance to the nearest transit stop? Not applicable. c. How many parking spaces would the completed project have? How many would the project eliminate? Not applicable. 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). Not applicable. e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. Not applicable. f How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would occur. None. g. Proposed measures to reduce or control transportation impacts, if any: Not applicable. 15. 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. No. Page 10 • • ENVIRONMENTAL CHECKLIST b. Proposed measures to reduce or control direct impacts on public services, if any. The plan aims to reduce surface water runoff hazards, protect public facilities and fishery habitat, and reduce the need . for emergency response. 16. Utilities a. Circle utilities currently available at the site: electricity, natural gas, water, refuse service, telephone, 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 viciniy which might be needed. None. 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: Date Submitted: Page 11 • • ENVIRONMENTAL CHECKLIST D. SUPPLEMENTAL SHEET FOR NON PROJECT ACTIONS (Do not use this sheet for project actions) Because these questions are very general, it may be helpful to read them in conjunction with the list of the elements of the environment. When answering these questions, be aware of the extent the proposal, or the types of activities likely to result form the proposal, would affect the item at a greater intensity or at a faster rate than in the proposal were not implemented. Respond briefly and in general terms. 1. How would the proposal be likely to increase discharge to water; emissions to air; production, storage, or release of toxic or hazardous substances; or production of noise? No. Proposed measures to avoid or reduce such increases are: Not applicable. 2. How would the proposal be likely to affect plants, animals, fish or marine life? The plan includes Best Management Practices to protect plants, animals, fish or marine life. Proposed measures to protect or conserve plants, animals, fish or marine life are: Control the quantity and quality of surface water leaving a site. 3. How would the proposal be likely to deplete energy or natural resources? None. Proposed measures to protect or conserve energy and natural resources are: Not applicable. 4. How would the proposal be likely to use or affect environmentally sensitive areas or areas designated (or eligible or under study) for government protection; such as parks, wilderness, wild and scenic rivers, threatened or endangered species habitat, historic or cultural sites, wetlands, floodplains, or prime farmlands? The plan provides measures to protect areas from flooding and water pollution. Proposed measures to protect such resources or to avoid or reduce impacts are: NA — non - project SEPA. 5. How would the proposal be likely to affect land and shoreline use, including whether it would allow or encourage land or shoreline uses incomplatible with existing plans? Page 12 1 • ENVIRONMENTAL CHECKLIST None. Proposed measures to avoid or reduce shoreline and land use impacts are: Not applicable. 6. How would the proposal be likely to increase demands on transportation or public services and utilities? NA — non - project SEPA. Proposed measures to reduce or respond to such demand(s) are: Not applicable. 7. Identify, if possible, whether the proposal may conflict with Local, state, or federal laws or requirements for the protection of the environment. Does not conflict. Page 13 • • ENVIRONMENTAL CHECKLIST F. SUPPLEMENTAL SHEET FOR ALL PROJECT AND NON PROJECT PROPOSALS The objectives and the alternative means of reaching the objectives for a proposal will be helpful in reviewing the foregoing items of the Environmental Checklist. This information provides a general overall perspective of the proposed action in the context of the environmental information provided and the submitted plans, documents, supportive information, studies, etc. 1. What are the objectives of the proposal? To provide a 20 -year plan for managing surface water. 2. What are the alternative means of accomplishing these objectives? None. 3. Please compare the alternative means and indicate the preferred course of action: Not applicable. 4. Does the proposal conflict with policies of the Tukwila Comprehensive Land Use Policy Plan? No. 5. Proposed measures to avoid or reduce the conflict(s) are: Not applicable. Page 14 RECEIVED MAY 1 8 2004 PERMIT CENTER City of Tukwila Comprehensive Surface Water Management Plan. Prepared for City of Tukwila November 2003 CH2MHILL CH2M HILL P.O. Box 91500 Bellevue, WA 98009 -2050 HRRERA 47. DAM! raw ts • Contents • Comprehensive Surface Water Management Plan 1. Introduction 1 1.1 Background 1 1.2 Objective 2 1.3 Report Organization 2 2. Drainage Basin Characteristics 3 2.1 General Description 3 2.2 Drainage Basins 3 2.3 Land Use 6 2.4 Future Development 6 3. Surface Water Issues 9 3.1 Available Data 9 3.2 General Description 9 3.3 Identified Problems 10 4. Regulations and Policies 11 4.1 Existing Regulatory Compliance 11 4.2 Potential Regulatory Changes 11 5. Storm Drainage CIP Projects 13 . 5.1 Projects 13 5.2 Alternative Approaches 14 6. Operations and Maintenance 18 6.1 Surface Water O &M 19 6.2 Regulatory Compliance 19 7.0 Recommendations 20 Tables 1 Drainage Basin Areas 3 2 Tukwila Land Use Zoning and Open Areas 6 3 Surface Water Problem Summary 11 4 Prioritized Flooding and Water Quality CIP Projects - 412 Fund 16 5 Ranking Summary for Fish Habitat CIP Projects — 301 Fund 17 6 Comprehensive Surface Water Management Plan Recommendation Summary 20 Figures 1 City of Tukwila Vicinity Map 4 2 Drainage Basins 5 3 Areas Where Infiltration is Not Allowed 7 4 Areas Where Level 2 Storm Water Detention Recommended 8 5 Prioritized Capital Improvement Projects 15 SEA31001174165.DOG032670010 Ill CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Appendices Appendix A: Annexation Review 1. Introduction A -1 1.1 Background A -1 2. Description A -1 2.1 North Annexation Area A -1 2.2 South Annexation Area A -2 3. Surface Water Management A -2 Figure A -1 Annexation Areas A -3 Appendix B: Regulations 1. Introduction B -1 2. Current Regulations B -3 2.1 Surface Water Management B -3 2.2 Water Quality B-7 2.3 Flood Protection B -12 2.4 Habitat Protection B -15 3. Potential Regulatory Changes B -20 3.1 NPDES Phase II Permit Conditions, Updated Water Quality Standards, and TMDLs B -20 3.2 Future Listings and Critical Habitat Designations under the Endangered Species Act B-21 4. References B -22 Tables B -1 Summary of Current and Pending Regulatory Requirements and the City of Tukwila's Compliance Status B -4 B -2 Major Water Bodies and Classification in Tukwila B-8 B-3 Section 303(d) List of Threatened and Impaired Surface Water Bodies Relevant to Tukwila's Surface Water Management Jurisdiction B-9 B-4 Ecology TMDL Priorities Relevant to Tukwila's Jurisdiction B-9 B -5 Ecology Priorities for Salmon Habitat Restoration in Tukwila's Jurisdiction Within WRIA 9 for 2004 -2009 B-19 Appendix C: Capital Improvement Projects 1. Introduction C -1 1.1 Background C -1 1.2 Objective C -1 2. Drainage Basins C -2 2.1 Duwamish River Mainstem C -7 2.2 Gilliam Creek C -7 iv SEA31001174165.DOC/032670010 • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 2.3 Nelson Place - Longacres C -8 2.4 P17 C -8 2.5 Riverton Creek C -9 2.6 SE Central Business District C -9 2.7 Southgate Creek C -10 3. Surface Water Management Issues C -10 3.1 Identification Process C -10 3.2 Identified Surface Water Management Problems C -11 4. Capital Improvement Program C -15 4.1 Project Development C -15 4.2 Project Selection Criteria and Methodology C -17 4.3 Capital Improvement Program Recommendations C -20 4.4 Capital Improvement Program Funding C -22 5. References C -22 Attachments Attachment A: Surface Water Management Issues Attachment B: CIP Projects Attachment C: Project. Summaries and Cost Estimates Attachment D: Project Ranking Tables C -1 Drainage Basin Areas 0 -4 C -2 Tukwila Land Use Zoning C -5 C -3 Open Areas in the City of Tukwila C -5 C -4 Surface Water Management Problem Summary C -11 C -5 Capital Improvement Program, Projects Under Development C -16 C -6 Projects Recommended for Removal from the Fund 301 and 412 CIP C -17 C -7 Prioritized Flooding and Water Quality CJP Projects - 412 Fund C -21 C -8 Prioritized Habitat -Only CIP Projects - 301 Fund C -22 C -9 Summary of Duwamish River Mainstem Surface Water Management Issues C -27 C -10 Summary of Gilliam Creek Surface Water Management Issues C =28 C -11 Summary of Nelson Place /Longacres Surface Water Management Issues C -29 C -12 Summary of P -17 Surface Water Management Issues C -30 C -13 Summary of Riverton Creek Surface Water Management Issues C -31 C -14 Summary of Southgate Creek Surface Water Management Issues C -32 C -15 Capital Improvement Program C -41 C -16 Related Projects from the Other CIP Funds C -44 Figures C -1 Drainage Basins C -3 C -2 Zoning Areas C -6 C -3 Surface Water Management Issues, Duwamish River Basin C -33. C -4 Surface Water Management Issues, Gilliam Creek Basin C -34 C -5 Surface Water Management Issues, Nelson Place /Longacres Basin C -35 C -6 Surface Water Management Issues, P17 Basin C -36 C -7 Surface Water Management Issues, Riverton Creek Basin C -37 SEA31001174165.DOC/032670010 V CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 C -8 Surface Water Management Issues, Southgate Creek Basin C -38 C -9 Capital Improvement Projects, Duwamish River. Basin C -45 C -10 Capital Improvement Projects, Gilliam Creek Basin C -46 C -11 Capital Improvement Projects, Nelson Place /Longacres Basin C -47 C -12 Capital Improvement Projects, P17 Basin C -48 C -13 Capital Improvement Projects, Riverton Creek Basin C -49 C -14 Capital Improvement Projects, Southgate Creek Basin C -50 Appendix D: Low Impact Development 1. Introduction D -1 1.1 What is Low Impact Development? D -1 1.2 What are the Benefits of Low Impact Development? D -2 1.3 What are the Issues and Drawbacks of Low Impact Development? D -3 2. Implementing Low Impact Development D -3 2.1 Comprehensive Plan Policy Changes D -5 2.2 Regulatory Changes D -5 2.3 Opportunities for Low Impact Development Implementation D -6 3. Conclusions D -7 4. Action Items D -7 5. References D -7 Figure D -1 Areas Where Infiltration is not Allowed D -4 Appendix E: Operations and Maintenance 1. Introduction E -1 1.1 Background E -1 2. Existing O &M Program E -2 2.1 Structure E -2 2.2 Maintenance Activities E -2 3. Complaint Response E -6 4. Maintenance Management System E -6 5. Regulatory Compliance E -7 5.1 Operations and Maintenance Activities of Concern and Associated BMPs E -7 5.2 Survey Responses and Analysis of Results E -8 6. Program Recommendations E -8 6.1 Activities E -8 6.2 Staff E -9 6.3 Regulatory Compliance E -10 7. References E -11 Attachments Attachment A: Annual Operation and Maintenance Costs Attachment B: Survey Forms Attachment C: Pollution- Generating Activities and BMPs VI SEA31001174165.DOG032670010 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Tables E -1 Water Quality and Retention /Detention Facilities E -3 E -2 City -Owned Pump Stations E -5 E -3 Green River Flood Phase Information E -6 E -4 Annual O &M Costs, Existing Level of Service E -15 E -5 Survey of O &M Activities that Potentially Pollute Stormwater Runoff E -19 E -6 Survey of Best Management Practices Used for Activities That Potentially Pollute Stormwater Runoff E -20 SEA31001 na165.DOC/032670010 vii • City of Tukwila Comprehensive Surface Water Management Plan 1. Introduction 1.1 Background The purpose of the Comprehensive Surface Water Management Plan (Surface Water Plan) is to provide a strategic framework for the management of surface water within Tukwila. The Surface Water Plan is intended to be a flexible document that may be readily revised should the priorities and focus of the City change. It is also intended to act as a reference for other City departments whose activities may impact surface water and could be affected by drainage. The role of surface water management in Tukwila is to: 1. Protect, conserve, and enhance watercourses, wetlands, infrastructure 2. Protect public safety, health and property 3. Maintain the City's surface water system 4. Meet federal, state, and local surface water regulatory requirements 5. Educate citizens and City employees The City uses the following tools to manage surface water: • Surface Water Management Policies • The Comprehensive Land Use Plan (Land Use Plan) • Comprehensive Surface Water Management Plan (Surface Water Plan) • Capital Improvement Program (CIP) • Citywide Operations and Maintenance (O &M) Program • Public Works' Development Guidelines and Infrastructure Design Standards • Development Review and Permit System The City of Tukwila Comprehensive Land Use Plan (Land Use Plan) provides guiding policy for surface water management in the City. The Surface Water Plan gives the Public Works Department a guide to implement the policy set in the Comprehensive Plan and is intended to assist the City to meet its surface - water- related legislated responsibilities as well as recommend improvements to operations and maintenance activities and the C1P. The Capital Improvement Program (C1P) is developed to set funding for projects and program elements that are recommended in the Surface Water Plan. The C1P is often developed concurrently with Comprehensive Plan development. The Operations and Maintenance (O &M) program gives the Public Works Department a guide for operating and maintaining the existing surface water infrastructure in the City. Public outreach and the development review process provide valuable opportunities to work proactively with citizens and sEA310011 4165 D0G032670010 1 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 developers to introduce new concepts of surface water management and promote an understanding of surface water issues and their impact on the City. This document is the first update since the first Surface Water Plan was prepared in 1993. It addresses changes that have taken place since 1993, including new federal regulations and changing surface water management techniques and strategies. The City has implemented many of the recommendations contained in the initial Surface Water Plan and has addressed its most pressing basic issues related to property damage from flooding. As the City moves through its hierarchy of needs, it is expected that the focus will shift from addressing these basic quantifiable needs to goals that relate more to the character of the City and the vision of its citizens and leaders. 1.2 Objective The objective of the Surface Water Plan is to provide a surface water management framework that will protect the public's safety, health and property, conserve and enhance natural systems within the City, and comply with local, state, and federal regulations. This update was developed using the following principles: • The Surface Water Plan should be a "living" document that encompasses alternative solutions such as Low Impact Development and can be adapted to conditions and priorities. • The recommendations should meet the current and anticipated requirements of federal regulations, particularly the Endangered Species Act (ESA) and Phase II of the National Pollution Discharge Elimination System (NPDES). 1.3 Report Organization The body of this plan summarizes the general surface water conditions in the City. Technical conclusions are detailed in appendices. The Plan comprises the following: • Section 1: Introduction to the City of Tukwila Comprehensive Surface Water Management Plan • Section 2: Summary of the physical surface water, drainage, and drainage - related characteristics of the City • Section 3: Review of the regulatory framework to assure the City's surface water management policies are in compliance with federal, state, and local regulations (also discussed in Appendix B) • Section 4: Documentation of surface water management issues in the City (also discussed in Appendix B) • Section 5: Identification of projects that address surface water management issues; these projects will be part of the City's CIP (also discussed in Appendix C). Summary of how Low Impact Development /Natural Drainage techniques can address surface water management issues (also discussed in Appendix D). 2 SEA31001174165.DOC/032670010 • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 • Section 6: Documentation of the existing O &M programs and recommendations to increase the efficiency and effectiveness of that program. Guidance for all City operations to meet federal regulations regarding water quality and the protection of natural surface water resources (also discussed in Appendix E) 2. Drainage Basin Characteristics Topography, land use, climate, soils, and other physical characteristics affect surface water runoff quantity and quality in the City. An overview of these physical characteristics is presented in this section so that the causes of surface water problems can be better understood. 2.1 General Description The City of Tukwila is located where the Black and Green Rivers converge and become the Duwamish River, and encompasses over 5,500 acres (see Figure 1). The climate is typical of areas west of the Cascade Mountains and is strongly influenced by the Pacific Ocean. Winters are generally wet and mild with temperatures varying from 30 °F to 50 °F. Summers are usually relatively dry and cool with temperatures rarely exceeding 80 °F. The average annual precipitation is between 32 and 38 inches. The Green and Duwamish Rivers dominate the geography and drainage of Tukwila. The topography comprises a relatively flat and poorly drained floodplain adjacent to the rivers and steeply sided valley walls to the west. Soils in the valley floor belong to the Newberg and Woodinville Series: a very fine sandy loam and a silty clay loam, respectively. The valley walls typically comprise soils from the Alderwood Series (interbedded silts and clays) and are characterized by numerous hillside springs and the accompanying potential for instability. 2.2 Drainage Basins Consistent with the initial Water Management Plan, the City has been divided into seven drainage basins (see Figure 2). Portions of basins listed in Table 1 are located outside City limits as shown in the table. TABLE 1 Drainage Basin Areas Total Basin Area Area of Basin in City Basin Name (acres)' (acres) % of Basin in City Duwamish -Green 3,800 2,200 58 Gilliam 1,800 1,300 72 Nelson 140 140 100 P17 1,300 790 61 Riverton 450 390 87 SE Central Business District (CBD) 120 120 100 Southgate 550 480 87 Total 8,200 5,400 66 'Basin areas are approximate. See Appendix C for a description of the drainage basin delineation done for this project. SEA31001174165.DOC/032670010 3 par • 9/30/03 • mm 176170.75.06_W0920030099EA • Figur S E ATT KING COUNTY KING COUNTY Bl'RIEN TUKWILA SouthCenter Mall SEATAC 188th Street I t I 0 0.5 1 Miles Figure 1 City of Tukwila Vicinity Map City of Tukwila Comprehensive Surface Water Management Plan l76 70.TS.oe_w002007000see l Flar. 20M/ 003003 I roy_nm Lake Washington Ison Plac�hJ ng Acre B --si, Southeast CBD Basin Legend /\/ Roads �i Streams Water Body/Wetland ® Basin Boundary Neighboring (Jurisdicitions) Study Area 0 1 0.5 1 Miles Data shown in this map are in Washington State Plane North, NAD 1983 Figure 2 Drainage Basins City of Tukwila Comprehensive Surface Water Management Plan CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Detailed information for each basin can be found in Appendix C. 2.3 Land Use The City of Tukwila has a population of approximately 17,000, and the land is fully developed. Land use within the City varies from undeveloped natural land to highly developed industrial areas. The City can be divided into three primary zones: • Manufacturing /industrial center to the north • Commercial area (including Southcenter) in central and south Tukwila • Residential development to the west and to the north Table 2 lists the areas for the different development land use zones and open areas for each basin within the City. Much of the undeveloped land comprises sensitive areas and locations that are difficult to build on such as steep slopes. TABLE 2 Tukwila Land Use Zoning and Open Areas • Existing and Undeveloped Basin Name Residential Commercial Industrial Planned Parks Land %of %of %of % o f %of Acres' Basin2 Acres' Basin2 Acres' Basin2 Acres' Basin2 Acres' Basin2 Duwamish -Green 686 31 127 6 1092 50 116 5 93 4 III Gilliam 731 56 332 25 0 0 37 3 45 3 Nelson Place 0 0 100 71 15 11 0 0 27 19 P17 71 9 559 71 96 12 18 2 75 9 Riverton 202 52 20 5 166 43 0 0 46 12 SE CBD 0 0 1 1 114 95 0 0 14 11 Southgate 355 74 63 13 45 9 18 4 24 5 'Basin areas are approximate. See Appendix C for a description of the drainage basin delineation done for this project. 2Notethat percentages are based on area of the basin within the City of Tukwila. 2.4 Future Development Apart from some minor boundary adjustments and annexations, the overall footprint of Tukwila is not expected to increase significantly. Surface water management issues related to the annexation areas are discussed in Appendix A. Similarly, the population is not expected to grow significantly, and then only as a result of redevelopment that may increase residential densities. Future development and re- development should be undertaken in accordance with the City's surface water manual (1998 King County Surface Water Design Manual at the time of this memorandum). The City has also identified areas where infiltration is not allowed and Level 2 storm water detention is recommended (shown in Figures 3 and 4, respectively). 6 SEA31001174165.DOC/032670010 • LEGEND jj/ Areas where infiltration not allowed Figure 3 Areas Where Infiltration is not Allowed City of Tukwila Comprehensive Surface Water Management Plan 0182 128 LEGEND a Areas where Level 2 Storm Water ��////JJ// detention recommended 4,000 Feet Figure 4 Areas Where Level 2 Storm Water Detention Recommended City of Tukwila Comprehensive Surface Water Management Plan • • • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Infiltration is not allowed in landslide hazard areas. Level 2 detention is recommended in order to protect downstream drainage courses from high peak flows and erosion. One major proposed redevelopment initiative is the Tukwila Urban Center (TUC). The TUC covers the area known as Southcenter. The TUC is bounded by I -5 to the west, I -405 to the north, the City limits to the east, and South 180th Street to the south. The TUC also includes the station at Longacres that serves Amtrak and the Sounder commuter rail. The City is currently preparing a strategic plan to guide the continuing growth and redevelopment of the TUC over the next 20 years, focusing on a transition from the current pattern of sub- urban development to an urban environment. The plan will foster the type of high- density, pedestrian- oriented development served by high - capacity transit. The plan will also coordi- nate the City's response to a number of significant transportation and land use pressures that provide both risks and opportunities for the long -term well being of the TUC. 3. Surface Water Issues This section summarizes existing river management practices and land uses affecting flooding, water quality, and aquatic habitat in Tukwila's surface waters, and describes existing surface water problems. 3.1 Available Data The following sources of information were used to identify drainage and habitat - related issues and problems: 1. Anecdotal and recorded information provided by City staff 2. Observations made during inspections by CH2M HILL, Herrera, and City staff 3. 1993 City of Tukwila Surface Water Management Comprehensive Plan 4. The following drainage studies: • 1993 Surface Water Management Comprehensive Plan • 1994 Gilliam Creek Detention and Water Quality Enhancements • 1996 Fostoria Basin Stormwater Quality Management Plan • 1997 Southgate Creek By -Pass Study • 1997 Riverton Creek Stormwater Quality Management Plan • 2001 Gilliam Creek Basin Storm Water Management Plan Problems may be resolved through the use of regulations, construction of CIPs, and /or implementation of O &M measures. 3.2 General Description The following types of surface water management issues are identified in this plan: • Flooding • Fish habitat • Water quality SEA31001174165.DOCJ032670010 9 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Localized flooding problems are the primary concern in the City. Right -of -way (ROW) and private flooding problems arise because there are no storm drainage systems, the existing conveyance systems are damaged or in need of maintenance, or the existing conveyance systems have inadequate hydraulic capacity. Flooding from the Green and Duwamish Rivers is not considered to be a significant concern because of the regulating effects of the Howard Hanson Dam, which was constructed in 1962. Levees built in conjunction with the Howard Hanson Dam construction also help contain flood levels in both rivers. Lower reaches of creeks have the potential to flood when high creek flows coincide with high water levels in the rivers. In 1985, the City entered into the "Green River Management Agreement" with King County and other neighboring communities. This agreement includes a number of guidelines to control impacts to the Green River. Available habitat for fish and other aquatic organisms has been significantly reduced in the creeks that drain Tukwila due to the effects of urban development and loss of riparian buffer areas. Uncontrolled runoff flows coupled with steep slopes in the upper reaches of Gilliam, Southgate, and Riverton Creeks cause channel erosion that in turn delivers sediments to the lower - gradient downstream reaches of these streams. Sediment deposition significantly reduces the conveyance capacity of several culverts, restricts fish passage, and hinders the potential for salmonid spawning in the lower reaches. Several long culverts with steep gradients and high vertical drops in all three of these creeks limit accessibility for fish to much of the stream network. In addition, the lower reaches of these creeks are generally lacking in pools and woody debris, which is typically a pool - forming feature of healthy stream systems. If there were better quality habitat in the lower reaches of these streams, they would provide great value to salmonids seeking refuge at many times of the year from high flows and predators in the Green /Duwamish River. Water quality problems are evident in all of the surface water bodies receiving runoff from developed areas in Tukwila. Untreated runoff from arterial streets with intensive traffic usage, areas of dense commercial development, parking lots in the Tukwila International Boulevard corridor and Westfield Mall area, and Interstates 5 and 405 contributes greatly to these problems. Gilliam Creek exhibits elevated turbidity in storm events, consistently high levels of fecal coliform bacteria, and also high levels of copper and zinc that occasionally exceed state standards. Riverton Creek exhibits high levels of fecal coliform bacteria, phosphorus, turbidity, total suspended solids, and copper, among other pollutants. Southgate Creek also exhibits high levels of fecal coliform bacteria and excessive turbidity and sediment loading related to channel erosion. The reach of the Green River in the vicinity of Tukwila is on the state's Section 303(d) list of threatened and impaired water bodies for fecal coliform bacteria, mercury, and temperature. Runoff conveyed to the river via Tukwila's streams is contributing to downstream water quality degradation. 3.3 Identified Problems Table 3 presents a summary of the number of identified flooding, fish habitat, and water quality problems. The surface water issues and the surface water issue identification process are discussed in detail in Appendix C. 10 SEA31001174165.DOC/032670010 • • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 . TABLE 3 Surface Water Problem Summary Number of Problems Flooding Fish Habitat Water Quality Duwamish -Green River Mainstem Gilliam Creek Nelson Place - Longacres P17 Riverton Creek SE CBD Southgate Creek 5 7 1 1 3 0 7 1 2 3 1 0 2 1 0 1 1 0 0 2 2 Totals 24 9 7 4. Regulations and Policies 4.1, Existing Regulatory Compliance Significant regulatory changes have occurred since the City approved the 1993 Surface Water Plan. These regulatory changes affect surface water management, water quality, flood protection, and habitat protection. Tukwila's surface water management program was evaluated with respect to all applicable regulations, and anticipated revisions to those regulations, to identify program improvements that need to be implemented to achieve compliance. Appendix B provides a detailed discussion of applicable regulations and the status of the City's efforts to meet the regulatory requirements. Recommended actions to improve upon regulatory compliance are presented in Section 7 of this report. In general, the City's surface water management activities support its regulatory compliance requirements and obligations, but there are some additional steps that must be taken to ensure regulatory compliance and to better coordinate environmental compliance activities across various City departments. 4.2 Potential Regulatory Changes A number of changes in regulations relevant to surface water management are expected to occur in the next five years. In general, these changes will increase the City's obligations to protect water quality and fish habitat, increase monitoring requirements, and implement • greater integration and coordination among programs aimed at improving environmental protection. Tukwila will need to accommodate such changes in its surface water management planning and program implementation. These changes relate to the City's NPDES Phase II municipal stormwater permit, the Washington State Department of Ecology's Total Maximum Daily Load (TMDL) program and its strengthened anti - degradation policy for protection of surface water quality, and the possibility that additional salmonid species will be listed under the Endangered Species Act. Appendix B provides SEA31001174165.DOC/032670010 11 CITY OF TUKWIIA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 more detailed discussion of regulatory issues that the City of Tukwila faces in its surface water management efforts in the coming years. 4.2.1 NPDES Phase 11 Changes in the City's surface water management program are required to comply with the anticipated requirements imposed by the Department of Ecology (Ecology) in its Phase II NPDES municipal stormwater permit. The City has applied for coverage under Ecology's NPDES Phase II permit program, but specific compliance measures that will be necessary in the coming years are yet to be determined by Ecology. To date, it is only clear that the City will need to abide by a minimum of six basic compliance measures. Those measures include: • Public education and outreach • Public participation and involvement • Detection and elimination of illicit discharges • Control of construction site runoff • Control of post construction runoff • Pollution prevention /good housekeeping The recommended actions listed in Section 7 of this report will help to ensure compliance with the City's eventual NPDES Phase II permit conditions. The Green /Duwamish River, Gilliam Creek, Southgate Creek, and Riverton Creek already exceed state water quality standards in terms of at least one parameter, and the more stringent water quality standards proposed by Ecology will likely result in more frequent exceedances. The City does not currently conduct water quality monitoring using methods specified by Ecology; therefore, the updated surface water quality standards (which would likely be tied directly to the City's new Phase II municipal NPDES permit) might trigger a need for more extensive water quality monitoring. 4.2.2 Department of Ecology TMDL Program and Anti - Degradation Policy Ecology will be undertaking TMDL studies in the Green /Duwamish watershed in the coming years to determine necessary limits of pollutant loadings to protect water quality. Pollutant loadings emanating from Tukwila will undoubtedly be included in these studies and in the ensuing action plans. The City will then be required to implement pollutant reduction measures in an effort to support TMDL achievement. The main "pollutants" of concern for Tukwila are likely to be fecal coliform bacteria and temperature. Ecology is also revising its anti- degradation policy. This may have the most significant effect on the City's water quality protection efforts. The proposed policy changes will apply to all actions that undergo compliance review by Ecology (which include any projects that trigger a SEPA review). In addition, the proposed changes require that all present or future actions that are likely to cause or contribute to the lowering of water quality must use all known, available, and reasonable methods of prevention, control, and treatment to reduce impacts on water quality. This anti- degradation policy may effectively require application of pre- and /or post - construction surface water BMPs on more projects than would otherwise be required. Over the next few years, the City should carefully assess how this policy translates into regulations. In a worst -case scenario, Ecology could require retrofitting of surface water 12 SEA31001174165.DOG032670010 • • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 treatment facilities into existing drainage systems in relation to this policy. The City should be cognizant of the pending need for additional surface water BMPs on a wide variety of projects, and incorporate them accordingly into planning for future City projects and into requirements imposed on private developments. 4.2.3 Potential Endangered Species Act Listing of Coho Salmon The potential Endangered Species Act (ESA) listing of coho salmon species may designate lowland areas used for rearing, foraging, and migration within the City's jurisdiction as critical habitat. That would likely require changes in City policies and programs including road maintenance practices, stormwater treatment, maintenance of storm drainage facilities, monitoring of water quality and flow, and watershed programs. 5. Storm Drainage CIP Projects 5.1 Projects Projects were developed to address identified problems listed in Section 4 together with detailed scopes and planning level cost estimates. The projects were prioritized and ranked in order of a "cost -to- benefit point" ratio. Appendix C includes a detailed discussion of project development and ranking. To address flooding problems in the City, conveyance system retrofits and new conveyance systems were recommended. One regional detention pond was recommended for the Gilliam Creek basin. Previous studies identified potential regional detention pond projects for the Riverton and Southgate Creek basins. However, these projects were not recommended by this report because the Tukwila International Boulevard bypass pipeline will address many of the flooding and erosion concerns in these two basins. Several projects for stream habitat improvement and fish passage barrier removal are recommended to address deficiencies in habitat quality, to improve accessibility to additional stream reaches for fish, and to restore habitat conditions in areas where it is cost - effective . to do so. Several of these projects are recommended in the Southgate Creek basin, and a few more are recommended in the Riverton Creek and Gilliam Creek basins. Several projects are also recommended along the mainstem of the Green /Duwamish River where riparian conditions are degraded. Many of the habitat projects are linked to watershed restoration efforts by the U.S. Army Corps of Engineers and other agencies, and therefore the City will need to coordinate their implementation with other agencies. Only one project is recommended to address water quality problems. This project entails installation of surface water treatment facilities for the Tukwila International Boulevard bypass. The recommended streambank stabilization projects and other habitat improvement projects should also provide water quality benefits. Almost all of the other water quality projects that were evaluated are not recommended at this time because of low benefits relative to the cost. It is very difficult to achieve significant water quality improvements with retrofitting of surface water treatment facilities in a built -out area with diffuse sources of runoff pollution as is the case in most of Tukwila. The City will likely realize greater water quality benefits through other non - project means, such as educational programs, improved construction site erosion and sediment control practices, improved surface water SEA31001174165.DOC/032670010 13 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 treatment facilities for development sites, and application of effective BMPs to operations and maintenance activities. Figure 5 shows the location of the prioritized projects. Table 4 summarizes the ranking of CIP projects that solve flooding and water quality problems in the City. Table 5 summarizes the ranking of CIP projects that improve fish habitat. Several projects included in Tables 4 and 5 are highlighted because they are not recommended for construction at the present time for one or more of the following reasons: • The City does not consider the project a high- priority project given its location or the extent of a problem it would address. • The benefits would be marginal if other recommended nearby CIP projects are constructed. • The project requires more analysis. When developing its annual CIP, the City will need to consider additional factors, including the availability of funds. 5.2 Alternative Approaches The projects listed above may be considered "traditional" approaches to solving urban surface water issues. These approaches can result in solutions such as new and /or oversized pipes at flooding locations, which are usually constructed as CIP projects. Another alter- native that can address surface water issues is low impact development. Low impact de- velopment, discussed in detail in Appendix D, is a different approach than conventional systems that convey runoff to large facilities where runoff is detained and pollutants are removed. 5.2.1 General Description Low impact development is a surface water management technique that attempts to mimic natural hydrology by using techniques that infiltrate, filter, store, evaporate, and detain runoff as close to its original source as possible. Low impact development techniques include: • Bioretention • Permeable pavements • Open swales • Vegetated (green) rooftops Compared to more traditional approaches, low impact development techniques are less expensive to install, and have lower O &M costs. Environmental benefits include enhanced aquatic habitats and water quality. Recent studies show that low impact approaches can infiltrate and treat between 95 to 100 percent of the annual volume of rainfall and that they are less expensive than traditional detention /retention and treatment techniques. 14 SEA31001174165.DOC/032670010 94 -DRO5A 94 -DRO5B Seattle King County 94 -DRO9 98 -DRO3 98 -DRO7 [17] King County 03 -DR11 03 -DR10 03 -DR21 03 -DR13 03 -D R20 03 -DR12 03 -DRO1 86 -DR22 03 -DRO6 Renton tati� , 03 -DR15 87 -DRO2 SeaTac 03 -DR16 (5) 98 -DRO5 03 -DR17 [9] �— 160 S. 03 -DRO5 86 -DR17 03 -DR19 (7) 03 -DR18 03 -DRO9 [3] 03 -DRO8 [7] Legend Stormwater CIPs ® Water Quality *Flooding ® Habitat A Water Quality /Habitat [21] Flooding/Water Quality Project Rank - 412 Fund Habitat Only CIP Project Rank - 301 Fund (7) 0 05 1 Miles Data shown in this map are in Washington State Plane North, NAD 1983 Figure 5 Prioritized Capital Improvement Projects City of Tukwila Comprehensive Surface Water Management Plan CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE 4 Prioritized Flooding and Water Quality CIP Projects — 412 Fund Cost Benefit Rank Points Project ID Basin Project Title Benefit Project Points Cost 1 2 3 $637.50 $1,057.14 $1,627.91 4 $2,610.47 5 $2,642.86 03 -DR12 94 -DR05A 03 -DR09 Southgate Duwamish Gilliam 86 -DR17 Gilliam 93 -DR08 Gilliam Southgate Creek Streambank Stabilization Duwamish Riverbank Stabilization 1(a) Gilliam Creek/Christensen Road Storm Drain System Connection Andover Park W 48 -inch Drain Rehabilitation Gilliam Creek 42 Ave S Culvert 80 70 172 $51,000 $74,000 $280,000 172 $449,000 , 112 $296,000 • a TP ITA r_.•: 7 8 10 11 12 13 14 15 $4,722.22 $6,875.00 $8,500.00 $9,462.50 $10,630.77 $12,000.00 $14,625.00 $16,571.43 17 19 $27,181.82 $90,666.67 03 -DR08 P -17 Minkler Boulevard Culvert Replacement 03 -DR04 Southgate S. 146th Street Pipe and 35th Avenue S Drainage System 94 -DR05B 86 -DR22 03 -DR06 03 -DR01 00 -DR10 03 -DR05 Duwamish Duwamish Gilliam Duwamish Gilliam Gilliam Duwamish Riverbank Stabilization I(b) S 143 Street Storm Drain System Northwest Gilliam Storm Drainage System 53rd Avenue S. Storm Drain System Gilliam Creek Regional Detention Pond Tukwila Parkway Drainage from Westfield Mall to Gilliam Creek 98 -DR07 Riverton Treatment Facilities for Tukwila International Boulevard Bypass. 87 -DR02 Nelson Nelson PI/Longacres Interceptor Pipe Place/Long acres 90 $425,000 80 $550,000 70 80 130 80 112 14 22 $595,000 $757,000 $1,382,000 $960,000 $1,638,000 $232,000 $598,000 6 $544,000 NOTE: Highlighted rows indicate inactive projects. 16 SEA31001174165.00C1032670010 • • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE 5 Ranking Summary for Fish Habitat CIP Projects - 301 Fund Cost Benefit Project Rank Points ID Basin Project Title Benefit Project Points Cost 1 $1,296.05 2 $1,643.94 3 $2,200.00 4 $2,325.58 03 -DR10 03 -DR21 03 -DR13 98 -DRO3 Riverton Southgate Southgate Riverton 7 $4,243.42 03 -DR19 Nelson Riverton Creek Upper Watershed Southgate Creek Habitat Restoration Southgate Creek Daylighting at S. 133rd Street Riverton Side Channel Lowei ilium Creek.Channefamprovements, _. Southgato;CreekSalmon Habdat R'estbration Downstrearii?of S133rd St �: • Nelson Salmon Habitat Side Channel Place /Long acres 8 $5,166.67 03 -DR20 Duwamish 9 $13,500.00 98 -DRO5 Gilliam Golf Course Riverbank Gilliam Creek Fish Barrier Removal 152 $197,000 132 $217,000 115 $253,000 129 $300,000 152 $645,000 84 $434,000 $675,000 50 3-DR I8 Tuck iil Pond Improvements 2;047,0( NOTE: Highlighted rows indicate inactive projects. 5.2.2 Implementation The success of low impact development is dependent on a number of factors, as follows: • Soil permeability • Water table depth • Land slope • Community perception Publicly funded projects offer opportunities to demonstrate the feasibility of alternative approaches. Other opportunities arise when new areas are developed and existing areas are re- developed. Changes to the traditional approaches include reducing street widths, pro- viding shared driveways, and replacing curbs and gutters with drainage swales or land- scaped areas. Incentives may be necessary until the practices are demonstrated locally. Possible opportunities for low impact development include: • Tukwila Village • Tukwila Urban Center • Tukwila Manufacturing /Industrial Center • Residential areas west of I -5 • CIP 8G -DR22: S. 143rd Street /Place Storm Drain System SEA31001174165.DOG032670010 17 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 • CIP 03 -DR01: S. 53rd Street Storm Drain System • CIP 03 -DR04: S. 146th Street Pipe and 35th Avenue S. Drainage System • CIP 03 -DR06: Northwest Gilliam Storm Drainage System • Public, private, and public /private redevelopment projects such as the Tukwila Urban Center • Residential areas where local, low- traffic streets need to be rebuilt or have significant subsurface utility installation or replacement, such as the areas between I -5 and Inter - national Boulevard Successfully implementing alternative approaches will require regulatory changes. Subdivision codes, zoning regulations, development guidelines, construction standards, and local ordinances might encourage the adoption of such practices. These rules are responsible for wide streets, expansive parking lots, and large -lot subdivisions that reduce open space and natural features. The goals and policies provided in the Land Use Plan should be evaluated to ensure that they are consistent with and provide the flexibility needed to implement alternative approaches. Sufficient information is not available to assess whether and where to implement low impact development in Tukwila. To assist the decision - making process, the City should perform a study to gain a better understanding of potential low impact development applications and the impacts of implementing low impact development in the City. At a minimum, the study should include the following: 1. Review of the current and future Department of Public Works Capital Improvement Program (CIP) projects to identify opportunities to implement low impact development techniques. 2. Review of the comprehensive land use plan, zoning, drainage, building codes, and street standards. Identify barriers to low impact development practices and recommend changes to encourage these practices. 3. Education on low impact development for staff and developers. 4. Recommendations for new regulations and incentives for low impact development implementation. 6. Operations and Maintenance The operation and maintenance of existing surface water facilities is an important part of the City's surface water management program. The O &M Department has a division dedicated to surface water issues. The other divisions of the O &M Department (sewer, street, and water) and City facilities (for example, pools, community centers, and fire departments) are not focused directly on surface water management; however, these divisions and facilities also affect surface water and must meet requirements of various surface water regulations. A detailed discussion of O &M practices of concern for potential water quality impacts is included in Appendix E. 18 SEA31001174165.DOC1032670010 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 • 6.1 Surface Water O &M Surface water O &M staff perform the following: • Respond to citizen complaints regarding surface water problems • Observe and document new and existing surface water issues • Maintain and operate surface water facilities In general, the O &M Program has well - established guidelines for its various activities. These guidelines are based on previous experience and are optimized for the available maintenance crew resources. • • Additional documentation is recommended for the surface water O &M Program in all areas, which include: existing drainage system mapping, complaint /complaint response, and location of surface water "hot spots." This institutional knowledge, much of which will be lost as experienced staff leave the department, is essential for the City to: • Understand the causes of surface water problems in the City • Adjust maintenance activities to address evolving O &M needs • Make staffing recommendations that may be required to address changes in maintenance activities It is also recommended that the City develop a vactor decant policy and locate and secure a permanent site to decant solids from vactor and street sweepings. 6.2 Regulatory Compliance The City, businesses, and residents are involved in activities that could potentially affect surface water. Water quality impacts from these activities can be offset by best management practices (BMPs). Many of these BMPs are recommended and /or required by these surface water regulations: • Clean Water Act • . Coastal Zone Management Act • National Pollutant Discharge Elimination System (NPDES) Phase II Permit • Puget Sound Action Team's Water Quality Management Plan Many water quality BMPs are currently being implemented by the City in its O &M work; however, gaps still exist between City operations and regulatory recommendations and requirements. Under its pending NPDES municipal stormwater permit, the City will be required to show progress in eliminating all non - stormwater discharges to surface water systems. The objective is that only uncontaminated stormwater may be discharged to the City's surface water drainage systems. SEA31001174165.DOC/032670010 19 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Ecology is obligated under the ESA to issue a permit that does not adversely affect federal - listed endangered and threatened species and critical habitat. That requirement necessitates that none of Tukwila's stormwater discharges, allowable non - stormwater discharges, or discharge- related activities will likely impact federal threatened or endangered species. Recommended changes to the City's operations and maintenance practices to achieve regulatory compliance are presented in Section 7 of this plan. 7.0 Recommendations Table 6 summarizes the recommendations made in this plan. TABLE 6 Comprehensive Surface Water Management Plan Recommendation Summary Regulations and Policies Required Formally adopt the 1998 King County Surface Water Design Manual. Subsequently review pending updates to the King County Surface Water Design Manual, as well as other manuals that are deemed equivalent to the Washington Department of Ecology's Stormwater Management Manual for Western Washington, and adopt a newer stormwater manual by December 2004, with specific provisions for the City of Tukwila as appropriate. Formalize a program for detecting and eliminating illicit (non - stormwater) discharges to surface water systems. Enforce erosion and sediment controls at construction sites. Update the flood ordinance as needed to meet Growth Management Act requirements and formally adopt it by December 2004. Recommended Implement a pollution identification and source control program in areas identified as contributing to pollutant Toads. Improve public education and awareness about pollution prevention. Investigate the Puget Sound Action Team as a funding source and technical information source for program actions Tukwila would like to implement to meet NPDES permit requirements. Update the SEPA Endangered Species Act screening checklist to include Coastal -Puget Sound bull trout. Use the SEPA Endangered Species Act screening checklist for City O &M activities and facilities management. Maintain a close watch on the status of coho salmon and coastal cutthroat trout populations in the Puget Sound area and prepare for changes in surface water management efforts should the status further decline. If coho salmon and/or coastal cutthroat trout are listed under the Endangered Species Act (ESA), review and update the City's surface water practices to ensure compliance with the ESA. Closely track NPDES permit requirements as soon as they are issued and keep track of TMDL activities in the watershed to enable timely assessment of any water quality monitoring needs. 20 SEA31001174165.DOC/032670010 • • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE 6 Comprehensive Surface Water Management Plan Recommendation Summary Surface Water Management Issues Recommended Incorporate the prioritized projects listed in Section 4 into the City's 6 -year CIP Take active steps to reduce pollution problems in city streams, with particular emphasis on fecal coliform bacteria, to reduce the severity of forthcoming state - imposed TMDL requirements. Perform targeted water quality monitoring in Gilliam, Southgate, and Riverton•creeks and in other drainages with outfalls to the Green River or Duwamish River to confirm pollutants of concern (or lack thereof) in relation to Section 303(d) listings for the Green and Duwamish rivers, identify pollutant sources, and provide a basis for developing TMDLs if required to do so by Ecology. Increase implementation of capital improvement projects for water quality and habitat improvements. Actively seek additional funding sources for these projects to expedite them. Low Impact Development Recommended Perform a study to gain a better understanding of potential low impact development applications and the impacts of implementing LID in the City. Operations and Maintenance Recommended Develop additional documentation for all aspects of the City's O &M program (e.g. existing drainage system mapping, surface water course mapping, complaint/complaint response, and location of surface water "hot spots." Develop a vactor decant policy and locate and secure a permanent site to decant solids from vactor and street sweepings. Until a permanent site is available for processing of vactor truck solids and decant water, the City should make it a priority to evaluate handling of vactor decant water at its existing maintenance yards and to implement additional water quality protection BMPs as necessary. Review and improve stormwater pollution control measures for City operations and maintenance work. Appendix E provides a basis for this. Designate a department/working group as the leaders responsible for effective source control BMP implementation at City-owned facilities and by City crews. That group should further investigate the City's O &M practices through interviews of department staff and site visits to facility locations. Review emergency spill response and containment procedures within each facility or department. Provide employee educational and training programs to address pollution prevention BMPs, safety, and spill response procedures. Perform regular inspections for all facilities storing liquids, chemicals, or solid waste. Perform site - specific evaluations to assess how stormwater runoff is handled at sites where refueling, vehicle maintenance, equipment repair, chemical applications, building or construction activities, and/or vehicle or equipment washing occurs. Drainage pattems should also be assessed at locations where permanent or mobile storage containers are kept. Develop pest management plans for O &M crews, the Parks Department, Foster Links Golf Course, and any other City operations that apply herbicides. SEA31001174165.DOC/032670010 21 • Appendices Appendix A: Annexation Review Appendix B: Regulations Appendix C: Capital Improvement Projects Appendix D: Low Impact Development Appendix E: Operations and Maintenance SEA31001174165.DOG032670010 • Appendix A Annexation Review • TECHNICAL MEMORANDUM CH2MHILL City of Tukwila Comprehensive Surface Water Management Plan Appendix A- Annexation Review PREPARED FOR: PREPARED BY: COPIES: DATE: 1. Introduction Ryan Larson, City of Tukwila Jill Mosqueda, City of Tukwila Dennis Galinato, CH2M HILL Roger Kitchin, CH2M HILL John Rogers, CH2M HILL September 18, 2003 This technical memorandum provides general physical descriptions of the proposed annexation areas in the City of Tukwila (the "City ") and summarizes related surface water management issues. 1.1 Background The Comprehensive Land Use Plan (City of Tukwila, December 4, 1995) identified potential annexation areas north and south of the City. These areas are shown in Figure A -1. When an area is annexed, residents gain access to services from the City such as enhanced water and sewer services, and enhanced police and fire protection, and building and land use controls. In turn, the City gains the ability to control new development and extend its boundaries in a logical, service - oriented manner. This memo focuses on the impact that annexation may have on surface water management in the City. 2. Description 2.1 North Annexation Area The approximate borders of the north annexation are SR 99 to the west, the Duwamish River to the east, Cloverdale Street to the north, and the existing City boundary to the south. Residential developments are located in the northwest corner of the area, while commercial property makes up the remaining developed area. There is a small agricultural field in the south corner of the annexation area. No creeks are located in this area, and it is assumed that all runoff drains east directly into the Duwamish River. SEA31002059532.DOC/032670007 A -1 CITY OF TUKWILA APPENDIX A- ANNEXATION REVIEW COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 2.2 South Annexation Area The approximate borders of the south annexation area are the I -5 corridor to the west, the Green River to the east, S 204th Street to the south, and the existing City boundary to the north. The steep area on the west side of the proposed annexation area surrounding the I -5 corridor is forested. Runoff from this area flows east into the Green River Valley. Agricultural fields are located in the relatively flat southeast and northeast sections of the annexation area. Runoff routing in the agricultural fields is controlled by irrigation ditches. Commercial development is located along the west side of Southcenter Parkway in the north half of the area. No creeks are located in this area. 3. Surface Water Management The City should create an inventory and basemap of the surface water systems (pipe, ditches, outfalls, etc.) located in the annexation areas shortly after annexation. This information should be included in the GIS database. In addition, Operation and Maintenance crews will need to incorporate these areas into their maintenance areas. Any development and /or redevelopment in the area should be undertaken in accordance with the City's storm drainage manual (1998 King County Surface Water Design Manual at the time of this memorandum). A -2 SEA31002059532.DOC/032670007 1TE170.T9.00_w00200300pese /AOatllmen1A- 1.pd1/ 100103 /mm Lake Washington e,t Tukwila Pkwy South Annexation Area Legend Annexation Areas Neighboring (Jurisdicitions) City of Tukwila 0 1 0.5 1 Miles Data shown in this map are in Washington State Plane North, NAD 1983 Figure A -1 Annexation Areas City of Tukwila Comprehensive Surface Water Management Plan Appendix B Regulations • • TECHNICAL MEMORANDUM HERRERA ENVIRONMENTAL CONSULTANTS City of Tukwila Comprehensive Surface Water Management Plan Appendix B— Regulations PREPARED FOR: Ryan Larson, City of Tukwila Jill Mosqueda, City of Tukwila PREPARED BY: Amanda Azous, Herrera Environmental Consultants Mark Ewbank, Herrera Environmental Consultants COPIES: Roger Kitchin, CH2M HILL John Rogers, CH2M HILL Dennis Galinato, CH2M HILL DATE: November 11, 2003 1. Introduction Federal and state regulations drive many aspects of the City of Tukwila's surface water management program. This technical memorandum provides a brief summary of current regulations affecting surface water management in Tukwila, identifies changes in regulations since the 1993 comprehensive surface water management plan (Tukwila 1993), and provides a status report of Tukwila's surface water regulatory compliance. Significant regulatory changes in recent years include revised state water quality standards, National Pollutant Discharge Elimination System (NPDES) permit requirements, requirements to develop total daily maximum loads (TMDLs) for Section 303(d) listed surface waters, and the 1999 listings of Puget Sound chinook salmon and Coastal -Puget Sound bull trout as threatened under the federal Endangered Species Act (ESA). As a result of this review the following initiatives are recommended for the City of Tukwila to achieve full compliance with federal and state regulations affecting stormwater management: • Formally adopt the 1998 King County Surface Water Design Manual. Subsequently review pending updates to the King County Surface Water Design Manual, as well as other manuals that are deemed equivalent to the Washington Department of Ecology's Stormwater Management Manual for Western Washington, and adopt a newer stormwater manual by December 2004 to satisfy the state Growth Management Act timeline for manual adoption, with specific provisions for the City of Tukwila as appropriate. SEA31001174166.DOG032670014 B-1 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 • Take active steps to reduce pollution problems in city streams to reduce the severity of state - imposed TMDL requirements that are likely forthcoming. • Perform targeted water quality monitoring in Gilliam, Southgate and Riverton creeks and in other drainages with outfalls to the Green/Duwamish River to confirm pollutants of concern (or lack thereof), identify pollutant sources, and provide a basis for developing TMDL action plans if required to do so by Ecology. • Implement a pollution identification and source control program in areas identified as contributing to pollutant loads. Formalize a program for detecting and eliminating illicit discharges to surface water systems. • Improve public education and awareness about pollution prevention. • Enforce erosion and sediment controls at construction sites. • Review and improve stormwater pollution control measures for City operations and maintenance work. • Investigate the Puget Sound Action Team as a funding source and technical information source for program actions the City would like to implement to meet NPDES requirements. • Update the flood ordinance as needed to meet Growth Management Act requirements by December 2004. • Update the SEPA Endangered Species Act (ESA) screening checklist to include Coastal -Puget Sound bull trout. • Use the ESA screening checklist for City O &M activities and facilities management. • Implement capital improvement projects that address the above list of initiatives. Actively seek additional funding sources for these projects to expedite them. • Complete inventory work for City -owned storm drainage infrastructure and surface water courses Closely track NPDES permit requirements as soon as they are issued and keep track of TMDL activities in the watershed to enable timely assessment of any water quality monitoring needs. B -2 SEA31001174166.DOC/032670014 CITY OFTUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 • Maintain a close watch on the status of coho salmon and coastal cutthroat trout populations in the Puget Sound area and prepare for changes in surface water management efforts should the status further decline. If Puget Sound coho salmon and/or coastal cutthroat trout are listed under the ESA, review and update the City's surface water practices to ensure compliance with the ESA. This summary covers surface water management, water quality, flood protection, and habitat protection regulations affecting the City's surface water management programs. Table B -1 summarizes the regulatory and programmatic requirements that apply to the City's surface water management program and provides a summary of the City's status in meeting these requirements. 2. Current Regulations This section summarizes the existing City, State, and Federal regulations related to surface water management, water quality, flood protection, and habitat protection. Each regulation is described, followed by a discussion of how it applies to surface management planning for Tukwila. Where applicable, the status of Tukwila's response is discussed and recommendations for achieving compliance are provided. 2.1 Surface Water Management The City of Tukwila manages surface water based on its Surface Water Management Ordinance 1755 §1 (part) of 1995 and Tukwila Municipal Code (TMC) 14.30. 2.1.1 Applicability TMC 14.30 sets the rules, regulations, and processes for managing surface water in Tukwila. It directs the City to follow the policies and rules in the City's comprehensive surface water management plan for property development. Pursuant to Ordinance 1932 §1 (part) of 2000, TMC 14.32 sets forth the City's storm and surface water utility rates and service charges. The updated plan addresses programmatic actions and identifies capital improvement projects for improving surface water conditions to better meet the intent of the code. SEA31001174166.D0C1032670014 B-3 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Table B -1 Summary of Current and Pending Regulatory Requirements and the City of Tukwila's Compliance Status Regulation or Program Tukwila Surface Water Management Program Areas Surface Water Water Quality Flood Protection Habitat Protection Surface Water Management Surface Water Management Ordinance, Tukwila Municipal Code 14.30, and resultant surface water management planning Many important capital improvement projects that have been identified need to be implemented to improve stormwater conveyance and flooding problems, but await funding. Some important capital improvement projects that have been identified need to be implemented to improve receiving water quality, but await funding. Not applicable Many important • capital improvement projects that have been identified need to be implemented to improve the protection of stream habitat, but await funding. Water Quality State surface water quality standards Not applicable Several water bodies do not meet standards. Need to identify specific pollution sources and implement pollution prevention programs. New anti- degradation standard may be difficult to achieve. Not applicable Degraded water quality has adverse impact on aquatic species' habitat, thus reducing the effectiveness of City efforts to restore fish populations. State Section 303(d) list Not applicable The Green River and Duwamish River are listed and will require the development of TMDLs that extend limitations into Tukwila' s surface water discharges if water quality is not improved. Not applicable Not applicable Total maximum daily loads (TMDLs) Not applicable Not yet applicable to Tukwila; however, the need for studies and implementation of TMDLs is pending. Not applicable Not applicable NPDES Phase I1 permit Surface water operations and maintenance practices need to be improved for better water quality protection. Existing programs offer a good base for NPDES permit compliance, but the City also needs to expand public education, identify illicit discharges, increase enforcement, and improve O &M practices. Not applicable Not applicable B -4 SEA31001174166.DOC/032670014 CITY OF TUKWILA APPENDIX B— REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Table B -1 Summary of Current and Pending Regulatory Requirements and the City of Tukwila's Compliance Status Regulation or Program Tukwila Surface Water Management Program Areas Surface Water Water Quality Flood Protection Habitat Protection Puget Sound Water Quality Action Team and Puget Sound Water Quality Management Plan Not applicable Tukwila currently does not interface with this agency but should consider doing so to capitalize on its information and resources Not applicable Not applicable Flood Protection Flood Disaster Protection Act Meets requirements Not applicable Meets requirements Not applicable 2003 Tukwila Flood Control Ordinance Meets requirements Not applicable Meets requirements Not applicable Habitat Protection Endangered Species Act City regulations and policies generally support compliance with the ESA and encourage salmon recovery. Understanding of environmental baseline conditions is critical to supporting ESA response actions, and is generally provided in the City's existing basin plans and other documents Not applicable Update the SEPA ESA screening checklist to include Coastal -Puget Sound bull trout State Salmon Recovery Planning Act Not applicable Not applicable - Not applicable The City has implemented and contributed to capital improvement projects that restore fish habitat for ESA - listed species, but should pursue funding sources for many additional projects Growth Management Act Must complete a utility inventory and adopt the Stormwater Management Manual for Western Washington or equivalent manual by December 2004 Must adopt the Stormwater Management Manual for Western Washington or equivalent manual by December 2004 Must update ordinance as needed to protect frequently flooded areas by December 2004. The City's recently updated flood control ordinance should generally suffice to meet GMA requirements. However, the City should consider provisions for levee setbacks to improve riparian habitat. Not applicable SEA31001174166.DOC/032670014 B-5 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Table B -1 Summary of Current and Pending Regulatory Requirements and the City of Tukwila's Compliance Status Regulation or Program Tukwila Surface Water Management Program Areas Surface Water Water Quality Flood Protection Habitat Protection Future Regulatory Changes NPDES Phase II permit requirements and potential TMDL pollution reduction requirements Not applicable Greater water quality protection is necessary to support improvement of degraded water quality, and the City may be faced with increased needs for monitoring water quality Not applicable Not applicable Future Endangered Species Act listings • Not applicable Indirectly applicable — would trigger even greater need for water quality protections Not applicable If coho salmon and coastal cutthroat trout are listed, many of the City's surface water programs will have to place greater emphasis on associated habitat 2.1.2 Status Tukwila is using King County's 1998 Surface Water Design Manual (King County 1998) for site design, stormwater facility requirements, related analytical procedures, and guidance for directing surface water management activities (TMC 14.30.080.A.1). Additional guidance is provided in the City's drainage basin plans, including the Fostoria Basin Stormwater Quality Management Plan (Tukwila 1996), the Riverton Stormwater Quality Management Plan (Tukwila 1997), and the Gilliam Creek Stormwater Management Plan (Tukwila 2000). The Washington State Department of Ecology (Ecology) has increased surface water management requirements for municipalities across western Washington through the NPDES municipal permit program (described in more detail later in this memorandum), and will require that Tukwila adopt the Stormwater Management Manual for Western Washington (Ecology 2001) or an approved equivalent manual in the near future as a permit condition. The Growth Management Act (GMA) also requires that jurisdictions within King County update their stormwater management manuals by December 2004. The City of Tukwila has used the 1998 King County Surface Water Design Manual for several years to guide surface water management efforts, but has not formally mandated it. It is recommended that the City formally adopt the 1998 King County manual, and subsequently review pending updates to the King County Surface Water Design Manual, as &6 SEA31001174166.DOC/032670014 • CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 well as other manuals that are deemed equivalent to the Washington Department of Ecology's Stormwater Management Manual for Western Washington, and adopt a newer stormwater manual, with specific provisions for the City of Tukwila as appropriate, for the longer term. This process should be completed by December 2004 to be in compliance with GMA requirements. 2.2 Water Quality There are various federal, state, and local laws related to water and sediment quality that significantly affect surface water management programs in Tukwila. The primary regulatory influences are the federal Clean Water Act and several state - administered water quality programs. 2.2.1 Clean Water Act (Water Pollution Control Act) The broad goal of the Clean Water Act (also referred to as the Water Pollution Control Act) is the restoration and maintenance of the chemical, physical, and biological integrity of the nation's waters. In Washington State, the U.S. Environmental Protection Agency (U.S. EPA) has delegated its responsibility for administering the Clean Water Act to Ecology. Ecology issues NPDES permits, develops water quality standards, identifies impaired surface waters on its Section 303(d) list, and establishes total maximum daily loads (TMDLs) of pollutants discharged to degraded receiving water bodies. The influence of these requirements on Tukwila's surface water management programs is discussed in the following subsections, which describe state - administered water quality programs that operate under the authority of the Clean Water Act. State Surface Water Quality Standards Surface water quality standards describe the quality of water that is expected to support- surface water uses. According to Section 303(c) of the Clean Water Act, water quality standards are the responsibility of states and qualified tribes. Ecology administers water quality standards in Washington State to be "consistent with public health and public enjoyment of the waters and the propagation and protection of fish, shellfish, and wildlife" (Washington Administrative Code [WAC] 173- 201A). Until recently, waters of the state were assigned to one of the following standard classifications: Class AA for extraordinary, Class A for excellent, Class B for good, Class C for fair; and Lake Class. Effective July 2003, Ecology restructured its surface water quality standards to more explicitly define water quality requirements for aquatic life, recreation, and water supply uses among others. For example, designated uses for aquatic life include: char, salmon and trout spawning, core rearing, non -core rearing and migration, redband trout and warm water species. There are now 18 designated uses and Ecology has established water quality criteria, such as maximum temperature and bacteria levels, for each of them. SEA31001174166.DOCJ032670014 B-7 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Applicability The City of Tukwila is responsible for regulating surface water discharges to receiving waters in its jurisdiction to meet Ecology's surface water quality standards. Table B -2 shows the designated uses assigned to the rivers and streams in and near Tukwila. The City is required to adapt to Ecology's new standards and manage surface water discharges from public and private drainage systems in a manner that meets the water quality requirements for these uses to the best of its ability. Table B -2 Major Water Bodies and Classification in Tukwila a Previous Water Body Classification Uses Designated in 2003 Duwamish River Class B • Salmon and trout rearing and migration • Secondary contact recreational uses • Industrial, agricultural and stock water uses • Wildlife habitat, harvesting, commerce/navigation, boating, and aesthetic values Green River Class A • Salmon and trout spawning, noncore rearing, and migration • Primary contact recreational uses • Domestic, industrial, agricultural and stock water uses • Wildlife habitat, harvesting, commerce/navigation, boating, and aesthetic values Gilliam Creek Class A Same as for Green River Southgate Creek Class A Same as for Green River Riverton Creek Class A Same as for Green River A Source: WAC 173 -201A amended July 1, 2003. Ecology is required to establish a TMDL for each pollutant identified in each impaired water body on the Section 303(d) list. TMDLs represent the daily limit of pollutants that a water body can contain while still complying with applicable water quality standards. A TMDL is established with the use of data and modeling to calculate how much of a pollutant (for example heat energy) can enter the water on a daily basis without causing the water to exceed the temperature standards. The TMDL is then divided among all point source polluters and nonpoint sources of the pollutant. The TMDL also typically includes a margin of safety, and accounts for future growth. Ecology can limit discharges of pollutants by prioritizing a TMDL allocation for the listed surface water or by using mechanisms such as the municipal NPDES permit program to B-8 SEA31001174166.D0CJ032670014 • CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 establish water quality control requirements for individual drainage basins. This could lead to mandatory limits on human activities in that basin. Status The Green River and Duwamish River are on Ecology's Section 303(d) list of impaired waters. Table B -3 shows the pollutants listed for these rivers in the reaches that are affected by drainage from Tukwila. Table B -3 Section 303(d) List of Threatened and Impaired Surface Water Bodies and Associated Pollutants Relevant to Tukwila's Surface Water Management Jurisdiction Water Body Duwamish River Green River Source: Ecology 1998 Associated Pollutants Fecal coliform bacteria Fecal coliform bacteria, mercury, and temperature All water bodies on the state's Section 303(d) list are required to have TMDLs by 2013 in order to comply with a 1997 agreement between the U.S. Environmental Protection Agency and Ecology. Ecology is currently developing TMDLs for the Green and Duwamish Rivers for the parameters listed in Table B-4. Table B -4 Ecology TMDL Priorities for the Green and Duwamish Rivers Water Body Parameter to be Limited by Total Maximum Daily Loads Duwamish River Lower Green River pH, dissolved oxygen, temperature, fecal coliform bacteria, mercury fecal coliform bacteria, dissolved oxygen, chromium, temperature Source: Ecology 2003 It is likely that the Green River and the Duwamish River will remain on the 303(d) list and that TMDLs will be required unless significant improvements to stormwater quality are achieved in the urbanized watershed. As part of an ongoing TMDL water cleanup plan in the coming years, Ecology will be assessing sources of problem pollutants in the Green/Duwamish watershed, and that assessment will include Tukwila's creeks and other drainage systems discharging to the river. This may lead to requirements for more stringent stormwater management practices in certain basins in Tukwila, and could provoke land use restrictions. The City of Tukwila should avoid being in a reactionary position to'the resultant SEA31001174166.D0C1032670014 B-9 CRY OF TUKWILA APPENDIX B--REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TMDL plans by actively monitoring water quality and by taking steps to reduce chronic pollutant loadings to its waters. Additional water quality monitoring focusing on the TMDL pollutants of concern to Ecology will enable the City and Ecology to better understand the extent to which Tukwila is responsible for contributing to the water quality improvement plans. Monitoring in the City's streams and other drainages should focus primarily on fecal coliform bacteria and temperature because they are the problematic pollutants in the river in the vicinity of Tukwila. NPDES Municipal Stormwater Phase II Permit Section 402 of the Clean Water Act requires certain municipalities to obtain an NPDES permit for municipal stormwater discharges to receiving waters. In Washington state, Ecology is responsible for issuing and renewing these permits. Discharges from municipal separate storm sewer systems (MS4s) are regulated as point sources. An MS4 is defined as a system that collects and conveys only stormwater (such as from road drainage, manmade channels, and storm drains). The municipal NPDES permit program seeks to control or reduce the discharge of pollutants to the maximum extent practicable, through primarily programmatic efforts. The City of Tukwila is classified as a small MS4 and is being regulated as a Phase II NPDES permittee. A small MS4 is any MS4 not already covered by the Phase I program as a medium or large MS4. Applicability Tukwila is subject to the NPDES Phase H municipal permit requirements, and in March 2003 the City applied to Ecology for permit coverage. Operators of regulated small MS4s are required to design their programs to reduce the discharge of pollutants to the maximum extent practicable (MEP), protect water quality, and satisfy the appropriate water quality requirements of the Clean Water Act. Implementation of the MEP standard typically requires the development and implementation of best management practices (BMPs). Ecology is initially requiring Phase II permittees to meet six basic permit requirements, which are considered minimum control measures and include the following activities: Public education and outreach. Distributing educational materials and performing outreach to inform citizens about the potential impacts of polluted stormwater runoff discharges on water quality. Public participation and involvement. Providing opportunities for citizens to participate in program development and implementation (includes effectively publicizing public hearings and/or encouraging citizen representatives on a stormwater management panel). Detection and elimination of illicit discharges. Developing and implementing a plan to detect and eliminate illicit discharges to surface waters (includes developing a system map 8-10 SEA31001174166.DOC/032670014 CITY OF TUKWILA • APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 and informing the community about hazards associated with illegal discharges and improper disposal of waste). Control of construction site runoff. Developing, implementing, and enforcing an erosion and sediment control program for construction activities that disturb 1 acre of land or more. Particular attention should be paid to minimize sedimentation impacts to wetlands and streams. Control of post construction runoff. Developing,'implementing, and enforcing a program to address discharges of post construction stormwater runoff from new development and redevelopment areas. Applicable controls could include preventive actions such as the protection of sensitive areas (e.g., wetlands), the use of structural best management practices for stormwater treatment and flow control, or retrofitting activities such as tree planting. Pollution prevention/good housekeeping. Developing and implementing a program with the goal of preventing or reducing pollutant runoff from municipal operations. The program must include training of municipal staff on pollution prevention measures and techniques. Status Tukwila is currently formulating and implementing a surface water management program that satisfies its evolving NPDES permit requirements. The City is involved in a variety of surface water management activities that collectively address, to some degree, each of the six control measures. However, to ensure permit compliance the City will need to accomplish the following: • Expand its current public education and outreach efforts • Increase public participation and involvement in stormwater management • Formalize a program for detecting and eliminating illicit discharges of non - stormwater substances to surface water systems • Enforce effective erosion and sediment controls at construction sites, including equipment staging and maintenance areas • Improve education and awareness about pollution prevention • Improve stormwater pollution control measures related to City operations and maintenance work. Even after an NPDES permit is issued by Ecology, Tukwila should plan further measures to improve pollution controls and water quality in order to meet state water quality standards. . SEA31001174166.DOC/032670014 B -11 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 2.2.2 Puget Sound Action Team and Management Plan The Puget Sound Action Team (PSAT) was originally established by Washington state statute in 1983 as the Puget Sound Water Quality Authority and was directed to identify pollution- related threats to Puget Sound's resources, conduct risk assessments, and coordinate and report on information relating to water quality. in Puget Sound. The Puget Sound Water Quality Management Plan was first drafted in 1987 and was most recently updated in 2001 for the period from 2001 through 2003 (PSAT 2000). The management plan is used to direct the work activities of the action team and to budget for addressing priority measures to restore and protect the health and diversity of the Sound. Applicability The management plan is not legally binding on the City of Tukwila. However, because Tukwila is located within the Puget Sound basin, many of the provisions of the large -scale plan affect the decisions of regulatory authorities in the region and, therefore, indirectly affect the City. Two goals of the action team are to protect and enhance the health of Puget Sound's aquatic species and habitat, natural hydrology and processes, and water quality and to achieve standards for water and sediment quality by managing stormwater runoff (PSAT 2003). The action team works with local jurisdictions and Ecology to obtain grants and loans through the Centennial Program and the State Revolving Fund. These grants and loans help local governments, such as the City of Tukwila, develop stormwater programs that support such specific initiatives, such as low - impact development practices and retrofitting watersheds. Status The City of Tukwila has no ongoing programs or projects with the PSAT at this time. The PSAT should be investigated as a source of educational resources and funding for implementing some of the programs Tukwila needs to meet NPDES requirements., 2.3 Flood Protection 2.3.1 Flood Disaster Protection Act The U.S. Congress established the National Flood Insurance Program (NFIP) with the passage of the National Flood Insurance Act of 1968. The NFIP is a federal program enabling property owners in participating communities to purchase insurance as a protection against flood losses in exchange for floodplain management regulations that reduce future flood damages. Participation in the NFIP is based on an agreement between communities and the federal government. If a community adopts and enforces a floodplain management ordinance to reduce future flood risk for new construction in floodplains, the federal government will make flood insurance available within the community as a financial protection against flood losses. This insurance is designed to provide an alternative to B-12 SEA31001174166.DOC/032670014 • • CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 disaster assistance to reduce the escalating costs of repairing damage to buildings and their contents caused by floods. The Federal Emergency Management Agency (FEMA) is currently responsible for the NFIP. Applicability Section 1315 of the National Flood Insurance Act is a key provision that prohibits FEMA from providing flood insurance unless a community adopts and enforces floodplain management regulations that meet or exceed the floodplain management criteria established under Section 1361(c) of the act. These floodplain management criteria are specified in the Code of Federal Regulations (CFR), Title 44, Part 60, Criteria for Land Management and Use. The emphasis of the National Flood Insurance Program (NFIP) floodplain management requirements is focused on reducing threats to lives and the potential for damages to property in flood -prone areas. In addition to providing flood insurance and reducing flood damages through floodplain management regulations, the NFIP identifies and maps the nation's floodplains. Mapping of floodplains creates broad -based awareness of the flood hazards and provides the data needed for floodplain management programs and for determining flood insurance rates for new construction. Status Mapped floodplains in Tukwila include those of the Green/Duwamish River and the lower reach of Gilliam Creek. Tukwila is compliant with the NFIP as it has a flood control ordinance and explicit standards for development in flood zones to reduce and prevent flood damage. 2.3.2 Tukwila Flood Control Ordinance The City of Tukwila currently manages floodplain hazards through the Flood Control Zone Permit Ordinance (TMC 16.52), which incorporates the requirements of the NFIP for national flood insurance eligibility. Applicability The current ordinance directs the City to do the following: • Establish restrictions and regulations to ensure that new and substantial redevelopments are adequately flood- proofed and qualify for the flood insurance program • Control local runoff by establishing and enforcing policies that allow for runoff and rates of runoff that are most compatible with the hydrology of the Green River SEA31001174166.DOC/032670014 B-13 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 • Establish levee /dike requirements, including standards for the protection of levees, dikes, and banks, and an improvement plan for dikes and levees (Green River management plan) • Ensure that adequate levees and dikes are provided throughout the city • Require easements and rights -of -way to maintain future dike and levee systems • Preserve natural riverbank barriers and control filling, grading, dredging, and other development that will unnaturally divert floodwaters or that may increase flood hazards in other areas (Ordinance 1462 §2 [part] 1988). Status This ordinance is being revised to address ongoing concerns about flood control. The Growth Management Act requires that ordinances to protect frequently flooded areas be updated by December 2004. Tukwila's updated ordinance will further restrict or prohibit uses that might result in a danger to health, safety, and property due to water or erosion hazards or that might increase erosion, flood heights, or flood velocities. The updated ordinance: • Requires that land uses vulnerable to floods, including facilities serving such uses, be constructed to protect against flood damage • Controls the alteration of surface water features, such as natural floodplains, stream channels, and natural protective barriers that retain or channel floodwaters Controls filling, grading, dredging, and other development that may increase flood damage • Prevents or regulates the construction of flood barriers that would unnaturally divert floodwaters or that might increase flood hazards in other areas. The City should also explore increasing levee setback requirements as a way to improve riparian habitat and to avoid flood damage. In some cases, floodplains could be utilized for side - channel habitat restoration projects. Under the revised ordinance, all development permits will be reviewed to determine if the proposed development is located in the floodway and to ensure that the encroachment provisions of TMC 16.52.100 (floodways) are met. For the foreseeable future, implementation and enforcement of the City's updated flood control ordinance should satisfy the applicable federal and state regulations. B -14 S EA31001174166. DOC/032670014 • CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 2.4 Habitat Protection 2.4.1 The Endangered Species Act The Endangered Species Act of 1973 provides broad protections for listed threatened and endangered species and their designated critical habitat. In 1999, both the Puget Sound chinook salmon and the Coastal -Puget Sound bull trout were listed as threatened by NOAA Fisheries and the U.S. Fish and Wildlife Service (USFWS), respectively. Critical Habitat was designated by NOAA Fisheries for chinook, but was later vacated. In 2000, NOAA Fisheries issued its final 4(d) rule for 14 threatened salmonid evolutionarily significant units (ESUs), including the Puget Sound chinook salmon. The 4(d) rule prohibits the take of chinook salmon, which is defined broadly to include harming, harassing, pursuing, hunting, shooting, wounding, killing, trapping, or collecting a listed species. Critical habitat designations for chinook salmon are expected to be proposed in June 2004, and final designations are expected in December 2004 or early 2005. Under Section 4(d), the USFWS has a standing rule that also prohibits the take of Coastal - Puget Sound bull trout. To date, a critical habitat designation has not been made by the USFWS for the Coastal -Puget Sound bull trout; however, the USFWS plans to designate this habitat in 2003. Applicability Puget Sound chinook salmon and the Coastal -Puget Sound bull trout are currently listed as threatened or endangered by NOAA Fisheries or the USFWS in the immediate vicinity of Tukwila. Puget Sound coho salmon are prevalent in Tukwila's streams and are identified as a candidate species for listing. If coho are listed, activities in lowland areas used for coho rearing, foraging, and migration within the City's jurisdiction would trigger the ESA. Likewise, if critical habitat for the Puget Sound chinook salmon or Coastal -Puget Sound bull trout is designated in the lower reach of Gilliam, Southgate, and/or Riverton Creeks, activities affecting these creeks will trigger ESA protections. Coastal cutthroat trout are also a species that is being watched closely by the USFWS. These salmonids may be present in one or more of Tukwila's streams. Although there is a lesser degree of concern for this species compared to the others listed above, the City needs to keep track of ESA - related applicability of protections for them. The ESA prohibitions against taking of a listed species apply to any person subject to the jurisdiction of the United States and it applies to both public and private lands and activities. This includes individuals, businesses, and federal, state, and local governments. Both a person whose actions harm or harass a protected species and a governmental entity that authorizes that person's actions can violate the ESA prohibitions. Thus, the City of Tukwila is responsible for implementation of plans and policies that support the ESA prohibitions. A taking may occur whenever development activities directly or indirectly modify fish habitat or kill or injure fish. Specific examples include: SEA31001174166.DOC/032670014 B-15 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 • Constructing or maintaining barriers that eliminate or impede a listed species' access to habitat essential for its survival or recovery; • Removing, poisoning, or contaminating plants, fish, wildlife, or other biota required by the listed species for feeding, sheltering, or other essential functions; • Discharging pollutants into a listed species' habitat; • Removing or altering rocks, soil, gravel, vegetation, or other physical structures that are essential to the integrity and function of a listed species' habitat; • Removing water or otherwise altering streamflow when it is likely to impair spawning, migration, or other essential functions; • Releasing non - indigenous or artificially propagated individuals into a listed species' habitat; • Constructing or operating inadequate fish screens or fish passage facilities at dams or water diversion structures in a listed species' habitat; • Constructing or using inadequate bridges, roads, or trails on stream banks or unstable hill slopes adjacent or above a listed species' habitat; • Constructing or using inadequate pipes, tanks, or storage devices containing toxic substances, where the release of such a substance is likely to significantly modify or degrade listed species' habitat; • Conducting timber harvest, grazing, mining or other land use activities that increase sediment loading to streams; • Disturbing streambeds so as to trample eggs or trap adult fish preparing to spawn; • Altering lands or waters in a manner that promotes unusual concentrations of predators; • Shoreline and riparian disturbances that retard or prevent the development of habitat conditions upon which listed species depend; or • Filling or isolating side channels, ponds and intermittent waters upon which listed species depend for refuge during high flows. Many of these development activities are applicable to the City of Tukwila, either because the City is engaged in them or because it writes permits for private developments to engage in them. B-16 SEA31001174166.DOC/032670014 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Status The City of Tukwila has designed an Endangered Species Act (ESA) screening checklist within the State Environmental Policy Act (SEPA) review process to evaluate the potential for a project to result in a potential take of chinook salmon, coho salmon, and/or cutthroat trout. The screening checklist requires specific details of site plans, grading and drainage plans, critical areas studies, and other concerns depending on the extent and character of the project. In general, the checklist addresses the following activities that may trigger impacts on ESA - listed species: ■ Grading of a site • Clearing of a site • Work below the ordinary high watermark of any wetlands, creeks, or the Green/Duwamish River • Processing, handling, storage, or treatment of hazardous substances • Withdrawal, interception, or injection of groundwater • Landscaping or reoccurring activities that require the application of herbicides, pesticides, and fertilizers • Physical alterations to a watercourse or its banks. Tukwila uses the information obtained from the checklist to determine whether a take will occur. The current ESA checklist within the SEPA review process is adequate to identify activities that may harm fish or fish habitat in relation to development projects. This checklist should also be routinely referenced by City staff involved in O &M activities and facility management to ensure that the City's work complies fully with the ESA. At the present time the checklist does not identify Coastal -Puget Sound bull trout as a listed species and should be revised accordingly. 2.4.2 State Salmon Recovery Planning Act The state has responded to the Endangered Species Act listings described above by enacting legislation authorizing but not mandating local governments and other stakeholders to take certain actions to promote salmon recovery. The Washington state legislature established the Salmon Recovery Planning Act (RCW 77.85) through House Bill 2496 for the improvement and recovery of salmonid fish runs throughout the state. This act established a Salmon , Recovery Office within the Office of the Governor to coordinate a state strategy for salmon recovery (to healthy sustainable population levels) with the purpose of coordinating and assisting the development of salmon recovery plans. S EA31001174166. DOC/032670014 B -17 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Applicability The Salmon Recovery Act authorizes a lead entity (a county, city, conservation district, special district, tribal government, or other entity) in a water resource inventory area (WRIA) to establish a committee to develop local watershed projects that address habitat concerns. The role of the committee is to compile a list of projects, establish priorities for individual projects, define the sequence in which the projects are to be implemented, and submit the list to the Salmon Recovery Funding Board (SRFB) for funding. Status Tukwila is in WRIA 9 ( Green/Duwamish River) and the City is a participant in the WRIA 9 near term action agenda (NTAA). The NTAA is the result of four years of collaborative efforts and one year of sustained discussion among elected officials, city and county staff, business and environmental groups, scientists, and concerned citizens in the Green/Duwamish and Central Puget Sound watershed. Also, the U.S. Army Corps of Engineers, in partnership with King County, Tukwila, and several other cities have developed the Green/Duwamish Ecosystem Restoration Project (ERP) to address ecosystem degradation problems in the basin. The City of Tukwila voluntarily contributes financial support to both watershed planning for salmon habitat and invests in salmon recovery programmatic and planning projects to support the WRIA 9 NTAA and the Green/Duwamish ERP initiative. Ecology's priorities for salmon restoration in and near Tukwila are indicated in Table B -5. Several of the capital improvement projects for habitat included in the City of Tukwila comprehensive surface water management plan are linked to the City's involvement in salmon recovery in WRIA 9, and support Ecology's priorities. Although the City has identified many capital projects to improve habitat, it has not been able to allocate funding to design and construct these projects. The City should step up its efforts to obtain funding for these types of projects. 2.4.3 Growth Management Act The Growth Management Act (GMA)'was passed by the Washington state legislature in 1990. The GMA was enacted in response to rapid population growth and concerns about suburban sprawl, environmental protection, quality of life, and related issues. The GMA has been amended several times and is codified in many chapters but primarily in Chapter 36.70A of the Revised Code of Washington. Under the requirements of Section 4 of the GMA, the City of Tukwila must develop and adopt comprehensive plans and development regulations that prevent the adverse effects of uncontrolled development and poor land use practices. One of the key directives of the GMA is to use "best available science" to support effective land use planning that can avert degradation of the environment. B -18 SEA31001174166.D0C1032670014 • • CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Table B -5 Ecology Priorities for Salmon Habitat Restoration in Tukwila's Jurisdiction Within WRIA 9 for 2004 -2009 Water Body Priorities Green/Duwamish River subwatershed Lower Green River subwatershed Restore Elliott Bay/Duwamish, nearshore, and lower Green River habitats. Conduct baseline habitat mapping in the Elliott Bay/Duwamish subwatershed. Restore lower Green River, Elliott Bay/Duwamish, and nearshore habitats. Identify and pursue opportunities on agricultural lands to enhance or restore high - quality salmon habitats while maintaining viable agriculture. Conduct baseline habitat mapping in the lower Green River. Source: King County 2002 WRIA = water resource inventory area Applicability The Growth Management Act (GMA) provides a framework for regional coordination. To satisfy the requirements of the GMA, Tukwila's comprehensive planning must include the following elements: land use, housing, capital facilities, utilities, and transportation. Tukwila's planning must be consistent with King County's planning efforts and growth policies. Tukwila is ineligible to receive state or federal funds if it is not compliant with the GMA. Status In general, the City of Tukwila is conducting planning efforts and regulating development in a manner that satisfies GMA requirements. However, to be consistent with the best available science requirements of the GMA, the City needs to do the following by December 2004 to be in compliance with the GMA: • Complete a thorough inventory of its drainage infrastructure and surface water systems • Update its regulations for frequently flooded areas • Adopt the Ecology Stormwater Management Manual for Western Washington or an approved equivalent manual. The City's comprehensive surface water management plan must also include a capital facilities plan that addresses the requirements of the Growth Management Act. SEA31001174166.DOC/032670014 B-19 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 3. Potential Regulatory Changes A number of changes in existing regulations relevant to surface water management are expected to occur in the next 5 years. In general, these changes are expected to increase the City of Tukwila's obligations to protect water quality and fish habitat, increase monitoring requirements, and require greater integration and coordination between programs aimed at improving environmental protection. This section summarizes expected changes and identifies where Tukwila will need to accommodate such changes in its surface water management standards and procedures. 3.1 NPDES Phase II Permit Conditions, Updated Water Quality Standards, and TMDLs As described previously, the City of Tukwila has applied for coverage under Ecology's NPDES program for municipalities as a "small MS4." The specific permit requirements that will be imposed on the City of Tukwila are not yet known. At about the same time, Ecology has modified the state surface water quality standards and will soon publish an updated Section 303(d) list of polluted water bodies. The result of these recent developments will not be known for a while, but it is clear that they collectively point to a need for the City to increase its water quality protection efforts, and will likely require greater City resources to accomplish water quality monitoring, complete studies, and implement water quality improvement actions and projects. Since several of Tukwila's streams already exceed the water quality standards for at least one parameter, the more stringent criteria in the updated surface water quality standards will likely result in more frequent exceedences of the standards. The proposed changes for temperature (a 303(d) list parameter for the Green River and dissolved oxygen (a 303(d) list parameter for the Duwamish River downstream of Tukwila) are based on the protection of a key fish species or life stage of a particular species and are time -based results (e.g., 7 -day average of maximum temperatures and 90 -day average of daily minimums or 1 -day minimum for dissolved oxygen) rather than a single measurement as is currently required. The City does not currently conduct water quality monitoring of this nature. Therefore, the updated surface water quality standards and pending TMDLs in the Green/Duwamish watershed (which may be tied directly to the City's new Phase II municipal NPDES permit) may trigger a need for more extensive water quality monitoring. The City should pay close attention to its NPDES permit requirements as soon as they are issued and keep track of TMDL activities in the watershed to enable timely assessment of any water quality monitoring needs. Changes in the antidegradation policy in the state surface water quality standards may have the most significant effect on the City's water quality management efforts. The proposed changes will apply to all actions that undergo a compliance review by Ecology (which B-20 SEA31001174166.DOC/032670014 • • CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER2003 include any projects that trigger a SEPA review). In addition, the proposed changes require that all present or future actions that are likely to cause or contribute to the lowering of water quality must use all known, available, and reasonable methods of prevention, control, and treatment (AKART) to reduce impacts on water quality. AKART is not specifically defined and has been the subject of much controversy in the past. Depending on how Ecology chooses to enforce this requirement, the City may be required to retrofit its existing drainage systems to improve water quality conditions in receiving water bodies in the Tukwila area. The cost implications of this type of retrofitting could be substantial. 3.2 Future Listings and Critical Habitat Designations Under the Endangered Species Act The USFWS plans to propose listing critical habitat for Coastal -Puget Sound bull trout in 2003, with a final decision by September 2004 (USFWS 2002). The Puget Sound coho salmon is identified by NOAA Fisheries as a candidate species for listing in Puget Sound. NOAA Fisheries defines a candidate species as a species whose status is of concern, but where more information is needed before the species can be formally listed (Ryan and Schuler 1998). Coastal cutthroat trout are currently identified by the USFWS as a species that does not warrant federally protected status, but are considered a species of concern by the state. Other than the Puget Sound chinook salmon and the Coastal -Puget Sound bull trout, no anadromous fish species are listed as threatened or endangered by NOAA Fisheries or the USFWS in the immediate vicinity of Tukwila. Because of the greater geographic range of coho salmon in Tukwila streams, and the potential for coastal cutthroat trout, listing of coho or cutthroat trout under the ESA could have a greater impact on upland areas of the city than the listing of chinook salmon. If the Puget Sound coho salmon or coastal cutthroat trout becomes a federally listed species (and its critical habitat is designated for protection), it could trigger significant changes in the City's policies and programs addressing instream and near -stream activities, shoreline activities, and all watershed activities, because these fish depend on smaller creeks for spawning habitat. Coho salmon are prevalent, or once were prevalent, in Gilliam Creek, Southgate Creek, and Riverton Creek in Tukwila. Coastal cutthroat trout may also be present in one or more of these streams. Coho and cutthroat trout are more prevalent in urban streams in the Puget Sound area than chinook salmon because of the relatively small size of many urban streams. These streams historically did not provide extensive habitat for chinook salmon because chinook use larger streams for spawning and rearing. Recent findings of unusually high numbers of pre -spawn coho mortalities in urban creeks in the central Puget Sound area have focused increased attention on coho salmon. There is a possibility that the Puget Sound coho salmon species will be listed as threatened by NOAA Fisheries in the near future. SEA31001174166.DOC/032670014 B -21 CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 If such an ESA listing occurs, and areas used for coho salmon rearing, foraging, and migration are identified in the City's jurisdiction, it could require changes in City policies and programs, including but not limited to road maintenance practices, stormwater treatment, maintenance of storm drainage facilities, monitoring of water quality and flow, and watershed programs. Similar concerns apply if coastal cutthroat trout are eventually listed under the ESA. At this time the City should maintain a close watch on the status of coho salmon populations in the Puget Sound area and prepare itself accordingly should the status further decline. 4. References Ecology. 1998. The 303(d) List of Impaired and Threatened Waterbodies 1998 List — by Water Resource Inventory Areas (WRIAs). Washington State Department of Ecology, Water Quality Program Home, 303(d) Home. Information obtained September 3, 2003, from agency website: <http: / /www.ecy.wa.gov/ programs/ wq /303d/1998 /1998_by_wri as.html >. Ecology. 2001. Stormwater Management Manual for Western Washington. Washington State Department of Ecology, Water Quality Program, Lacey, Washington. Ecology. 2002. Surface Water Quality Standards Schedule for Rule- Making. Washington State Department of Ecology, Olympia, Washington. Information obtained December 12, 2002, from agency website: <http: / /www.ecy.wa.gov /programs /wq /swgs/schedle.html >. Ecology. 2003. Water Quality Plans: TMDLs under Development. Information obtained September 17, 2003, from agency website: <http: / /www.ecy.wa.gov /programs /wq /tmdl/index.html >. King County. 1998. Surface Water Design Manual. King County Surface Water Management, King County, Washington. King County. 2002. Near -Term Action Agenda for Salmon Habitat Conservation, Green/Duwamish and Central Puget Sound Watershed Water Resource Inventory Area 9, King County Department of Natural Resources. May 2002. Obtained September 2, 2003, from website: < http:// dnr .metrokc.gov/Wrias/9/NTAA.htm>. PSAT 2003.2003 -2005 Puget Sound Water Quality Work Plan. Puget Sound Action Team, Olympia, Washington. August 2003. Obtained August 31, 2003, from agency website: < http:// www. psat .wa.gov/Publications/workplan 03 /wp03_fma /WORKPLAN web.pdf>. PSAT 2000. 2000. Puget Sound Water Quality Management Plan 2000. Puget Sound Water Quality Action Team, Olympia, Washington. Adopted December 14, 2000. Obtained August 29, 2003, from Puget Sound Action Team website: <http: / /www.psat.wa.gov/ Publications /manplan00 /mp_index.htm>. B-22 SEA31001174166.DOC/032670014 • • CITY OF TUKWILA APPENDIX B- REGULATORY INFLUENCES COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Ryan, Patrick W, and Galen Schuler. 1998. The Endangered Species Act—A Primer. Perkins Coie LLP, Seattle, Washington. Obtained August 27, 2003, from website: <http://mrsc.org/subjects/environment/esa/esaprime.aspx?r=1>. Tukwila, City of. 1993. City of Tukwila Surface Water Management Comprehensive Plan Final Report. Prepared for the City of Tukwila by KCM, Inc., Seattle, Washington. April 1993. Tukwila, City of. 1996. Fostoria Basin Stormwater Quality Management Plan. Prepared for City of Tukwila Department of Public Works by Herrera Environmental Consultants, Inc., Seattle, Washington. Tukwila, City of. 1997. Riverton Stormwater Quality Management Plan: Water Quality, Stream Habitat, and Flood Control. Prepared for the City of Tukwila Department of Public Works by Entranco, Taylor Associates, and Envirovision. Tukwila, City of. 2000. Gilliam Creek Basin Stormwater Management Plan. Prepared for the City of Tukwila Department of Public Works by Herrera Environmental Consultants, Inc., Seattle, Washington. USFWS. 2002. Information about bull trout. U.S. Fish and Wildlife Service. Obtained August 30, 2003, from agency website: < http : / /pacific.fws.gov/bulltrout/ >. SEA31001174166.DOC/032670014 B -23 • Appendix C Capital Improvement Projects • • TECHNICAL MEMORANDUM CH2MHILL City of Tukwila Comprehensive Surface Water Management Plan Appendix C— Capital Improvement Projects PREPARED FOR: PREPARED BY: COPIES: DATE: Ryan Larson, City of Tukwila Jill Mosqueda, City of Tukwila Dennis Galinato, CH2M HILL Mark Ewbank, Herrera Environmental Consultants Roger Kitchin, CH2M HILL John Rogers, CH2M HILL September 26, 2003 1. Introduction 1.1 Background The City of Tukwila, population 17,181, is located in the Green River Valley, south of the City of Seattle and east of Sea -Tac Airport. The Green and Duwamish Rivers, which flow through the City, dominate the geography and drainage. The topography is composed of a relatively flat and poorly drained floodplain adjacent to the rivers and steeply sided valley slopes. The Capital Improvement Program includes funding for projects and program elements that are recommended in the Surface Water Management Comprehensive Plan. Projects with surface water components are generally funded under the following City Programs: • Surface Water Program (Fund 412) • Parks and Recreation Program (Fund 301) • Commercial Streets Program (Fund 104) • Water Program (Fund 403/01) • Sewer Program (Fund 403/02) Projects that address flooding and water quality problems are listed in Fund 412, while projects that enhance stream habitat, yet do not address flooding or water quality problems, are listed in Fund 301. Projects financed under the commercial streets, water, and sewer programs might also have a storm drainage component that solves a surface water management problem. 1.2 Objective The overall objective of this technical memorandum is to present a prioritized list of CIP projects to be included in the updated Comprehensive Plan. SEA 032660009 C -1 CITY OF TUKWILA APPENDIX C- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER2003 The following tasks, which were performed in order to meet this objective, are summarized in this memorandum: • Task 1- Identify Surface Water Problems • Task 2 - Review and Update City of Tukwila Surface Water and Parks and Recreation CIP projects (Funds 412 and 301) • Task 3 - Review and Update CIP projects from existing documents: 1. 1988 Nelson Place - Longacres Way Storm Drainage System Preliminary Design 2. 1993 Surface Water Management Comprehensive Plan 3. 1994 Gilliam Creek Detention and Water Quality Enhancements 4. 1996 Fostoria Basin Stormwater Quality Management Plan 5. 1997 Southgate Creek By -Pass Study 6. 1997 Riverton Creek Stormwater Quality Management Plan 7. 2001 Gilliam Creek Basin Storm Water Management Plan • Task 4 - Develop Additional CIP Projects as necessary • Task 5 - Recommend a 6 -year CIP for the City Readers should note that all descriptions of the magnitude and frequency of drainage problems are based on available data, anecdotal information provided by City staff, and field observations. Hydrologic and hydraulic modeling was not included in the scope of work. 2. Drainage Basins The City of Tukwila may be divided into the following drainage basins, which are shown in Figure C -1: • Duwamish River Mainstem • Gilliam Creek • Nelson Place - Longacres • P17 • Riverton Creek • SE Central Business District (CBD) • Southgate Creek Tukwila is bordered by the cities of Seattle, Renton, Kent, and Sea -Tac, and unincorporated areas of King County, and portions of the basins are located outside the City. A summary of the drainage basin areas is presented in Table C -1. C -2 SEA/032660009 170170.TS.06_wN200300ewa / FlwnC -1.pd1 / 003003 / men !son Placee ng Acree - Bfsin Southeast CBD Basin Legend "/ Roads Streams Water Body ® Basin Boundary Neighboring (Jurisdicitions) Study Area 1 0 0.5 1 Mlles � Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -1 Drainage Basins City of Tukwila Comprehensive Surface Water Management Plan CITY OF TUKWILA APPENDIX CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE C -1 Drainage Basin Areas Basin Name Total Basin Area Area of Basin in City (acres)' (acres) % of Basin in City Duwamish -Green 3,800 2,200 58 Gilliam 1,800 1,300 72 Nelson 140 140 100 P17 1,300 790 61 Riverton 450 390 87 SE Central Business District (CBD) 120 120 100 Southgate 550 480 87 Total 8,200 5,400 66 'Basin areas are approximate. See Attachment C for a description of the drainage basin delineation done for this project. Basin boundary delineation was based on information from field visits, the City Geographic Information System (GIS), previously developed basin plans, topographic maps provided by the City, and anecdotal information from City staff. Both the GIS data and staff knowledge are generally limited to within the City limits. Basin boundaries outside the City limits were based only on topographic maps and previous reports. The basin boundaries should be reevaluated when basemapping of the City storm drainage system is complete. Finally, the reader should note that the following basins have multiple outlets into the Green /Duwamish River: • Duwamish River Basin • Nelson Place /Longacres Basin • P17 Basin • Southeast CBD Basin Land use within the City of Tukwila varies from undeveloped natural land to highly developed industrial areas. Most of the City has already been developed. Much of the new development is on land that is difficult to build on (for example, land with steep slopes and /or poor drainage). Redevelopment is also occurring in the City. Table C -2 lists the areas for the different development land use zones. Table C -3 shows the open areas in the City. This information is also shown on Figure C -2. C -4 SEA/032660009 • • CITY OF TUKWILA APPENDIX CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE C -2 Tukwila Land Use Zoning Existing and Undeveloped Basin Name Residential Commercial Industrial Planned Parks Land % of % of % of % of % of Acres' Basin2 Acres' Basin2 Acres' Basin2 Acres' Basin2 Acres' Basin2 Duwamish- 686 31 127 6 1092 50 116 5 93 4 Green Gilliam 731 56 332 25 0 0 37 3 45 3 Nelson Place 0 0 100 71 15 11 0 0 27 19 P17 71 9 559 71 96 12 18 2 75 9 Riverton 202 52 20 5 166 43 0 0 46 12 SE CBD 0 0 1 1 114 95 0 0 14 11 Southgate 355 74 63 13 45 9 18 4 24 5 'Basin areas are approximate. See Appendix C for a description of the drainage basin delineation done for this project. 2Note that percentages are based on area of the basin within the City of Tukwila. TABLE C -3 Open Areas in the City of Tukwila Basin Name Undeveloped Land Existing and Planned Parks Total Open Space Acres % of Basin' Acres % of Basin' Acres % of Basin' Duwamish 93 4 116 5 209 10 Gilliam 45 3 37 3 82 6 Nelson Place - Longacres 27 19 0 0 27 19 P17 75 9 18 2 93 12 Riverton 46 12 0 0 - 46 12 SE CBD 14 11 0 0 14 11 Southgate 24 5 18 4 42 9 'Percentages are based on area of the basin within the City of Tukwila. SEA/032660003 C -5 175170.T5.002r09200]009..e r Flpur.0 -2.pAr 093003 r ror.nn Legend Zoning Commercial Industrial Residential State Right-of-Way 0 0.5 1 Mlles r � Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -2 Zoning Areas City of Tukwila Comprehensive Surface Water Management Plan CITY OF TUKWILA APPENDIX CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 2.1 Duwamish River Mainstem The Green River flows along the eastern portion of the City until it joins the Black River to form the Duwamish River. The Duwamish river flows north and discharges into the Puget Sound. Howard A. Hanson Dam, constructed in the 1960s, diminished flooding in the Green River. The Corps of Engineers built levees along the Green River in conjunction with the Hanson Dam construction to contain high river flow. The Corps also constructed levees along the Duwamish River. In 1985, the City of Tukwila entered into the "Green River Management Agreement" with King County and other neighboring communities. This agreement includes guidelines to control impacts to the Green River. Controlled releases from the Howard A. Hanson Dam maintain consistent flood elevations for the 10 -, 50- ,100 -, and 500 -year floods, which allows the City to consistently predict flood elevations along the Green River. Tides and storm surges in Puget Sound also raise Duwamish River water levels. While the 10 -, 50- ,100 -, and 500 -year flood stages are controlled by the Howard A. Hanson Dam, the influences of tides and storm . surges sometimes make it difficult to accurately estimate flood stages in the Duwamish River. The portion of the City of Tukwila located north and east of the Riverton Creek and Southgate Creek basins, between the Gilliam Creek and Nelson Place - Longacres basins, and east of the P17 basin, have been designated the Duwamish River Mainstem basin. These areas drain directly into the Green and Duwamish Rivers through various outfalls. The Duwamish River Mainstem Basin is almost entirely developed. Industrial areas, including portions of the Boeing Airfield, make up the development in the area north of the Riverton Creek Basin. The areas east of the Riverton and Southgate Creek basins and north of the Gilliam Creek basin are mostly residential. This area also includes the Foster Golf Course and Fort Dent Park. The area east of the P17 basin is mostly commercial. 2.2 Gilliam Creek The Gilliam Creek Drainage basin is located in the central region of Tukwila and has a gross drainage area of approximately 1,783 acres. Again, most of the basin is located in the City of Tukwila, with a portion (27 percent) located in the City of Sea -Tac. The basin has been almost fully developed except for the steep slopes above the I -5 corridor. The portion of the basin located north of I -405 and east of I -5 is made up mostly of residential developments, with some commercial areas located along Southcenter Boulevard. The portion of the basin west of I -5, with the exception of the Tukwila International Boulevard corridor, is made up of mostly residential developments. Commercial developments are located along the Tukwila International Boulevard corridor. The Southcenter Mall and other commercial areas have been developed in the portion of the basin east of I -5 and south of I -405. Concepts for redevelopment of the Southcenter Mall commercial area are currently being reviewed by the City. This will be discussed further in the Storm Drainage Comprehensive Plan. SEN032660009 C -7 CITY OF TUKWILA APPENDIX CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Surface runoff within the drainage basin is collected and conveyed mainly through a network of catch basins and pipes. Drainage ditches and open channels also collect drainage within the basin. Although several portions of the Gilliam Creek system exhibit good habitat characteristics, major fish passage barriers in the system pose a significant constraint on the productivity of the watercourse. The fish barriers are discussed in detail in Section 3. Historically, the low area that is now known as the Tukwila Pond drained north into Gilliam Creek via surface and subsurface flow. The Tukwila Pond was formed when the drainage paths blocked as the surrounding area was developed. During the 1970s storm, drain pipes were constructed along Andover Park West to drain the pond south into the P17 basin. In the mid 1980s, an overflow was built to the north along Andover Park West, connecting the pond to the Gilliam Creek basin. A gate valve was also built at the overflow pipe to the north. The gate valve is usually closed. When opened, it performs one of the following two functions: • Drains Tukwila Pond into the Gilliam Creek basin when the pond is at high levels • Provides storage when the Green River is at high levels and backs water into the storm drain systems in the lower portion of the Gilliam Creek basin 2.3 Nelson Place - Longacres The Nelson Place - Longacres basin is located east of the Green River on the eastern edge of the City of Tukwila and has a gross drainage area of approximately 144 acres. The Green River and the Tukwila Urban Center form the west basin boundary, while the Renton City limits form the east basin boundary. Commercial developments line the West Valley Highway corridor. The areas east and west of the West Valley Highway corridor are mostly undeveloped. Runoff from the West Valley Highway and the area to the west drains directly into the Green River through numerous storm drainage outfalls. Runoff from the area east of the West Valley Highway drains to the open ditch and culvert system located on the east side of the basin adjacent to the $urlington Northern Sante Fe Railroad track. A 24 -inch- diameter pipe located under the BNSF Burlington Northern Sante Fe Railroad tracks directs drainage from this series of open ditches and culverts east to drainage systems in the City of Renton. 2.4 P17 The P17 basin is located south of the Gilliam Creek basin and has a drainage area of approximately 1,339 acres. About 790 acres (or 59 percent) of the basin is located within the City; the remainder is located in the City of Sea -Tac. The basin is almost fully developed except for the steep slopes adjacent to the I -5 corridor. Private residences make up the majority of the development west of I -5, while commercial areas make up the development east of I -5. The P17 basin accepts the primary outflow for the Tukwila Pond. A drainage pipe running adjacent to Andover Park West conveys outflow south from the pond into the basin. As C -8 SEA/032660009 • • CITY OF TUKWILA APPENDIX C— CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 discussed in Section 2.3, drainage is routed north to the Gilliam Creek basin when the gate valve at the overflow pipe is open. Surface runoff within the drainage basin is collected and conveyed mainly through a network of catch basins and underground pipes. Runoff from the northern portion of the basin is routed to the P17 pump station located at the east end of Minkler Boulevard. The pump station discharges into the Green River. King County is responsible for the maintenance of the ditches in the basin and operation of the P17 pump station. However, the City has maintained the ditches in recent years. The southern portion of the basin drains directly into the Green River through multiple outfalls. 2.5 Riverton Creek The Riverton Creek Basin is located in the northwest region of Tukwila and has a gross drainage areal of approximately 452 acres. Almost the entire basin is located within the City of Tukwila, with a small portion located in unincorporated King County and a portion located in the City of Sea -Tac. The basin is almost entirely developed except for about 50 acres of forested land west of Tukwila International Boulevard. Residential and commercial developments are located on the steep -sided slopes in the southern and western portions of the basin. Light industrial developments are located in the valley floor in the . northern portion of the basin. Underground drainage systems consisting of catch basins and pipes collect surface runoff in the basin. These systems drain into tributaries of Riverton Creek at various points in the basin. There are two major forks to Riverton Creek, the East Fork and the West Fork. These forks merge just upstream of the crossing of SR 599. The lower reach of Riverton Creek flows through a wetland located north of SR 599, and then drains into the Duwamish River via two culverts. There is a flap gate on each culvert at the outlet of Riverton Creek to the Duwamish River. One of the gates failed in 2000, and now, during high flow events, river water backs up through that culvert into the lower reach of the creek. 2.6 SE Central Business District The SE Central Business District basin is located east of the Green River in the southeast corner of the City of Tukwila and comprises approximately 125 acres. The Green River forms the west basin boundary, while the Burlington Northern Sante Fe Railroad track forms the east basin boundary. Most of the basin has been developed with commercial areas along the West Valley Highway corridor. Wetland areas are located along the east side of the basin adjacent to the Burlington Northern Sante Fe Railroad track. Drainage from the West Valley Highway and the area to the west drain directly into the Green River through numerous storm drainage outfalls. The area east of the West Valley Highway drains into the wetlands on the east side of the basin. Outflow from these wetlands drains east into the City of Renton through culverts under the Burlington Northern Sante Fe Railroad tracks. 1 Gross drainage area may include areas such as wetlands that may have no outlet and will not contribute to streamflow. SEA/032660009 C -9 CITY OF TUKWILA APPENDIX CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 2.7 Southgate Creek The Southgate Creek Basin is located in the northwest region of Tukwila, south of Riverton Creek, and has a gross drainage area of approximately 546 acres. Most of the basin is located in the City of Tukwila, with a small portion (11 percent) located in the City of Sea -Tac. Commercial and residential developments are located on the steep -sided slopes in the west portion of the basin (west of Tukwila International Boulevard) and lowlands in the central portion of the basin (between Tukwila International Boulevard and 42nd and 43rd Avenue South). The east portion of the basin, also located in the lowlands, is the least - developed portion of the basin. Private residences are the primary type of development (77 percent) in this area. An underground drainage system consisting of catch basins and pipes collects surface runoff from the eastern portion of the basin. The central portion of the basin is drained primarily by tributaries of Southgate Creek. A ditch and culvert system collects drainage from the east portion of the basin. Several forks merge near South 133rd Street to form the lower mainstem of the creek. Each of these forks contributes minor flows, and the upper reaches of several are ephemeral and typically dry in mid to late summer. As a result, only the lower reaches of the tributary forks and the lower mainstem provide useful fish habitat. 3. Surface Water Management Issues 3.1 Identification Process To identify drainage and habitat - related problems, the following sources of information were used: • Anecdotal and recorded information provided by City staff • Observations made during inspections on December 10, 2002, and May 1, 2003, by CH2M HILL, Herrera, and City staff (notes from these site visits are included in Appendix E) • 1993 City of Tukwila Surface Water Management Comprehensive Plan • The following drainage studies: 1. 1993 Surface Water Management Comprehensive Plan 2. 1994 Gilliam Creek Detention and Water Quality Enhancements 3. 1996 Fostoria Basin Stormwater Quality Management Plan 4. 1997 Southgate Creek By -Pass Study 5. 1997 Riverton Creek Stormwater Quality Management Plan 6. 2001 Gilliam Creek Basin Storm Water Management Plan • Drainage and habitat- related problems C -10 SEA/032660009 CITY OF TUKWILA APPENDIX C-- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER2003 3.2 Identified Surface Water Management Problems 3.2.1 Summary of Identified Problems Table C -4 presents a summary of the number of flooding, fish habitat, and water quality problems identified during the project. TABLE C4 Surface Water Management Problem Summary Basin Name Number of Problems Flooding Fish Habitat Water Quality Duwamish River Mainstem 5 1 2 Gilliam Creek 7 3 1 Nelson Place - Longacres 1 1 0 P17 1 0 1 Riverton Creek 3 2 1 SE Central Business District 0 0 0 Southgate Creek 7 2 2 Totals 24 9 7 Problem descriptions are listed in Tables C -9 through C -14 in Attachment A. The problems are discussed further below in Sections 3.2.2 to 3.2.8. Figures C -3 to C -8 in Attachment A show locations of surface water management problems. 3.2.2 Duwamish River Mainstem Flooding City staff identified right -of -way and private property flooding along South 143rd Street, east of Interurban Avenue, and 53rd Avenue South, east of I -5. No drainage system exists along South 143rd Street, and flooding occurs about every 2 to 5 years. A damaged and /or undersized drainage system causes flooding along 53rd Avenue South and occurs about once every 5 years. Fish Habitat The riparian corridor of the river is significantly degraded from its natural condition in many areas of the city, such as along Foster Golf Links, north of SR 599, and east of Southcenter. Urban development in and near the City of Tukwila has greatly reduced the vegetated buffer of the river and increased pollutant loading to the river, contributing to several factors that are limiting habitat productivity in the river. SEA/032660009 C -11 CITY OF TUKWILA APPENDIX CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER2003 Water Quality While drainage originating in the City does contribute pollution to the Duwamish River, it does not have a significant impact on the water quality of the river. Water quality is affected to a much greater degree by influences further upstream and outside the City limits. 3.2.3 Gilliam Creek Flooding City staff identified the northwest entrance of the Southgate Mall and Andover Park West adjacent to the mall as potential flooding areas. The pipe that serves as the outlet to Gilliam Creek for the storm drainage system in the northwest section of the mall parking lot was constructed with a reverse slope in the mid 1960s. This system has the potential to flood the parking lot and 2 or 3 businesses. The outlet for the storm drainage system located in Andover Park West was also constructed with a reverse slope, which has resulted in the accumulation of sediment and debris in the pipes. Failure of this system would cause flooding along a highly used arterial street. Annual flooding of several businesses and arterial streets southeast of Southgate Mall was identified by City staff, and in the Gilliam Creek Basin Stormwater Basin Plan and the 1993 Surface Water Management Comprehensive Plan. Causes of flooding are inadequate hydraulic capacity in the existing storm drainage systems due to undersized pipes and culverts and /or an accumulation of sediment and debris. Flooding of the Park Place by the Woods Apartment complex, located north of Southcenter Boulevard and between TIB and I -5, was identified in previous basin plans. One flooding incident at this location occurred when vandals clogged the storm drainage pipe inlet. Also, the storm drainage pipe located under the apartment complex is old and believed to be in poor condition. Failure of this privately owned pipe would cause flooding of the apartment complex living areas and adjacent parking lot, and Southcenter Boulevard. Flooding in the residential area, located northeast of the TIB and SR 518 interchange, was identified by City staff. The cause is reported to be damaged and undersized storm drainage systems. Fish Habitat Woody debris and other habitat features in the channel in the lower reach of Gilliam Creek below the crossing of I -5 (which is impassable to fish) have been repeatedly washed away by high flows. This lower reach exhibits sediment deposition that is likely related to the erosion occurring in the steeper portions of the watershed upstream. This reach was also impacted by sediments in runoff from major construction work on I -5 in 1997. A 9 -foot- diameter flap gate and concrete splash pad are located at the mouth of Gilliam Creek at the Green River. The gate renders the mouth impassable to adult fish. Because of the relatively high cost to improve fish habitat on Gilliam Creek, the City has focused its fish habitat enhancement and fish population recovery efforts on Riverton and Southgate Creeks. Until such time that flows are significantly attenuated and stormwater quality is markedly improved, Gilliam Creek will continue to be of limited value for fish and other aquatic organisms. C -12 SEA/032660009 • • CITY OF TUKWILA APPENDIX C- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Water Quality Of all the watercourses in the City, Gilliam Creek is considered to have experienced the greatest degree of alteration due to human influences and watershed development. Although much of its watershed is undeveloped due to steep slopes, the areas that are developed have a significantly adverse effect on water quality and aquatic habitat. As documented in the Gilliam Creek Stormwater Management Plan (Herrera, 2001), untreated runoff from impervious areas has significantly degraded water quality. These areas include numerous arterial streets with intensive traffic usage (including Tukwila International Boulevard) and associated commercial development, parking lots in the Westfield Mall area, and Interstates 5 and 405. High flows from these areas, coupled with steep channel gradients in the upper portion of the watershed, have also caused channel bed and bank erosion. 3.2.4 Nelson Place - Longacres Flooding The 1993 Surface Water Management Comprehensive Plan identified annual flooding in the undeveloped area in the northeast corner of the basin. A network of ditches and culverts drains this area, and flooding occurs because the outlet pipe for this system is undersized. Fish Habitat The riparian corridor of the Green River between Andover Park East and West Valley Highway is significantly altered from its natural condition. Development has encroached upon the riverbanks in many areas, and blackberries and other less desirable tree and shrub species have replaced native riparian vegetation. The riverbanks are lined with riprap in this area (as in many other nearby reaches), and good quality fish habitat is generally lacking. The former alignment of the river, prior to construction of I -405 in 1962, extended through the Nelson farm property and into the Homestead Studio Suites property. Part of that former alignment has been filled, isolating a pond area and reducing off - channel habitat and floodplain connectivity in this reach of the river. Water Quality No water quality problems were identified in this basin. 3.2.5 P17 Flooding Wendy's fast -food restaurant and several other commercial developments located at the intersection of Minkler Boulevard and Southcenter Parkway flood about every 5 years. This problem, identified by City staff, is believed to be due to backwater from a dual culvert crossing at the intersection Minkler Boulevard and Andover Park West. Backwater conditions are a result of insufficient hydraulic capacity. Fish Habitat No fish habitat problems were identified in this basin. Water Quality No water quality problems were identified in this basin. SEA/032660009 C -13 CITY OF TUKWILA APPENDIX CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 3.2.6 Riverton Creek Flooding The Riverton Creek Stormwater Quality Management Plan and the 1993 Surface Water Management Comprehensive Plan identified several areas where flooding of non - arterial streets was observed every 2 to 5 years. The causes of flooding are a combination of undersized culverts and /or culvert blockages and high flows. Culvert blockages are generally a result of accumulations of sediment and /or debris. High flows originate from Tukwila International Boulevard (TIB) and the developed areas upstream from the Boulevard. Fish Habitat Long reaches of the creek are contained within culverts that hinder fish passage. Intensive development in the lower portions of the watershed has also significantly reduced the vegetative buffers along the creek to the extent that the buffers are virtually non - functional. The lower reaches of the east and west forks and the mainstem are lacking in pools and woody debris, which is typically a pool - forming feature of healthy riverine systems. Fish usage of the lower reaches of the Riverton Creek system is severely limited compared to the predeveloped watershed. The upper reach of the east fork of Riverton Creek exhibits good habitat characteristics and has a significant vegetated buffer along much of its length. However, a 20- foot -high concrete spillway within the channel near South 125th Street prevents anadromous salmonids from accessing this habitat. At this time, resident cutthroat trout are the only fish species to make limited use of the upper reaches of this watershed. Water Quality As documented in the Riverton Creek Stormwater Quality Management Plan (Entranco et al., 1997), Riverton Creek exhibits high levels of fecal coliform bacteria, phosphorus, turbidity, total suspended solids, and copper, among other pollutants. Runoff from streets and parking lots is believed to contribute much of the pollutant loading to the creek. Steep, eroding side slopes in roadside ditches in the basin are also contributing to the sediment and phosphorus loading. Sediment loading from areas in the upper watershed is linked to sediment deposition in the lower, flatter reaches of the east and west tributaries of Riverton Creek and the mainstem of the creek downstream of the confluence of the two tributaries. Sediment deposition significantly reduces the conveyance capacity of several culverts, restricts fish passage, and hinders the potential for salmonid spawning in the lower readies. 3.2.7 SE Commercial Business District No flooding, fish habitat, or water quality problems were identified in this basin. 3.2.8 Southgate Creek Flooding The Fostoria Basin Stormwater Quality Management Plan and the 1993 Surface Water Management Comprehensive Plan identified flooding of low -use streets and private property in the reaches of Southgate Creek downstream of Tukwila International Boulevard. Flooding occurs every 2 to 5 years, and like Riverton Creek, the causes are accumulations of C -14 SEA/032660009 • • CITY OF TUKWILA APPENDIX C- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 sediment and /or debris, which reduce the hydraulic capacity. Another contributing cause of flooding in these locations is runoff from TIB and the developed areas upstream. Flooding was also identified in the residential areas upstream of Tukwila International Boulevard. A high groundwater table and inadequate drainage system cause the flooding. Fish Habitat Several long culverts with steep grades and high vertical drops in the channel limit accessibility for fish to much of the stream network. Urban development has also encroached on a significant portion of the natural stream buffer and altered the alignment of several reaches. In addition, the combination of steep channel gradient and uncontrolled stormwater runoff in the south fork of Southgate Creek has resulted in severe bank erosion and channel incision downstream of 40th Avenue S. The eroded material has been deposited in the lower reach of the creek, contributing to reduced culvert capacities and limiting potentially productive coho salmon spawning near the mouth. Water Quality Southgate Creek, which comprises several forks and minor tributaries, exhibits many of the same characteristics as Riverton Creek. As documented in the Fostoria Basin Stormwater Quality Management Plan (Herrera, 1996), the water quality of Southgate Creek is degraded due to high levels of fecal coliform bacteria in basin runoff, and localized reaches exhibit. The desirable range for pH in streams is 6.5 to 8.5. The observed values have been both below and above this range in various areas of the basin and at different times of the year. 4. Capital Improvement Program 4.1 Project Development After the surface water management problems presented in Section 3 were identified, potential remedial projects were developed. Development of potential projects identified in the 1993 Comprehensive Plan, basin plans, and drainage studies were reviewed to help develop potential projects. CH2M HILL, Herrera Environmental Consultants, and City staff met on May 29 and June 6, 2003, to review the list of capital improvement projects (CIPs). The project list was further refined based on discussions at these meetings. Table C -15 in Attachment B presents the project list and planning level costs. Figures C -9 to C -14 in Attachment B show the locations of the CIP projects. Attachment C contains project summary sheets with project scopes, benefits, detailed sketches, and cost estimates for the developed CIP projects. Some of the surface water management problems identified are not readily solved using discrete CIP projects. For example, widespread water quality problems in urban runoff entering Riverton, Southgate, and Gilliam Creeks are difficult to address with capital improvements. The CIP projects presented in this memorandum are primarily focused on rectifying discrete flooding or fish habitat problems. Very few water quality projects have been developed because individual, small-scale runoff treatment system retrofits would not make a significant difference in receiving water quality. It is more appropriate to address SEA/032669009 C -15 CITY OF TUKWILA APPENDIX C-- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN • NOVEMBER 2003 most of these problems with land use or storm water management regulations (for example, requiring water quality treatment for redevelopment projects). The water quality projects that have been developed and are described in this section have taken advantage of most, if not all, of the cost - effective opportunities available for the City to provide significant water quality improvement. The cost of providing regional -scale runoff treatment facilities, likely required in these drainage basins, would be prohibitive, as would numerous small-scale treatment system retrofits. 4.1.2 Projects Under Development Several of the problems identified in Section 3 will be addressed'by projects that are under design or being constructed at the time of this study (see Table C -5). Because these projects are currently being implemented, the scopes and costs are not included. TABLE C -5 Capital Improvement Program, Projects Under Development City of Tukwila Surface Water Management Master Plan CIP Project ID Problem Type Problem No. Project Title 98 -DRO7 Flooding /Erosion R -F1, R -F2, R -F4, S -F1, S -F2, S -F4, S -WQ1 00 -DRO6 Flooding 87 -DRO1 Flooding 86 -DRO1 Flooding 89 -DRO2 00 -DRO5 Flooding 98 -DRO6 Habitat 97 -PK04 Habitat S -F5 S -F6 D -F3, D -F4 D -F5 D -H1 D -H1 Tukwila International Boulevard High -Flow Bypass Cascade View Drainage Improvements Fostoria Drainage — Phases II and III Strander Boulevard and Christensen Road Pipe Replacement Allentown/Foster Point Drainage Systems Codiga Farm Side Channel Codiga Farm Park 4.1.3 Projects Recommended for Removal from the 301 and 412 CIP Lists Several projects in the Fund 301 and 412 lists were not developed for the following reasons: • Project is located on private property. • Alternative solutions are under development (that is, design and construction). • Alternative solutions were developed in this study. These projects are listed in Table C -6. C -16 SEAI032660009 • CITY OF TUKWILA APPENDIX CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE C-6 Projects Recommended for Removal from the Fund 301 and 412 CIP Project No. Fund Project Title Comment 95 -DRO3 412 Gilliam Creek North Fork 01 -DRO7 412 Riverton Basin Regional Detention 00 -DRO8 412 Southgate Basin Regional Detention 00 -DRO9 412 Tukwila Remaining Basin Regional Detention 86 -DR19 412 Gilliam Creek 250 cfs Storm Drain Pump Station Problem is located on private property. Replaced by Tukwila International Boulevard High - Flow Bypass Project (98 -DR07) Replaced by Tukwila International Boulevard High - Flow Bypass Project (98 -DR07) Potential detention facilities identified with individual projects. Replaced by Christensen Road pump station, storm drain retrofit, and connection of Gilliam Creek outfall to the Christensen Road storm drainage system (projects 89 -DR01, 89-DR-02, and 03- DR09). 4.1.4 Related Projects From Other CIP Funds Implementation of the Surface Water CIP projects recommended in this study should be coordinated with projects from other CIP funds such as the Commercial Streets, Sewer, and Water funds. Projects related to the Surface Water CIP projects are listed in Table C -16, Attachment B. Many of the projects listed in other funds include recommendations for storm drainage system improvements. 4.2 Project Selection Criteria and Methodology Typically, the ratio of project cost to monetary value of benefits is the primary method used to rank projects. Secondary and qualitative benefits are sometimes included by applying a factor to the monetary value of benefits. To overcome this shortcoming, a scoring system was developed to evaluate the projects developed in Section 3. Benefit points were assigned to the projects based on the type and severity of the problem addressed and the anticipated benefit. The point system is a powerful tool that allows both qualitative and quantifiable benefits (to which a monetary value may be attributed) to be systematically combined when comparing projects. It also provides the opportunity to weight benefits based on the relative value of each to the City and its residents. Scores were divided into the following categories and projects could receive benefit points in more than one category: • Flooding • Fish habitat • Water quality • Erosion The total project points were totaled and compared to the point totals for other projects. In general, a project would receive more points if it solved a more severe problem and /or SEA/032660009 C -17 CITY OF TUKWILA APPENDIX C CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 more than one type of problem. The scoring for these four categories and how they were developed are described in subsections 4.2.1 through 4.2.4. Attachment D presents the results of the project scoring. CH2M HILL, Herrera Environmental Consultants, and City staff met on June 17, 2003, to review and refine the evaluation criteria. The refined criteria and point system provide the City with a rational method of ranking CIP projects and a means of documenting their ranking process. The total number of points for each project provides an indication of the relative benefits. While the allocation of points is somewhat subjective, the methodology is based on scientific principles, and the results provide a logical basis for ranking projects. The benefit score presented in this memorandum for a CIP is simply an indication of the relative benefit. 4.2.1 Flooding CIP projects intended to alleviate flooding problems were divided into the following two types: • Roadway flooding • Property flooding Benefit points were given to projects based on the type of problems the projects addressed. The categories used to evaluate projects that addressed road flooding were: • The type of road being flooded • The depth of flooding Categories used to evaluate projects that addressed private property flooding were: • The number of properties affected by flooding • The type of property (commercial or residential) affected by the flooding Projects that provided solutions to both types of flooding received points for both. Benefit points for road flooding and property flooding were summed, and a multiplier for the estimated frequency of flooding was applied. This process provides a good basis for determining the relative benefits of flooding projects, but it does not include an assessment of risk of failure. The latter is an important " consideration when attempting to integrate City revenues with the CIP implementation strategy. All else being equal, a CIP where the damages would not increase significantly should there be a complete failure of the problem would have a lower priority than a CIP where failure is imminent and such failure would significantly increase damages. To provide a logical method for including this important consideration, the benefit (or damage) score was determined assuming a complete failure of the drainage system component. The difference between the points assuming complete failure and the points for current conditions provides an indication of the increase in damage should implementation of the CIP be delayed to the extent that failure occurs. A factor representing the likelihood of failure was then applied to the difference in points and added to the accumulated benefit C -18 SEA/032660009 • • CITY OF TUKWILA APPENDIX C-- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 score. Thus, a CIP would receive a significantly higher benefit score if there is a risk of an imminent failure that would markedly increase damages. 42.2 Fish Habitat CIP projects intended to enhance fish habitat were divided into the following two types: • Stream habitat improvements • Fish passage improvements Some of the habitat improvement projects included in this plan incorporate both stream habitat and fish passage components. Stream Habitat Improvements Stream habitat improvement projects were given benefit points for the following types of habitat improvements that would be provided: • Enhance riparian buffer • Create rearing pools • Provide spawning gravel • Provide large woody debris • Provide off - channel or side channel rearing habitat. Additionally, projects were given higher benefit points if endangered species, such as salmonids, are present in the affected water body. Benefit points for the type of habitat improvement and fish presence were summed, and a multiplier, based on the length of stream reach that would be improved, was applied. Fish Passage Improvements Benefit points were assigned to projects that would provide for improved fish passage in a stream. Greater points were assigned if the project would remove a complete fish passage barrier as opposed to improving upon a partial barrier. This difference recognizes the significance (greater value) of opening up a complete barrier to fish passage. Benefit points were also assigned based on the length of upstream habitat that would be made accessible to fish upon removal of the passage barrier. Greater points were assigned for projects that would make a greater length of upstream habitat accessible. 4.2.3 Water Quality CIP projects intended to improve water quality conditions were given points based on the following criteria: • Type of water body affected • Relative effectiveness of the proposed improvement Greater points were assigned to projects that would improve water quality in a stream than one that would improve the water quality of a pond or wetland. Projects that would improve water quality conditions in the Green and Duwamish Rivers were assigned the SEN032660009 C -19 CITY OF TUKWILA APPENDIX C- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 least amount of benefit points in this scoring category because any localized improvements by the City are not considered to provide a substantial difference in river water quality. Benefit points were assigned to a project if it would result in a significant improvement in water quality for any of the water bodies described above. Projects that would result in moderate water quality improvements were assigned fewer points. 4.2.4 Erosion CIP projects intended to address erosion problems were assigned benefit points based on the following criteria: • Project would repair an erosion problem due to sheet flow from a roadside area or other upland location • Project would repair an erosion problem caused by concentrated flow at a pipe outfall More points were allocated to projects that alleviate erosion caused by concentrated flow because, generally, concentrated flow from a pipe will cause more severe erosion problems than sheet flow from a road or upland area. Additional benefit points were assigned to erosion projects that would result in significant improvements to downstream water quality or stream channel condition versus moderate benefits to downstream water quality or stream channel condition. 4.2.5 Risk of Failure Analysis Evaluation of flooding projects included a risk of failure analysis. This analysis is described in detail in subsection 4.2.1. The evaluation of projects that address habitat, erosion, and /or water quality problems did not include a risk of failure analysis because the corresponding problems are not likely to degrade to a point that requires an immediate solution if left unattended. None of these types of problems is linked to infrastructure failure or other human safety issues. Although continuation of the existing problem condition is a concern for aquatic habitat degradation or other environmental impacts, the extent of the problem would likely be similar in the future if the CIP project were not constructed. 4.3 Capital Improvement Program Recommendations 4.3.1 Project Ranking Project rankings were given to the projects according to a cost -to- benefit point ratio. The project with the lowest cost -to- benefit ratio is ranked the highest. Table C -7 summarizes the ranking of storm drainage CIP projects that solve local problems in the City. Table C -8 summarizes the ranking of CIP projects that improve fish habitat. C -20 SEN032660009 • • CITY OF TUKWILA APPENDIX CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE C -7 Prioritized Flooding and Water Quality CIP Projects — 412 Fund Cost Benefit Project Rank Points ID Basin Project Title Benefit Project Points Cost Summary of Storm Drainage CIP Projects 1 $637.50 03 -DR12 Southgate Southgate Creek Streambank Stabilization 80 $51,000 2 $1,057.14 94 -DR05A Duwamish Duwamish Riverbank Stabilization I(a) 70 $74,000 3 $1,627.91 03 -DR09 Gilliam Gilliam Creek/Christensen Road Storm Drain 172 $280,000 System Connection 4 $2,610.47 86 -DR17 Gilliam Andover Park W 48 -inch Drain Rehabilitation 172 $449,000 Gilliam Creek 42 Ave S Culvert 5 $2,642.86 93 -DR08 Gilliam 7 $4,722.22 03 -DR08 P -17 8 $6,875.00 Duwamish Riverbarik`Stabdlzational, 112 Minkler Boulevard Culvert Replacement 03 -DR04 Southgate S. 146th Street Pipe and 35th Avenue S Drainage System 10 $8,500.00 94 -DR05B Duwamish 11 $9,462.50 86 -DR22 Duwamish 12 $10,630.77 03 -DR06 Gilliam 13 $12,000.00 03 -DR01 Duwamish 14 $14,625.00 00 -DR10 Gilliam 15 $16,571.43 03 -DR05 Gilliam 17 19 $27,181.82 $90,666.67 Duwamish Riverbank Stabilization I(b) S 143 Street Storm Drain System Northwest Gilliam Storm Drainage System 53rd Avenue S. Storm Drain System Gilliam Creek Regional Detention Pond Tukwila Parkway Drainage from Westfield Mall to Gilliam Creek 98 -DR07 Riverton Treatment Facilities for Tukwila International Boulevard Bypass. 87 -DR02 Nelson Nelson PI /Longacres Interceptor Pipe Place/Long acres g0 $296,000 $425,000 80 $550,000 70 $595,000 80 $757,000 130 $1,382,000 80 $960,000 112 $1,638,000 14 $232,000 22 $598,000 6 $544,000 NOTE: Highlighted rows indicate inactive projects. See Section 4.3.2. SEA/032660009 C -21 CITY OF TUKWILA APPENDIX C-- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE C -8 Prioritized Habitat -Only CIP Projects - 301 Fund 1 $1,296.05 2 $1,643.94 3 $2,200.00 4 $2,325.58 03 -DR10 Riverton Riverton Creek Upper Watershed 03 -DR21 Southgate Southgate Creek Habitat Restoration 03 -DR13 Southgate Southgate Creek Daylighting at S. 133rd Street 98 -DRO3 Riverton Riverton Side Channel 7 $4,243.42 1, LowerGilliarn Creek Channel Improve' i ents Southgate Cree ,Salmon: Habitat Restoratio Do'.Wwstream S. 133rd 03 -DR19 Nelson Nelson Salmon Habitat Side Channel Place /Long acres 8 $5,166.67 03 -DR20 Duwamish Golf Course Riverbank 9 $13,500.00 98 -DRO5 Gilliam Gilliam Creek Fish Barrier Removal 152 $197,000 132 $217,000 115 $253,000 129 $300,000 152 $645,000 84 $434,000 50 $675,000 t. $127,937 50rr_ 3 DR 4 ,Tukwila Pond Improvements ftAZ 2;047,000; . NOTE: Highlighted rows indicate inactive projects. See Section 4.3.2. 4.3.2 Inactive Projects Several projects that were included in the cost - benefit analysis are recommended for inclusion on an "inactive list" of CIP projects because of one or more of the following reasons: • The City does not consider the project to be a high - priority project given its location or the extent of a problem it would address. • The benefits would be marginal if other recommended nearby CIP projects are constructed. • The project requires more analysis with respect to other considerations. These projects are highlighted in Tables C -7 and C -8. 4.4 Capital Improvement Program Funding The projects recommended in this study will be funded by the City's Surface Water Management Fund. Revenue for this fund comes from utility fees and sales, property, and utility taxes. Collection of revenue, assignment of funds for the Surface Water CIP, and other CIP policies are discussed in detail in the City's Financial Planning Model and Capital Improvement Program report (published annually). 5. References City of Tukwila. Adopted 2003 -2008 Financial Planning Model and Capital Improvement Program. December 16, 2002. C -22 SEA1032660009 • • CITY OF TUKWILA APPENDIX C- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 City of Tukwila webpage. http: / /www.ci.tukwila.wa.us Entranco. Riverton Creek Stormwater Quality Management Plan. November 1997. Herrera Environmental Consultants. Fostoria Basin Stormwater Quality Management Plan. March 1996. Herrera Environmental Consultants. Gilliam Creek Basin Stormwater Management Plan. March 2001. KCM, Inc. Nelson Place - Longacres Way Storm Drainage System Preliminary Design. June 1988. KCM, Inc. Surface Water Management Comprehensive Plan, Final Report. July 1993. Perteet Engineering, Inc. Southgate Creek By -Pass Study, Southgate Creek and Riverton Drainage Basins. September 1997. Perteet Engineering, Inc. Gilliam Creek Detention and Water Quality Enhancements. October 1994. • • Attachment A Surface Water Management Issues • City of Tukwila Surface Water Management Compr Plan Table C -9 - SUMMARY OF DUWAMISH RIVER MAINSTEM SURFACE WATER MANAGEMENT ISSUES ID Project Location Source Problem Type Problem Description D -F1 Southgate Creek at S. 143rd Street City of Tukwila Public Works Flooding No drainage system on S 143rd Street. D -F2 53rd Avenue South between S 137th St and S 144th St City of Tukwila Public Works Flooding Existing conveyance system has inadequate capacity. D -F3 Strander Blvd near Andover. Park E Gilliam Creek Basin Stormwater Management Plan, March 2001, by Herrera (Project D5) Flooding Existing drainage system has inadequate capacity. 1993 Surface Water Management Comprehensive Plan (Project G1) D -F4 James Christensen Rd Gilliam Creek Basin Stormwater Management Plan, March 2001, by Herrera (Project D6) Flooding Localized flooding - . 1993 Surface Water Management Comprehensive Plan (Project G3) D -F5 Allentown and Foster Point Areas ! 1993 Surface Water Management Comprehensive Plan (Projects FD1, FD2) Flooding Existing drainage system has inadequate capacity. D -WQ1 Duwamish River right (east) bank at S. 104th St. City of Tukwila Public Works Water Quality Riverbank is eroding, causing failure of the road shoulder and degrading local habitat in the river. D -WQ2 Duwamish River right bank adjacent to S 115 St between 42 Ave S & East Marginal Way S and adjacent to 42nd Ave S from S 115 St to Interurban Ave S. City of Tukwila Public Works Water Quality Riverbank is eroding, causing failure of the road shoulder and degrading local habitat in the river. D -H1 Duwamish River bank adjacent to Foster Golf Links City of Tukwila Public Works Habitat Invasive vegetation on the riverbank degrades riparian habitat quality SEA310016517.xls/032160004.xds 0-27 11/17/2003 City of Tukwila Surface Water Management Comprehensive Plan Table C -10 - SUMMARY OF GILLIAM CREEK SURFACE WATER MANAGEMENT ISSUES ID Project Location Source Problem Type Problem Description G -F1 Andover Park W Gilliam Creek Basin Stormwater Management Plan, March 2001, by Herrera (Project D3) Flooding Existing storm drain system has been damaged. 1993 Surface Water Management Comprehensive Plan (Project G2) G -F2 North of Southcenter Blvd. and east of 42nd Ave S Gilliam Creek Basin Stormwater Management Plan, March 2001, by Herrera (Project D4) Flooding/Water Quality Erosion and flooding in downstream drainage system. 1993 Surface Water Management Comprehensive Plan (Project C2) G -F5 Gilliam Creek crossing at 42nd Ave SE (between S 154th St and HWY 518) 1993 Surface Water Management Comprehensive Plan (Project C1) _ Flooding Existing culvert has inadequate capacity., G -F6 Tukwila Parkway at northwest Southcenter Mali access City of Tukwila Public Works Flooding Outlet pipe for Southcenter Mall Drainage System has a reverse slope. G -F7 From 42nd Av. S. to Tukwila International Boulevard S. 146th St, S. 148th St., S. 150th St., S. 152nd St. City of Tukwila Public Works Flooding Existing storm drainage system has inadequate capacity resulting in road and private property flooding. G -F8 Andover Park W. and Tukwila Parkway City of Tukwila Public Works Flooding ROW flooding in the area of Tukwila Parkway, Andover Park W, Andover Park E, and Strander Boulevard during large storm events. G -FH1 Outlet of Gilliam Creek to Green River Gilliam Creek Basin Stormwater Management Plan, March 2001, by Herrera (Project H2) Flooding/Habitat Flap gates are fish barriers. Flap gates close during when the Green River is at high levels causing flooding in Gilliam Creek. 1993 Surface Water Management Comprehensive Plan (Project G3) G -WQ1 Basinwide, particularly in vicinity of Tukwila Intemational Boulevard and Southcenter Mall Gilliam Creek Basin Stormwater Management Plan, March 2001, by Herrera Water Quality High levels of pollutants in basin runoff - notably fecal coliform bacteria throughout the basin, and copper and zinc in runoff from the Tukwila Intl Blvd. area are degrading water quality in Gilliam Creek G -H1 Along Tukwila Parkway between 1 -5 culvert and outfall to Green River Gilliam Creek Basin Stormwater Management Plan, March 2001, by Herrera (Project H3) Habitat Lack of habitat diversity and riparian vegetation G -H2 South of S 154th St near 52nd Ave S intersection Gilliam Creek Basin Stormwater Management Plan, March 2001, by Herrera (Project H5) Habitat Lack of riparian vegetation S EA310016517. xl s/032160004. xI s 11/17/200 C -28 • City of Tukwila Surface Water Management Compr lie Plan Table C -11 - SUMMARY OF NELSON PLACE/LONGACRES SURFACE WATER MANAGEMENT ISSUES ID Project Location Source Problem Type Problem Description N -F1 Area bounded by State HWY 181 , Green River, Burlington Northern RR, and Strander Blvd. 1993 Surface Water Management Comprehensive Plan (Project N1) Flooding Existing drainage system does not have a functional outlet. N -H1 Nelson farm property between Green River and W. Valley Hwy City of Tukwila Public Works Habitat Former river channel/oxbow has been blocked off by levee and upland fill, reducing off- channel habitat quality and floodplain connectivity in this reach of the river. SEA31 001 651 7.xls/032160004.xls C -29 11/17/2003 City of Tukwila Surface Water Management Comprehensive Plan Table C -12 - SUMMARY OF P -17 SURFACE WATER MANAGEMENT ISSUES ID Project Location Source Problem Type Problem Description P -F1 Intersection Minkler Blvd and Andover Park W City of Tukwila Public Works . Flooding Undersized culvert on Minkler that causes water to back up on to Southcenter Pkwy and floods Wendy's through a 66 -inch diameter pipe. P -WQ1 Tukwila Pond City of Tukwila Public Works Water Quality Water in Tukwila Pond is stagnant and warm in summer months, and likely degraded due to inflow from surrounding urban land uses. SEA310016517.x1s/032160004.xls C -30 11/17/200 • • City of Tukwila Surface Water Management Comore Plan Table C -13 - SUMMARY OF RIVERTON CREEK SURFACE WATER MANAGEMENT ISSUES ID Project Location Source Problem Type Problem Description R -F1 Riverton Creek Crossing at S. 128th St. and S. 126th St Riverton Creek Stormwater Quality Management Plan, November 1997, by Entranco (Project 4) Flooding Existing drainage system has inadequate capacity for future land -use conditions. 1993 Surface Water Management Comprehensive Plan (Projects CAV7, CAV8, CAV9) R -F2 Pacific Hwy S. Riverton Creek Stormwater Quality Management Plan, November 1997, by Entranco (Project 5) Flooding/Water Quality Erosion and flooding in Riverton Creek R -F4 South of Pacific Highway S and SR -599 intersection Riverton Creek Stormwater Quality Management Plan, November 1997, by Entranco (Project 8) Flooding/Water Quality Erosion and flooding in Riverton Creek R -WQ1 Multiple locations in the basin Riverton Creek Stormwater Quality Management Plan, November 1997, by Entranco Water Quality High levels of pollutants in basin runoff - notably fecal coliform bacteria throughout the basin. phosphorus. turbidity and R -H1 Riverton outfall into Duwamish River Riverton Creek Stormwater Quality Management Plan, November 1997, by Entranco (Project 1) Habitat Outfall is a partial fish passage barrier R -H3 Upstream of Tukwila International Blvd in ravine City of Tukwila Public Works Habitat/Water Quality Streambank is eroding, contributing to downstream water quality and instream habitat degradation SEA310016517.xls/032160004.xis 11/17/2003 C -31 City of Tukwila Surface Water Management Comprehensive Plan Table C -14 - SUMMARY OF SOUTHGATE CREEK SURFACE WATER MANAGEMENT ISSUES ID Project Location Source Problem Type Problem Description S -F1 SR -599 south of Southgate Creek crossing Fostoria Basin Stormwater Quality Management Plan, March 1996, by Herrera (Project 15) Flooding Existing drainage system has inadequate capacity. 1993 Surface Water Management Comprehensive Plan (Project F8) S -F2 Pacific HWY Fostoria Basin Stormwater Quality Management Plan, March 1996, by Herrera (Project 17) Flooding Flooding and erosion in Southgate Creek Riverton Creek Stormwater Quality Management Plan, November 1997, by Entranco (Projects 5, 8) 1993 Surface Water Management Comprehensive Plan (Project CAV1) Existing drainage system has inadequate capacity. S -F3 S 146th St between Military Road S and Pacific HWY S Gilliam Creek Basin Stormwater Management Plan, March 2001, by Herrera (Project D10) Flooding Existing drainage system has inadequate capacity for future land -use conditions. 1993 Surface Water Management Comprehensive Plan (Project CAV2) S -F4 S 133rd St, west of intersection with S 134th St (Central Drain) Fostoria Basin Stormwater Quality Management Plan, March 1996, by Herrera (Project 2) Flooding Flooding in existing channel S -F5 Vicinity of Pacific Highway South and S 140th Street City of Tukwila Public Works Flooding Residential flooding from high groundwater and inadequate drainage systems. S -F6 S 134 St east of S 133rd St City of Tukwila Public Works Flooding Flooding and ponding along S. 134th Street S -WQ1 South Fork Southgate Creek between 40th Ave S and S 133rd St Fostoria Basin Stormwater Quality Management Plan, March 1996, by Herrera (Project 11a) Water Quality Erosion and sedimentation in existing channel. 1993 Surface Water Management Comprehensive Plan (Project F3) S -WQ2 South Fork Southgate Creek crossing at Pacific HWY Fostoria Basin Stormwater Quality Management Plan, March 1996, by Herrera (Project 11b) Water Quality Erosion of hillside downstream of the crossing S -H1 Culvert crossing S. 133rd Street City of Tukwila Public Works Habitat Culvert is likely a fish passage barrier much of the time and also requires frequent removal of sediment/gravel accumulation at upstream end S -FH1 Southgate Creek between S 133rd Place and SR -599. Fostoria Basin Stormwater Quality Management Plan, March 1996, by Herrera (Project 14) Flooding/Habitat Existing channel is overgrown with reed canary grass resulting in reduced hydraulic capacity. S EA310016517. xl s/032160004. xl s 11/17/2003 • C -32 • • Lake Washington Stormwater Problems Drainage Course AI Freeway N Roads *Water Quality *Flooding Flooding/Water Quality *Habitat • Flooding /Habitat 0 600 1,200 Feet Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -3 Surface Water Management Issues Duwamish River Basin City of Tukwila Comprehensive Surface Water Management Plan 3 a 1 i S 137 St Sunwo S152St S152`� ..� S 1524 • S 156 St S 158 S 160 St rn Q S162 Laker Blvd Saxon Dr S 180 St Stormwater Problems'■•Drainage Course Freeway Roads *Water Quality *Flooding • Flooding/Water Quality *Habitat • Flooding /Habitat 0 1,200 2,400 Feet Data shown in this map are in Washington State Plane North, NAD 1983 ee Park DGtr Figure C -4 Surface Water Management Issues Gilliam Creek Basin . City of Tukwila Comprehensive Surface Water Management Plan • • Stormwater Problems ••Drainage Course *Water Quality Freeway Roads *Flooding •Flooding/Water Quality *Habitat • Flooding /Habitat I r 1 0 300 600 Feet Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -5 Surface Water Management Issues Nelson Place /Longacres Basin City of Tukwila Comprehensive Surface Water Management Plan W Baker Blvd Stormwater Problems' -Drainage Course **Freeway Roads *Water Quality *Flooding •Flooding/Water Quality *Habitat • Flooding /Habitat 0 900 1,800 Feet Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -6 Surface Water Management Issues P17 Basin City of Tukwila Comprehensive Surface Water Management Plan S 113 St S 114 St King County Stormwater Problems'•■•Drainage Course Freeway Roads *Water Quality *Flooding ® Flooding/Water Quality *Habitat • Flooding /Habitat 0 600 1,200 Feet Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -7 Surface Water Management Issues Riverton Creek Basin City of Tukwila Comprehensive Surface Water Management Plan S 124 St S 128 St S 128 St DS 1,3S)� S -WQ2 S 136 St —m 0 137 St u, S139St _140SL, 140 St _5_142 S 42 St S 146 St 5 145 St 148 St S 152 St Stormwater Problems'•.Drainage Course Freeway ti Roads * Water Quality * Flooding * Habitat Flooding /Habitat t � I 0 600 1,200 Feet Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -8 Surface Water Management Issues Southgate Creek Basin City of Tukwila Comprehensive Surface Water Management Plan • Attachment B CIP Projects • • City of Tukwila Surface Water Management Comore• Plan Table C -15 - Capital Improvement Program City of Tukwila Surface Water Management Comprehensive Plan CIP Project ID Problem Type Problem No. Frequency' Location Ownership Private Property Property Flooding Project Title Project Cost Public Property Duwamish River Mainstem 86 -DR22 flooding F -F1 2 S 143 Street east of the intersection with Interurban Avenue S X X X S 143 Street Storm Drain System $ 757,000 03 -DR01 flooding F -F2 3 S 153rd Street between S. 144th and S 137th Street 53rd Avenue S. Storm Drain System $ 960,000 94 -DR05A erosion/ water quality D -E1 Duwamish River right (east) bank at S 104th Street and East Marginal Way X Duwamish Riverbank Stabilization la ' $ 74,000 94 -DR05B erosion/ water quality D -E1 Duwamish River right (east) bank at S 104th Street and East Marginal Way X Duwamish Riverbank Stabilization lb $ 595,000 94 -DR09 erosion/ water quality D -E2 Duwamish River right bank adjacent to S 115 St between 42 Ave S & East Marginal Way S and adjacent to 42nd Ave S from S 115 St to Interurban Ave S. X X ?? Duwamish Riverbank Stabilization II $ 285,000 03 -DR20 habitat D -H1 Duwamish River bank adjacent to Foster Golf Unks X Golf Course Riverbank $ 434,000 Gilliam Creek 03 -DR09 flooding G -FH1 3 Gilliam Creek Overflow at Strander Boulevard X Gilliam Creek/Christensen Road Storm Drain System Connection $ 280,000 86 -DR17 flooding G -F1 4 Andover Park W, South of Tukwila Parkway X Andover Park W 48 -inch Drain Rehabilitation $ 449,000 00 -DR10 fiooding/wa ter quality G -F2 3 Gilliam Creek Downstream of S 154th Street Crossing X - X X Gilliam Creek Regional Detention Pond $ 1,638,000 93 -DR08 flooding G -F5 2 Gilliam Creek Crossing at 42nd Avenue S X X Gilliam Creek 42 Ave S Culvert $ 296,000 03 -DR05 flooding G -F6 4 Tukwila Parkway at Northwest Southcenter Mall Access X X Tukwila Parkway Drainage from Westfield Mall to Gilliam Creek $ 232,000 03 -DR06 flooding G -F7 1 From 42nd Av. S. to Tukwila international Boulevard S. 146th St, S. 148th St., S. 150th St., S. 152nd St. X X Northwest Gilliam Storm Drainage System $ 1,382,000 S EA310016518. xl s/032160005. xl s C -41 11/17/2003 City of Tukwila Surface Water Management Comprehensive Plan Table C -15 - Capital Improvement Program City of Tukwila Surface Water Management Comprehensive Plan CIP Project ID Problem Type Problem No. Frequency' Location Ownership Property Flooding Project Title Project Cost Public Property Private Properly 98 -DRO5 habitat G -FH1 Outlet of Gilliam Creek to Green River X Gilliam Creek Fish Barrier Removal $ 675,000 03 -DR17 water quality G -WQ1 Gilliam Creek northwest tributary near SR 518 right -of -way and/or undeveloped parcels at south end of 40th Ave S. WSDOT possibly other private ownership Treatment Pond for Gilliam Creek Northwest Tributary $ 274,000 03 -DR15 water quality / flooding G -WQ1 Between 51st Ave S and 52nd Ave S, north of S 154th St (vacant property for sale) X Retrofit Stormwater Treatment and/or Detention Pond for Runoff from 51st Ave S. $ 1,009,000 03 -DR16 habitat G -H1 Along Tukwila Parkway between Andover Park W and outfall to Green River X Lower Gilliam Creek Channel Improvements $ 248,000 03 -DR18 water quality G -W02 Tukwila Pond X Tukwila Pond Improvements $ 2,047,000 Nelson Place - Longacres 87 -DRO2 flooding N -F1 3 Vicinity of SW Grady Way and the Interurban Trail X X X Nelson PVLongacres Interceptor Pipe $ 544,000 03 -DR19 habitat N -H1 Green River upstream from 1 -405 X X Nelson Salmon Habitat Side Channel $ 645,000 P -17 03 -DRO8 flooding P -F1 3 Intersection of Minkler Boulevard and Andover Park E X X Minkler Boulevard Culvert Replacement $ 425,000 Riverton Creek 98 -DRO3 habitat R -H1 Mouth of Riverton Creek at Duwamish River WSDOT Riverton Side Channel $ 300,000 03 -DR10 habitat / _ water quality R -H3 Riverton Creek upstream of Hwy 99 Highline Hospital Riverton Creek Upper Watershed $ 197,000 98 -DR07 water quality R -WQ1 Tukwila International Blvd. From S 138th St to Duwamish River X Treatment Facilities for TIB Bypass $ 598,000 03 -DR11 water quality/ habitat R -WQ1, R -H3 Riverton Creek downstream of Tukwila Intemational Boulevard X Property Acquisition for Riverton Creek Sediment Trap $ 425,000 SE CBD None Southgate Creek - 03- DR04 flooding S -F3 3 S. 146th Street between Military Rd S and Tukwila International Blvd. X X S 146th Street Pipe and 35th Avenue S Drainage System $ 550,000 03 -DR12 habitat / water quality (erosion) S -E1 Southgate Creek Park to Robinson property X Southgate Creek Streambank Stabilization $ 51,000 S E A310 01651$. xl s /0321600 05. x l s C -42 • 7/2003 City of Tukwila Surface Water Management Compr Plan Table C -15 - Capital Improvement Program City of Tukwila Surface Water Management Comprehensive Plan CIP Project ID Problem Type Problem No. Frequency Location Ownership Property Flooding Project Title Project Cost Public Property Private Property 03 -DR21 habitat S -E1 Southgate Creek from Scanlon property to S 133rd St. X Southgate Creek Habitat Restoration $ 217,000 03 -DR13 habitat S -FH1 Southgate Creek adjacent to S. 133rd St. X Southgate Creek Daylighting at 5 133rd Street $ 253,000 Small Drainage Projects Studies 03 -DR21 I I (City Wide 1 1 I 'Low Impact Development Study 1 $ 25,000 1. Flooding Ranking System: 1: Annual Flooding 2: Flooding every 2 -5 years 3: Flooding frequency greater than 5 years 4.. Reduced system capacity from sediment buildup. Potential flooding problem. S EA310016518.rds/032160005.xls C -43 11/17/2003 City of Tukwila Surface Water Management Comprehensive Plan • Table C -16 - Related Projects from the Other CIP Funds City of Tukwila Surface Water Management Master Plan Surface Water /Habitat Projects (Funds 301 and 412) Related Commercial Streets Projects Fund 104/102) Related Water Projects (Fund 403/01) Related Sewer Projects (Fund 403/02) CIP Project ID Fund Location Project Title CIP Project) ID Project Title CIP Project ID Project Title CIP Project ID Project Title Duwamish River Mainstem 86 -DR22 412 S 143 P1 east of the intersection with Interurban Avenue S S 143 Street Storm Drain System 84 -RW25 S. 143rd Street (Interurban Duwamish) 84 -WTO7 Moule Avenue /Interurban Avenue S. Water Main -none - Gilliam Creek 03 -DRO9 412 Gilliam Creek Overflow at Strander Boulevard Gilliam Creek/ Christensen Road Storm Drain System Connection -none- -none- -none- 86 -DR17 412 Andover Park W, South of Tukwila Parkway Andover Park W 48 -inch Drain Rehabilitation 88 -RWO4 Andover Park West (Tukwila Parkway to Strander Boulevard) 98 -WTO5 Andover Park W New Water Main 97 -SW05 Gravity Sewer Under 1-405 to Tukwila Parkway 97 -SW06 Andover Park W. Sewer Main Capacity Upgrade Nelson -Long Acres -none - P -17 -none - Riverton Creek -none - SE CBD -none - Southgate Creek 03 -DRO4 412 S. 146th Street between Military Rd S and Pacific HWY S. S. 146th Street Pipe Replacement 91 -RWO3 Tukwila International Boulevard Phase I -none- -none - SEA319b16518.xls/032160005.xls •7/2003 8 8 Stormwater CIPs *Water Quality R Flooding ® Flooding/Water Quality *Habitat ® Flooding/Habitat Water Quality /Habitat .Drainage Course AP Freeway N Roads 0 0.25 0.5 Miles Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -9 Capital Improvement Projects Duwamish River Basin City of Tukwila Comprehensive Surface Water Management Plan Stormwater CIPs'∎.Drainage Course **Freeway *1 Water Quality s, Roads * Flooding * Habitat 0 900 1,800 Feet Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -10 Capital Improvement Projects Gilliam Creek Basin City of Tukwila Comprehensive Surface Water Management Plan Stormwater CIPs *Water Quality * Flooding O Flooding/Water Quality *Habitat ',Flooding/Habitat • Water Quality/Habitat •••Drainage Course 411Freeway Roads 0 300 600 Feet Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -11 Capital Improvement Projects Nelson Place /Longacres Basin City of Tukwila Comprehensive Surface Water Management Plan 8 8 Upland Dr Midland Dr Triland Dr S 180 St Stormwater CIPs *Water Quality *Flooding ®Flooding/Water Quality *Habitat Flooding /Habitat •Water Quality /Habitat — Drainage Course 411 Freeway Roads 0 900 1 1,800 Feet Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -12 Capital Improvement Projects P17 Basin City of Tukwila Comprehensive Surface Water Management Plan 8 a P. Stormwater CIPs *Water Quality *Flooding i Flooding/Water Quality *Habitat Flooding/Habitat •Water Quality/Habitat — Drainage Course AO Freeway "/ Roads I � l 0 900 1,800 Feet Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -13 Capital Improvement Projects Riverton Creek Basin City of Tukwila Comprehensive Surface Water Management Plan 03 -DR12 135 St > Stormwater CIPs *Water Quality *Flooding ® Flooding/Water Quality *Habitat Flooding/Habitat • Water Quality /Habitat ...Drainage Course 41111 Freeway Roads 0 0.25 0.5 Miles Data shown in this map are in Washington State Plane North, NAD 1983 Figure C -14 Capital Improvement Projects Southgate Creek Basin City of Tukwila Comprehensive Surface Water Management Plan • Attachment C Project Summaries and Cost Estimates • • ATTACHMENT C Project Summaries and Cost Estimates • This attachment contains'project summary sheets for the Capital Improvement Program (CIP) projects that were developed for the City of Tukwila Comprehensive Surface Water Management Plan. The sheets provide planning level design and cost information for all the CIP projects described in Section 4 of the technical memorandum. Each project summary sheet contains a project summary, a sketch of the associated improvements, and a cost estimate. The sheets are numbered in the upper right corner to match the project IDs in Section 4. The first set of numbers in the ID indicate the year the project was initially developed; "DR" indicates that it is a drainage /surface water project; and the second set of numbers is the ID number for that particular year. The projects in this attachment are grouped by year. The cost estimates for several of the CIP projects described in this attachment were updated based on estimates presented in previous plans. Several of the habitat project costs are based on the City's recent construction project experience, and some are based on preliminary cost estimates developed jointly by the City and the U.S. Army Corps of Engineers for which detailed backup information is not available. Itemized cost estimates were not prepared for these projects. For the CIP projects that do not have itemized cost estimates, notes on those summary sheets indicate the basis for the project cost estimate. Cost estimates for projects that were previously prepared and documented in a basin plan or other City report were updated to 2003 dollars, and in some cases re- estimated for consistency to incorporate construction unit prices used for the other CIP cost estimates documented here. Projects with itemized cost estimates use unit costs based on Puget Sound bid tabs and CH2M HILL experience in the area. The unit costs are appropriate for common applications and are quantity sensitive. They should, therefore, be assessed and adjusted as necessary before applying them to any CIP projects developed separately from this plan. Property acquisition costs associated with project implementation were based on assessed property values from the Planning Map on King County's "iMap" web page. The adjusted costs (land only) listed in the individual cost estimate include a 20 percent markup to adjust for market values, a 20 percent markup to adjust for condemnation values, and a $7,000 administrative fee. It is assumed that the City will not have to purchase storm drainage easements associated with project implementation from private property owners. The City will negotiate with land owners to acquire these easements. Costs associated with acquiring storm drainage easements are not included in the cost estimates. Conveyance pipe, ditch, and detention pipe sizes specified in the projects are based on field observations of existing drainage systems and engineering judgement. Hydrologic and hydraulic calculations should be included in the final design of these projects. A material contingency (usually 15 percent) was added to the cost in order to take the lack of SEN032660009 C -53 CITY OF TUKWILA APPENDIX C- CAPITAL IMPROVEMENT PROJECTS COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN . NOVEMBER 2003 calculations into account. This contingency should be revised as additional analysis is provided for individual projects. Detailed geotechnical investigations, survey, utility locates, and field inspections were not performed during the development of the project scopes. A 15 percent contingency is used to account for "unknowns" during construction, such as soil condition, time of construction, lack of detailed survey, etc. As with the materials contingency, this contingency should be adjusted as project designs are finalized. C -54 SEA/032660009 • • • 86 -DR17 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: Andover Park W. 48 -inch Drain Rehabilitation DESCRIPTION: Line Item: Project No: 86 -DR17 Clean sediment from approximately 2,000 LF existing 48" diameter pipe from Strander Boulevard to Tukwila Boulevard. Relocate the system outfall further to the east in order to provide an outlet with positive drainage to Gilliam Creek. JUSTIFICATION: Reduces potential for flooding along Andover Park W. by increasing the hydraulic capacity of the storm drainage system and providing a positive slope at the system outlet. Reduces maintenance requirements for the storm drainage system. STATUS: MAINT. IMPACT: COMMENTS: Final design should be coordinated with WSDOT widening of I- 405. The Corps of Engineers is planning improvements to lower Gilliam Creek. This project may be included with the Corp's plans along with projects 98 -DR05, 03 -DRO5 and 03 -DR16. PROJECT MANAGER: ESTIMATED COST: $449,000 1986- DR17.DOC Project Summary Sheet 1 OF 3 September 2003 86 -DR17 Tukwila Surface Water Management Comprehensive Plan Project Sketch Andover Park W. 48 -inch Drain Rehabilitation Clean Sediment Out of Existing Pipe from Strander Blvd to Tukwila Parkway 170170.TS01 W092001OO61EA. /13.13R17 man a ht 011,0113.or Project Summary Sheet September 2003 2 of 3 1986- DR17.DOC • 86 -DR17 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate Andover Park W. 48 -inch Drain Rehabilitation Item Unit Quantity Unit Cost Amount CATCH BASINS, AND INLETS CATCH BASIN TYPE 2 48 " -54" EA 4 $3,780.00 $15,120.00 EXCAVATION TRENCH SAFETY SYSTEM SF 4200 $0.80 $3,360.00 MISC ITEMS TEMPORARY BYPASS LS 1 $5,000.00 $5,000.00 MISC ITEMS - Project Specific CLEAN SEDIMENT FROM EXISTING 48 -INCH DIAMETER PIPE LS 1 $9,240.00 $9,240.00 PIPES IN PAVED AREAS CORROGATED METAL PIPE 42 " -54° DIA. LF 700 $130.00 $91,000.00 REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE/ABANDON PIPE LF 150 $20.00 $3,000.00 UTILITY RELOCATION LS 1 $40,000.00 $40,000.00 Material Subtotal: $166,720 OTHER ITEMS DEWATERING 10 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 2 TRAFFIC CONTROL 10 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 20 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN/PERMIT 32 % Total Estimated Project Cost (Rounded): $449,000 1986- DR17.DOC Project Summary Sheet 3 OF 3 September 2003 • • • 86 -DR22 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: S. 143rd Street Storm Drain System Line Item: Project No: 86 -DR22 DESCRIPTION: JUSTIFICATION: STATUS: MAINT. IMPACT: Design and construct closed pipe drainage system along S. 143rd Street and S. 143rd Place. Provide a WO treatment manhole (e.g. stormceptor) and a flap gate at the outlet of the drainage system. Convert existing drainage ditch, located on private property, to a bioswale. Provide asphalt overlay, curb and gutter, and sidewalks for S. 143rd Street. Provide asphalt overlay for S. 143rd Place. New conveyance system will reduce ROW and private property flooding. Bioswale will treat stormwater runoff before its routed to the Duwamish River. Flap gate will help prevent flooding when the Duwamish River is at high stages. COMMENTS: Assumes that parking adjacent to existing ditch will not be disturbed. Potential for LID /ND improvements (not included in estimated cost). PROJECT MANAGER: ESTIMATED COST: $757,000 1986- DR22.DOC Project Summary Sheet 1 OF 3 September 2003 86 -DR22 Tukwila Surface Water Management Comprehensive Plan Project Sketch S. 143rd Street Storm Drain System Provide Storm Drainage System, Asphalt Overlay, Curb and Gutter, and Sidewalk Provide Storm Drainage System, Asphalt Overlay, and Extruded Asphalt Curb 175170.1-5.01_W0520030065EA, 88-0022 sum 4s 07 -31 -03 . gr Project Summary Sheet September 2003 2 of 3 1986- DR22.DOC 86 -DR22 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate S. 143rd Street Storm Drain System Item CATCH BASINS, AND INLETS CATCH BASIN TYPE 1 CATCH BASIN TYPE 2 48" -54" CEMENT CONCRETE SIDEWALKS AND CEMENT CONCRETE SIDEWALK OR DRIVEWAY CURB RAMP, CEMENT CONCRETE CURB AND GUTTER CURB AND GUTTER, CEMENT AND CONC. EXCAVATION TRENCH SAFETY SYSTEM FLOW CONTROL SYSTEMS STORMCEPTOR WQ MANHOLE (STC 4800) STORMCEPTOR DELIVERY STORMCEPTOR INSTALLATION MISC ITEMS - TEMPORARY BYPASS BIOSWALE SEEDING MISC ITEMS - Project Specific PAVEMENT OVERLAY, ASPHALT CONCRETE CL B (S 143RD ST) WASHED DRAIN ROCK/STRUCTURAL FILUPIPE BEDDING REGRADE EXISTING DITCH 18 " -24° DIAMETER FLAP GATE PIPES IN PAVED AREAS 8° - 12" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE 18" - 24° DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE/ABANDON PIPE UTILITY RELOCATION OTHER ITEMS Unit Quantity Unit Cost Amount EA EA 8 $1,330.00 $10,640.00 2 $3,780.00 $7,560.00 SY 1533 EA $35.00 $53,655.00 12 $425.00 $5,100.00 $19.30 $44,390.00 $0.80 $12,800.00 LF 2300 SF 16000 EA EA EA 1 $22,960.00 2 $200.00 2 $5,250.00 $22,960.00 $400.00 $10,500.00 LS 1 $5,000.00 $5,000.00 SF 4000 $1.50 $6,000.00 TN 1305 $55.00 $71,775.00 TN 420 $23.00 $9,660.00 LF 500 $5.00 $2,500.00 EA 1 $3,000.00 $3,000.00 LF 1100 $43.00 $47,300.00 LF 500 $75.00 $37,500.00 LF 85 $20.00 LS 1 $10,000.00 Material Subtotal: DEWATERING OTHER ITEMS EROSION & SEDIMENTATION CONTROL TRAFFIC CONTROL CONTINGENCY MOBILIZATION (GENERAL REQUIREMENTS) CONSTRUCTION MANAGEMENT SALES TAX ENG INEERING/LEGAUADMI N /PERMIT Total Estimated Project Cost (Rounded): $1,700.00 $10,000.00 $362,440 5 % 15 3 % 4 % 15 % 10 % 15 % 8.8 % 10 % $757,000 1986- DR22.DOC Project Summary Sheet 3 OF 3 September 2003 • • 87 -DRO2 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: DESCRIPTION: JUSTIFICATION: STATUS: Nelson Place/Longacres Interceptor Pipe Line Item: Project No: 87 -DRO2 Provide 48" interceptor pipe under BNRR tracks, connecting upstream interceptor to recently built P -1 interceptor through Renton. Reduces private property flooding by providing a hydraulic connection to the recently constructed P -1 interceptor. MAINT. IMPACT: COMMENTS: PROJECT MANAGER: ESTIMATED COST: $544,000 1987- DR02.DOC Project Summary Sheet 1 OF 3 September 2003 87 -DRO2 Tukwila Surface Water Management Comprehensive Plan Project Sketch Nelson Place /Longacres Interceptor Pipe Provide Storm Drainage Pipe to P -1 Interceptor Existing Storm Drainage System (P1 Interceptor) 176170.73.01 A62003006SEA. 87 -DR022 sum MI 08.12-03. gr Project Summary Sheet September 2003 2 of 3 1987- DR02.DOC • 87 -DRO2 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate Nelson Place /Longacres Interceptor Pipe Item CATCH BASINS, AND INLETS CATCH BASIN TYPE 2 72 " -96" MISC ITEMS TEMPORARY BYPASS MISC ITEMS - Project Specific RAILROAD INSPECTOR PIPES - JACK & BORE CONSTRUCTION 42" DIA. SMOOTH WALL INTERIOR CORROGATED POLYETHENE, JACK & BORE CONSTRUCTION JACKING AND RECEIVING PIT REMOVAL OF STRUCTURES AND OBSTRUCTIONS UTILITY RELOCATION OTHER ITEMS Unit Quantity Unit Cost EA 1 $12,250.00 LS 1 $5,000.00 HR 24 $50.00 LF 225 $890.00 EA 1 $35,500.00 LS 1 $10,000.00 Material Subtotal: DEWATERING OTHER ITEMS EROSION & SEDIMENTATION CONTROL TRAFFIC CONTROL CONTINGENCY MOBILIZATION (GENERAL REQUIREMENTS) CONSTRUCTION MANAGEMENT SALES TAX ENGINEERING/LEGAUADMIN /PERMIT Total Estimated Project Cost (Rounded): Amount $12,250.00 $5,000.00 $1,200.00 $200,250.00 $35,500.00 $10,000.00 $264,200 2 % 15 % 2 % 1 % 15 % 10 % 15 % 8.8 % 15 % $544,000 1987- DR02.DOC Project Summary Sheet 3 OF 3 September 2003 • 93 -DRO8 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: Gilliam Creek 42nd Avenue S. Culvert DESCRIPTION: JUSTIFICATION: STATUS: Line Item: Project No: 93 -DRO8 Replace existing culvert. Remove sediment and existing weir. Provide log weirs for grade control. Reduces private property flooding by providing a hydraulic connection to the recently constructed P -1 interceptor. MAINT. IMPACT: COMMENTS: PROJECT MANAGER: ESTIMATED COST: $296,000 1993- DR08.DOC Project Summary Sheet 1 OF 3 September 2003 93 -DRO8 Tukwila Surface Water Management Comprehensive Plan ,_ Project Sketch Gilliam Creek 42nd Avenue S. Culvert Remove sediment and existing weir. Provide log weirs for grade control. t7617OrS.01 vw62Oro00s5EA.07DROBsumMI08 -O8. 3 gr Project Summary Sheet September 2003 2 of 3 1993- DR08.DOC • • 93 -DRO8 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate Gilliam Creek 42nd Avenue S. Culvert Item EXCAVATION TRENCH SAFETY SYSTEM MISC ITEMS TEMPORARY BYPASS PIPES IN PAVED AREAS BOX CULVERT (28 -38 sf) REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE AND REPLACE CEM. CONC. SIDEWALK (INCLUDES SAWCUTTING, REMOVAL, AND DISPOSAL) REMOVE AND REPLACE CURB AND GUTTER (INCLUDES SAWCUTTING, REMOVAL, AND DISPOSAL) REMOVE/ABANDON PIPE UTILITY RELOCATION OTHER ITEMS Unit Quantity Unit Cost SF 752 $0.80 LS 1 $20,000.00 LF 94 $910.00 SY 60 $57.50 LF 60 $29.25 LF 94 $20.00 LS 1 $10,000.00 Material Subtotal: DEWATERING OTHER ITEMS EROSION & SEDIMENTATION CONTROL TRAFFIC CONTROL CONTINGENCY MOBILIZATION (GENERAL REQUIREMENTS) CONSTRUCTION MANAGEMENT SALES TAX ENGINEERING/LEGAUADMIN /PERMIT Total Estimated Project Cost (Rounded): Amount $601.60 $20,000.00 $85,540.00 $3,450.00 $1,755.00 $1,880.00 $10,000.00 $123,226 7 % 15 % 15 % 5 % 15 % 10 % 15 % 8.8 % 15 % $296,000 1993- DRO8.DOC Project Summary Sheet 3 OF 3 September 2003 • • 94 -DRO5A Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Duwamish Riverbank Stabilization 1 A DESCRIPTION: Line Item: Project No: 94 -DRO5A Prevent the eroding and failing riverbank adjacent to E Marginal Way S and S 104th St between Boeing Access Rd (old Skagen Marine bldg) and S 104 St. from being a traffic hazard and degrading river habitat. This alternative would leave the road open and would include bank stabilization on the existing grade with bioengineering techniques. JUSTIFICATION: Prevent street damage, and protect the river from deposition of eroded material. STATUS: MAINT. IMPACT: COMMENTS: CIP project #94 -DRO5B would be a larger habitat restoration project at this site involving road abandonment and regrading and restoration of 400 LF of riverbank. PROJECT MANAGER: ESTIMATED COST: $74,000 94 -DROSA DUWAMISH RIVERBANK STABILIZATION IA .DOC Project Summary Sheet 1 OF 3 November 2003 94 -DR05A Tukwila Comprehensive Surface Water Management Plan Project Sketch Duwamish Riverbank Stabilization 1A Regrade;and stabilize 400feet of failing riverbank+ onmxisting :gradwand:leave':the roadway; open:.; Project Summary Sheet November 2003 2 of 3 94 -DRO5A DUWAMISH RIVERBANK STABILIZATION 1ADOC 94 -DRO5A Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Duwamish Riverbank Stabilization 1A Item MISC ITEMS BIOENGINEERING BANK STABILIZATION OTHER ITEMS Unit Quantity Unit Cost Amount LF 300 $100.00 $30,000.00 Material Subtotal: $30,000.00 DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 10 % TRAFFIC CONTROL 10 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN /PERMIT 25 % Total Estimated ProjectCost (Rounded): $74,000.00 94 -DRO5A DUWAMISH RIVERBANK STABILIZATION 1ADOC Project Summary Sheet 3 OF 3 November 2003 94 -DRO5B Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Duwamish Riverbank Stabilization 1B DESCRIPTION: Line Item: Project No: 94 -DRO5B Prevent the eroding and failing riverbank adjacent to E Marginal Way S and S 104th St between Boeing Access Rd (old Skagen Marine bldg) and S 104 St. from being a traffic hazard and degrading river habitat. This alternative would include permanent closure (abandonment) of the road, pulling back the riverbank, restoring river edge habitat with relatively large wood structures, and planting riparian vegetation. JUSTIFICATION: Prevent street damage, and protect the river from deposition of eroded material. STATUS: MAINT. IMPACT: COMMENTS: CIP project #94 -DRO5A would be a smaller bank stabilization project at this site involving bioengineering methods on approximately 300 LF of riverbank without alteration or abandonment of the roadway. PROJECT MANAGER: ESTIMATED COST: $595,000 94 -DROSB DUWAMISH RNERBANK STABILIZATION 1 B.DOC Project Summary Sheet 1 OF 3 November 2003 94 -DRO5B Tukwila Comprehensive Surface Water Management Plan Project Sketch Duwamish Riverbank Stabilization 1B Rerade.andsstabiIize'400 feet °offailing. nverbank and ' abandon "existing roadway. Project Summary Sheet November 2003 2 of 3 94 -DRO5B DUWAMISH RIVERBANK STABIUZATION 1B.DOC 94 -DRO5B Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Duwarnish Riverbank Stabilization 1B Item Unit Quantity Unit Cost Amount EXCAVATION COMMON EXCAVATION {QTY >= 1000} CY 4440 $15.00 $66,600.00 LANDSCAPING TOPSOIL CY 890 $28.00 $24,920.00 MISC ITEMS - Project Specific REMOVE AND HAUL RIPRAP CY 70 $20.00 $1,400.00 REMOVE PAVEMENT - SY 1110 $15.00 $16,650.00 COIR MATTING SY 1780 $6.00 $10,680.00 RIPARIAN SEEDING/PLANTING SY 1780 $25.00 $44,500.00 LARGE WOOD BANK STABILIZATION STRUCTURES EA 3 $25,000.00 $75,000.00 FLOW DIVERSION LS 1 $20,000.00 $20,000.00 Material Subtotal: $259,750.00 OTHER ITEMS DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 5 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN /PERMIT 25 % Total Estimated ProjectCost (Rounded): $595,000.00 94 -DRO5B DUWAMISH RIVERBANK STABILIZATION 1 B.DOC Project Summary Sheet 3 OF 3 November 2003 • • • 94 -DRO9 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: DESCRIPTION: JUSTIFICATION: STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: Duwamish Riverbank Stabilization 1I Line Item: Project No: 94 -DRO9 Stabilize the sloughing riverbank sections adjacent to S 115 St between 42 Ave S & East Marginal Way S and adjacent to 42nd Ave S from S 115 St to Interurban Ave S. Prevent street damage, and protect the river from deposition of eroded material. The total length of riverbank in this area is 4900 LF. Approximately % of that length, or 1200 LF, requires stabilization under this project. Native, mature trees and shrubs on the bank should be preserved. There is insufficient space to flatten and regrade the bank, so bioengineering methods on the existing grade are assumed. ESTIMATED COST: $285,000 94 -DRO9 DUWAMISH RIVERBANK STABILIZATION 2.DOC Project Summary Sheet 1 OF 3 November 2003 94 -DRO9 Tukwila Comprehensive Surface Water Management Plan Project Sketch Duwamish Riverbank Stabilization II 1 ,Stabilize 4 900,LF '*of.riverbarik Project Summary Sheet November 2003 2 of 3 94-DRO9 DUWAMISH RIVERBANK STABILIZATION 2.DOC • 94 -DRO9 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Duwamish Riverbank Stabilization II Item MISC ITEMS BIOENGINEERING BANK STABILIZATION OTHER ITEMS Unit Quantity Unit Cost Amount LF 1200 $100.00 $120,000.00 Material Subtotal: $120,000 DEWATERING 0 OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 10 % TRAFFIC CONTROL 10 CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAL/ADMIN /PERMIT 20 % Total Estimated Project Cost (Rounded): $285,000 94 -DRO9 DUWAMISH RIVERBANK STABILIZATION 2.DOC Project Summary Sheet 3 OF 3 November 2003 98 -DRO3 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Riverton Side Channel DESCRIPTION: JUSTIFICATION: Line Item: Project No: 98 -DRO3 Remove two culverts and flap gates at outfall to Duwamish River; create open channel confluence with river; install trail bridge over new open channel; restore /revegetate 200 feet of creek channel upstream of new trail bridge, 450 feet of pond shoreline, and enhance an additional 400 feet of channel between SR 599 and pond. The project will increase habitat available for salmonid rearing and flood refuge in the lower Duwamish River. It will improve fish access to Riverton Creek, and enhance habitat near the mouth of the creek where fish can rear and rest. STATUS: Project timing is uncertain because funding has yet to be allocated by the Corps of Engineers and design has yet to be prepared. MAINT. IMPACT: COMMENTS: King County is contributing $50,000 in kind services. The Corps of Engineers is currently planning on contributing $142,000 for construction. The estimated cost is based on estimate developed by the Corps of Engineers in 2000, subject to change as project design is finalized. PROJECT MANAGER: ESTIMATED COST: $300,000 98- DR031998 -DRO3 RIVERTON SIDE CHANNELDOC Project Summary Sheet 1 OF 2 November 2003 r 98 -DRO3 Tukwila Comprehensive Surface Water Management Plan Project Sketch Riverton Side Channel ^"RemovetwocuIverts andflap'gates at;outfall' • Enhance: channel' Construct trait bridge; :over new;channel Enhance shoreline: and riparian.: 'corrldor_of Riverton Pond Extend channel improvements' SR 599: Project Summary Sheet November 2003 2 of 2 1998 -DRO3 RIVERTON SIDE CHANNELDOC • • • • 98 -DRO5 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Gilliam Creek Fish Barrier Removal Line Item: Project No: 98 -DRO5 DESCRIPTION: Construct fish ladder leading to existing flap gate location, and replace flap gate with self - regulating tide gate. JUSTIFICATION: Enable fish access to lower Gilliam Creek under wider range of flow conditions. STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: The city's estimated share is approximately 25% of the total cost. The Corps of Engineers has plans for restoration of lower Gilliam Creek, including the flap gate retrofit. Therefore, this project will evolve as the Corps' plans are further detailed. Project 86 -DR17, 03 -DR05, and 03 -DR16 may also be included in the Corps' plans. ESTIMATED COST: $675,000 98 -DRO5 GILLIAM CREEK FISH BARRIER REMOVALDOC Project Summary Sheet 1 OF 3 November 2003 98 -DRO5 Tukwila Comprehensive Surface Water Management Plan Project Sketch Gilliam Creek Fish Barrier Removal Replaceaexlstlng ffap. gate with.fish. ipassage ,facility Project Summary Sheet November 2003 2 of 3 98 -DROS GILLIAM CREEK FISH BARRIER REMOVALDOC 98 -DRO5 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Gilliam Creek Fish Barrier Removal Item Unit Quantity Unit Cost Amount CLEARING, GRUBBING, AND ROADSIDE CLEANUP CLEARING AND GRUBBING AC 0 $5,000.00 $0.00 EXCAVATION COMMON EXCAVATION (QTY < 1000) CY ` 30 $27.00 $810.00 LANDSCAPING TOPSOIL CY 130 $28.00 $3,640.00 LANSCAPING HYDROSEEDING AC 0 $1,000.00 $0.00 MISC ITEMS BIOENGINEERING BANK STABILIZATION LF 0 $100.00 $0.00 MISC ITEMS - Project Specific EMBANKMENT COMPACTION CY 20 $22.00 $440.00 GRAVEL, CLASS B TN 75 $22.00 $1,650.00 STREAMBED GRAVEL TN 35 $30.00 $1,050.00 RIPRAP TN 3200 $45.00 $144,000.00 CONCRETE CLASS A (INCL. FORMS AND REBAR) CY 110 $550.00 $60,500.00 LANDSCAPING (WETLAND ENHANCEMET) LS 1 $20,000.00 $20,000.00 108° DIA. SELF - REGULATING TIDE GATE EA 1 $50,000.00 $50,000.00 Material Subtotal: $282,090 OTHER ITEMS DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 5 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING /LEGAL/ADMIN/PERMIT 30 % Total Estimated Project Cost (Rounded): $675,000 98 -DRO5 GILLIAM CREEK ASH BARRIER REMOVALDOC Project Summary Sheet 3 OF 3 November 2003 98 -DRO7 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Treatment Facilities for Tukwila International Boulevard Bypass Line Item: Project No: 98 -DRO7 DESCRIPTION: Construct runoff treatment facilities at seven (7) high flow bypass inlets. JUSTIFICATION: Improved water quality discharged from the Riverton and Southgate Creek basins into the Duwamish River. STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: Runoff treatment assumed to be accomplished using Stormceptors at 6 locations and a wet pond near SR 599. Cost estimate is approximate due mainly to uncertainty of treatment pond size near SR 599. ESTIMATED COST: $598,000 Project Summary Sheet 1998-DRO7 TUKWILA INTL BLVD BYPASS TREATMENT.DOC 1 OF 3 November 2003 03 -DR07 Tukwila Comprehensive Surface Water Management Plan Project Sketch Treatment Facilities for Tukwila International Boulevard Bypass V � 3 1 lb II „jog AzolimP ,321 ,Storm water treatment pond: Project Summary Sheet November 2003 2 of 3 1998 -DRO7 TUKW ILA INTL BLVD BYPASS TREATMENT.DOC 98 -DRO7 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Treatment Facilities for Tukwila International Boulevard Bypass , Item Unit Quantity Unit Cost Amount CLEARING, GRUBBING, AND ROADSIDE CLEANUP CLEARING AND GRUBBING AC 1 $5,000.00 $5,000.00 EXCAVATION COMMON EXCAVATION {QTY >= 1000) CY 4270 $15.00 $64,050.00 FLOW CONTROL SYSTEMS OUTLET STRUCTURE EA 1 $6,000.00 $6,000.00 MISC ITEMS - Project Specific WET POND SEEDING AC 1 $1,000.00 $1,000.00 INLET AND OUTLET PIPES LF 150 $40.00 $6,000.00 OVERFLOW SPILLWAY - RIPRAP TN 28 $45.00 $1,260.00 ACCESS DRIVEWAY - CRUSHED GRAVEL TN 71 $25.00 $1,775.00 POND PERIMETER LANDSCAPING LS 1 $10,000.00 $10,000.00 STORMCEPTOR VAULTS (cost from Perteet Engineering 2002 EA 6 $25,000.00 $150,000.00 design report) Material Subtotal: $245,085 OTHER ITEMS DEWATERING 0 T. OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 10 % TRAFFIC CONTROL 10 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN/PERMIT 25 % Total Estimated Project Cost (Rounded): $598,000 Project Summary Sheet 1998 -DRO7 TUKWILA INTL BLVD BYPASS TREATMENT.DOC 3 OF 3 November 2003 • • 00 -DR10 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: Gilliam Creek Regional Detention Pond Line Item: Project No: 00 -DR10 DESCRIPTION: JUSTIFICATION: Create an in- channel detention pond in the existing natural depression by constructing a control structure at the inlet to the existing storm drain line that conveys flow out of the depression. Replace 850 LF of the existing storm drain line from the depression to the open channel section along Southcenter Boulevard. Replace the portion under the existing apartment building with slipline or relining techniques. Create a high -flow by -pass by constructing a flow splitter at the manhole located upstream of the western Southcenter Boulevard crossing. Construct a storm drain line along Southcenter Boulevard to route by- passed flows around the apartment complex. The detention pond reduces peak flows in Gilliam Creek downstream of the project area. The high flow by -pass and rehabilitated storm drain line under the apartment building reduce private property flooding. STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: ESTIMATED COST: $1,638,000 2000-DR1O.DOC Project Summary Sheet 1 OF 3 September 2003 00-DR1 0 Tukwila Surface Water Management Comprehensive Plan Project Sketch Gilliam Creek Regional Detention Pond Purchase Land for Regional Detention Pond mwmilmjimitigralp IIb 122141111MIS WAN*Leig e Existin ' 1` 11 Drain Piper �,� m �I wav/uu�ilTer a�_w 176170.TS 01 W062003006SEA. 0043R10 sumdd 0741-0 .gr Project Summary Sheet September 2003 2 of 3 2000- DR10.DOC • 00-DR1 0 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate Gilliam Creek Regional Detention Pond Item Unit Quantity Unit Cost Amount CATCH BASINS, AND INLETS CATCH BASIN TYPE 2 48 " -54" EA 10 $3,780.00 $37,800.00 CHAIN LINK FENCE AND GATES CHAIN LINK FENCE LF 1625 $12.00 $19,500.00 CHAIN LINK GATE 6' WIDE EA 1 $480.00 $480.00 EXCAVATION TRENCH SAFETY SYSTEM SF 12330 $0.80 $9,864.00 FLOW CONTROL SYSTEMS FLOW CONTROL STRUCTURE, 54 -INCH EA 1 $6,400.00 $6,400.00 MISC ITEMS TEMPORARY BYPASS LS 1 $5,000.00 $5,000.00 MISC ITEMS - Project Specific 48 -INCH DIAMETER PVC SLIPLINE (ASSUMES THERE IS NO LF 350 $275.00 $96,250.00 SIGNIFICANT DAMAGE TO THE EXISTING PIPE) EXTRA DEPTH (BEYOND 101, FLOW CONTROL STRUCTURE VF 20 $400.00 $8,000.00 FLOW SPLITTER EA 1 $7,000.00 $7,000.00 TRENCH SAFETY SYSTEMS (SHEET PILES) SF 9000 $30.00 $270,000.00 EXTRA DEPTH (BEYOND 101, 1 TYPE 2 CB VF 20 $400.00 $8,000.00 PIPES IN PAVED AREAS 18° - 24' DIA. SMOOTH INTERIOR WALL CORROGATED LF 1880 $75.00 $141,000.00 POLYETHENE PIPES IN UNDEVELOPED AREAS 30" - 36' DIA. SMOOTH INTERIOR WALL CORROGATED LF 675 $100.00 $67,500.00 POLYETHENE REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE/ABANDON PIPE LF 1510 $20.00 $30,200.00 UTILITY RELOCATION LS 1 $40,000.00 $40,000.00 Material Subtotal: $746,994 OTHER ITEMS DEWATERING 3 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 10 % TRAFFIC CONTROL 6 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN /PERMIT 10 % Total Estimated Project Cost (Rounded): $1,638,000 2000•DR10.DOC Project Summary Sheet 3 OF 3 September 2003 03 -DRO1 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: 53rd Avenue S. Storm Drain System DESCRIPTION: Line Item: Project No: 03 -DRO1 Replace existing storm drainage system. Provide bioswales along 53rd Avenue S. and a WO treatment manhole (e.g., stormceptor) at the downstream end of the system to treat stormwater runoff. Purchase ROW for bioswale construction. Provide asphalt overlay and extruded curb for 53rd Avenue S. JUSTIFICATION: New conveyance system will reduce ROW and private property flooding. STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: Potential for LID /ND improvements (not included in estimated cost). ESTIMATED COST: $960,000 2003- DR01.Doc Project Summary Sheet 1 OF 3 September 2003 03 -DRO1 Tukwila Surface Water Management Comprehensive Plan Project Sketch 53rd Avenue S. Storm Drain System c, Existing Stonn 4.74kleafill *�� /� Drainage System or AI .'154 ilk Lee Philips Field Foster Memorial Park I �Replace Existing Storm Drainage System. Provide Asphalt Overlay and Extruded Curb. i1 Mil %ill Rf1iti.M m_al, `, ii1 �a Allsill1111• minimum 19 173170.TS.0, VVOM0030O6SEA 03-DRO1 Barn 1d O643-03.at MAI a �. . iu iEv r �1,21. t t � br MIN I I �R1 � mu. I i'I� i ~� d1 ItMyiV I. i MICK L-' \1 '� 1i--,,. --pr osimu , fNN ; 1 >il At m `inursh'w►w►��►`!laf -e Project Summary Sheet September 2003 2 of 3 2003- DRO1.DOC • • Item CATCH BASINS, AND INLETS CATCH BASIN TYPE 1 EA 18 $1,330.00 $23,940.00 CATCH BASIN TYPE 2 48 " -54" EA 6 $3,780.00 $22,680.00 CURB AND GUTTER CURB, EXTRUDED (ASPHALT OR CEMENT CONCRETE) . LF 4400 $8.20 $36,080.00 EXCAVATION TRENCH SAFETY SYSTEM SF 15360 $0.80 $12,288.00 FLOW CONTROL SYSTEMS. STORMCEPTOR WQ MANHOLE (STC 2400) EA 1 $14,835.00 $14,835.00 STORMCEPTOR DELIVERY EA 2 $200.00 $400.00 STORMCEPTOR INSTALLATION EA 1 $5,250.00 $5,250.00 MISC ITEMS - Project Specific BIOSWALE CONSTRUCTION (INCLUDES EXCAVATION SF 8184 $5.00 $40,920.00 GRADING AND SEEDING) PAVEMENT PAVEMENT, ASPHALT CONCRETE CL B {QTY > 500} TN 1933 $45.00 $86,985.00 PIPES IN PAVED AREAS 8" - 12" DIA. SMOOTH INTERIOR WALL CORROGATED LF 1460 $43.00 $62,780.00 POLYETHENE 18" - 24" DIA. SMOOTH INTERIOR WALL CORROGATED LF 1100 $75.00 $82,500.00 POLYETHENE REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE/ABANDON PIPE LF 2200 $20.00 $44,000.00 UTILITY RELOCATION LS 1 $20,000.00 $20,000.00 Material Subtotal: $452,658 OTHER ITEMS DEWATERING 2 % 03 -DRO1 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate 53rd Avenue S. Storm Drain System Unit Quantity Unit Cost Amount OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 2 % TRAFFIC CONTROL 5 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN/PERMIT 15 % Total Estimated Project Cost (Rounded): $960,000 2003- DR01.DOC • Project Summary Sheet 3 OF 3 September 2003 • • 03 -DRO4 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: DESCRIPTION: JUSTIFICATION: STATUS: MAINT. IMPACT: S. 146th Street Pipe and 35th Avenue S. Drainage System Line Item: Project No: 03 -DRO4 Replace existing storm drainage system on S. 146th Street. Provide new storm drainage system for 35th Avenue S. Provide asphalt overlay and extruded asphalt curb for both streets. Reduce ROW and private property flooding by increasing the hydraulic capacity of the storm drainage system. COMMENTS: Potential for LID /ND improvements (not included in estimated cost). PROJECT MANAGER: ESTIMATED COST: $550,000 2003- DR04.DOC Project Summary Sheet 1 OF 3 September 2003 03 -DRO4 Tukwila Surface Water Management Comprehensive Plan Project Sketch S. 146th Street Pipe and 35th Avenue S. Drainage System Replace Exist ng Sto m Drainage System. Provide Asphalt Overlay and Extruded Asphalt Curb 176170.TS.01 W062003000SEA. 03-0R04 sum sM 07,31 -03 . or Project Summary Sheet September 2003. 2 of 3 2003- DRO4.DOC • • 03 -DRO4 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate S. 146th Street Pipe and 35th Avenue S. Drainage System Item Unit Quantity Unit Cost Amount CATCH BASINS, AND INLETS CATCH BASIN TYPE 2 48" -54° EA 5 $3,780.00 $18,900.00 CURB AND GUTTER CURB, EXTRUDED (ASPHALT OR CEMENT CONCRETE) LF 2700 $8.20 $22,140.00 EXCAVATION TRENCH SAFETY SYSTEM SF 9660 $0.80 $7,728.00 MISC ITEMS TEMPORARY BYPASS LS 1 $5,000.00 $5,000.00 PAVEMENT PAVEMENT, ASPHALT CONCRETE CL B (QTY > 500) TN 1062 $55.00 $58,410.00 PIPES IN PAVED AREAS 8" - 12° DIA. SMOOTH INTERIOR WALL CORROGATED LF 560 $43.00 $24,080.00 POLYETHENE 18° - 24" DIA. SMOOTH • INTERIOR WALL CORROGATED LF 1050 $75.00 $78,750.00 POLYETHENE REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE/ABANDON PIPE LF 1000 $20.00 $20,000.00 REMOVE/ABANDON CATCH BASIN EA 5 $300.00 $1,500.00 UTILITY RELOCATION LS 1 $10,000.00 $10,000.00 Material Subtotal: $246,508 OTHER ITEMS DEWATERING 5 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 6 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN /PERMIT 15 % Total Estimated Project Cost (Rounded): $550,000 2003- DR04.DOC Project Summary Sheet 3 OF 3 September 2003 • • • 03 -DRO5 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: Tukwila Parkway Drainage from Westfield Mall to Gilliam Creek DESCRIPTION: Line Item: Project No: 03 -SR05 Replace 30" outlet pipe from manhole, located at the northwest access to Southcenter Mall (at Tukwila Parkway), to Gilliam Creek. JUSTIFICATION: Reduces flooding by providing an outlet to Gilliam Creek with a positive slope. STATUS: MAINT. IMPACT: COMMENTS: The Corps of Engineers is planning improvements to lower Gilliam Creek. This project may be included with the Corp's plans along with projects 86 -DR17, 98 -DRO5 and 03 -DR16 may also be included in the Corp's plans. PROJECT MANAGER: ESTIMATED COST: $232,000 2003- DR05.DOC Project Summary Sheet 1 OF 3 September 2003 03 -DRO5 Tukwila Surface Water Management Comprehensive Plan Project Sketch Tukwila Parkway Drainage from Westfield Mall to Gilliam Creek Project Summary Sheet September 2003 2 of 3 2003- DR05.DOC 03 -DRO5 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate Tukwila Parkway Drainage from Westfield Mall to Gilliam Creek Item Unit Quantity Unit Cost Amount CATCH BASINS, AND INLETS CATCH BASIN TYPE 2 48 " -54" EA 1 $3,780.00 $3,780.00 EXCAVATION TRENCH SAFETY SYSTEM SF 1760 $0.80 $1,408.00 MISC ITEMS BIOENGINEERING BANK STABILIZATION LF 50 $100.00 $5,000.00 TEMPORARY BYPASS LS 1 $5,000.00 $5,000.00 MISC ITEMS - Project Specific TRENCH SAFETY SYSTEMS (SLIDE RAILS SYSTEM) SF 1760 $10.00 $17,600.00 RIPRAP, 2" TO 6" IN QUARRY SPALLS TN 1 $45.00 $45.00 PIPES IN PAVED AREAS 30" - 36" DIA. SMOOTH INTERIOR WALL CORROGATED LF 110 $116.00 $12,760.00 POLYETHENE PIPES IN UNDEVELOPED AREAS 30" - 36" DIA. SMOOTH INTERIOR WALL CORROGATED LF 110 $100.00 $11,000.00 POLYETHENE REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE/ABANDON PIPE LF 220 $20.00 $4,400.00 UTILITY RELOCATION LS 1 $40,000.00 $40,000.00 Material Subtotal: $100,993 OTHER ITEMS DEWATERING 8 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 7 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAL/ADMIN/PERMIT 15 % Total Estimated Project Cost (Rounded): $232,000 2003- DR05.DOC Project Summary Sheet 3 OF 3 September 2003 03 -DRO6 Tukwila Surface Water Management. Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: Northwest Gilliam Storm Drainage System Line Item: Project No: 03 -DRO6 DESCRIPTION: JUSTIFICATION: STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: Upgrade existing storm drainage system. Provide WQ treatment manholes (e.g., Stormceptors) at the downstream end of the retrofited drainage systems. Provide asphalt overlay and extruded asphalt curb for all streets. Reduces ROW and private property flooding by increasing the hydraulic capacity of the existing storm drainage system. WQ manholes remove sediment and oil from street runoff. Potential for LID /ND improvements (not included in estimated cost). ESTIMATED COST: $1,382,000 2003- DRO6.DOC Project Summary Sheet 1 OF 3 September 2003 03 -DRO6 Tukwila Surface Water Management Comprehensive Plan Project Sketch Northwest Gilliam Storm Drainage System ...-Evirmilitialimumirivi /�/i m w Al Rep ace Existing re4�� in Provide WQ i Storm Drainage System. r Treatment Manhole �� i m1111111 i f ANNA -Eill111161 ,.. 1 Alli i 1:11M1;14-111.4"Hrell T..1 I`. +�` = i tdesek it . i, L!IJi?;2J ' 1diel....... aY �riiii RlEt�� j!4L1#J1I; II Storm Drainage System. 11,1I Provide WQ Provide Asphalt Overlay ������ d �� Treatment Manhole and Extruded Curb. I�a�i1�1�7.I ,wl •� �' .....,,,_ , ___:_, -tit .____.•_ 0 ir..41%-aAL---- 111/1111111111111Tifilibiat iThwArraidiLVKII- iinilwillfirj ILI-Li 170170TS.01_W0620030066EA. 030R06 eum eM 0&1303 .Or Project Summary Sheet September 2003 2 of 3 2003- DR06.DOC • • 03 -DRO6 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate Northwest Gilliam Storm Drainage System Item Unit Quantity Unit Cost Amount CATCH BASINS, AND INLETS CATCH BASIN TYPE 1 EA 45 $1,330.00 $59,850.00 CURB AND GUTTER CURB, EXTRUDED (ASPHALT OR CEMENT CONCRETE) LF 3740 $8.20 $30,668.00 EXCAVATION TRENCH SAFETY SYSTEM SF 31440 $0.80 $25,152.00 FLOW CONTROL SYSTEMS STORMCEPTOR WQ MANHOLE (STC 2400) EA 1 $14,835.00 $14,835.00 STORMCEPTOR WQ MANHOLE (STC 4800) EA 2 $22,960.00 $45,920.00 STORMCEPTOR WQ MANHOLE (STC 7200) EA 1 $35,640.00 $35,640.00 STORMCEPTOR DELIVERY EA 12 $200.00 $2,400.00 STORMCEPTOR INSTALLATION EA 4 $5,250.00 $21,000.00 MISC ITEMS TEMPORARY BYPASS LS 1 $5,000.00 $5,000.00 PAVEMENT PAVEMENT, ASPHALT CONCRETE CL B {QTY > 500) TN 1000 $55.00 $55,000.00 PIPES IN PAVED AREAS 8" - 12" DIA. SMOOTH INTERIOR WALL CORROGATED LF 5240 $43.00 $225,320.00 POLYETHENE REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE/ABANDON PIPE LF 2620 $20.00 $52,400.00 REMOVE/ABANDON CATCH BASIN EA 25 $300.00 $7,500.00 UTILITY RELOCATION LS 1 $100,000.00 $100,000.00 Material Subtotal: $680,685 OTHER ITEMS DEWATERING 1 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 2 % TRAFFIC CONTROL 5 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN /PERMIT 10 % Total Estimated Project Cost (Rounded): $1,382,000 2003- DR06.DOC Project Summary Sheet 3 OF 3 September 2003 • • • 03 -DR08 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: Minkler Boulevard Culvert Replacement DESCRIPTION: JUSTIFICATION: STATUS: Line Item: Project No: 03 -DRO8 Replace undersized culvert across Andover Park E and existing storm drainage lines into the P -17 canal. Reduces flooding at upstream properties by providing a culvert with increased hydraulic capacity. MAINT. IMPACT: COMMENTS: PROJECT MANAGER: ESTIMATED COST: $425,000 2003- DR08.DOC Project Summary Sheet 1 OF 3 September 2003 03 -DRO8 Tukwila Surface Water Management Comprehensive Plan Project Sketch Minkler Boulevard Culvert Replacement Existing Storm Drainage System Abandon Existing Storm Drain Line Provide New Storm Drainage System Outlet Replace Existing Culvert Existing Storm Drainage System 17e170.TS.o1_1w52o0300ssEA . 03 -0RO8 seen $ht 07-31-03. gr Project Summary Sheet September 2003 2 of 3 2003- DR08.DOC 03 -DRO8 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate Minkler Boulevard Culvert Replacement Item CEMENT CONCRETE SIDEWALKS AND CEMENT CONCRETE SIDEWALK OR DRIVEWAY Unit Quantity Unit Cost Amount SY 27 $43.00 $1,161.00 CURB AND GUTTER CURB AND GUTTER, CEMENT AND CONC. LF 40 $19.30 $772.00 EXCAVATION TRENCH SAFETY SYSTEM SF 1320 $0.80 $1,056.00 MISC ITEMS . TEMPORARY BYPASS LS 1 $5,000.00 $5,000.00 MISC ITEMS - Project Specific REGRADE EXISTING DITCH LF 40 $5.00 $200.00 PIPES IN PAVED AREAS 30" - 36" DIA. SMOOTH INTERIOR WALL CORROGATED LF 110 $116.00 $12,760.00 POLYETHENE BOX CULVERT (39 -48 sf) LF 110 $1,020.00 $112,200.00 REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE/ABANDON PIPE LF 220 $20.00 $4,400.00 UTILITY RELOCATION LS 1 $60,000.00 $60,000.00 Material Subtotal: $197,549 OTHER ITEMS DEWATERING 2 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 2 % TRAFFIC CONTROL 7 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN/PERMIT 15 % Total Estimated Project Cost (Rounded): $425,000 2003- DR08.DOC Project Summary Sheet 3 OF 3 September 2003 • • 03 -DRO9 Tukwila Surface Water Management Comprehensive Plan PROJECT SUMMARY SHEET PROJECT: Gilliam Creek/Christensen Road Storm Drain System Connection DESCRIPTION: JUSTIFICATION: STATUS: MAINT. IMPACT: Line Item: Project No: 03 -DRO9 Provide storm drain system to route Gilliam Creek outflow to the new Christensen Road Storm Drain Pump when the flap gates at the Gilliam Creek outlet are closed. Reduces flooding at downstream properties by providing a culvert with increased hydraulic capacity. Help reduce flooding along the lower portion of Gilliam Creek when the flap gates, located at the creek outlet are closed. COMMENTS: PROJECT MANAGER: ESTIMATED COST: $280,000 2003- DR09.DOC Project Summary Sheet 1 OF 3 September 2003 03 -DRO9 Tukwila Surface Water Management Comprehensive Plan Project Sketch Gilliam Creek/Christensen Road Storm Drain System Connection 176171118.01 MIS20090013SEA. 03.DR09 sun d0642.03 .0 Project Summary Sheet September 2003 2 of 3 2003- DR09.DOC 03 -DRO9 Tukwila Surface Water Management Comprehensive Plan Project Cost Estimate Gilliam Creek/Christensen Road Storm Drain System Connection Item Unit Quantity Unit Cost Amount CATCH BASINS, AND INLETS CATCH BASIN TYPE 2 48` -54° EA 4 $3,780.00 $15,120.00 EXCAVATION TRENCH SAFETY SYSTEM SF 6000 $0.80 $4,800.00 MISC ITEMS TEMPORARY BYPASS LS 1 $5,000.00 $5,000.00 PIPES IN PAVED AREAS 18° - 24` DIA. SMOOTH INTERIOR WALL CORROGATED LF . 1000 $75.00 $75,000.00 POLYETHENE REMOVAL OF STRUCTURES AND OBSTRUCTIONS UTILITY RELOCATION LS 1 $20,000.00 $20,000.00 Material Subtotal: $119,920 OTHER ITEMS DEWATERING 10 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 3 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN /PERMIT 20 % Total Estimated Project Cost (Rounded): $280,000 2003- DR09.DOC. Project Summary Sheet 3 OF 3 September 2003 • PROJECT: 03-DR1 0 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET Riverton Creek Upper Watershed Line Item: Project No: 03 -DR10 DESCRIPTION: Stabilization of eroding streambank and enhancement of the stream channel habitat. Includes placement of bioengineered bank protection measures and some instream channel structures for habitat improvement. JUSTIFICATION: The placement of woody debris and associated bioengineering structures will limit further habitat degradation, provide for an increase in habitat diversity, productivity, and improve water quality. STATUS: MAINT. IMPACT: COMMENTS: • PROJECT MANAGER: Project incorporates funding to assist with fish passage improvements at Riverton Creek crossing of Tukwila International Blvd. The estimated cost is based on similar work performed by the Surface Water Utility at other sites, and does not include city staff labor costs. ESTIMATED COST: $197,000 03 -DR10 2003 -DR10 RIVERTON CREEK UPPER WATERSHED.DOC 1 OF 2 Project Summary Sheet November 2003 03-DR1 0 Tukwila Comprehensive Surface Water Management Plan Project Sketch Riverton Creek Upper Watershed ;Possible; Fish :Passager. ::Culvert Replacement Apgroxihlate alignment of sewe1 pipe,totb- treUectekduring: construction; Stabilize: bank erosion and install woodydebris .: Project Summary Sheet November 2003 2 of 2 2003 -DR10 RIVERTON CREEK UPPER WATERSHED.DOC 03 -DR11 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Property Acquisition for Riverton Creek Sediment Trap Line Item: Project No: 03 -DR11 DESCRIPTION: Purchase property that is the site of a former fish hatchery, and that contains pools and weirs and a streamflow diversion, to consider for use as a sediment trapping facility. JUSTIFICATION: Trapping of sediments in streamflow would result in improved water quality and habitat conditions in the lower reaches of Riverton Creek. STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: The City approached the property owner recently in an attempt to purchase for $300,000 and the owner asked $400,000. An appraisal is needed better define a fair price. Legal costs and other administrative costs will also be incurred, in addition to the purchase price. ESTIMATED COST: $425,000 03DR11 RIVERTON BASIN PROPERTY ACOUISITION.DOC Project Summary Sheet 1 OF 2 November 2003 03 -DR11 Tukwila Comprehensive Surface Water Management Plan Project Sketch Property Acquisition for Riverton Creek Sediment Trap Project Summary Sheet November 2003 2 of 2 2003 -DR11 RIVERTON BASIN PROPERTY ACOUISITION.DOC 03 -DR12 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Southgate Creek Streambank Stabilization Line Item: Project No: 03 -DR12 DESCRIPTION: Streambank stabilization, habitat restoration and enhancement using bioengineering features. JUSTIFICATION: Reduced erosion,, improving water quality and habitat conditions in lower reaches of Southgate Creek, and increased habitat diversity and productivity. STATUS: MAINT. IMPACT: COMMENTS: PROJECT. MANAGER: Cost estimate assumes city construction crew does the work, and the improvements do not require detailed design. ESTIMATED COST: $51,000 03 -DR12 SOUTHGATE CREEK STREAMBANK STABILIZATION.DOC 1 OF 3 Project Summary Sheet November 2003 03-DR1 2 Tukwila Comprehensive Surface Water Management Plan Project Sketch Southgate Creek Streambank Stabilization Phase 1: Streambank Stabilization and Habitat Restoration ;Southgate Park; Remove; abandoned;' embankment and culvert Project Summary Sheet November 2003 2 of 3 03 -DR12 SOUTHGATE CREEK STREAMBANK STABILIZATION.DOC 03 -DR12 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Southgate Creek Streambank Stabilization Item Unit Quantity Unit Cost Amount MISC ITEMS BIOENGINEERING BANK STABILIZATION LF 150 $100.00 $15,000.00 TEMPORARY BYPASS LS 1 $2,000.00 $2,000.00 MISC ITEMS - Project Specific REMOVE EMBANKMENT AND CULVERT CY 220 $30.00 $6,600.00 Material Subtotal: $23,600 OTHER ITEMS DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 10 % TRAFFIC CONTROL 10 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 0 % ENGINEERING/LEGAUADMIN /PERMIT 15 % Total Estimated Project Cost (Rounded): $51,000 03 -DRI2 SOUTHGATE CREEK STREAMBANK STABILIZATION.DOC 3 OF 3 Project Summary Sheet November 2003 03 -DR13 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Southgate Creek Daylighting at S. 133`d Street DESCRIPTION: Line Item: Project No: 03 -DR13 Construct new open channel reach of Southgate Creek along south side of S. 133rd Street within City right -of -way to reduce culverted length of stream, beginning at existing headwall structure on south side of street. Connect downstream end of new channel to the existing stream reach downstream of S. 133rd Street via a new culvert crossing the roadway at the underpass. JUSTIFICATION: Increased fish passage success in greater flow range and increased habitat diversity and productivity. STATUS: MAINT. IMPACT: COMMENTS: City utilities need to be relocated in the road right -of -way where the new channel is constructed and the existing culvert is to be abandoned in place. PROJECT MANAGER: ESTIMATED COST: $253,000 03 -DR13 SOUTHGATE CREEK DAYLIGHTING.DOC Project Summary Sheet 1 OF 3 November 2003 03-DR1 3 Tukwila Comprehensive Surface Water Management Plan Project Sketch Southgate Creek Daylighting at S. 133`d Street 03 -DR13 SOUTHGATE CREEK DAYLIGHTING.DOC Project Summary Sheet 2 OF 3 November 2003 ( 03 -DR13 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate. Southgate Creek Daylighting at S. 133rd Street Item CLEARING, GRUBBING, AND ROADSIDE CLEANUP CLEARING AND GRUBBING EXCAVATION CHANNEL EXCAVATION MISC ITEMS FISH HABITAT STRUCTURE (ROOT WAD) MISC ITEMS - Project Specific DEWATERING COIR MATTING STREAMBED GRAVEL RIPARIAN SEEDING/PLANTING, REMOVE CONCRETE HEADWALL ABANDON EXISTING CULVERT IN PLACE TEMPORATY FLOW DIVERSION INSTALL NEW CULVERT CROSSING S. 133RD STREET REMOVAL OF STRUCTURES AND OBSTRUCTIONS REMOVE AND REPLACE PAVEMENT (INCLUDES SAWCUTTING, REMOVAL, AND DISPOSAL) UTILITY RELOCATION Unit Quantity Unit Cost AC 0 CY 580 EA 15 LS SY TN LS LS LS LS LF 1 280 40 1 1 1 1 125 SY 150 $5,000.00 $16.00 $400.00 $5,000.00 $6.00 $40.00 $10,000.00 $2,500.00 $1,000.00 $5,000.00 $350.00 Amount $0.00 $9,280.00 $6,000.00 $5,000.00 $1,680.00 $1,600.00 $10,000.00 $2,500.00 $1,000.00 $5,000.00 $43,750.00 $45.00 $6,750.00 LS 1 $10,000.00 $10,000.00 Material Subtotal: $102,560 OTHER ITEMS DEWATERING OTHER ITEMS EROSION & SEDIMENTATION CONTROL TRAFFIC CONTROL CONTINGENCY MOBILIZATION (GENERAL REQUIREMENTS) CONSTRUCTION MANAGEMENT SALES TAX ENGINEERING/LEGAL/ADMIN/PERMIT Total Estimated Project Cost (Rounded): 0 % 15 % 10 % 10 % 15 % 10 % 15 % 8.8 25 % $253,000 03-DR13 SOUTHGATE CREEK DAYLIGHTING.DOC Project Summary Sheet 3 OF 3 November 2003 03 -DR14 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: DESCRIPTION: JUSTIFICATION: Southgate Creek Salmon Habitat Restoration Downstream of S. 133rd St. Line Item: Project No: 03 -DR14 Restoration and enhancement of the stream channel for salmon habitat. This includes the creation of 150 feet of new streambed, placement of woody debris, bioengineering structures and native vegetation to increase habitat diversity and productivity. Increase habitat diversity and juvenile coho rearing productivity. STATUS: MAINT. IMPACT: COMMENTS: Most of the estimated cost is for land acquisition. PROJECT MANAGER: ESTIMATED COST: $287,000 03 -DR14 SOUTHGATE CREEK SALMON HABITAT.DOC Project Summary Sheet 1 OF 3 November 2003 03-DR1 4 Tukwila Comprehensive Surface Water Management Plan Project Sketch Southgate Creek Salmon Habitat Restoration Downstream of S. 133rd St. Construct "150 feet of new - stream., channel With-woody .debris;.' bioengineering structures;; and_ native '.ripari ane vegetation: tJ Project Summary Sheet November 2003 2 of 3 03 -DR14 SOUTHGATE CREEK SALMON HABITAT.DOC • • 03-DR1 4 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate. Southgate Creek Salmon Habitat Restoration Downstream of S. 133rd St. Item Unit Quantity Unit Cost Amount CLEARING, GRUBBING, AND ROADSIDE CLEANUP CLEARING AND GRUBBING AC 0 $5,000.00 $0.00 EXCAVATION COMMON EXCAVATION (QTY < 1000) CY 350 . $27.00 $9,450.00 MISC ITEMS - Project Specific STREAMBED GRAVEL TN 20 $40.00 $800.00 LARGE WOODY DEBRIS EA 7 $800.00 $5,600.00 ROOTWADS EA 2 $200.00 $400.00 BOULDERS TN 10 $50.00 $500.00 INSTALL FISH HABITAT STRUCTURES LS 1 $5,000.00 $5,000.00 FLOW DIVERSION LS 1 $5,000.00 $5,000.00 COIR MATTING SY 170 $6.00 $1,020.00 RIPARIAN PLANTINGS LS 1 $7,000.00 $7,000.00 Material Subtotal: $34,770 OTHER ITEMS DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 10 % TRAFFIC CONTROL 10 CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING /LEGAUADMIWPERMIT 35 % LAND ACQUISITION $150,000.00 LAND ACQUISITION CONTINGENCY 30 % Total Estimated ProjectCost (Rounded): $287,000 03 -DR14 SOUTHGATE CREEK SALMON HABITAT.DOC Project Summary Sheet 3 OF 3 November 2003 03 -DR15 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Retrofit Stormwater Treatment and/or Detention Pond for Runoff from 51st Ave S. DESCRIPTION: JUSTIFICATION: STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: Line Item: Project No: 03 -DR15 Construct treatment and/or detention pond on vacant property adjacent to S 154th St. and 52nd Ave S Reduced peak flows and/or improved water quality in lower Gilliam Creek Currently vacant property for sale. According to the King County Assessor's data, 5 parcels comprise the site and all are expensive to purchase. The pond would not be capable of treating significant flows in Gilliam Creek. ESTIMATED COST: $1,009,000 Project Summary Sheet 03 -DR15 DETEN -WQ POND AT 52ND AVE S AND S 154TH.DOC 1 OF 3 November 2003 03 -DR15 Tukwila Comprehensive Surface Water Management Plan Project Sketch Retrofit Stormwater Treatment and/or Detention Pond for Runoff from 51st Ave S. :Route;runofffrom 52nd >Ave:;S, into pond if,possible nt'a or Cr : Route;runoff.trom: ".;. 7 j 51st.Ave$`into,pond.;, ./ Construct treatmendl detention pond.with approximate< dlmensions;o? 100' Xi200 Project Summary Sheet November 2003 2 of 3 03 -DR15 DETEN -WO POND AT 52ND AVE S ANDS 154TH.DOC 03 -DR15 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Retrofit Stormwater Treatment and/or Detention Pond for Runoff from 51st Ave S. Item Unit Quantity Unit Cost Amount CATCH BASINS, AND INLETS CATCH BASIN TYPE 1 EA 2 $1,330.00 $2,660.00 CHAIN LINK FENCE AND GATES CHAIN LINK FENCE LF 850 $12.00 $10,200.00 CLEARING, GRUBBING, AND ROADSIDE CLEANUP ' CLEARING AND GRUBBING AC 1 $5,000.00 $5,000.00 CURB AND GUTTER CURB, EXTRUDED (ASPHALT OR CEMENT CONCRETE) LF 200 $6.00 $1,200.00 EXCAVATION COMMON EXCAVATION (QTY >= 1000) CY 5000 $15.00 $75,000.00 FLOW CONTROL SYSTEMS FLOW CONTROL STRUCTURE, '48 -INCH EA t 1 $4,000.00 $4,000.00 . LANDSCAPING TOPSOIL CY 400 $28.00 $11,200.00 LANSCAPING HYDROSEEDING AC 1 $1,000.00 $1,000.00 MISC ITEMS TRASH RACK EA 1 $500.00 $500.00 MISC ITEMS - Project Specific EMBANKMENT COMPACTION CY 7000 $3.00 $21,000.00 STRUCTURAL FILL(INCL. COMPACTION) CY 200 $15.00 $3,000.00 CRUSHED GRAVEL ACCESS ROAD TN 50 $20.00 $1,000.00 GRAVEL, CLASS B TN 10 $22.00 $220.00 RIPRAP SPILLWAY TN 5 $45.00 $225.00 ASPHALT PATCHING SY 200 $25.00 $5,000.00 12" DIA. INLET AND OUTLET PIPES LF 200 $35.00 $7,000.00 CHAIN LINK GATE (14' WIDTH) EA 1 $950.00 $950.00 LANDSCAPING LS 1 $8,000.00 $8,000.0 Material Subtotal: $157,155 OTHER ITEMS DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 5 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADM IN/PERM IT 25 % LAND ACQUISITION $500,000.00 LAND ACQUISITION CONTINGENCY Total Estimated Project Cost (Rounded): 30 % $1,009,000 Project Summary Sheet 03 -DR15 DETEN -WQ POND AT 52ND AVE S AND S 154TH.DOC 3 OF 3 November 2003 03 -DR16 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Lower Gilliam Creek Channel Improvements Line Item: Project No: 03 -DR16 DESCRIPTION: Widen stream channel downstream of Andover Park W, install large woody debris and riparian vegetation, increase sinuosity. JUSTIFICATION: Increase habitat diversity and juvenile coho rearing productivity. STATUS: MAINT. IMPACT: COMMENTS: 1 -405 improvements by WSDOT may impact the riparian area at this site, and thus may affect the project layout. The Corps of Engineers is planning improvements to lower Gilliam Creek that include this area. The project concept and funding are linked to the Corps' plans. 'Projects 86 -DR17, 98 -DRO5 and 03 -DRO5 may also be included in the Corps' plans. PROJECT MANAGER: ESTIMATED COST: $248,000 03 -DR16 LOWER GILLIAM CHANNEL IMPROVEMENTS.DOC Project Summary Sheet 1 OF '3 November 2003 03 -DR16 Tukwila Comprehensive Surface Water Management Plan Project Sketch Lower Gilliam Creek Channel Improvements , -- Wlden:and enhance channel;; increase-sinuosity''- Project Summary Sheet November 2003 2 of 3 2003 -DR16 LOWER GILLIAM CHANNEL IMPROVEMENTS.DOC • 03-DR1 6 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Lower Gilliam Creek Channel Improvements Item CLEARING, GRUBBING, AND ROADSIDE CLEANUP CLEARING AND GRUBBING EXCAVATION COMMON EXCAVATION {QTY < 1000} LANDSCAPING TOPSOIL MISC ITEMS - Project Specific STREAM GRAVEL LARGE WOODY DEBRIS. ROOTWADS BOULDERS INSTALL FISH HABITAT STRUCTURES FLOW DIVERSION COIR MATTING RIPARIAN PLANTINGS Unit Quantity Unit Cost Amount AC 0 $5,000.00 $0.00 CY 500 $27.00 $13,500.00 CY 440 $28.00 $12,320.00 TN 300 $40.00 $12,000.00 EA 15 $800.00 $12,000.00 EA 5 $200.00 $1,000.00 TN 40 $50.00 $2,000.00 LS 1 $10,000.00 $10,000.00 LS 1 $15,000.00 $15,000.00 SY 890 $6.00 $5,340.00 LS 1 $20,000.00 $20,000.00 Material Subtotal: $103,160 OTHER ITEMS DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 10 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAUADMIN /PERMIT 25 % Total Estimated Project Cost (Rounded): $248,000 03 -DR16 LOWER GILLIAM CHANNEL IMPROVEMENTS.DOC Project Summary Sheet 3 OF 3 November 2003 03 -DR17 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: DESCRIPTION: JUSTIFICATION: STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: Treatment Pond for Gilliam Creek Northwest Tributary Line Item: Project No: 03 -DR17 Create wet pond on vacant property adjacent to confluence of southwest and northwest tributaries to Gilliam Creek, east of apartment complex near the south end of 40th Ave. S. Provides water quality improvement in Gilliam Creek by treating runoff from one of the more contaminated subbasin areas. Requires acquisition of one parcel of property. Requires installing a flow splitter to direct low flows from northwest tributary into wet pond, via a pipe trenched beneath apartment access driveway. ESTIMATED COST: $274,000 03 -DR17 TREATMENT FOR GILLIAM CREEK NW TRIB.DOC Project Summary Sheet 1 OF 3 November 2003 03 -DR17 Tukwila Comprehensive Surface Water Management Plan Project Sketch Treatment Pond for Gilliam Creek Northwest Tributary Wet: pond`,witkapprozimate' dimensions =115';X 415'`';' ;, ;,Bypass�low�flowssin__:: NW tfibu[arji into'_pond Project Summary Sheet November 2003 2 of 3 03 -DR17 TREATMENT FOR GILLIAM CREEK NW TRIB.DOC 03-DR1 7 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Treatment Pond for Gilliam Creek Northwest Tributary Item Unit Quantity Unit Cost Amount CLEARING, GRUBBING, AND ROADSIDE CLEANUP CLEARING AND GRUBBING AC 0 $5,000.00 $0.00 EXCAVATION COMMON EXCAVATION (QTY >= 1000) CY 2180 $16.00 $34,880.00 FLOW CONTROL SYSTEMS FLOW SPLITTER LS 1 $5,000.00 $5,000.00 OUTLET STRUCTURE EA 1 $6,000.00 $6,000.00 LANDSCAPING POND PARAMETER LANDSCAPING LS 1 $5,000.00 $5,000.00 MISC ITEMS - Project Specific INLET PIPE TRENCHED ACROSS PRIVATE DRIVEWAY LF 200 $60.00 $12,000.00 WET POND SEEDING LS 1 $500.00 $500.00 OUTLET PIPE LF 50 $40.00 $2,000.00 OVERFLOW SPILLWAY - RIPRAP TN 28 $45.00 $1,260.00 OUTLET ENERGY DISSIPATER LS 1 $1,500.00 $1,500.00 ACCESS DRIVEWAY- CRUSHED GRAVEL TN 71 $25.00 $1,775.00 Material Subtotal: $69,915 OTHER ITEMS DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 5 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENG I NEER I NG/LEGAUADM I N/PERM IT 40 % LAND ACQUISITION $72,000.00 LAND ACQUISITION CONTINGENCY Total Estimated Project Cost (Rounded): 30 % $274,000 03 -DR17 TREATMENT FOR GILLIAM CREEK NW TRIB.DOC Project Summary Sheet 3 OF 3 November 2003 03 -DR18 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Tukwila Pond Improvements Line Item: Project No: 03 -DR18 DESCRIPTION: Excavate deeper pool areas in pond, place excavated material to create islands in pond, plant islands, and divert spring flow to provide freshwater flushing in summer months. JUSTIFICATION: Improve water quality in Tukwila Pond to promote recreational use of the pond. STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: This project would be done in conjunction with a major effort to enhance Tukwila Pond as a recreational and aesthetic resource. The improvements described here would provide significant aesthetic benefits in addition to water quality benefits. ESTIMATED COST: $2,047,000 03 -DR18 TUKWILA POND.DOC Project Summary Sheet 1 OF 3 November 2003. 03-DR1 8 Tukwila Comprehensive Surface Water Management Plan Project Sketch Tukwila Pond Improvements 'ConstrUCt pttlet.connection to 48 ',Arai'n to north. Evacuate 114:Ot pondfootpnnt;; 2= 3'feetideepersand construct :vegetated ∎ habrtat> is la nd s Project Summary Sheet November 2003 2 of 3 03 -DR1B TUKWILA POND.DOC • • 03 -DR18 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Tukwila Pond Improvements Item Unit Quantity Unit Cost Amount CLEARING, GRUBBING, AND ROADSIDE CLEANUP CLEARING AND GRUBBING AC 4 $5,000.00 $20,000.00 EXCAVATION COMMON EXCAVATION (QTY >= 1000) CY 16140 $11.00 $177,540.00 LANDSCAPING TOPSOIL CY 2420 $42.00 $101,640.00 LANSCAPING HYDROSEEDING AC 3 $1,500.00 $4,500.00 MISC ITEMS - Project Specific DEWATERING, CONTINUOUS DA 90 $140.00 $12,600.00 FILL PLACEMENT FOR ISLANDS CY 16140 $8.00 $129,120.00 POND PERIMETER LANDSCAPING AC 1 $5,000.00 $5,000.00 12° DIA. OUTLET PIPE CONNECTION TO ANDOVER PARK W LF 75 $35.00 $2,625.00 CONNECTION TO DRAINAGE STRUCTURE AT ANDOVER PARK EA 1 $5,000.00 $5,000.00 W DIVERSION OF SPRING FLOW FROM NORTHWEST INTO POND LS 1 $500,000.00 $500,000.00 Material Subtotal: $958,025 OTHER ITEMS DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 5 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 ENGINEERING/LEGAL/ADMIN/PERMIT 15 % Total Estimated Project Cost (Rounded): $2,047,000 03 -DR18 TUKW ILA POND.DOC Project Summary Sheet 3 OF 3 November 2003 03 -DR19 Tukwila Comprehensive Surface Water Management Plan • PROJECT SUMMARY SHEET • • PROJECT: Nelson Salmon Habitat Side Channel Line Item: Project No: 03 -DR19 DESCRIPTION: Excavate pasture area to re- create side channel connection to the . river, extending east into the existing stormwater pond for a motel. JUSTIFICATION: Increase habitat diversity and juvenile salmonid rearing' productivity. STATUS: MAINT. IMPACT: COMMENTS: PROJECT MANAGER: Originally envisioned as a joint city /Corps of Engineers project, but that may be unlikely due to WSDOT plans for 1 -405 improvements. If constructed, the project should avoid removal of existing mature trees. A new setback levee may be needed near West Valley Highway to prevent river water in the side channel from causing flood damage. The estimated cost is based on similar side channel construction work performed on a joint city /Corps of Engineers project at Codiga Farm on the Duwamish River downstream of this site. ESTIMATED COST: $645,000 03 -DR19 NELSON SIDE CHANNELDOC Project Summary Sheet 1 OF 2 November 2003 03-DR1 9 Tukwila Comprehensive Surface Water Management Plan Project Sketch • Nelson Salmon Habitat Side Channel jEzcai/ate_connectionIoAref; Project Summary Sheet November 2003 2 of 2 NELSON SIDE CHANNELDOC • 03 -DR20 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Golf Course Riverbank DESCRIPTION: Line Item: Project No: 03 -DR20 Habitat restoration and enhancement of the riverbank environment to improve riverine habitat for ESA listed species. This would include the placement of woody debris and revegetation using native species. JUSTIFICATION: Restore habitat for ESA listed species. STATUS: MAINT. IMPACT: COMMENTS: Project length extends along most of golf course riverfront. Success of new plantings will hinge on effective eradication of roots and seed stock of invasive species. PROJECT MANAGER: ESTIMATED COST: $434,000 03 -DR20 GOLF COURSE RIVERBANKDOC Project Summary Sheet 1 OF 3 November 2003 03 -DR20 Tukwila Comprehensive Surface Water Management Plan Project Sketch Golf Course Riverbank Revegetate;bank;wkh ' native riparian_ ' plants; and - Install woody debris _` Project Summary Sheet November 2003 2 of 3 03 -DR20 GOLF COURSE RNERBANK.DOC • 03 -DR20 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Item LANSCAPING HYDROSEEDING MISC ITEMS TEMPORARY BYPASS MISC ITEMS - Project Specific REMOVE EXISTING INVASIVE VEGETATION LS 1 $10,000.00 $10,000.00 SOIL AMENDMENT CY 200 $30.00 $6,000.00 PLANTINGS LS 1 $200,000.00 $200,000.00 Material Subtotal: $219,000 OTHER ITEMS DEWATERING 0 % OTHER ITEMS 15 % EROSION & SEDIMENTATION CONTROL 5 % TRAFFIC CONTROL 5 % CONTINGENCY 15 % MOBILIZATION (GENERAL REQUIREMENTS) 10 % CONSTRUCTION MANAGEMENT 15 % SALES TAX 8.8 % ENGINEERING/LEGAL /ADMIN /PERMIT 5 % Total Estimated Project Cost (Rounded): $434,000 Golf Course Riverbank Unit Quantity Unit Cost Amount AC 3 $1,000.00 $3,000.00 LS 0 $5.00 $0.00 03 -DR20 GOLF COURSE RIVERBANKDOC Project Summary Sheet 3 OF 3 November 2003 • 03 -DR21 Tukwila Comprehensive Surface Water Management Plan PROJECT SUMMARY SHEET PROJECT: Southgate Creek Habitat Restoration DESCRIPTION: Line Item: Project No: 03 — DR21 Continuation of stream habitat restoration and enhancement (see project 03 -DR12) from the Scanlon property north toward S. 133rd St. Includes creation of a side channel pool area, approximately 80' x 80' in area on property owned by Scanlon east of the creek, stream bank stabilization along a total length of approximately 300 feet, and placement of woody debris and bioengineering structures throughout the restored reach. JUSTIFICATION: Increased habitat diversity and juvenile coho rearing productivity. STATUS: MAINT. IMPACT: COMMENTS: It is assumed that the side channel pool can be constructed on the Scanlon property without requiring purchase of the property and with minimal cost for a temporary construction easement because the owner is interested in stream restoration. See Southgate Creek Phase I (03 -DR12) for upstream habitat improvements. 410 PROJECT MANAGER: ESTIMATED COST: $217,000 03 -DR21 SOUTHGATE CREEK HABITAT RESTORATION.DOC Project Summary Sheet 1 OF 3 November 2003 03 -DR21 Tukwila Comprehensive Surface Water Management Plan Project Sketch Southgate Creek Habitat Restoration Bank Stabiiization and • Habitat; Improvem,'e."nts �' �� • �. Sr: t Project Summary Sheet November 2003 2 of 3 03 -DR21 SOUTHGATE CREEK HABITAT RESTORATION.DOC • 03 -DR21 Tukwila Comprehensive Surface Water Management Plan Project Cost Estimate Southgate Creek Habitat Restoration Item CLEARING, GRUBBING, AND ROADSIDE CLEANUP CLEARING AND GRUBBING EXCAVATION COMMON EXCAVATION (QTY > =1000} CHANNEL EXCAVATION MISC ITEMS BIOENGINEERING BANK STABILIZATION FISH HABITAT STRUCTURE (ROOT WAD) MISC ITEMS - Project Specific COIR MATTING RIPARIAN SEEDING/PLANTING FLOW DIVERSION FOR IN- CHANNEL WORK Unit Quantity Unit Cost Amount AC 0 $5,000.00 CY 1190 $15.00 CY 67 $16.00 LF 500 $60.00 EA 30 $400.00 LS LS LS 180 $6.00 1 $10,000.00 1 $5,000.00 Material Subtotal: OTHER ITEMS DEWATERING OTHER ITEMS EROSION & SEDIMENTATION CONTROL TRAFFIC CONTROL CONTINGENCY MOBILIZATION (GENERAL REQUIREMENTS) CONSTRUCTION MANAGEMENT SALES TAX ENGINEERING/LEGAUADMIN /PERMIT Total Estimated Project Cost (Rounded): $0.00 $17,850.00 $1,072.00 $30,000.00 $12,000.00 $1,080.00 $10,000.00 $5,000.00 $77,002 0 15 % 10 % 5 % 15 % 10 % 15 % 8.8 % 50 % $217,000 03 -DR21 SOUTHGATE CREEK HABITAT RESTORATION.DOC 3 OF 3 Project Summary Sheet November 2003 • • Attachment D Project Ranking • Conceptual Points Summary Category Erosion Flooding Roadway Flooding Property Flooding FRIDAY, NOVEMBER 14, 2003 Points Type of Problem Addressed Sheet erosion along roadway or streambank 10 Concentrated erosion at outfali or streambank 20 Benefits of Repairing Erosion Problem Moderate benefits to stream channel and/or water quality 10 Significant benefits to stream channel and/or water quality 20 Type of Roadway Flooding Addressed by the Project Low Use Street 10 High Use Street 15 Water Depth Multiplier Flooding depth less than 6- inches 1 Flooding depth equal or greater than 6- inches 2 Number of Properties Affected 1 property 2 2 -4 properties 4 5 -9 properties 7 > 10 properties 10 Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) 1 Private driveway, garage, or parking lot 2 Living / work area of a residence or building 3 Recurrence, Existing or Expected Occurs 1 or more times per year 4 Flooding every 2 -5 years 3 Flooding frequency less than 5 years 2 Project Eliminates or Reduces Maintenance Needs Yes 2 Risk of Failure Adjustment Risk of Failure (0 -1) C -165 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Habitat (a) Stream Habitat Improvements Type of Habitat Improvement Provided Improve quality of existing buffer / riparian vegetation without widening 4 Increase buffer width (with good quality buffer characteristics) 10 Rearing pools 6 Spawning gravel 4 Large woody debris to stablize channel and /or enhance habitat diversity 4 Off- channel or side channel rearing habitat 8 Presence of Fish In Project Area Known presence of salmonids 10 No salmonids but adequate habitat exists 2 Length of Stream Reach Improved by Project 100 feet or less 2 between 100 feet and 250 feet 4 250 feet or greater 6 (b) Fish Passage Project Corrects Fish Passage Restriction Removes a complete barrier and replaces with effective passage 10 Water Quality C -166 Improves upon a partial barrier 5 Project Enables Fish Access to Upstream Habitat for 0 to 100 feet 2 100 to 250 feet 5 Greater than 250 feet 10 Number of of Fish Passage Barriers Downstream of No barriers downstream of project 10 1 barrier downstream of project 5 2 or more barriers downstream of project 2 Type of Water Body Affected Wetland or Pond 6 Stream 10 Green/Duwamish River 2 Effectiveness of Improvement Proposed improvements would moderately improve water quality 10 Proposed improvements would significantly improve water quality 25 FRIDAY, NOVEMBER 14, 2003 • Project Points Summary y Duwamish 03 -DRO1 Flooding Point Descriptions Points Risk of Failure Adjustment Risk of Failure (0 -1) 0.25 Existing Condition Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) 1 Number of Properties Affected > 10 properties 10 Recurrence, Existing or Expected Flooding frequency less than 5 years . 2 Type of Roadway Flooding Addressed by the Project Low Use Street 10 Water Depth Multiplier Flooding depth Tess than 6- inches 1 Failure Condition Multiplier for Type of Property Affected Living / work area of a residence or building 3 Number of Properties Affected > 10 properties 10 Recurrence, Existing or Expected Occurs 1 or more times per year 4 Type of Roadway Flooding Addressed by the Project Low Use Street 10 Water Depth Multiplier Flooding depth equal or greater than 6- inches 2 Total Project Benefit Points: 80 03 -DR2O. Habitat Point Descriptions Points Length of Stream Reach Improved by Project 250 feet or greater 6 Presence of Fish in Project Area Known presence of salmonids 10 Type of Habitat Improvement Provided Improve quality of existing buffer / riparian vegetation without widening 4 86 -DR22 Flooding Point Descriptions Risk of Failure Adjustment Risk of Failure (0 -1). Existing Condition Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) FRIDAY, NOVEMBER 14, 2003 Total Project Benefit Points: 84 Points C -167 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Number of Properties Affected > 10 properties 10 Recurrence, Existing or Expected Occurs 1 or more times per year 4 Type of Roadway Flooding Addressed by the Project Low Use Street 10 Water Depth Multiplier Flooding depth less than 6- inches 1 Failure Condition Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) 1 Number of Properties Affected > 10 properties 10 Recurrence, Existing or Expected Occurs 1 or more times per year 4 Type of Roadway Flooding Addressed by the Project Low Use Street 10 Water Depth Multiplier Flooding depth Tess than 6- inches 1 Total Project Benefit Points: 80 94 -DRO5A Erosion . Point Descriptions Points Benefits of Repairing Erosion Problem Moderate benefits to stream channel and/or water quality 10 Type of Problem Addressed Concentrated erosion at outfall or streambank 20 Habitat Point Descriptions Points Length of Stream Reach Improved by Project between 100 feet and 250 feet 4 Presence of Fish In Project Area Known presence of salmonids 10 94 -DRO5B Erosion Point Descriptions C -168 Total Project Benefit Points: 70 Points Benefits of Repairing Erosion Problem Moderate benefits to stream channel and/or water quality 10 Type of Problem Addressed Concentrated erosion at outfall or streambank 20 Habitat Point Descriptions Points Length of Stream Reach Improved by Project between 100 feet and 250 feet 4 Presence of Fish In Project Area Known presence of salmonids 10 Total Project Benefit Points: 70 FRIDAY, NOVEMBER 14, 2003 • • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Gilliam 00 -DR10 Flooding Point Descriptions Risk of Failure Adjustment Risk of Failure (0 -1) Existing Condition Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) Number of Properties Affected 1 property Recurrence, Existing or Expected Flooding every 2 -5 years Type of Roadway Flooding Addressed by the Project High Use Street Water Depth Multiplier Flooding depth equal or greater than 6- inches Failure Condition Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) Number of Properties Affected 1 property Recurrence, Existing or Expected Occurs 1 or more times per year Type of Roadway Flooding Addressed by the Project High Use Street Water Depth Multiplier Flooding depth equal or greater than 6- inches Points 0.5 2 3 15 2 1 2 4 15 2 Total Project Benefit Points: 112 03 -DRO5 Flooding Point Descriptions Points Risk of Failure Adjustment Risk of Failure (0 -1) Existing Condition Multiplier for Type of Property Affected Private driveway, garage, or parking lot Number of Properties Affected 1 property Recurrence, Existing or Expected Flooding frequency less than 5 years Failure Condition Multiplier for Type of Property Affected Private driveway, garage, or parking lot Number of Properties Affected 1 property Recurrence, Existing or Expected Occurs 1 or more times per year 0.8 2 2 2 2 4 Total Project Benefit Points: 14 03 -DRO6 Flooding Point Descriptions Points Risk of Failure Adjustment Risk of Failure (0 -1) Existing Condition Multiplier for Type of Property Affected Private driveway, garage, or parking lot FRIDAY, NOVEMBER 14, 2003 0.5 2 C -169 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Number of Properties Affected > 10 properties 10 Recurrence, Existing or Expected Flooding frequency less than 5 years 2 Type of Roadway Flooding Addressed by the Project Low Use Street 10 Water Depth Multiplier Flooding depth Tess than 6- inches 1 Failure Condition Multiplier for Type of Property Affected Private driveway, garage, or parking lot 2 Number of Properties Affected > 10 properties 10 Recurrence, Existing or Expected Occurs 1 or more times per year 4 Type of Roadway Flooding Addressed by the Project High Use Street 15 Water Depth Multiplier Flooding depth equal or greater than 6- inches 2 Total Project Benefit Points: 130 03 -DRO9 Flooding Point Descriptions Points Project Eliminates or Reduces Maintenance Needs Yes Risk of Failure Adjustment Risk of Failure (0 -1) Existing Condition • Type of Roadway Flooding Addressed by the Project High Use Street Water Depth Multiplier Flooding depth equal or greater than 6- inches Failure Condition Multiplier for Type of Property Affected Private driveway, garage, or parking lot Number of Properties Affected > 10 properties Recurrence, Existing or Expected Occurs 1 or more times per year Type of Roadway Flooding Addressed by the Project High Use Street Water Depth Multiplier Flooding depth equal or greater than 6- inches 2 0.8 15 2 2 10 4 15 2 Total Project Benefit Points: 172 03 -DR15 Water Quality Point Descriptions Points C -170 Effectiveness of Improvement Proposed improvements would moderately improve water quality 10 Type of Water Body Affected Stream 10 Total Project Benefit Points: 20 FRIDAY, NOVEMBER 14, 2003 • • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 03 -DR16 Habitat Point Descriptions Points Length of Stream Reach Improved by Project between 100 feet and 250 feet 4 Presence of Fish in Project Area Known presence of salmonids 10 Type of Habitat Improvement Provided Rearing pools 6 Large woody debris to stablize channel and/or enhance habitat diversity 4 Improve quality of existing buffer / riparian vegetation without widening 4 Total Project Benefit Points: 96 03 -DR17 Water Quality Point Descriptions Points Effectiveness of Improvement Proposed improvements would significantly improve water quality 25 Type of Water Body Affected Stream 10 Total Project Benefit Points: 35 86 -DR17 Flooding Point Descriptions Points Project Eliminates or Reduces Maintenance Needs Yes Risk of Failure Adjustment Risk of Failure (0 -1) Existing Condition Type of Roadway Flooding Addressed by the Project High Use Street Water Depth Multiplier Flooding depth equal or greater than 6- inches Failure Condition Multiplier for Type of Property Affected Private driveway, garage, or parking lot Number of Properties Affected > 10 properties Recurrence, Existing or Expected Occurs 1 or more times per year Type of Roadway Flooding Addressed by the Project High Use Street Water Depth Multiplier Flooding depth equal or greater than 6- inches 2 0.8 15 2 2 10 4 15 2 Total Project Benefit Points: 172 98 -DRO5 Habitat Point Descriptions Points Length of Stream Reach Improved by Project 100 feet or less Number of of Fish Passage Barriers Downstream of Project No barriers downstream of project Presence of Fish in Protect Area Known presence of salmonids FRIDAY, NOVEMBER 14, 2003 2 10 10 C -171 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Project Corrects Fish Passage Restriction Removes a complete barrier and replaces with effective passage 10 Project Enables Fish Access to Upstream Habitat for Length of: Greater than 250 feet 10 Total Project Benefit Points: 50 Nelson Place /Longacres 03 -DR19 Habitat Point Descriptions Points Length of Stream Reach Improved by Project between 100 feet and 250 feet 4 Presence of Fish in Project Area Known presence of salmonids 10 Type of Habitat Improvement Provided Rearing pools 6 Increase buffer width (with good quality buffer characteristics) 10 Large woody debris to stablize channel and/or enhance habitat diversity 4 Off - channel or side channel rearing habitat 8 Total Project Benefit Points: 152 87 -DRO2 Flooding Point Descriptions Points Risk of Failure Adjustment Risk of Failure (0 -1) Existing Condition Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) Number of Properties Affected 1 property Recurrence, Existing or Expected Flooding every 2 -5 years Failure Condition Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) Number of Properties Affected 1 property Recurrence, Existing or Expected Flooding every 2 -5 years P -17 03 -DRO8 Flooding Point Descriptions Risk of Failure Adjustment Risk of Failure (0 -1) Existing Condition Multiplier for Type of Property Affected Private driveway, garage, or parking lot Number of Properties Affected 2 -4 properties Recurrence, Existing or Expected Flooding every 2 -5 years C -172 1 1 2 3 1 2 3 Total Project Benefit Points: 6 Points 0.25 2 4 3 FRIDAY, NOVEMBER 14,2003 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Type of Roadway Flooding Addressed by the Project High Use Street 15 Water Depth Multiplier Flooding depth less than 6- inches 1 Failure Condition Multiplier for Type of Property Affected Private driveway, garage, or parking lot 2 Number of Properties Affected 2 -4 properties 4 Recurrence, Existing or Expected Occurs 1 or more times per year 4 Type of Roadway Flooding Addressed by the Project High Use Street 15 Water Depth Multiplier Flooding depth equal or greater than 6- inches 2 03 -DR18 Water Quality Point Descriptions Total Project Benefit Points: 90 Points Effectiveness of Improvement Proposed improvements would moderately improve water quality 10 Type of Water Body Affected Wetland or Pond 6 Total Project Benefit Points: 16 Riverton 03 -DR1O Erosion Point Descriptions Points Benefits of Repairing Erosion Problem Moderate benefits to stream channel and/or water quality 10 Type of Problem Addressed Concentrated erosion at outfall or streambank 20 Flooding Point Descriptions Points Risk of Failure Adjustment Risk of Failure (0 -1) Failure Condition Recurrence, Existing or Expected Occurs 1 or more times per year Type of Roadway Flooding Addressed by the Project High Use Street Water Depth Multiplier Flooding depth less than 6- inches Habitat Point Descriptions 0.1 4 15 1 Points Length of Stream Reach Improved by Project between 100 feet and 250 feet 4 Presence of Fish In Project Area Known presence of salmonids 10 Type of Habitat Improvement Provided Large woody debris to stablize channel and/or enhance habitat diversity 4 Spawning gravel 4 Rearing pools 6 FRIDAY, NOVEMBER 14, 2003 C -173 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN ' NOVEMBER 2003 Water Quality Point Descriptions Points Effectiveness of Improvement Proposed improvements would moderately improve water quality 10 Type of Water Body Affected Stream 10 03 -DR11 Water Quality Point Descriptions . - Total Project Benefit Points: 152 Points Effectiveness of Improvement Proposed improvements would moderately improve water quality 10 Type of Water Body Affected Stream 10 98 -DRO3 Habitat Point Descriptions Total Project Benefit Points: 20 Points Length of Stream Reach Improved by Project between 100 feet and 250 feet 4 Number of of Fish Passage Barriers Downstream of Project No barriers downstream of project 10 Presence of Fish in Project Area Known presence of salmonids 10 Project Corrects Fish Passage Restriction Improves upon a partial barrier 5 Project Enables Fish Access to Upstream Habitat for Length of: Greater than 250 feet 10 Type of Habitat Improvement Provided Large woody debris to stablize channel and /or enhance habitat diversity 4 Off- channel or side channel rearing habitat 8 Improve quality of existing buffer / riparian vegetation without widening 4 98 -DRO7 Water Quality Point Descriptions Total Project Benefit Points: 129 Points Effectiveness of Improvement Proposed improvements would moderately improve water quality 10 Type of Water Body Affected Green/Duwamish River 2 Stream 10 Southgate 03 -DRO4 Flooding Point Descriptions Risk of Failure Adjustment Risk of Failure (0 -1) C -174 Total Project Benefit Points: 22 Points 0.25 FRIDAY, NOVEMBER 14, 2003 • • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Existing Condition. Multiplier for Type of Property Affected Private driveway, garage, or parking lot Number of Properties Affected > 10 properties Recurrence, Existing or Expected Flooding frequency Tess than 5 years Type of Roadway Flooding Addressed by the Project Low Use Street Water Depth Multiplier Flooding depth less than 6- inches Failure Condition Multiplier for Type of Property Affected Private driveway, garage, or parking lot Number of Properties Affected > 10 properties Recurrence, Existing or Expected Occurs 1 or more times per year Type of Roadway Flooding Addressed by the Project High Use Street Water Depth Multiplier Flooding depth less than 6- inches 03 -DR12 Erosion Point Descriptions Benefits of Repairing Erosion Problem Moderate benefits to stream channel and/or water quality Type of Problem Addressed Concentrated erosion at outfall or streambank Flooding Point Descriptions Risk of Failure Adjustment Risk of Failure (0 -1) Failure Condition Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) Number of Properties Affected 5 -9 properties Recurrence, Existing or Expected Flooding every 2 -5 years Habitat Point Descriptions Length of Stream Reach Improved by Project 100 feet or Tess Presence of Fish In Project Area Known presence of salmonids Type of Habitat Improvement Provided Large woody debris to stablize channel and/or enhance habitat Rearing pools 03 -DR13 Flooding Point Descriptions Risk of Failure Adjustment Risk of Failure (0 -1) Failure Condition Recurrence, Existing or Expected FRIDAY, NOVEMBER 14, 2003 2 10 2 10 1 2 10 4 15 1 Total Project Benefit Points: 80 diversity Points 10 20 Points 0.5 1 7 3 Points 2 10 4 6 Total Project Benefit Points: 80 Points 0.25 C-1 75 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Occurs 1 or more times per year 4 Type of Roadway Flooding Addressed by the Project High Use Street 15 Water Depth Multiplier Flooding depth Tess than 6- inches 1 Habitat Point Descriptions Points Length of Stream Reach Improved by Project between 100 feet and 250 feet 4 Number of of Fish Passage Barriers Downstream of Project 1 barrier downstream of project 5 Presence of Fish in Project Area Known presence of salmonids 10 Project Corrects Fish Passage Restriction Improves upon a partial barrier 5 Project Enables Fish Access to Upstream Habitat for Length of: Greater than 250 feet 10 Type of Habitat Improvement Provided Rearing pools 6 Large woody debris to stablize channel and/or enhance habitat diversity 4 Total Project Benefit Points: 115 03 -DR14 Flooding Point Descriptions Points Risk of Failure Adjustment Risk of Failure (0 -1) 0.25 Failure Condition Multiplier for Type of Property Affected Landscaped property or farm use (but not pasture) 1 Number of Properties Affected 1 property 2 Recurrence, Existing or Expected Occurs 1 or more times per year 4 Habitat Point Descriptions Points Length of Stream Reach Improved by Project between 100 feet and 250 feet 4 Presence of Fish in Project Area Known presence of salmonids 10 Type of Habitat improvement Provided Large woody debris to stablize channel and /or enhance habitat diversity 4 Improve quality of existing buffer / riparian vegetation without widening 4 Rearing pools 6 Total Project Benefit Points: 98 03 -DR21 Erosion Point Descriptions Points Benefits of Repairing Erosion Problem Moderate benefits to stream channel and/or water quality 10 Type of Problem Addressed Sheet erosion along roadway or streambank, 10 Habitat Point Descriptions Points Length of Stream Reach Improved by Protect between 100 feet and 250 feet Presence of Fish in Project Area C -176 4 FRIDAY, NOVEMBER 14, 2003 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Known presence of salmonids 10 Type of Habitat Improvement Provided Rearing pools 6 Large woody debris to stablize channel and/or enhance habitat diversity 4 Off- channel or side channel rearing habitat 8 FRIDAY, NOVEMBER 14, 2003 Total Project Benefit Points: 132 C -177 Appendix D Low Impact Development • • TECHNICAL MEMORANDUM CH2MHILL City of Tukwila Comprehensive Surface Water Management Plan Appendix D —Low Impact Development PREPARED FOR: PREPARED BY: COPIES: DATE: 1. Introduction Ryan Larson, City of Tukwila Jill Mosqueda, City of Tukwila Eric Wolin, CH2M HILL John Rogers, CH2M HILL Roger Kitchin, CH2M HILL Dennis Galinato, CH2M HILL September 18, 2003 1.1. What is Low Impact Development? Low impact development is an approach to managing surface water that mimics natural predevelopment hydrology by using various techniques that infiltrate, filter, store, evaporate, and detain runoff as close to its original source as possible. Also referred to as "natural drainage," low impact development is a different approach than conventional systems that convey stormwater runoff to large facilities where runoff is detained and pollutants are removed. In a forest, less than 1 percent of the annual rainfall becomes surface runoff. Approximately 25 percent of the annual rainfall makes its way to a stream by moving through shallow soils, with the remainder infiltrating into deeper soils or taken up by vegetation. In a developed environment, trees and topsoil are removed and replaced with rooftops, - pavement, and compacted soil. These hard surfaces typically result in 35 percent of the annual rainfall becoming surface runoff, which is directly routed to streams, lakes, rivers, or Puget Sound. This runoff greatly increases the peak flows and volumes discharged to streams, which results in high rates of streambank erosion, flooding, damage to fish habitat, and reduced dry weather flows. Also, this runoff introduces pollutants and increases stream temperatures. Conventional surface water management facilities are costly and only moderately effective in mitigating these problems. Low impact development more closely resembles natural processes than systems designed to meet conventional surface water management requirements, such as the King County or Ecology Manual that addresses increases in peak flows from large, infrequent events but does not address the increase in annual volume or increases in peak flows from small frequent events. Low impact development can infiltrate and treat 95 percent or more of the annual volume, and can be integrated into both redevelopment and new development projects. Some of the more common. Low impact development techniques are: SEA31001174163.D0G032460008 D -1 CITY OF TUKWILA APPENDIX D —LOW IMPACT DEVELOPMENT COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 • Disconnectivity — Direct runoff from impervious areas to landscaped and vegetated areas to reduce the volume of runoff, encourage groundwater recharge, and filter runoff. • Bioretention — Construct landscaped areas with a special soil and plant mix that is conducive to filtering and storing runoff and is aesthetically attractive. • Permeable Pavements — Install porous concrete, porous asphalt, geo -grid, or pavement blocks that allow water to flow to an underground gravel area where water can infiltrate and /or be slowly released. • Open Swales — Provide grass or other vegetated areas at the edges of parking lots or other runoff- producing areas to slow and filter the runoff, promote infiltration, and remove pollutants. • Vegetated (Green) Rooftops — Provide a combination of special planting media and vegetation as a flat roof cover. These "green roofs" reduce the energy costs of the building, enhance air quality, and conserve land that would otherwise be required for stormwater runoff controls. 1.2. What are the Benefits of Low Impact Development? Studies published by the U.S. Environmental Protection Agency (EPA) and various scientific journals are beginning to show that efforts to mitigate the effects of development through traditional surface water management practices have not proven entirely successful. Locally, surface water management in the Northwest has not been effective in preserving critical habitat for salmonids. Conventional collection, conveyance, detention, and treatment systems can effectively remove some pollutants, but during the process of conveyance and treatment, natural hydrological functions are affected. These conditions result in flooding, water quality degradation, stream erosion, and the need to construct and maintain costly end -of -pipe best management practices (BMPs) that are only moderately effective. The traditional surface water management practice of detention addresses peak flows from large, infrequent events but does not address the increases in volume discharged to streams or the increases in peak flows from small, frequent storms. The effective use of low impact development practices can result in both economic and environmental benefits. Economic benefits include construction cost savings for smaller stormwater facilities and fewer control mechanisms, as well as long -term operation and maintenance of stormwater facilities. According to an EPA publication, Low Impact Development: A Literature Review, an alternative low impact development stormwater control design for a new 270 -unit apartment complex in Aberdeen, North Carolina, will save the developer approximately 72 percent, or $175,000 of the stormwater construction costs (EPA, 2002). Environmental benefits include better - protected watershed hydrology that can lead to enhanced aquatic habitat for endangered species. Studies for Pierce County and the City of Seattle by CH2M HILL have demonstrated that low impact development can infiltrate and treat between 95 to 100 percent of the annual volume of rainfall on till soils in this region. These studies have also demonstrated that the costs to do this are less than the traditional approach of detention and treatment. D -2 SEA31001 na163.DOG032460008 CITY OF TUKWILA APPENDIX D -LOW IMPACT DEVELOPMENT COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 110 1.3. What are the Issues and Drawbacks of Low Impact Development? To effectively apply low impact development, a set of specific principles and Best Management Practices (BMPs) must be developed to address the unique landscape features and water resource protection objectives. For example, a city that lies in a valley will have to implement a different combination of BMPs than a city located at a higher elevation that has different hydrological characteristics. Furthermore, each city may have different surface water management objectives that are based on their community goals and policies and compliance with regional, state, and federal regulations. Cities with salmon - bearing streams and other critical areas will have different needs and standards to comply with than others without those features. In some cases, it may be necessary to use traditional surface water management structural BMPs in conjunction with low impact development techniques to achieve watershed objectives. The appropriateness of these techniques is dependent on a variety of site conditions, some of which can be generally characterized and located via a Geographic Information System (GIS) across a city. The most typical, and important, are: • Soil permeability • Water table depth • Land slope Identifying these characteristics will help reduce the application of an low impact development technique that is not appropriate for a site or area. For example, enhancing infiltration with grasscrete, pavers, or others in an area upgradient of where landslide • hazards are high could potentially accelerate the occurrence of landslides. Figure D -1 shows areas where infiltration facilities are not allowed by the City. In addition to physical constraints, community perception of low impact development may prevent its successful implementation, which can have numerous aspects. The city's policies and goals (that is, within its comprehensive plan) help guide future decisions regarding surface water management, land use, and the environment. Acceptance by developers and homeowners is also important, in addition to the city's development -code support of low impact development use. The following sections provide the types of changes that would need to occur to a city's policy and regulation framework to effectively implement this alternative approach to development and the related stormwater facilities. • 2. Implementing Low Impact Development Implementation of low impact development concepts requires regulatory changes and education and may require incentives until the practices are demonstrated to be successful locally. For example, land use regulations often have surface water management requirements that do not "credit" the benefits provided by these concepts, and have street standards that often prohibit the narrow streets recommended to reduce impervious surfaces. SEA31001174163.DOC/032460008 D -3 1 t_ it,Slrander Sled LEGEND %� Areas where infiltration not allowed Corporate Dr N SW 43' Figure D -1 Areas Where Infiltration is not Allowed City of Tukwila Comprehensive 0 4,000 Feet Surface Water Management Plan • CITY OF TUKWILA APPENDIX D -LOW IMPACT DEVELOPMENT COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER2003 2.1. Comprehensive Plan Policy Changes A city's comprehensive plan provides long -term guidance for managing a number of elements that are key to a city's growth and positive future. If low impact development is to be encouraged, it is important that a city's comprehensive plan include goals and /or policies that promote and encourage its implementation. Updated policies should draw the connection that low impact development techniques can help reduce drainage, flooding, and water quality problems, as well as impacts to fish and wildlife habitat. Below is one example of a policy that could be included within the "Environmental" or "Stormwater" element of the City of Tukwila's Comprehensive Plan: "The City shall protect groundwater recharge by promoting low impact development /natural drainage techniques that infiltrate runoff where site conditions permit, except where potential groundwater contamination cannot be prevented by pollution source controls and stormwater pretreatment." To help show how low impact development incorporates land use practices, surface water management, and the environment, policies encouraging the use of low impact development should be included in the comprehensive plan. Below is an example of a land use policy that encourages low impact development: Example of Low Impact Development - Supportive Land Use Policy — Minimize the amount of impervious surfaces in new development through the use of appropriate low impact development /natural drainage techniques, and removing paved areas or using retrofit options in existing developments, where applicable, to minimize runoff. 2.2. Regulatory Changes Subdivision codes, zoning regulations, parking and street standards, and other local ordinances that make up a city's development code may restrict innovative practices that would reduce impervious cover. These rules are responsible for wide streets, expansive parking lots, and large -lot subdivisions that reduce open space and natural features (EPA, 2002). Development rules that discourage the implementation of those practices should be modified to accommodate a "greener" way of managing stormwater. Guidance documents that help cities comply with state and federal regulations are beginning to encourage low impact development practices. "New Ecology Stormwater Manual Promotes Low Impact Development" acknowledges that Washington's streams need protection through aggressive application of these techniques (O'Brien and Barrett, 2001), and Ecology's newly published Stormwater Management Manual for Western Washington promotes these in several ways (Ecology, 2001). Under this manual, a detention pond designed to serve a standard residential development (that is, with conventional measures) of four homes per acre is required to be 1.4 to 4 times larger than required by the old standard. Therefore, if the developer resorts to standard development practices, and does not implement low impact development techniques, a loss of potential building area will occur. National Oceanic and Atmospheric Administration (NOAA) Fisheries Service recently published a document entitled ESA Guidance for Analyzing Stormwater Effects that includes SEA31001174163.DOCJ032460008 D -5 CITY OF TUKWILA APPENDIX D -LOW IMPACT DEVELOPMENT COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 model terms and conditions for local governments to follow (NOAA Fisheries, 2003) to encourage low impact development that will result in surface water quality and quantity within their jurisdictions that support ESA - listed fish. The document goes on to list specific BMPs that use natural watershed features and processes to minimize or avoid effects of stormwater runoff, while mentioning that new development should be required to explore these types of BMPs before an applicant resorts to engineered methods of treatment. Regulatory changes can be difficult to implement because of concerns over new practices, particularly by the public and developers who are accustomed to current requirements and conventional facilities. For example, homeowners may hold the belief that without curbs and gutters their houses may be flooded, developers may prefer conventional detention ponds, with which they have extensive experience, and city staff may be wary of the potential increase in maintenance requirements. If concerns can be identified, it is possible to show that low impact development can provide many benefits, including functional, cost, aesthetic, and reliability. 2.3. Opportunities for Low Impact Development Implementation Opportunities to implement these techniques can include: • Actions to encourage inclusion of low impact development with private projects • Modification of projects currently on the City's CIP to incorporate low impact development techniques • Development of projects that demonstrate low impact development Public projects offer opportunities to set a good example and demonstrate the feasibility of these innovative practices. One way to start is by making modifications to a city's CIP projects list. Permeable pavements can be applied to a street or parking lot re- paving CIP. These surfaces are appropriate for low- traffic areas, such as parking lots and sidewalks, and allow stormwater to infiltrate into underlying soils, thus promoting pollutant treatment and recharge of groundwater. Other opportunities include reduction of street widths, shared driveways and parking lots, center islands in cul -de -sacs, and replacement of curb and gutters with drainage swales or landscaped areas. Combining these techniques with planned CIPs results in a "two- fold" effect for cities: they can reduce the overall rate and flow of runoff while satisfying the original objectives of the project. Low impact development techniques may be applied in the following projects /areas: • Tukwila Village • Tukwila Manufacturing /Industrial Center • CIP 8G -DR22: S. 143rd Street /Place Storm Drain System • CIP 03 -DR01: S. 53rd Street Storm Drain System • CIP 03 -DR04: S. 146th Street Pipe and 35th Avenue S. Drainage System • CIP 03 -DR06: Northwest Gilliam Storm Drainage System D -6 SEA31001174163.1300032460008 CITY OF TUKWILA APPENDIX D -LOW IMPACT DEVELOPMENT COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 • Public, private, and public /private redevelopment projects such as the Tukwila Urban Center • Residential areas where local, low- traffic streets need to be rebuilt or have significant subsurface utility installation or replacement, such as the areas between I -5 and Inter- national Boulevard 3. Conclusions Low impact development techniques provide an opportunity for restoring the natural hydrological characteristics of a watershed, while providing numerous other quantifiable and qualitative benefits to a community. These measures can be applied in conjunction with conventional stormwater practices to form hybrid solutions to managing surface water, where necessary, to address critical peak flow issues from large infrequent events. Implementing them can reduce government's exposure to incidental "takes" of endangered species, such as salmonids. 4. Action Items The City should perform a study to gain a better understanding of potential low impact development applications and the impacts of implementing low impact development in the city. At a minimum, the study should include the following: 1. Review of the current and future Department of Public Works Capital Improvement Program (CIP) projects to identify opportunities to implement low impact development techniques. 2. Review of the comprehensive land use plan, zoning, drainage, building codes and street standards. Identify barriers to low impact development practices and recommend changes to encourage these practices. 3. Education on low impact development for staff and developers. 4. Recommendations for new regulations and incentives for low impact development implementation. 5. References Center for Watershed Protection. Better Site Design: A Handbook for Changing Development Rules in Your Community. 1998. Department of Ecology (Ecology). Stormwater Management Manual for Western Washington. September 2001. Environmental Protection Agency (EPA). Low Impact Development: A Literature Review. EPA- 841-B-00-005. Office of Water, Washington, October 2002. National Oceanic and Atmospheric Administration (NOAA) Fisheries Service. ESA Guidance for Analyzing Stormwater Effects. HCD Stormwater On -Line Guidance, March 2003. SEA31001174163.D0G032460008 D -7 CITY OF TUKWILA APPENDIX D -LOW IMPACT DEVELOPMENT COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 O'Brien, Ed and Tony Barrett. "New Ecology Stormwater Manual Promotes Low Impact Development." Sound Waves. Vol. 16, No. 4, Puget Sound Water Quality Action Team, Fall 2001. D -8 SEA31001174163.DOC/032460008 Appendix E Operations and Maintenance • • TECHNICAL MEMORANDUM CH2MHILL Ci ty of Tukwila Comprehensive Surface Water Management Plan Appendix E— Operations and Maintenance PREPARED FOR: PREPARED BY: COPIES: DATE: 1. Introduction Ryan Larson, City of Tukwila Jill Mosqueda, City of Tukwila Dennis Galinato, CH2M HILL Mark Ewbank, Herrera Environmental Roger Kitchin, CH2M HILL John Rogers, CH2M HILL November 7, 2003 This technical memorandum: • Documents the City of Tukwila's existing surface water operations and maintenance (O &M) program • Makes recommendations to increase the efficiency and effectiveness of the existing surface water O &M program • Provides guidance for all City maintenance departments and other City operations to meet federal regulations regarding water quality and the protection of natural surface water resources. 1.1 Background As in all areas of surface water management in the City of Tukwila, the O &M program aims to protect public health, safety, and welfare, and to protect the natural surface water resources. To meet these goals, the surface water O &M program: • Responds to citizen complaints regarding surface water problems • Observes and documents new and existing drainage problems • Maintains and operates surface water facilities The goals of other divisions of the O &M program (sewer, streets, and water) and City facilities (for example, pools, community centers, and fire departments) are not focused directly on surface water management. However, operations from these programs and facilities may affect surface water, and they must meet requirements of various federal surface water regulations. SEA31002059530.DOC/032660007 E -1 CITY OF TUKWILA APPENDIX E -OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 2. Existing O &M Program 2.1 Structure The surface water division of the O &M Department conducts most of the surface water maintenance activities in the City. The department is staffed by. the Surface Water Superintendent, Surface Water Foreman, and four maintenance technicians. The street division maintains ditches located in the right of way and storm drain system. outfalls. The surface water division funds this work, which is included in the average annual O&M budget summary described in Section 2.2. 2.2 Maintenance Activities CH2M HILL and Herrera staff met City public works personnel on March 29, 2003, to review the City's existing O &M activities. Attachment A summarizes the existing O &M tasks and estimated annual costs. City staff provided quantities and labor and equipment costs. 2.2.1 Berms Asphalt berms are installed on an as- needed basis. Berms are constructed along existing catch basins and improperly placed catch basins in response to complaints of road runoff flowing onto private property. Approximately 200 linear feet of asphalt berms are constructed per year. 2.2.2 Streets Street sweeping helps reduce localized flooding by preventing debris from blocking catch basins and driveway culverts. Preventing sediment and debris from entering drainage systems also helps improve water quality. City street maintenance crews perform street sweeping with a vacuum and mechanical sweeper. The surface water maintenance budget does not fund this work; therefore, this work is not included in the O &M cost summary in Attachment A. 2.2.3 Ditches Maintenance staff keep an informal list of problem areas in the City ditch system. These problem areas are maintained every 3 to 5 years. Crews maintain approximately 9,600 linear feet of ditch annually (the total amount of ditch in the City is approximately 1,000,000 linear feet). Maintenance consists of removal of ditch vegetation and excess sediments with a backhoe and ditch bucket, coupled with dump truck hauling. To maintain hydraulic capacity, sediments are removed. In addition, mowing, brush cutting, and headwall and trash rack maintenance /repair are performed on an as- needed basis. 2.2.4 Pipes The City's piped storm drainage system (approximately 50,000 linear feet) has been delineated into zones by the Public Works staff. Pipe system maintenance is scheduled by E -2 SEA31002059530.DOC/032660007 • • CITY OF TUKWILA APPENDIX E- OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 zone, and each zone is maintained on a 3- to 5 -year cycle. Pipe system maintenance includes cleaning and repair of catch basins as well as the storm drainage pipes. As with the ditch systems, particular attention is given to chronic problem areas, and areas for which complaints have been received from citizens. A standard method for leaning has been established and is generally followed. The method involves measuring accumulations of sediments in basins. If sediments are greater than 6 inches in depth, the basin is cleaned. Jetting and rodding of pipes are performed on an as.- needed basis. 2.2.5 TV Inspections Every year approximately 5,000 linear feet of existing pipe is inspected with TV equipment. TV inspections help identify illegal connections to drainage systems and damaged sections of pipe. TV inspections are also a useful tool when creating an inventory of the storm drainage system. 2.2.6 Outfells Drainage system outfalls into the Green /Duwamish River are inspected twice a year. The City has recorded the locations of 75 outfalls; however, the outfalls are not yet included in the Geographic Information System (GIS) database. Outfall maintenance includes mowing, brush cutting, herbicide application, clearing debris from pipe /ditch, and installing /repairing energy dissipation (for example, rip -rap splash pads). Street maintenance crews perform vegetation maintenance; however, the surface water maintenance budget funds this work. 2.2.7 Water Quality and Retention/Detention Facilities The City maintains a variety of water quality (WQ) and retention /detention (R /D) facilities. These facilities include Stormceptors, water quality ponds, R/D ponds, R/D vaults, and R/D pipes. Table E -1 lists the WQ and R/D facilities the City maintains. TABLE E -1 Water Quality and Retention/Detention Facilities Facility Name Location Function PONDS 42nd Avenue Detention Pond 40th Avenue Tank/Pond P -17 Channel Pond Tukwila Pond S. 180th Street Pond and Wetland Interurban Bridge Pond (new) SEA31002059530.DOC/032660007 East of 42nd Avenue S. CO S. 152nd St. West along 40th Ave. S. © S. 134th St. End of Minkler Blvd. c- Green River Andover Park West south of Target Near railroad underpass — Pump Sta. 16 Interurban ® Green River R/D R/D R/D R/D WQ Unknown E -3 CITY OF TUKWILA APPENDIX E -OPERATIONS AND MAINTENANCE COMPREHENSNE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE E -1 Water Quality and Retention/Detention Facilities Facility Name Location Function VAULTS 51st Avenue Vault Mapletree Vault West of 51st, south of 144th St. @ Bonsai S. 151st PI. and 62nd PI. S. Unknown Unknown Silverview Vault 51st Avenue /160th St. Vault 53rd Avenue Vault 42nd/139th Vault 42nd/142nd Vault Macadam Road Vault Fosterview Vaults Interurban Bridge Vault (new) 53rd PI. S. south of Slade Way 51st Avenue S. @ South 160th Street 53rd Avenue S. south of Klickitat Dr. 42nd Avenue S. CAD S.139th Street 42nd Avenue S. © S.142nd Street Macadam Rd. near S. 137th St. 43rd PI. S. near S .137th Street Interurban Bridge at Green River STORMCEPTOR SE Corner of TIB and S. 139th Street SE Corner of TIB and S. 146th Street SE Comer of TIB and S. 148th Street Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown WQ WQ WQ Facility maintenance includes vegetation control, control structure repair, and application of biological controls for mosquito larvae and other pests. Sediment removal is performed once every 10 years. 2.2.8 Streams Inspection of open channel sections, plunge pools, and outlet structures is done in response to citizen complaints and as part of the downstream analysis required by the King County Surface Water Design Manual during development of private and OP projects. Maintenance is performed when required. Stream system maintenance includes sediment removal, rip -rap placement at outfalls, repair /fill plunge pools, hydroseeding, and watercress removal. 2.2.9 Pumps Pump stations that the City currently owns or will own in the future are listed in Table E -2 The P -17 pump station is located in the City, but it is owned and operated by King County. E -4 SEA31002059530.DOC/032660007 CITY OF TUKWILA APPENDIX E -OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE E -2 City-Owned Pump Stations Station Name Location Status 15 5880 S. 180th Street In operation 16 7500 S. 180th Street In operation 17 Strander Boulevard Under design 18 Allentown — 4225 S. 122nd Street In operation The City performs annual inspections of the pump stations and monitors the stations during storm events. Removal of sediment in the forebay and repairs of the pump stations are performed when required. Equipment overhauls are done in accordance with recommendations of the manufacturer of pumps and monitoring equipment. 2.2.10 Waste Disposal Saturated solids cleaned from the City drainage systems are currently stored in the undeveloped area south of I -405 between the Burlington Northern Railroad and West Valley Highway. This area is not considered a permanent location for storing waste products from the City's O &M activities because it may be redeveloped in the future. 2.2.11 Training/Education City crews receive annual safety training, which includes traffic control flagging, trench shoring, and first aid. Other training includes operation and maintenance of pump systems, electrical systems, and vactor equipment. Maintenance crews also receive an annual informal update on federal and state regulations that affect O &M activities. 2.2.12 Miscellaneous In addition to the activities listed above, City maintenance crews are responsible for the following: • Emergency flooding response during large storm events. This includes levee flood patrol along the Green /Duwamish River. City crews begin patrolling with King County staff during flood phase 2 (see Table E -3). • Hazardous material spills response. City crews are only responsible for spills within the ROW, but they are often the first group to respond to spill complaints regardless of where they are located. SEA31002059530.DOC/032660007 E -5 CITY OF TUKWILA APPENDIX E- OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE E -3 Green River Flood Phase Information Phase Flow and Auburn Gage (cfs) Description Condition 1 2 4 5,000 Internal alert 7,000 Minor flooding 9,000 Moderate flooding Lowland flooding in valley upstream of Auburn Flooding of varied depths occurs in valley upstream of Auburn and lower Mill Creek basin. SE Green Valley Rd and West Valley Rd may overtop. 12,000 Extreme flooding Levees may exhibit seepage and/or weaken from saturation 3. Complaint Response The City responds to all surface water - related complaints that are submitted by residents and business owners. Complaints are submitted to the City in the following ways: • Request for Action (RFA) • City Council Meetings • Letters • E -mail • Telephone complaints RFAs are available at the Public Works Office and provide a record of the party filing the complaint, the type of complaint, and the action taken. Complaints received at City Council meetings, and from letters and e-mail are usually recorded as RFAs. Telephone complaints are forwarded to, and addressed by, the surface water division of the O &M Department. However, the City keeps no records. Ten to 20 RFAs have been recorded annually in the City since 1999. Because telephone complaints are unrecorded, the total number of complaints submitted to the City is unknown. Most complaints were solved by asphalt berming, installing new catch basin /pipe, or cleaning ditches. The Capital Improvement Program's Small Drainage projects addressed some complaints. Other complaints were not the City's responsibility. These complaints include incidents of downspouts flooding neighbors' crawl spaces or damaging structural foundations. 4. Maintenance Management System The surface water maintenance department is currently developing a maintenance management systems (MMS) database. The MMS will be used to track hours and material costs spent completing O &M activities, complaints, and problem locations. The information E -6 SEA31002059530.DOC/032660007 • • CITY OF TUKWILA APPENDIX E- OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 logged in the MMS would allow the City to locate problem "hotspots" and set O &M budgets. 5. Regulatory Compliance City of Tukwila staff are involved in a variety of O &M activities that can potentially affect surface waters. In addition to the Public Works divisions involved in O &M activities for streets, sewers, surface water systems, and water systems, several other City departments perform O &M activities in outdoor areas with potential for surface water impacts. O &M activities may cause degradation of receiving water quality if appropriate BMPs are not implemented. The City is faced with many environmental regulations related to surface water protection that require application of effective BMPs in relation to routine O &M activities. This section describes the activities performed at City -owned facilities and in the field by City crews that can potentially impact surface water quality, and the BMPs that are implemented in conjunction with those activities to protect surface water quality. The section concludes with recommendations for additional evaluation of O &M practices and implementation of additional BMPs to improve upon the City's water quality protection efforts. 5.1 Operations and Maintenance Activities of Concern and Associated BMPs To determine the extent of potentially polluting activities occurring in relation to the City's O &M work, a survey was prepared and distributed to several City departments and facility managers. The survey requested confirmation of the O &M activities being conducted, and information on the BMPs being used to offset potential water quality impacts or otherwise to meet regulatory requirements. The survey forms are presented in Attachment B. The survey was distributed to managers and staff from the following City crews and facilities: • Streets • Surface Water • Sewer • Water • Tukwila Pool— Facilities and Operations • Tukwila Community Center • Foster Golf Links — Maintenance and Operations • Parks and Recreation Department Maintenance Division • Internal Operations, Facilities, and Fleet • Fire Stations 51, 52, 53, and 54 Copies of the survey responses are attached to this memorandum. SEA31002059530.DOC/032660007 E -7 CITY OF TUKWILA APPENDIX E —OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 5.2 Survey Responses and Analysis of Results The survey results provide an overview of City O &M activities and the adequacy of currently used BMPs. Further evaluations, such as interviews and site visits, are not within the scope of this update. They are needed to more specifically evaluate onsite practices to see if they are consistent with survey results from each department or facility and to verify and identify any additional areas of concern. Some departments and facilities may actually be doing more than what was identified in their survey response, and others may not be as consistent and thorough as what is implied in their response. Attachment C presents a matrix summarizing the survey results. The results indicate that the City's departments are aware of the importance of BMPs and most routinely use practices recommended for minimizing and preventing non -point source pollution. Some activities, however, may need more vigorous oversight. Attachment C also shows BMPs that currently are not practiced by the City of Tukwila and that are recommended for some of the activities. In general, the activity needing the most review is to ascertain whether drainage from certain facilities is being discharged to surface water systems instead of discharged to the sanitary sewer system. This is especially true for areas where vehicle storage, vehicle maintenance, chemical applications, concrete or asphalt production, and building repair occur. In addition, the City should verify that stormwater is not able to flow into activity areas where painting, coating, or other chemical applications occur. The survey indicated that several activities that require an emergency spill and cleanup response plan were deficient in this practice. Spill containment plans are required by state law in any location where dangerous and polluting agents are stored. A spill containment and emergency response plan provides for spill cleanup materials to be stored nearby, maintained, and clearly marked. In addition, employees should be educated and well trained in emergency response procedures. This was not listed as a BMP in the survey, but should be addressed in future inquiries as the survey results suggest emergency spill response procedures may not be adequately addressed at many City-owned facilities. Regular inspections of storage containers within City facilities, both permanent and mobile, is also a simple but effective BMP. This practice is not being followed at several City-owned facilities where such containers exist. Enforcing this BMP would significantly improve safety conditions in activity areas where liquid, chemical, and /or solid wastes are stored. 6. Program Recommendations 6.1 Activities In general, the O &M program has well- established guidelines for its various activities. These guidelines are based on previous experience and are optimized for the maintenance crews that are available. The O &M program needs additional documentation in all areas, including: existing drainage system mapping; complaint /complaint response; and location of surface water E -8 SEA31002059530.DOC/032660007 • • • • CITY OF TUKWILA APPENDIX E -OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 problem "hot spots." If it is not documented, much of this information will be lost as experienced staff leave their City positions or retire. In addition, this information is essential to: • Understand the causes of surface water problems in the City • Adjust maintenance activities (that is, recommend new levels of O &M service) to adequately address constantly evolving O &M needs • Make staffing recommendations that may be required to address changes in maintenance activities In order to increase program efficiency, the following recommendations are made: • Complete GIS mapping and inventory of the City's storm drainage systems. • Incorporate recorded outfall size and location information into the City GIS. • Develop maintenance management system database for recording activities, hours, problems, and other pertinent information. The system should also provide for tracking of complaints by drainage basin. • Develop departmental procedures to document all drainage complaints that are submitted to the City as RFAs. • Develop a permanent City vactor decant policy consistent with Ecology and Metro regulations and requirements. • Locate and secure a permanent site for disposal of decant solids from vactor and street sweepings following Ecology regulations and using the results of the decant analysis (Materials Handling /Transfer Facility). • Provide additional training for maintenance staff focused on erosion control and BMP implementation. A new level of service for O &M activities is not recommended as part of this report. Recommendations to change the level of service should be the result of a study comparing drainage complaint history and surface water complaints /problems that could not be addressed with the current staff to the existing activity schedule. The cause of perpetual drainage complaints should also be investigated because some of these complaints might be addressed with a surface water CIP project. 6.2 Staff The existing staff have made suggestions to add two more full-time employees (F 1'Es) to the surface water maintenance division to staff a standalone ditch - cleaning crew and vactor truck crew. Without additional information, however, no staffing recommendations can be made as part of this report. Staffing recommendations should come from a comparison of the existing level of O &M service to the recommended level of service. SEA31002059530.DOC/032660007 E -9 CITY OF TUKWILA APPENDIX E -OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 6.3 Regulatory Compliance The provisions of the federal Clean Water Act and Coastal Zone Management Act, the City's National Pollutant Discharge Elimination System (NPDES) permit, and the Puget Sound Action Team's Water Quality Management Plan require that pollution source control BMPs be implemented among all businesses, residences, and public agencies in the City of Tukwila. All permanent and temporary activities at public facilities, commercial and industrial facilities, agriculture and livestock farms, and residential dwellings are included. Anyone involved in a particular activity, whether as an employee, supervisor, manager, landlord, tenant, or homeowner, must take part in implementing appropriate BMPs for these activities. Under its NPDES municipal stormwater permit, the City of Tukwila is required to show progress in eliminating all non - stormwater discharges to its surface water systems. In other words, nothing but uncontaminated stormwater may be discharged to the City's surface water drainage system. The Washington Department of Ecology (Ecology) is obligated by the federal Endangered Species Act (ESA) to issue a permit that does not adversely affect federal - listed endangered and threatened species and critical habitat. That requirement necessitates that none of Tukwila's surface water discharges, allowable non - stormwater discharges, or discharge - related activities will likely impact federal threatened or endangered species. To better satisfy these applicable regulatory requirements, the following should be pursued: • A department /working group should be designated as the leaders responsible for effective source control BMP implementation at City -owned facilities and by City crews. That group should further investigate the City's O &M practices through interviews of department staff and site visits to facility locations. • The City should review emergency spill response and containment procedures within each facility or department. • Steps should be taken to ensure the existence of an ongoing educational . and training program for new and longer -term employees to address pollution prevention BMPs, safety, and spill response procedures. • Regular inspections should performed for all facilities storing liquids, chemicals, or solid waste. • Site - specific evaluations should be performed to assess how stormwater runoff is handled at sites where refueling, vehicle maintenance, equipment repair, chemical applications, building or construction activities, and /or vehicle or equipment washing occurs. Drainage patterns should also be assessed at locations where permanent or mobile storage containers are kept. • Develop pest management plans for O &M crews; the Parks Department, Foster Links Golf Course, and any other City operations that apply herbicides. • Until such time that a permanent site is available for processing of vactor truck solids and decant water, the City should make it a priority to evaluate handling of vactor E =10 SEA31002059530.DOC/032660007 CITY OF TUKWILA APPENDIX E- OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 decant water at its existing maintenance yards and to implement additional water quality protection BMPs as necessary. 7. References Ecology. 2001. Stormwater Management Manual for Western Washington (Volume IV - Source Control BMPs). Washington State Department of Ecology, Water Quality Program, Lacey, Washington. KCM, Inc. 1993. City of Tukwila Surface Water Comprehensive Plan Final Report. King County. 1995. Stormwater Pollution Control Manual, Best Management Practices for Businesses. Prepared by King County Surface Water Management Division, Seattle, Washington. Washington Department of Transportation (WSDOT) Regional Road Maintenance Technical Working Group. 2003. Available at WSDOT website: <http:/ /www.wsdot.wa.gov /biz /maintenance /htm /esa.htm>. SEA31002059530.DOC/032660007 E -11 • Attachment A Annual Operation and Maintenance Costs • TUKWILA COMPREHENSIVE SURFACE WATER MA ENT PLAN NOVEMBER 2003 Tukwila O&M tech memo atachment e-1 As/033100001.4a E -15 Table E-4 City of Tukwila Stormwater Management Facilities Annual O&M Costs, Existing Level of Service Faclllty /Activity Total Qty Unit Frequency Per Year Annual Work Qty, Daily Production Labor - Equlpment Total Annual _ Cost Daily Qty Unit Crew Size Labor CosUDay Annual Labor Cost _ Equlpment Equlpment Cost/Day Annual Equipment Cost Asphalt Berm Installation Along Existing Paving/Catchbasins 200 LF 7.5 1500 1 200 LF /day 3 $ 350 $ 7,8751 3 $ 200 $ 1,500 1$ 9,375 Ditches 100000 0.0096 9t�00 300 00 5 $ 6,400 54,267 WaterCleaning cress 1 Tons 1 I Tonsd/day 4 $ 350 $ 3,733 3 $ 200 $ 533 1 $ Pipes T.V. Inspection 50000 LF 0.1 5000 800 LF /day 2.5 $ 350 $ 5,469 2 $ 200 $ 1,250 $ 6,719 Add New /Replace Pipes 500 LF .1 500 100 LF /day 5 $ 350 $ 8,750 5 $ 200 $ 1,000 $ 9,750 Ditch to Pipe Conversion 200 LF 1 200 100 LF /day 5 $ 350 $ 3,500 5 $ 200 $ 400 $ 3,900 Clean Pipe (Up to 24 ") 11000 LF 0.5 5500 100 LF /day 4 $ 350 $ 77,000 2 $ 200 $ 11,000 $ 88,000 Cleaning Enclosed Drainage System (culverts <18 ") 20000 LF 0.05 1000 50 LF /day 3 $ 350 $ 21,000 2 $ 200 $ 4,000 $ 25,000 Hand Clean Drainage System (culverts >18") 2000 EA 0.05 100 50 EA/day 3 $ 350 $ 2,100 2 $ 200 $ 400 $ 2,500 Repair/Replace Headwall and Trash Racks 2 EA 1 2 1 EA/day 3 $ 350 $ 2,100 2 $ 200 $ 400 $ 2,500 Clean Headwalls and Trash Racks (Flood Response) 6 EA 2 12 20 EA/day 2 $ 350 $ 420 1 $ 200 $ . 120 $ 540 Catch Basins and Manholes Clean Catch Basins/Manhole 120000 EA 0.0091667 1100 50 EA/day 3.5 $ 350 $ 26,950 2 $ 200 $ 4,400 $ 31,350 Clean Catch Basins /Manhole (Flood Response) 50 EA 1 50 50 EA/day 2 $ 350 $ 700 2 $ 200 $ 200 $ 900 Repair Catch Basins Type I & II 12 EA 0.5 6 1 EA/day 4 $ 350 $ 8,400 3 $ 200 $ 1,200 $ 9,600 Add New /Replace Catch Basins Type I & II 5 EA 0.5 2.5 1 EA/day 4 $ 350 $ 3,500 1 $ 200 $ 500 $ 4,000 Add New /Replace Catch Basins/Manhole Lids 5 EA 1 5 3 EA/day 3 $ 350 $ 1,750 5 $ 200 $ 333 $ 2,083 Maintain Slotted Drains 5000 LF 0.4 2000 1000 EA/day 4 $ 350 $ 2,800 3 $ 200 $ 400 $ 3,200 Outfalls Repair ion /Maintenance 1 75 EA 0.1 7.5 2 EA/day 1 3 $ 350 1 $ 3,9381 2 $ 200 3 7 $ 750 1 $ 4,688 Vegetation Control (ROW and Outfalls) - Mowing 50000 LF 3 150000 10000 EA/day 1 $ 350 $ 5,250 1 $ 200 $ 3,000 $ 8,250 Brush Cutting 75 EA 1 75 10 EA/day 2 $ 350 $ 5,250 1 $ 200 $ 1,500 $ 6,750 Herbicide Application(outfalls) 75 EA 1 75 10 EA/day 2 $ 350 $ 5,250 2 $ 200 $ 1,500 $ 6,750 Vaults & Ponds Facilities Inspection 16 EA 0.2 3.2 2 EA/day 3 $ 350 $ 1,680 1 $ 200 $ 320 $ 2,000 Pond Vegetation Control 1 EA 1 1 1 EA/day 4 $ 350 $ 1,400 2 $ 200 $' 200 $ 1,600 Tank/Pond Sediment Removal (every 5 yrs) 2 EA 0.5 1 1 EA/day 5 $ 350 $ 1,750 3 $ 200 $ 200 $ 1,950 Clean Stormceptor 4 EA 1 4 2 EA/day 3 $ 350 $ 2,100 2 $ 200 $ 400 $ 2,500 Clean Control Structures 10 EA 0.1 1 3 EA/day 3 $ 350 $ 350 2 $ 200 $ 67 $ 417 Repair Vaults & Structures 16 EA 0.25 4 2 EA/day 3 $ 350 $ 2,100 2 $ 200 $ 400 $ 2,500 Clean Pipe 150 LF 0.5 75 20 LF /day 3 $ 350 $ 3,938 2 $ 200 $ 750 $ 4,688 Biological Controls (Mosquito larvae, et. al.) 10 EA 0 0 2 EA/day 2 $ 350 $ - 1 $ 200 $ - $ - Misc. Maintenance 1 EA 2 2 5 EA/day 2 $ 350 $ 280 1 $ 200 $ 80 $ 360 Tukwila O&M tech memo atachment e-1 As/033100001.4a E -15 CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Tukwila memo elachmenl e- 1acls1093100001.ds • Table E-4 City of Tukwila Stormwater Management Facilities Annual O&M Costs, Existing Level of Service Facility /Activity Total Qty Unit Frequency Per Year Annual Work Qty Daily Production Labor Equipment Total Annual Cost Daily Qty Unit Crew Size Labor Cost/Day Annual Labor Cost Equipment Equipment Cost/Day Annual Equipment Cost Stream System Inspection/Plunge Pool & Stream 2 LF 0 0 3 EA/day 2 $ 350 $ - 1 $ 200 $ - $ - Maintenance Sediment Removal 1 LF 0.5 0.5 1 EA/day 6 $ 350 $ 1,050 3 $ 200 $ 100 $ 1,150 Rehabilitation (Rip -Rap, Hydroseed, etc...) 1 LF 0.5 0.5 0.25 EA/day 6 $ 350 $ 4,200 5 $ 200 $ 400 $ 4,600 Watercress Removal 2 LF 0 0 1 EA/day 4 $ 350 $ - 3 $ 200 $ - $ - Pump Systems Inspect/Maintain Pump tEquipment 1 EA 52 156 3 2 $ 30 $ Replace/Repalr Pumping 3 EA 52 156 I 1 EA/week 2.5 $ 30 $ 11,7001 2 $ 200 $ 30,200 I $ 42,900 Education Place Stencils at Catch Basins 1 EA 1 1 0.5 EA/hr 2 $ 30 $ 120 1 $ 200 $ 400 $ 520 Distribute Educational Brochures 1 EA 1 1 0.5 EA/hr 1 $ 30 $ 60 1 $ 200 . $ 400 $ 460 Crew Safety 7 EA 5 35 7 EA/day 7 $ 350 $ 12,250 0 $ - $ 12,250 Training/Education 5 EA 10 50 7 EA/day 7 $ 200 $ 10,000 0 $ - $ 10,000 Supervision 1 EA 260 260 1 EA/hr 2 $ 40 $ 20,800 0 $ - $ 20,800 Technical Support 1 EA 52 52 1 EA/hr 1 $ 40 $ 2,080 0 $ - $ 2,080 Complaint Response 1 EA 10 10 0.5 EA/day 1 $ 350 $ 7,000 1 $ 200 $ 4,000 $ 11,000 Hazardous Material Response 1 EA 2 2 0.5 EA/day 2 $ 350 $ 2,800 .1 $ 200 $ 800 $ 3,600 River Flood Patrol 1 EA 2 2 1 EA/day 2 $ 350 $ 1,400 1 $ 200 $ 400 $ 1,800 TOTAL $ 341,212 _ $ 94,303 $ 435,516 Tukwila memo elachmenl e- 1acls1093100001.ds • • Attachment B Survey Forms • • • CITY OF TUKWILA APPENDIX E —OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE E -5 Survey of O &M Activities That Potentially Pollute Stormwater Runoff Please indicate all potentially polluting activities that are performed in and around your facility by answering yes or no to each line, then put the number(s) of the corresponding BMPs currently used (from the attached list) next to each potentially polluting activity occurring. Please elaborate on BMPs with comments as necessary. POTENTIALLY POLLUTING ACTIVITIES IN OUTDOOR AREAS BMPs ACTIVITY BEING OCCURRING? APPLIED COMMENTS (yes or no) Storage of liquid materials in stationary tanks (other than clean water) Storage of liquid materials in portable containers (other than clean water) Storage/stockpiling of soil, sand, salt and/or other erodible materials Storage of pesticides and/or fertilizers Storage and treatment of contaminated soils Storage and/or processing of food items Storage of solid wastes and/or food wastes Storage of scrap and recycling materials Treatment, storage, or disposal of dangerous wastes Cleaning or washing of tools and equipment Cleaning or washing of cooking equipment Vehicle washing Pressure washing of buildings, rooftops, and other items Truck or rail loading and unloading of liquid materials Fueling Vehicle repair and maintenance Concrete and/or asphalt production Concrete and/or asphalt paving Painting, finishing, and/or coating of vehicles, products, or equipment Chemical applications - other than for landscaping Landscaping activities, including applications of pesticides, herbicides, or fertilizers Clearing, grading, and preparation of construction sites Demolition of buildings Building repair, remodeling, and construction Vehicle and/or equipment parking and storage Sidewalk maintenance (washing, sweeping, etc.) Swimming pool or spa cleaning and maintenance Keeping animals in controlled areas Geotechnical drilling or other subsurface explorations Other - please describe (BMP #s from attached list) SEA31002059530.DOC/032660007 E-1 9 CITY OF TUKWILA APPENDIX E- OPERATIONS AND MAINTENANCE COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 TABLE E -6 Survey of Best Management Practices Used for Activities That Potentially Pollute Stormwater Runoff ILIST OF BEST MANAGEMENT PRACTICES (BMPs) 1. Discharge drainage from activity area to the sanitary sewer system 2. Avoid activity when rain expected 3. Perform activity under roof or other enclosure 4. Regular sweeping of dust accumulation using vacuum filter equipment 5. Cover stockpiled materials with a tarp, roof, or awning 6. Store materials indoors or in enclosure protected from rain when not in use 7. Containment and elevation: surround with dike or berm, or elevate area 8. Prevent stormwater runoff from flowing into activity area 9. Follow integrated pest management plan, where pesticides are used only as a last resort 10. Clean catch basins in activity area regularly 11. Stormwater treatment prior to discharge from site (please describe type of treatment system) 12. Natural vegetated buffer between activity and site runoff discharge point 13. Infiltration of runoff from affected area 14. Implement emergency spill response and cleanup plan 15. Keep suitable cleanup materials on site 16. Use dedicated equipment in activity area to avoid cross contamination of other areas of site (do not use contaminated tools or equipment in other areas of site) 17. Place tight fitting lids on all containers 18. Place drip pans beneath all potential drip and spill locations during product transfer 19. Regular inspection of container storage areas 20. Activity areas are paved and sloped towards a holding tank with sufficient volume to capture either the entire volume of waste water generated or a potential spill, whichever is the larger volume 21. Cover dumpsters and other waste storage containers 22. Install temporary storm drain covers or filters near work area to prevent runoff from entering storm drainage system 23. Use sandbags, wattles, or other material to prevent contaminated runoff from flowing along curb line or to otherwise contain runoff 24. Other - please describe E -20 SEA31002059530.D0C1032660007 • Attachment C Pollution- Generating Activities and BMPs • CITY OF TUKWILA COMPREHENSIVE SURFACE WATER MANAGEMENT PLAN NOVEMBER 2003 Attachm ent C. Ci ty of Tukwila Ope rations an d Mainte nance - Pollution Gene rating Activities and BMP s POTENTIALLY POLLUTING ACTIVITIES AND BMPs 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 BMPs Used BMPs Recommended Discharge drainage from activity area to the sanitary sewer system Avoid activity when rain expected Perform activity under roof or other enclosure Regular sweeping of dust accumulation using vacuum filter equipment Cover stockpiled materials with a tarp, roof, or awning Store materials indoors or in enclosure protected from rain when not in use Containment and elevation: surround with dike or berm, or elevate area Prevent stormwater runoff from flowing into activity area Follow integrated pest management plan, where pesticides are used only as a last resort Clean catch basins in activity area regularly Stormwater treatment prior to discharge from site (please describe type of treatment system) Natural vegetated buffer between activity and site runoff discharge point Infiltration of runoff from affected area Implement emergency Keep spill suitable response cleanup and materials cleanup on site plan Use dedicated equipment In activity area to avoid cross contamination of other areas of site (do not use contaminated tools or equipment in other areas of site) Place tight fitting lids on all containers Place drip pans beneath all potential drip and spill locations dunng product transfer Regular inspection of container storage areas Activity areas are paved and sloped towards a holding tank with sufficient volume to capture either the entire volume of waste water generated or a potential spill, whichever is the larger volume Cover dumpsters and other waste storage containers Install temporary storm drain covers or fitters near work area to prevent contaminated runoff from entering storm drainage system Use sandbags, wattles, or other material to prevent contaminated runoff from flowing along curb line or to otherwise contain runoff Employee education and training on safety and spill response procedures Storage of liquid materials in stationary tanks (other than dean water) Storage of liquid materials in portable containers (other than dean water) Storage /stockpiling of soil, sand, salt and/or other erodible materials Storage of pesticides and /or fertilizers Storage of solid wastes and/or food wastes Storage of scrap and recycling materials Treatment, storage, or disposa of dangerous wastes Cleaning or washing of tools and equipment Cleaning or washing of cooking: ;;, equipment Vehicle washing Pressure washing of buildings, rooftops, and other items Truck or rail loading and unloading of liquid materials Fueling Vehicle repair and maintenance Concrete and/or asphalt production Painting, finishing, and/or coating of vehicles, products, or equipment Chemical applications - other than for landscaping Landscaping activities, including applications of pesticides, herbicides, or fertilizers Building repair, remodeling, and construction Vehicle and/or equipment parking and storage Sidewalk maintenance (washing, sweeping, etc.) Swimming pool or spa cleaning and maintenance E -23