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HomeMy WebLinkAboutPermit 91-03-CA - CITY OF TUKWILA - SENSITIVE AREAS OVERLAY AMENDMENTS91-3-ca CRITICIAL AREA SENSITIVE AREA ORDINANCE ZONING CODE AMENDMENT COMPREHENSIVE LAND USE PLAN AMENDMENT COMPREHENSIVE PLAN AMENDMENT CITY OF TUKWILA WASHINGTON ORDINANCE NO. l�' G g AN ORDINANCE OF THE CITY OF TUKWILA, WASHINGTON AMENDING CERTAIN PROVISIONS OF ORDINANCE NO. 1599 RELATING TO SENSITIVE AREAS AND SEPA REQUIREMENTS, AND AMENDING TUKWILA MUNICIPAL CODE CHAPTERS 18 AND 21. WHEREAS,•the Planning Commission and the City Council have previously considered at length the regulation of development on and around sensitive areas within the City of Tukwila; and WHEREAS, the City Council enacted Ordinance No. 1599 relating to sensitive areas on June 10, 1991; and WHEREAS, the amendments set forth below are necessary to correct and clarify various provisions of Ordinance No. 1599 as originally adopted; NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF TUKWILA, WASHINGTON, DO HEREBY ORDAIN AS FOLLOWS: Section 1. Chapter 18.45.080 Uses and Standards. Tukwila Municipal Code Chapter 18.45.080.E.4.A is hereby amended to read as follows: 4. Geotechnical Report: a. The applicant shall submit a Geotechnical Report appropriate to both the site conditions and the proposed development. A geotechnical investigation shall be required for development in Class 2, Class 3, Class 4 areas, and any areas identified as seismic or coal mine hazard areas unless waived pursuant to TMC 18.45.020.F.2. b. Geotechnical reports for Class 2 areas shall include at a minimum a site evaluation review of available information regarding the site and a surface reconnaissance of the site and adjacent areas. Subsurface exploration of site conditions is at the discretion of the geotechnical consultant. c. Geotechnical reports for Class 3, Class 4 and Coal Mine Hazard areas shall include a site evaluation review of available information about the site, a surface reconnaissance of the site and adjacent areas, and a subsurface exploration of soils and hydrology conditions. Detailed slope stability analysis shall be done if the geotechnical consultant recommends it in Class 3 or Coal Mine Hazard areas, and must be done in all Class 4 areas. d. Seismic hazard areas shall include an evaluation of site response and liquefaction potential for the proposed development area. For one or two story single family dwellings this evaluation may be based on the performance of similar structures under similar foundation conditions. For proposed developments including occupied structures other than one and two story single family dwellings, the evaluation shall include sufficient subsurface exploration to provide a site coefficient (S) for use in the static lateral force procedure described in the Uniform Building Code. e. Applicants shall retain a Geotechnical Engineer to prepare the reports and evaluations required in this Section. The Geotechnical Report and completed Site Evaluation checklist shall be prepared in accordance with the generally accepted geotechnical practices, under the supervision of and signed and stamped by the Geotechnical Engineer. The report shall be prepared in consultation with the appropriate City department. Where appropriate, a Geologist must be included as part of the geotechnical consulting team. The report shall make•specific recommendations concerning development of the site. f. The geotechnical engineers required under this section must meet the qualification standards approved by the Director of DCD. Applicants shall provide a list of qualifications of the firm or individuals who will be doing the technical studies, and those shall be approved by the Director of DCD. If the engineers' credentials are not sufficient, the City may require applicants to use a different engineer or firm which does meet the City's standards. 1 g. The opinions and recommendations contained in the report shall be supported by field observations and, where appropriate or applicable, by literature review, conducted by the Geotechnical Engineer which shall include appropriate explorations, such as borings or test pits, and an analysis of soil characteristics conducted by or under the supervision of the engineer in accordance with standards of the American Society of Testing and Materials or other applicable standards. If the evaluation involved geologic evaluations or interpretations, the report shall be reviewed and approved by a Geologist. h. An independent review of geotechnical reports will be required per TMC 21.04.140. Section 2. Chapter 21.04.300 Environmentally Sensitive Areas. Tukwila Municipal Code Chapter 21.04.300 is hereby amended to read as follows: 21.04.300 Environmentally Sensitive Areas. A. Environmentally sensitive areas designated on the zoning maps and/or as now defined in TMC 18.45.020, or as hereafter amended, designate the locations of environmentally sensitive areas within the City and are adopted by reference. In addition to those areas identified in WAC 197 -11 -908 and for purposes of this chapter, environmentally sensitive areas shall also include wooded hillsides, and the Green/Duwamish River and its shoreline zone as defined by the Tukwila Master Program. For each environmentally sensitive area, all categorical exemptions within WAC 197 -11 -800 are applicable. B. The City shall treat proposals located wholly or partially within an environmentally sensitive area no differently than other proposals under this chapter, making a threshold determination for all such proposals. The City shall not automatically require an EIS for a proposal merely because it is proposed for location in an environmentally sensitive area. C. Certain exemptions do not apply on lands covered by water, and this remains true regardless of whether or not lands covered by water are mapped. Section 3. Chapter 18.45.040(B' Special Buffer Studies. Tukwila Municipal Code Chapter 18.45.040 is hereby amended to read as follows: 1 8.45.040 Sensitive Area Buffers. A. General. 1. Any land alteration must be located out of the buffer areas as required by this section. Buffers in general are intended to: a. Minimize long -term impacts of development on properties containing Sensitive Areas; b. Protect Sensitive Areas from adverse impacts during development; c. Preserve the edge of the Sensitive Area for its critical habitat value; and d. Prevent loading of potentially unstable slope formations. Land alteration is permitted for public access, supplemental planting and approved land uses of 18.45.080. An undisturbed sensitive area or buffer may substitute for the yard setback and landscape requirements of TMC 18.50 and 18.52. Wetland and Watercourse Buffers are intended to: a. Provide shading to maintain stable water temperatures and vegetative cover for additional wildlife habitat; b. Provide input of organic debris, and uptake of nutrients; c. Provide an area to stabilize banks, to absorb overflow during high water events, and to allow for slight variation of aquatic system boundaries over time due to hydrologic or climatic effects; d. Reduce erosion and increased surface water runoff; e. Reduce loss of or damage to property; f. Intercept fine sediments from surface water runoff and serve to minimize water quality impacts; 2 g. Preserve the edge for its habitat value; and h. Protect the sensitive area from human and domestic animal disturbance. 3. Buffers for Areas of Potential Geologic Instability are intended to: a. Protect slope stability; b. Provide erosion control and attenuation of precipitation surface and storm water runoff; c. Reduce loss of or damage to property; and d. Preserve the natural character of wooded hillsides where they exist. B. Special Buffer Studies. Applicants for a use or development on a legal lot of record within a sensitive area maximum buffer shall be required to conduct a sensitive area study to provide a buffer analysis for the sensitive area. This study may be waived by the DCD Director pursuant to 18.45.020 F.2. C. Ratings and Buffer Width. Ratings and appropriate buffers for wetlands and watercourses are listed below. 1. For wetlands: a. Type 1 - 100 -foot wide buffer b. Type 2 - 50 -foot wide buffer c. Type 3 - 25 -foot wide buffer 2. For watercourses, the buffer shall be as follows: a. Type 1 - 70 -foot wide buffer b. Type 2 - 35 -foot wide buffer c. Type 3 - 15 -foot wide buffer 3. Setbacks: a. All commercial and industrial developments shall be set back 15 feet and all residential development shall be set back 10 feet. This setback shall be measured from the foundation to the buffer's edge. b. The Director of DCD may waive setback requirements when a site plan demonstrates there will be no impacts to the buffer zone. 4. Variation of Standard of Creation of Variable Width Wetland/Watercourse Buffers: a. The DCD Director may reduce the standard wetland/watercourse buffers on a case - by -case basis, provided the buffer does not contain slopes 15% or greater. The approved buffer width shall not result in greater than a 50 percent reduction in width, and the reduced buffer shall not be less than 15 feet for wetlands and 10 feet for watercourses. Any buffer reduction proposal must demonstrate to the satisfaction of the DCD Director that it will not result in direct or indirect, short - term or long -term adverse impacts to wetlands or watercourses, and that: (1) The buffer is vegetated and includes an enhancement plan as may be required to improve the buffer function and value; or (2) If there is no significant vegetation in the buffer, a buffer may be reduced only if an enhancement plan is provided. The plan must include using a variety of native vegetation that improves the functional attributes of the buffer and provides additional protection for the wetland or watercourse functions and values. b. Buffers for all types of wetlands and watercourses will be increased when they are determined to be particularly sensitive to disturbance or the proposed development will create unusually adverse impacts. Any increase in the width of the buffer shall be required only after completion of a wetland or watercourse study by a qualified 3 wetlands specialist or expert which documents the basis for such increased width. An increase in buffer width may be appropriate when: (1) The development proposal has the demonstrated potential for significant adverse impacts upon the wetland or watercourse which can be mitigated by an increased buffer width; or (2) The area serves as habitat for endangered, threatened, sensitive or monitor species listed by the federal government or the State of Washington. c. Every reasonable effort shall be made to maintain the existing viable plant life in the buffers. Vegetation may be removed from the buffer as pan of an enhancement plan approved by the Director of DCD. Enhancements will ensure that slope stability and wetland and watercourse quality will be maintained or improved. Any disturbance of the buffers for wetlands or watercourses shall be replanted with a diverse plant community of native northwest species that are appropriate for the specific site as determined by the DCD Director. If the vegetation must be removed, or because of the alterations of the landscape the vegetation becomes damaged or dies, then the applicant for permit must replace existing vegetation along wetlands and watercourses with comparable specimens, approved by the DCD Director, which will reproduce the existing buffer value within 5 years. d. The DCD Director shall require subsequent corrective actions and long -term monitoring of the project if adverse impacts to regulated wetlands, watercourses or their buffers are identified. D. Areas of Potential Geologic Instability. 1. Each development proposal for a legal lot of record containing an area of potential geologic instability shall be subject to a geotechnical report pursuant to the requirements of Sections 18.45.060 and 18.45.080(6). The geotechnical report shall analyze and make recommendations on the need for and width of any buffers necessary to achieve the goals and requirements of this ordinance. Development proposals shall then include the buffer distances as defined within the geotechnical report. Buffers may be increased by the DCD Director when an area is determined to be particularly sensitive to the disturbance created by a development. Such a decision will be based on a City review of the report as prepared by a qualified geotechnical consultant and by a site visit. Section 4, Chapter 18.45.060 Procedures. Tukwila Municipal Code Chapter 18.45.060 is hereby amended to read as follows: 18.45.060 Procedures. General: When an applicant submits an application for any building permit, subdivision, short subdivision or any other land use review which approves a use, development or future construction, the location of any sensitive areas and buffers on the site shall be indicated on the plans submitted. When a sensitive area is identified, the following procedures apply. The DCD Director may waive item numbers 1, 2, 4 and 5 of the following if the size and complexity of the project does not warrant that step in the procedures and the Director grants a waiver pursuant to TMC 18.45.020.F.2. 1. Sensitive Areas Study and'Geotechnical Report: The applicant shall submit the relevant study as required in TMC 21.04.140 and this chapter. It is intended that sensitive areas studies and information be utilized by applicants in preparation of their proposals and therefore shall be undertaken early in the design stages of a project. Any new residential subdivision, residential short subdivision, residential boundary line adjustment, or multiple family residential proposal which includes a sensitive area or its buffer on the site shall apply for a Planned Residential Development permit and meet the requirements of Chapter 18.46 of the Tukwila Zoning Code. 3. Denial of Use or Development: A use or development will be denied if it is determined by the DCD Director that the applicant cannot ensure that potential dangers and costs to future inhabitants of the development, adjacent and local properties, and Tukwila are minimized and mitigated to an acceptable level. 4 4. Pre- development Conference: The applicant, specialist(s) of record, contractor, and Department representatives will be required to attend pre - construction conferences prior to any work on the site. 5. Construction Monitoring: The specialist(s) of record shall be retained to monitor the site during construction. 6. The DCD Director may require the boundary between a sensitive area and its buffer and any development or use to be permanently identified with fencing, or with a wood or metal sign with treated wood, concrete or metal posts. Size will be determined at the time of permitting, and wording shall be as follows: "Protection of this natural area is in your care. Alteration or disturbance is prohibited pursuant to TMC 18.45. Please call the City of Tukwila for more information." Section 5. Chapter 18.45.080 Uses and Standards. Tukwila Municipal Code 18.45.080(A), and Ordinance 1599 in part, are hereby amended to read as follows: 18.45.080 Uses and Standards. A. General. The uses set forth in this entire section, including subsections A -H, may be located within a sensitive area or buffer, subject to the provisions of TMC 21.04 and of this section. 1. Maintenance and repair of existing uses and facilities provided no alteration or additional fill materials will be placed or heavy construction equipment used in the sensitive area or buffer. 2. Non - destructive education and research. 3. Passive recreation and open space. 4. Maintenance and repair of essential streets, roads, rights -of -way, or utilities. 5. Actions to remedy the effects of emergencies that threaten the public health, safety or welfare. Section 6. Refund of SEPA Checklist Fees, The Mayor shall authorize the Finance Director to refund SEPA Checklist fees received, between the effective date of Ordinance No. 1599 and the effective date of this ordinance, from applicants now made exempt pursuant to Section 1 of this Ordinance. Section 7. Chapter 18.45.020 Sensitive Area Designation, Rating methodologies, Classifications and Applicability. Tukwila Municipal Code Chapter 18.45.020.F.2 is hereby amended to read as follows: F. Sensitive Areas Special Studies 1. Required. An applicant for a development proposal that includes sensitive areas, shall submit those studies as required by the City to adequately identify and evaluate the sensitive area and its buffers. Waiver. If there is agreement between the Director of DCD and the applicant concerning the sensitive area classification and type, the Director of DCD may waive the requirement for sensitive area studies. There must be substantial evidence that the sensitive areas classification is correct, that there will be no detrimental impact to the sensitive areas or buffers, and that the goals, purposes, objectives and requirements of this ordinance will be followed. 3. Review of studies. The Department of Community Development will review the information submitted in the sensitive area studies to verify the information, confirm the nature and type of the sensitive area, and ensure the study is consistent with this Chapter. Section 8. Severabilitv. If any section, sentence, clause or phrase of this ordinance should be held to be invalid or unconstitutional by a court of competent jurisdiction, such invalidity or unconstitutionality shall not affect the validity or constitutionality of any other section, sentence, clause or phrase of this ordinance. Section 9. Effective Date. This ordinance shall take effect and be in full force five (5) days after publication of the attached summary which is hereby approved. PASSED BY TUE CITY COUNCIL OF THE CITY OF KWILA, WASHINGTON, at a regular meeting thereof this c of 4‘c7.,.,, , 199 ATTEST/AUTHENTICATED: Jane E. Cantu, City Clerk APPROVED AS TO FORM: OFFICE OF THE CITY ATTORNEY: By /) e lop .34). 1 4 /_44-. 4 - 3 0 • 1( FILED WITH THE TY CLERK: PASSED BY THE CITY COUNCIL; q -- PUBLISHED: 10- 3 •- , EFFECTIVE DATE: i o— 1 ? - g l ORDINANCE NO.: ) L 0 6 Dusen, Mayor • SUMMARY OF ORDINANCE NO. /668 AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF TUKWILA, WASHINGTON, AMENDING CERTAIN PROVISIONS OF ORDINANCE NO. 1599 RELATING TO SENSITIVE AREAS AND SEPA REQUIREMENTS, AND AMENDING TUKWILA MUNICIPAL CODE CHAPTERS 18 AND 21. On , the City Council of the City of Tukwila passed Ordinance No /44, amending th Sens'tive Areas Ordinance No. 1599 to correct and clarify various provisions of the ordinance as originally adopted; providing for severability; and establishing an effective date. The full text of this ordinance will be mailed without charge to anyone who submits a written request to the City Clerk of the City of Tukwila for a copy of the text. APPROVED by the City Council at its meeting of 5 PUBLISHED: VALLEY DAILY NEWS - WEDNESDAY, OCTOBER 9, 1991 E. Cantu, City Clerk HEARING DATE: FILE NUMBER: APPLICANT: REQUEST: PLANNING STAFF: ATTACHMENTS: l . y off;., ..... . CITY OF T Uli WILA 6200 SOUTHCENTER BOULEVARD. TUIi lt'ILA. WASHINGTON 98188 STAFF REPORT TO THE PLANNING COMMISSION Prepared September 5, 1991 PHONE #120614334 800 Gary L. t anDusrn, Mayor September 12, 1991 91 -3 -CA: Sensitive Areas Overlay Zone Amendments City of Tukwila 1. Amend the environmental code (TMC 21.04.300) to reinstate the categorical exceptions for sensitive areas and their buffers. 2. Amend the zoning code (TMC 18.45) to: a. Exempt single family dwellings from the sensitive areas overlay zone when proposed construction is not located on the area of potential geologic instability. b. Allow. DCD Director to waive the PRD requirement for certain proposals. c. Eliminate a special buffer study for development on a lot within 100 feet of a lot which contains sensitive areas or their buffers. d. Clarify requirements in Uses and Standards section. 3. Authorize refunds of the State Environmental Policy Act (SEPA) checklist fee for certain proposals impacted by Ordinance number 1599. Jack Pace and Gary Schulz A. Draft Ordinance (pink sheets) B. Adopted Ordinance (white sheets) Staff Report to the Planning Commission Page 2 BACKGROUND FINDINGS 91 -3 -CA: S.A.O. Admendments The Sensitive Areas Ordinance (No. 1599), Attachment B, was adopted by the City in June 1991. There has been two months of experience with the ordinance. The several months of implementation experience reveals the need to streamline cerain sections that to remove unintended burdens and unproductive procedures. The majority of the permits issued under the new ordinance relate to single family development on lots with slopes. Public notice of the amendments and Planning Commission hearing was published in the Valley Daily News on September 1 and 8. Additional notices were sent to previous hearing participants, the Sensitive Areas Citizens Committee and current building permit and short plat applicants affected by the sensitive areas ordinance. An article on the proposed changes also appeared in the City's Hazelnut publication. PROCEDURE Zoning code section 18.80.010 states that the Council may amend regulations of the zoning code but before acting upon any proposed amendments shall refer them to the Planning Commission. The Planning Commission, after public notice and hearing, shall then submit a report to the Council containing its recommendation. All of the proposed amendments except the SEPA changes are part of the Zoning Code. Because of the interrelated nature of the material, the amendments are being treated as a package as they were initially treated. Attachment A, the Draft Ordinance, has new language underlined and existing ordinance language to be deleted :igm to . Staff comments regarding the origination and reasons for the changes follow each amended section. CONCLUSIONS 1. The amended ordinance will continue to implement the policies and goals of the Tukwila Comprehensive Plan and the Puget Sound Water Quality Management Plan. Staff Report to the Planning Commission 91 -3 -CA: S.A.O. Admendments Page 3 2. The proposed amendments will remove unnecessary review relative to potential impacts and will give discretion to administrators on procedures for single family development. 3. With adoption of the procedures and standards of the sensitive areas ordinance, environmental review pursuant to the State Environmental Policy Act (SEPA) becomes redundant for the small scale project with limited construction impacts. When SEPA was adopted there were no regulations protecting sensitive areas. The intention behind SEPA was to provide site by site information and impact disclosure and then review and analysis of all environmental impacts. Cities are going beyond the SEPA concept and establishing standards of impact. 4. The adopted buffer standards will be sufficient to prevent adverse impacts and minimize its long term impacts on the sensitive area from development. 5 Information from the SEPA checklists for the single family homes, remodels or short plats has been irrelevant with regard to the decisions on the permits. The minor level of SEPA review and action justifies refunds of the review fees. RECOMMENDATION The Planning Division Staff recommends that the Planning Commission adopt the Findings and Conclusions of this report and recommend approval of the draft ordinance to the City Council. SENSITIVE AREAS ORDINANCE AMENDMENTS ATTACHMENT A 9/6/91 AN ORDINANCE OF THE CITY OF TUKWILA, WASHINGTON AMENDING CERTAIN PROVISIONS OF ORDINANCE NO. 1599 RELATING TO SENSITIVE AREAS AND SEPA REQUIREMENTS, AND AMENDING TUKWILA MUNICIPAL CODE CHAPTERS 18 AND 21. WHEREAS, the Planning Commission and the City Council have previously considered at length the regulation of development on and around sensitive areas within the City of Tukwila; and WHEREAS, the City Council enacted Ordinance No. 1599 relating to sensitive areas on June 10, 1991; and WHEREAS, the amendments set forth below are necessary to correct and clarify various provisions of Ordinance No. 1599 as originally adopted; NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF TUKWILA, WASHINGTON DO ORDAIN AS FOLLOWS: Section 1. Chapter 18.45.115 Exceptions. Tukwila Municipal Code Chapter 18.45.115 is hereby amended to read as follows: 18.45.115 Exceptions. A. General. With the approval of the Director of DCD, isolated wetlands that are 400 square feet or smaller in area, and which are low value according to the rating methodology used in the City's Water Resource Rating and Buffer Study, may not require the compensatory mitigation standards of this chapter. B. This chapter shall not apply to a legal lot of record used or proposed for single - family occupancy as defined in TMC 18.06.220, 18.06.221, or 18.06.240 or to a site used or proposed for an accessory use thereto as defined in TMC 18.06.870 where: (1) a proposed development is within a Class 2 area of potential instability, or (2) a proposed development does not • a. detrimentally impact any Class 3 or Class 4 slopes, or abandoned coal mine areas, on any legal lot of record. COMMENT: Several sections within Areas of Potential Geologic Instability 18.45.080(E) require items which are extraordinary given the scope of single family remodeling and building activities. For example, prior to permitting alterations of any slope (15% or greater) the existing regulations say the applicant must demonstrate that (1) there is no instability and quantitative analysis indicates slope stablility or (2) modification can occur while maintaining slope stability. In effect, this requires a geotechnical engineer regardless of the type or quantity of slope disturbance. With or without slope disturbance, an indemnity letter and filing of restrictive covenants is required. 1 These requirements, reflective of a Seattle administrative rule, were drafted for Class 3 and 4 and not Class 2 areas, where landslide potential is moderate. Requirements for erosion hazard, which is high, are available through the land altering ordinance. This amendment is proposed to allow single family construction and /or remodeling on sites that, for example, might be 100 feet deep with a 30% slope on the back 10 feet of the site. This amendment would allow single family development on the flat, front portion of the site without being subject to geotechnical reports or surveys. This amendment is also proposed to allow staff discretion on geotechnical reports and topographic surveys depending on the scope of proposed single family development. Many projects involve no or minimal excavation, for example - deckposts. C. Piping. Piping will be allowed in Type 1 and Type 2 watercourses only where relocation or alteration of a watercourse is denied and would result in denial of all reasonable use. D. Reasonable Use Exceptions. 1. If application of this Chapter would deny all reasonable use of the property containing wetlands, watercourses or their buffers, the property owner or the proponent of a development proposal may apply for a reasonable use exception. 2. The application for a reasonable use exception shall be in a format specified by and filed with the Department of Community Development. Requirements may include an environmental impact statement pursuant to Washington Administrative Code 197 -11 -400. Reasonable use exceptions shall be decided by the Planning Commission following a public hearing notice as specified in 18.92. 3. If the applicant demonstrates to the satisfaction of the Planning Commission that application of this Chapter would deny all reasonable use of the property, development may be allowed which is consistent with the general purposes of this ordinance and the public interest. 4. The Commission, in granting approval of the reasonable use exception, must determine that: a. No reasonable use with less impact on the sensitive area and its buffer is possible; b. There is no feasible on -site alternative to the proposed activities, including reduction in size or density, phasing of project implementation, change in timing activities, revision of road and lot layout, and /or related site planning activities that would allow a reasonable economic use with fewer adverse impacts to the sensitive area and its buffer; c. As a result of the proposed development there will be no increased or unreasonable threat of damage to off -site public or private property and no threat to the public health, safety or welfare on or off the development proposal site; 2 d. Alterations permitted shall be the minimum necessary to allow for reasonable use of the property; e. The proposed development is compatible in design, scale and use with other development with similar site constraints in the immediate vicinity of the subject property; f. Disturbance of sensitive areas has been minimized by locating the necessary alterations in the buffers to the greatest extent possible; g. The inability to derive reasonable use of the property is not the result of actions by the applicant in segregating or dividing the property and creating the undevelopable condition after the effective date of this Chapter; and h. Any approved alteration of a sensitive area under this section shall be subject to conditions as established by this chapter and will require mitigation under an approved mitigation plan. If a development is approved as a reasonable use, Board of Architectural process, review and standards shall be applied. Section 2. Chapter 21.04.300 Environmentally Sensitive Areas. Tukwila Municipal Code Chapter 21.04.300 is hereby amended to read as follows: 21.04.300 Environmentally sensitive areas. A. Environmentally sensitive areas designated on the zoning maps and /or as now defined inr 3'IIC '' TM C 1 8 0 or as hereafter amended, designate the locations of environmentally sensitive areas within the city and are adopted by reference. In addition to those areas identified in WAC 197 -11 -908 and for purposes of this chapter environmentally sensitive areas shall also include wooded hillsides, and the Green /Duwamish River and its shoreline zone as defined by the Tukwila Master Program. For each environmentally sensitive area, j ... all categorical exemptions within WAC 197 -11 -800 are inapplicable_ l:Cl env ronme ail :: ; : se s ve::;: • ar:eas.:: > 3 COMMENT: Before the adoption of the Sensitive Areas Ordinance, certain activities were exempt from the SEPA process. That process includes payment of a $225.00 fee, completion of an environmental checklist and issuance of a Determination by the City. Exempt activities are those which are assumed will not have a significant impact on the environment and include for example: construction of a residential structure (up to 4 units,) fill activity (up to 500 cubic yards,) and repair, maintenance and remodeling. There is no benefit to the SEPA process other than public comment and review that cannot be had from the City's specific sensitive areas and land altering ordinances. SEPA has no standards for development. Therefore we should reinstate the SEPA exemptions and not create an additional process for minor activities because they occur on a lot with sensitive areas. B. The city shall treat proposals located wholly or partially within an environmentally sensitive area no differently than other proposals under this chapter, making a threshold determination for all such proposals. The city shall not automatically require an EIS for a proposal merely because it is proposed for location in an environmentally sensitive area. C. Certain exemptions do not apply on lands covered by water, and this remains true regardless of whether or not lands covered by water are mapped. Section 3. Chapter 18.45.040(B) Special Buffer Studies. Tukwila Municipal Code Chapter 18.45.040 is hereby amended to read as follows: 18.45.040 Sensitive Area Buffers. A. General. 1. Any land alteration must be located out of the buffer areas as required by this section. Buffers in general are intended to: a. Minimize long -term impacts of development on properties containing Sensitive Areas; b. Protect Sensitive Areas from adverse impacts during development; c. Preserve the edge of the Sensitive Area for its critical habitat value; and d. Prevent loading of potentially unstable slope formations. Land alteration is permitted for public access, supplemental planting and approved land uses of 18.45.080. An undisturbed sensitive area or buffer may substitute for the yard setback and landscape requirements of TMC 18.50 and 18.52. 2. Wetland and Watercourse Buffers are intended to: a. Provide shading to maintain stable water temperatures and vegetative cover for additional wildlife habitat; b. Provide input of organic debris, and uptake of nutrients; c. Provide an area to stabilize banks, to absorb overflow during high water events, and to allow for slight variation of aquatic system boundaries over time due to hydrologic or climatic effects; d. Reduce erosion and increased surface water runoff; e. Reduce loss of or damage to property; f. Intercept fine sediments from surface water runoff and serve to minimize water quality impacts; g. Preserve the edge for its habitat value; and - 4 - h. Protect the sensitive area from human and domestic animal disturbance. 3. Buffers for Areas of Potential Geologic Instability are intended to: a. Protect slope stability; b. Provide erosion control and attenuation of precipitation surface and storm water runoff; c. Reduce loss of or damage to property; and d. Preserve the natural character of wooded hillsides where they exist. COMMENT: The required buffers of 18.45.040(C) are the maximum that will likely be recommended by specialists and then required by the City for each type of wetland or watercourse. In addition, there are legal and administrative difficulties with property owners, of properties 100 feet off -site from sensitive area lots, surveying and studying a sensitive area on someone else's property. B. Ratings and Buffer Width. Ratings and appropriate buffers for wetlands and watercourses are listed below. 1. For wetlands: a. Type 1 - 100 -foot wide buffer b. Type 2 - 50 -foot wide buffer c. Type 3 - 25 -foot wide buffer 2. For watercourses, the buffer shall be as follows: a. Type 1 - 70 -foot wide buffer b. Type 2 - 35 -foot wide buffer c. Type 3 - 15 -foot wide buffer 3. Setbacks: a. All commercial and industrial developments shall be set back 15 feet and all residential development shall be set back 10 feet. This setback shall be measured from the foundation to the buffer's edge. b. The Director of DCD may waive setback requirements when a site plan demonstrates there will be no impacts to the buffer zone. 4. Variation of Standard of Creation of Variable Width Wetland /Watercourse Buffers: a. The DCD Director may reduce the standard wetland /watercourse buffers on a case -by -case basis, provided the buffer does not contain slopes 15% or greater. The approved buffer - 5 - width shall not result in greater than a 50 percent reduction in width, and the reduced buffer shall not be less than 15 feet for wetlands and 10 feet for watercourses. Any buffer reduction proposal must demonstrate to the satisfaction of the DCD Director that it will not result in direct or indirect, short - term or long -term adverse impacts to wetlands or watercourses, and that: (1) The buffer is vegetated and includes an enhancement plan as may be required to improve the buffer function and value; or (2) If there is no significant vegetation in the buffer, a buffer may be reduced only if an enhancement plan is provided. The plan must include using a variety of native vegetation that improves the functional attributes of the buffer and provides additional protection for the wetland or watercourse functions and values. b. Buffers for all types of wetlands and watercourses will be increased when they are determined to be particularly sensitive to disturbance or the proposed development will create unusually adverse impacts. Any increase in the width of the buffer shall be required only after completion of a wetland or watercourse study by a qualified wetlands specialist or expert which documents the basis for such increased width. An increase in buffer width may be appropriate when: (1) The development proposal has the demonstrated potential for significant adverse impacts upon the wetland or . watercourse which can be mitigated by an increased buffer width; or (2) The area serves as habitat for endangered, threatened, sensitive or monitor species listed by the federal government or the State of Washington. c. Every reasonable effort shall be made to maintain the existing viable plant life in the buffers. Vegetation may be removed from the buffer as part of an enhancement plan approved by the Director of DCD. Enhancements will ensure that slope stability and wetland and watercourse quality will be maintained or improved. Any disturbance of the buffers for wetlands or watercourses shall be replanted with a diverse plant community of native northwest species that are appropriate for the specific site as determined by the DCD Director. If the vegetation must be removed, or because of the alterations of the landscape the vegetation becomes damaged or dies, then the applicant for permit must replace existing vegetation along wetlands and watercourses with comparable specimens, approved by the DCD Director, which will reproduce the existing buffer value within 5 years. d. The DCD Director shall require subsequent corrective actions and long -term monitoring - 6 - of the project if adverse impacts to regulated wetlands, watercourses or their buffers are identified. C. Areas of Potential Geologic Instability. 1. Each development proposal for a legal lot of record containing an area of potential geologic instability shall be subject to a geotechnical report pursuant to the requirements of Sections 18.45.060 and 18.45.080(6). The geotechnical report shall analyze and make recommendations on the need for and width of any buffers necessary to achieve the goals and requirements of this ordinance. Development proposals shall then include the buffer distances as defined within the geotechnical report. 2. Buffers may be increased by the DCD Director when an area is determined to be particularly sensitive to the disturbance created by a development. Such a decision will be based on a City review of the report as prepared by a qualified geotechnical consultant and by a site visit. Section 4. Chapter 18.45.060 Procedures. Tukwila Municipal Code Chapter 18.45.060 is hereby amended to read as follows: 18.45.060 Procedures. General: When an applicant submits an application for any building permit, subdivision, short subdivision or any other land use review which approves a use, development or future construction, the location of any sensitive areas and buffers on the site shall be indicated on the plans submitted. When a sensitive area is identified, the following procedures apply. The DCD Director may waive item numbers 1, 2, 4 and 5 of the following if the size and complexity of the project does not warrant that step in the procedures. 1. Sensitive Areas Study and Geotechnical Report: The applicant shall submit the relevant study as required in TMC 21.04.140 and this chapter. It is intended that sensitive areas studies and information be utilized by applicants in preparation of their proposals and therefore shall be undertaken early in the design stages of a project. 2. Any new subdivision, short subdivision, boundary line adjustment, or multiple family residential proposal which includes a sensitive area or its buffer on the site shall apply for a Planned Residential Development permit and meet the requirements of Chapter 18.46 of the Tukwila Zoning Code. This requirement may be waived by the DCD Director on commercial and industrial sites, on existing developed sites, and in other cases where substantial evidence exists that such waiver will not have a material negative impact on any sensitive area or buffer. COMMENT: Without the amendment, property owners of commercial, industrial, and developed lots, who are platting lots or adjusting property lines must apply for a Planned Residential Development. A PRD process is inappropriate for commercial, industrial or developed lots. 3. Denial of Use or Development: A use or development will be denied if it is determined by the DCD Director that the applicant cannot ensure - 7 - that potential dangers and costs to future inhabitants of the development, adjacent and local properties, and Tukwila are minimized and mitigated to an acceptable level. 4. Pre - development Conference: The applicant, specialist(s) of record, contractor, and Department representatives will be required to attend pre- construction conferences prior to any work on the site. 5. Construction Monitoring: The specialist(s) of record shall be retained to monitor the site during construction. 6. The DCD Director may require the boundary between a sensitive area and its buffer and any development or use to be permanently identified with fencing, or with a wood or metal sign with treated wood, concrete or metal posts. Size will be determined at the time of permitting, and wording shall be as follows: Section 5. Chapter 18.45.080 Uses and Standards. Tukwila Municipal Code 18.45.080(A), and Ordinance 1599 in part, are hereby amended to read as follows: 18.45.080 Uses and Standards. A. General. The uses set forth in this entire section, including subsections A -H, may be located within a sensitive area or buffer, sub jectto the provisions of TMC 21.04 1. Mainentance and repair of existing uses and facilities provided no alteration or additional fill materials will be placed or heavy construction equipment used in the sensitive area or buffer. 2. Non - destructive education and research. 3. Passive recreation and open space. 4. Maintenance and repair of essential streets, roads, rights -of -way, or utilities. 5. Actions to remedy the effects of emergencies that threaten the public health, safety or welfare. "Protection of this natural area is in your care. Alteration or disturbance is prohibited pursuant to TMC 18.45. Please call the City of Tukwila for more information." 8 is section. COMMENT: This amendment is designed to remove a possible ambiguity regarding SEPA application. As currently written, the "general uses" enumerated in subsection (A) are clearly subject to SEPA (TMC 21.04). Given the additional enumeration in subsection (A)(6) of the other uses set forth in subsections (B)- (H), the better argument is that the uses set forth in (B) -(H) are also subject to SEPA. There is some ambiguity, however, and the proposed amendment is designed simply to remove that arguable ambiguity and make clear that all uses in this section 18.45.080 are subject to SEPA unless otherwise exempted (e.g. pursuant to TMC 18.45.115). Section 6. Refund of SEPA Checklist Fees. The Mayor shall authorize the Finance Director to refund SEPA Checklist fees received, between the effective date of Ordinance No. 1599 and the effective date of this ordinance, from applicants now made exempt pursuant to Section 1 of this Ordinance. Comment: Minimal staff time was spent on processing the SEPA checklist for single family development and short plats. Section 7. Severability. If any section, sentence, clause or phrase of this ordinance should be held to be invalid or unconstitutional by a court of competent jurisdiction, such invalidity or unconstitutionality shall not affect the validity or constitutionality of any other section, sentence, clause or phrase of this ordinance. Section 8. Effective Date. This ordinance shall take effect and be in full force five (5) days after publication of the attached summary which is hereby approved. PASSED BY THE CITY COUNCIL OF THE CITY OF TUKWILA, WASHINGTON, at a regular meeting thereof this day of , 1991. ATTEST /AUTHENTICATED: Jane Cantu, City Clerk APPROVED AS TO FORM: OFFICE OF THE CITY ATTORNEY Filed with the City Clerk: Passed by the City Council: Ordinance No. SAO APPROVED: Mayor Gary L. VanDusen WASHINGTON ORDINANCE NO. /S' 9 9 AN ORDINANCE OF THE CITY OF TUKWILA, WASHINGTON, REGULATING DEVELOPMENT ON SENSITIVE AREAS AND BUFFERS; AMENDING ORDINANCE NOS 1247 AND 1289 AND TUKWILA MUNICIPAL CODE (TMC) TITLE 18; AMENDING ORDINANCE NOS. 1331 AND 1334 AND TMC TITLE 21.04; AMENDING ORDINANCE NO 1014 AND TMC TITLE 17; AND PROVIDING FOR AN EFFECTIVE DATE. WHEREAS, the City Council considered regulation of development on sensitive areas within the City of Tukwila and referred the issue to the Planning Commission; and WHEREAS, the State of Washington has subsequently through RCW 36.70A mandated that local jurisdictions pass legislation protecting sensitive areas; and WHEREAS, the SEPA Responsible Official made a determination of non - significance on October 25, 1989; and WHEREAS, the City Council upheld the determination of non - significance at an appeal heard on December 18, 1989; and WHEREAS, the Planning Commission held public hearings on November 9, 1989, November 16, 1989, August 30, 1990, and September 6, 1990; and WHEREAS, the City Council President and the Mayor appointed a citizens' committee on November 27, 1989 to study the issue; and WHEREAS, the City Council authorized certain consultants' reports as follows: 1. Wetlands Inventory by Jones & Stokes Associates, Inc., dated September 1989; superseded by Water Resource Rating and Buffer Recommendations dated May 1990. 2. Abandoned Underground Coal Mine Hazard Assessment by Hart Crowser, Inc., dated May 3, 1990. 3. Geologic Hazards Evaluation by GeoEngineers dated May 9, 1990. 4. Tukwila. Hillsides — Design and Development Standards by Johnson Architecture /Planning dated March 6, 1990 5. Watercourse Rating Data Sheets by Jones & Stokes, Inc., dated October 1990; and CITY OF TUKWILA WHEREAS, After considering the testimony at public hearings, the recommendations of the citizens' committee and the consultants' reports, the Planning Commission made Findings and recommended a draft Sensitive Areas Ordinance to the City Council on October 25, 1990; and WHEREAS, public hearings were held before the City Council on April 22, 1991 and April 24, 1991; and WHEREAS, after considering the recommendations of the Planning Commission and the citizens' committee, the consultants' reports and the testimony at the public hearings and after numerous public meetings of the City Council, the City Council has determined that it is necessary and desireable and in the interest of the public health, safety arid welfare to regulate development on sensitive areas and their buffers; NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF TUKWILA, WASHINGTON, DO ORDAIN AS FOLLOWS: SECTION 1. FINDINGS. The City Council finds as follows: 1. The environmental features identified as sensitive areas which require regulation by Tukwila are: coal mine hazard areas, areas of potential geologic instability, watercourses, wetlands and important geologic and archaeologic resources. 2. The Sensitive Areas Ordinance will implement goals and policies of the 1978 Tukwila Comprehensive Land Use Policy Plan and the Puget Sound Water Quality Management Plan. 3. The 1990 Washington State Legislature approved ESHB 2929 (1990 Wash. Laws 17) (RCW 36.70A) which mandates that certain counties, and cities within those counties, address the protection of critical ATTACHMENT B Sensitive Areas Ordinance Page 2 areas. Critical areas as defined in ESHB 2929 correlate generally with the Tukwila definitions and categories of sensitive areas. This Sensitive Areas Ordinance is designed to meet the challenges and satisfy the requirements of this act with regard to all critical areas except aquifer recharge areas and flood plains which will require a different regulatory approach or are regulated in an existing title of the Tukwila Municipal Code. 4. Regulation of the use of sensitive areas benefits property owners by preventing and avoiding activities which would have adverse impacts on property. 5. Development in wetlands, watercourses and erosion hazard areas results in: 1) increased soil erosion and sedimentation of downstream water bodies, including navigable channels; 2) increased shoreline erosion; 3) degraded water quality due to increased turbidity and loss of pollutant removal processes; 4) elimination or degradation of wildlife and fisheries habitat; 5) loss of fishery resources from water quality degradation, increased peak flow rates, decreased summer low flows, and changes in the stream flow regimen; 6) loss of stormwater retention capacity and slow - release detention resulting in flooding, degraded water quality, and changes in the stream flow regimen of watersheds. 6. Development in areas of geologic instability present a danger to the development on the site as well as neighboring sites and natural resources, and require special design, construction and site development measures to minimize risks from these hazards. 7. Tukwila is in an earthquake prone region subject to ground shaking, subsidence, landslide and liquefaction. Special building design and construction measures are necessary to minimize risk from this hazard. 8. In their natural state, wetlands and watercourses provide many valuable social and ecological services, which are critical and cannot adequately be replicated or replaced, including: a. controlling flooding and stormwater runoff by storing or regulating natural flows; b. protecting water resources by filtering out water pollutants, processing biological and chemical oxygen demand, recycling and storing nutrients, and serving as settling basins for naturally occurring sedimentation; c. providing areas for groundwater recharge; d. providing habitat areas for many species of fish, wildlife, and vegetation, many of which are dependent on these water resources for their survival; e. providing open space and visual relief from intense development in urbanized area; f. providing recreation opportunities; and g. serving as areas for scientific study and natural resource education. 9. Tukwila in enacting this ordinance has relied on extensive scientific documentation and testimony concerning these sensitive areas and the appropriate methods and mechanisms for their protection. This documentation is available in the Department of Community Development in file 89 -2 -CA: Sensitive Areas Ordinance. SECTION 2. ORDINANCE NO. 1247 AND TMC 18.06 AMENDED. TMC 18.06 is hereby amended to add the following sections: 18.06.045 Applicant "Applicant" means any person or business entity which applies for a development proposal, permit or approval subject to review under the Sensitive Areas Chapter. 18.06.049 Areas of Potential Geologic Instability. "Area of Potential Geologic Instability" means those areas subject to potential landslides and /or potential seismic instabilities. 18.06.175 Compensatory Mitigation "Compensatory mitigation" means replacing project - induced wetland and buffer losses or impacts, and includes, but is not limited to, the following: 1. Restoration — Actions performed to reestablish wetland and its buffer functional char- acteristics and processes which have been lost by alterations, activities, or catastrophic events within an area which no longer meets the definition of a wetland. 2. Creation — Actions performed to intentionally establish a wetland and its buffer at a site where it did not formerly exist. 3. Enhancement — Actions performed to improve the condition of an existing degraded wetland or its buffer so that the functions they provide are of a higher quality. Table of Contents Sensitive Areas Ordinance Paces Zoning Code Chapter 45 Sensitive Areas Overlay Zone Definitions 2 - 5 Sensitive Areas Designated 5 - 7 Sensitive Areas Studies 7 Buffer Standards 8 Buffer setbacks 8 Variation of buffer standards 8 - 9 Procedures 9 Uses, general 10 wetland uses, additional 10 - 12 watercourse uses, additional 12 - 15 areas of potential geologic instability additional 15 landscape plan required 15 geotechnical report requirements 16 disclosure, declarations covenants 16 Assurance device 17 construction monitoring 18 abandoned mine area uses, additional 18 areas of important geological archaeological evidence uses, additional 18 uses subject to exception approval 18 sensitive area tracts 18 Exceptions 18 wetlands piping use exception process 19 Appeals Recording 19 Assurance devices 19 Assessment Relief 20 Zoning Code 18.45, Planned Residential Developments, Subdivision Code and the Environmental Code were also amended. Cut and paste the sections into your personal codes. Chapter 46 Planned Residential Developments Purpose 20 Permitted Uses 20 Site acreage minimum 20 Relationship to other sections 21 Density Standards 21 Open Space 23 Relationship to adjacent areas 23 Application procedures 23 Review Criteria 24 Application for building permit 24 Chapter 18.70 Nonconforming structures 25 Subdivision Code Short Plat /BLA criteria 25 Application requirements 25 Review Procedures 26 Preliminary Plat procedures 26 Purpose of code 27 Environmental considerations 27 Grading 28 Streets 28 Street Layout 28 Public rights -of -way (Subdivision design) 28 Definitions Threshold Determination environmental checklist mitigated DNS Environmentally sensitive areas Environmental Code 30 30 32 Sensitive Areas Ordinance ` Page 3 18.06.176 Constructed Wetlands or Watercourses. "Constructed wetland" or "constructed watercourses" means those wetlands or watercourses which an applicant can demonstrate were intentionally created from non - wetland or non - watercourse sites, including, but not limited to, irrigation and drainage ditches, grass -lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities; and does not mean those wetlands and watercourses created through compensatory mitigation. 18.06.203 Density Transfer. "Density transfer" is a percentage number which represents a credit for housing units which are not allowed to be built in wetlands, watercourses or their buffers. The density transfer is used in a formula for determining the number of residential units allowed on the buildable portion of a lot containing wetlands, watercourses and their buffers. 18.06.255 Emergent Wetland. "Emergent wetland" means a regulated wetland with at least 30 percent of the surface area covered by erect, rooted, herbaceous vegetation as the uppermost vegetative strata. 18.06.262 Essential street, road, right -of -way or utility. "Essential street, road, right -of -way or utility" means a utility facility,utility system, street, road or right -of -way where no feasible alternative location exists based on an analysis of technology and system efficiency. 18.06.295 Forested wetland. "Forested wetland" means a regulated wetland with at least 20 percent of the surface area covered by trees greater than 20 feet in height. 18.06.322 Geologist. "Geologist" means a person who has earned a degree in geology from an accredited college or university, or a person who has equivalent educational training and has experience as a practicing geologist. 18.06.323 Geotechnical Engineer. " Geotechnical engineer" means a practicing, geotechnical /civil engineer licensed as a professional Civil Engineer with the State of Washington who has at least four years of professional employment as a geotechnical engineer with experience in landslide evaluation. 18.06.385 Impervious. Surface. "Impervious Surface" means those hard surfaces which prevent or retard the entry of water into the soil in the manner that such water entered the soil under natural conditions pre- existent to development, grading or alteration of the land. Such surfaces include, but are not limited to, rooftops, asphalt or concrete paving, driveways, parking lots, walkways, patio areas, storage areas, compacted surfaces, or other surfaces which similarly affect the natural infiltration or runoff patterns existing prior to development. 18.06.388 Isolated Wetlands. "Isolated wetlands" means those wetlands which: 1. are outside of and not contiguous to any 100 -year floodplain of a lake, river, or stream that is designated as a shoreline according to the City's Shoreline Master plan; and 2. have no contiguous hydric soil and hydrophytic vegetation between the wetland and any surface water. 18.06.455 Lot Coverage. "Lot Coverage" means the surface of the subject property covered with impervious surface, other than outdoor pools. 18.06.585 Ordinary High Water Mark "Ordinary high water mark" (OHWM) means the mark that will be found by examining the bed and banks of a stream and ascertaining where the presence and action of waters are so common and usual as to distinctly mark the soil from that of the abutting upland, in respect to vegetation. *In any area where the OHWM cannot be determined, the channel bank shall be substituted. In braided channels, the OHWM or substitute shall be measured so as to include the entire stream. 18.06.605 Performance Standards. Specific criteria for fulfilling environmental goals, and for beginning remedial action, mitigation, or contingency measures, which may include water quality standards, or other hydrological, geological, or ecological criteria. 18.06.625 Reach. "Reach" is a segment of a watercourse with uniform characteristics. Sensitive Areas Ordinance Page 4 18.06.655 Regulated Activities "Regulated Activities" means any of the following activities which are directly undertaken or originate in a regulated wetland or watercourse or their buffers: 1. The removal, excavation, grading, or dredging of soil, sand, gravel, minerals, organic matter, or material of any kind; 2. The dumping, discharging, or filling with any material; 3. The draining, flooding, or disturbing of the water level or water table; 4. The driving of pilings; 5. The placing of obstructions; 6. The construction, reconstruction, demolition, or expansion of any structure; 7. The destruction or alteration of wetlands, watercourses or their buffers through clearing, harvesting, shading, intentional burning, or planting of vegetation that would alter the character of a regulated wetland, watercourse or buffer, provided that these activities are not part of a forest practice governed under Chapter 76.09 RCW and its rules; or 8. Activities that result in a significant change to the water sources of wetlands or watercourses. These alterations include a significant change in water temperature; physical or chemical characteristics, including quantity; and the introduction of pollutants. 18.06.656 Regulated Wetlands. "Regulated wetlands" means ponds or lakes thirty acres or less and those lands subject to the "wetland" definition contained in this chapter. Isolated wetlands that are 400 square feet or smaller in area may not require compensatory mitigation. 18.06.692 "Scrub -Shrub Wetland. "Scrub -shrub wetland" means a regulated wetland with at least 30 percent of its surface area covered by woody vegetation less than 20 feet in height as the uppermost strata. 18.06.695 Sensitive Areas. • "Sensitive Areas" means wetlands; watercourses; areas of potential geologic instability other than Class 1 areas; abandoned coal mine areas; and important geological or archaeological sites. 18.06.697 Sensitive Area Buffer. "Sensitive Area Buffer" means the area contiguous to a sensitive area that is required for the continued maintenance, function and structural stability of the sensitive area. • 18.06.698 Sensitive Area Tract. "Sensitive Area Tract" means a tract which is created to protect the sensitive area and its buffer, whose maintenance is assured, and which is recorded on all documents of title of record for all affected lots and subsequent owners. 18.06.762 Significant Tree. "Significant tree" is any woody vegetation, in any sensitive area or buffer, that is essential to or contributes to the function of a sensitive area and its buffers. 18.06.915 Utilities. "Utilities" are all lines and facilities related to the provision, distribution, collection, transmission or disposal of water, storm and sanitary sewage, oil, gas, power, information, telecommunication and telephone cable, or refuse, and includes facilities for the generation of electricity. 18.06.935 Watercourse. "Watercourse" means a course or route formed by nature or modified by man, generally consisting of a channel with a bed and banks or sides substantially throughout its length along which surface water flows naturally other than the Green /Duwamish River. The channel or bed need not contain water year- round. Watercourses do not include irrigation ditches, storm water runoff channels or devices, or other entirely artificial watercourses unless they are used by salmonids or to convey or pass through stream flows naturally occurring prior to construction of such devices. 18.06.938 Wetlands. "Wetlands" means those areas that are inundated or saturated by ground or surface water at a frequency and duration sufficient to support and that under normal circumstances do support a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include bogs, swamps, marshes, ponds, lakes and similar areas. Constructed wetlands are not considered wetlands for the purpose of this Chapter. However, those artificial wetlands intentionally created from non - wetland areas to mitigate conversion of wetlands as permitted by the City shall be considered wetlands. Sensitive Areas Ordinance Page 5 18.06.939 Wetland Edge. "Wetland edge" means the boundary of a wetland as delineated based on the methodology used in the "Federal Manual for Identifying and Delineating Jurisdictional Wetlands" (1989), as revised or updated. SECTION 3. ORDINANCE NO. 1247 AND TMC 18 AMENDED. A new chapter 18.45 entitled "Sensitive Areas Overlay Zone" is hereby added to the Tukwila Municipal Code (TMC) to read as follows: 18.45.010 Purpose . A. The purpose of the Sensitive Areas Overlay Zone is to establish special standards for the use and development of lands based on the existence of natural conditions thereon in order to protect environmentally sensitive areas, including the natural character of Tukwila's wooded hillsides. B. Standards are hereby established to meet the following goals of protecting environmentally sensitive areas: 1. Minimize developmental impacts on the natural functions and values of these areas. 2. Protect quantity and quality of water resources. 3. Minimize turbidity and pollution of wetlands and fish - bearing waters and maintain wildlife habitat. 4. Prevent erosion and the loss of slope and soil stability caused by the removal of trees, shrubs, and root systems of vegetative cover. 5. Protect the public against avoidable losses, public emergency rescue and relief operations cost, and subsidy cost of public mitigation from landslide, subsidence, erosion, and flooding. 6. Protect the community's aesthetic resources and distinctive features of natural lands and wooded hillsides. 7. Prevent unlawful disturbance of archaeologic or geologic sites with historic or prehistoric artifacts. 8. Balance the private rights of individual property owners with the preservation of envi- ronmentally sensitive areas. 9. Prevent the loss of wetland and watercourse function and acreage, and strive for a gain over present conditions. 18.45.020 Sensitive Area Designation, Rating methodologies, Classifications and Applicability. A. This chapter applies to any use or development proposed on any legal lot of record, any portion of which is a sensitive area or a sensitive area buffer as defined in TMC Sections 18.06.695 and 18.06.697, and specifically including one or more of the following and their buffers: 1. Abandoned coal mines 2. Areas of Potential Geologic Instability - Class 2,3,4 and seismic instability areas (TMC 18.06.049 and 18.45.020(E)) 3. Wetlands (TMC 18.06.938) 4. Watercourses (TMC 18.06.935) 5. Areas that contain archaeological remnants of value to the archaeological research community, which includes but is not limited to colleges, universities or societies of professional archaeologists, or which is designated as important to save as a record of the area's past by the State Office of Archaeology and Historic Preservation. B. Sensitive Areas Maps and Inventories. 1. The distribution of many sensitive areas in Tukwila is displayed on the Sensitive Areas Maps, dated 1990, and on file with the DCD. 2. Studies, preliminary inventories and ratings of potential sensitive areas are on file with the DCD in the Sensitive Areas Notebook dated May 1990. 3. The maps and preliminary inventories and ratings are hereby adopted by reference. The actual presence or absence of sensitive areas as defined by or otherwise referred to in this chapter and as determined by the City of Tukwila will govern. The actual ratings and buffers for any sensitive area will be determined by the City of Tukwila using the methodologies and procedures provided in this chapter for each type of sensitive area. 4. All revisions, updates and reprintings of sensitive areas maps, inventories, ratings and buffers shall conform to this ordinance. Sensitive Areas Ordinance Page 6 C. Wetlands: For the purposes of this Chapter, wetlands are defined in TMC 18.06.938. A wetland boundary is the line delineating the outer edge of a wetland established by using the Federal Manual for Identifying and Delineating Jurisdictional Wetlands dated January 10, 1989, as revised or updated, and jointly published by the U.S. Environmental Protection Agency, the U.S. Fish and Wildlife Service, the U.S. Army Corps of Engineers, and the U.S. Soil Conservation Service. Wetland types and rating criteria are listed below. 1. Type 1 Wetlands. Those wetlands which meet any of the following criteria: a. The presence of species listed by the federal government or state as endangered, or threatened or the presence of critical or outstanding actual habitat for those species; b. Wetlands having 40% to 60% permanent open water in dispersed patches with two or more classes of vegetation; c. Wetlands equal to or greater than five acres in size and having three or more wetland classes, one of which may be substituted by permanent or open water; or 2. Type 2 Wetlands. Those wetlands which meet any of the following criteria: (3) a. Wetlands greater than one acre in size; b. Wetlands equal to or less than one acre in size and having three classes; c. Wetlands equal to or less than one acre that have a forested wetland at least 20 percent coverage of total surface area; or d. The presence of heron rookeries or raptor nesting trees. e. The presence of native plant associations of infrequent occurrence. or more wetland class comprised of 3. Type 3 Wetlands. Those wetlands which are equal to or less than one acre in size and that have two or fewer wetland classes. For the purposes of this section, the U.S. Fish and Wildlife Service's Classification of Wetlands and Deepwater Habitats of the United States FWS /OBS -79/31 (Cowardin et al, 1979) contains the descriptions of wetland classes and subclasses. D. Watercourses: For the purposes of this Chapter, watercourses are defined in TMC 18.06.935. The City of Tukwila's Watercourse Study (1990) includes the methodology and criteria that will be used for determining watercourse ratings. Watercourse ratings are based on the existing habitat functions. Each segment or reach of a watercourse is rated individually. The rating system will score a reach point total for each side of the watercourse. Watercourse types, rating scores, and rating criteria are described below. 1. Watercourse Types and Rating Scores: a. Type 1 Watercourse - 21 to 33 Points b. Type 2 Watercourse • 11 to 20 Points c. Type 3 Watercourse • -3 to 10 Points 2. Watercourse Rating Criteria a. Instream Features (1) Width of Watercourse - A measure of the average width of the channel at the ordinary high water mark. (2) Channel Capacity - Quantifies the ability of the channel to convey high flows without flooding. Channel Stability - Measures the stability of the channel by evaluating evidence of bank failure, scour, and downcutting. (4) Fish Use and Fish Habitat - Anadromous and resident salmonid need protection measures if present. Rating depends on the number of different types of habitat present. b. Corridor Quality (1) Width of Unmaintained Vegetation - A measure of the width of unmaintained vegetation from the Ordinary High Water Mark. (2) Vegetation Diversity - Quantifies the elements of terrestrial habitat associated with the watercourse corridor. Sensitive Areas Ordinance Page 7 (3) Corridor Barrier Function - Provides some measure of effectiveness of the buffer to limit intrusion and disturbance. (4) Surrounding Land Use - Evaluation of the land use immediately outside the of the vegetated corridor. E. Areas of Potential Geologic Instability. Areas of potential geologic instability are defined in TMC 18.06.049, and are classified as follows: 1. Class 1 areas, where landslide potential is low, which slope less than 15 percent. 2. Class 2 areas, where landslide potential is moderate, which slope between 15 and 40 per- cent and which are underlain by relatively permeable soils. 3. Class 3 areas, where landslide potential is high, which include areas sloping between 15 and 40 percent and which are underlain by relatively impermeable soils or by bedrock, and which also include all areas sloping more steeply than 40 percent. 4. Class 4 areas, where landslide potential is very high, which include sloping areas with mappable zones of ground water seepage, and which also include existing mappable landslide deposits regardless of slope. 5. Areas of potential seismic instability, with soft soils, loose sand and a shallow ground water table. F. Sensitive Areas Special Studies 1. Required. An applicant for a development proposal that includes sensitive areas, shall submit those studies as required by the City to adequately identify and evaluate the sensitive area and its buffers. 2. Waiver. If there is agreement between the Director of DCD and the applicant concerning the sensitive area classification and type, the Director of DCD may waive the requirement for sensitive area studies. There must be substantial evidence that the sensitive area classification is correct, that there will be no alteration of the sensitive areas or buffers, and that the goals, purposes, objectives and requirements of this ordinance will be followed. 3. Review of studies. The Department of Community Development will review the information submitted in the sensitive area studies to verify the information, confirm the nature and type of the sensitive area, and ensure the study is consistent with this Chapter. G. When this chapter imposes greater restrictions or higher standards upon the development or use of land than other laws, ordinances or restrictive covenants, the provisions of this chapter shall prevail. H. All other relevant standards of the TMC must also be met. 18.45.030 Interpretation The provisions of this chapter shall be held to be minimum requirements in their interpretation and application and shall be liberally construed to serve the purposes of this chapter. 18.45.040 Sensitive Area Buffers A. General. 1. Any land alteration must be located out of the buffer areas as required by this section. Buffers in general are intended to: a. Minimize long -term impacts of development on properties containing Sensitive Areas; b. Protect Sensitive Areas from adverse impacts during development; c. Preserve the edge of the Sensitive Area for its critical habitat value; and d. Prevent loading of potentially unstable slope formations. Land alteration is permitted for public access, supplemental planting and approved land uses of 18.45.080. An undisturbed sensitive area or buffer may substitute for the yard setback and landscape requirements of TMC 18.50 and 18.52. 2. Wetland and Watercourse Buffers are intended to: a. Provide shading to maintain stable water temperatures and vegetative cover for additional wildlife habitat; b. Provide input of organic debris, and uptake of nutrients; c. Provide an area to stabilize banks, to absorb overflow during high water events, and to allow for slight variation of aquatic system boundaries over time due to hydrologic or climatic effects; d. Reduce erosion and increased surface water runoff; Sensitive Areas Ordinance Page 8 e. Reduce loss of or damage to property; f. Intercept fine sediments from surface water runoff and serve to minimize water quality impacts; g. Preserve the edge for its habitat value; and h. Protect the sensitive area from human and domestic animal disturbance. 3. Buffers for Areas of Potential Geologic Instability are intended to: a. Protect slope stability; b. Provide erosion control and attenuation of precipitation surface and storm water runoff; c. Reduce loss of or damage to property; and d. Preserve the natural character of wooded hillsides where they exist. B. Special Buffer Studies. Applicants for a use or development on a legal lot of record within one hundred feet of a sensitive area shall be required to conduct a sensitive area study to provide a buffer analysis for the sensitive area. This study may be waived by the DCD Director following 18.45.020 F.2. C. Ratings and Buffer Width. Ratings and appropriate buffers for wetlands and watercourses are listed below. 1. For wetlands: a. Type 1 — 100 -foot wide buffer b. Type 2 — 50 -foot wide buffer c. Type 3 — 25 -foot wide buffer 2. For watercourses, the buffer shall be as follows: a. Type 1 — 70 -foot wide buffer b. Type 2 — 35 -foot wide buffer c. Type 3 — 15 -foot wide buffer 3. Setbacks: a. All commercial and industrial developments shall be set back 15 feet and all residential development shall be set back 10 feet. This setback shall be measured from the foundation to the buffer's edge. b. The Director of DCD may waive setback requirements when a site plan demonstrates there will be no impacts to the buffer zone. 4. Variation of Standard or Creation of Variable Width Wetland/Watercourse Buffers: a. The DCD Director may reduce the standard wetland /watercourse buffers on a case -by- case basis, provided the buffer does not contain slopes 15% or greater. The approved buffer width shall not result in greater than a 50 percent reduction in width, and the reduced buffer shall not be less than 15 feet for wetlands and 10 feet for watercourses. Any buffer reduction proposal must demonstrate to the satisfaction of the DCD Director that it will not result in direct or indirect, short -term or long -term adverse impacts to wetlands or watercourses, and that: (1) The buffer is vegetated and includes an enhancement plan as may be required to improve the buffer function and value; or (2) If there is no significant vegetation in the buffer, a buffer may be reduced only if an enhancement plan is provided. The plan must include using a variety of native vegetation that improves the functional attributes of the buffer and provides additional protection for the wetland or watercourse functions and values. b. Buffers for all types of wetlands and watercourses will be increased when they are determined to be particularly sensitive to disturbance or the proposed development will create unusually adverse impacts. Any increase in the width of the buffer shall be required only after completion of a wetland or watercourse study by a qualified wetlands specialist or expert which documents the basis for such increased width. An increase in buffer width may be appropriate when: (1) The development proposal has the demonstrated potential for significant adverse impacts upon the wetland or watercourse which can be mitigated by an increased buffer width; or (2) The area serves as habitat for endangered, threatened, sensitive or monitor species listed by the federal government or the State of Washington. Sensitive Areas Ordinance Page 9 c. Every reasonable effort shall be made to maintain the existing viable plant life in the buffers. Vegetation may be removed from the buffer as part of an enhancement plan approved by the Director of DCD. Enhancements will ensure that slope stability and wetland and watercourse quality will be maintained or improved. Any disturbance of the buffers for wetlands or watercourses shall be replanted with a diverse plant community of native northwest species that are appropriate for the specific site as determined by the DCD Director. If the vegetation must be removed, or because of the alterations of the landscape the vegetation becomes damaged or dies, then the applicant for permit must replace existing vegetation along wetlands and watercourses with comparable specimens, approved by the DCD Director, which will reproduce the existing buffer value within 5 years. d. The DCD Director shall require subsequent corrective actions and long -term monitoring of the project if adverse impacts to regulated wetlands, watercourses or their buffers are identified. D. Areas of Potential Geologic Instability. 1. Each development proposal for a legal lot of record containing an area of potential geologic instability shall be subject to a geotechnical report pursuant to the requirements of Sections 18.45.060 and 18.45.080(6). The geotechnical report shall analyze and make recommendations on the need for and width of any buffers necessary to achieve the goals and requirements of this ordinance. Development proposals shall then include the buffer distances as defined within the geotechnical report. 2. Buffers may be increased by the DCD Director when an area is determined to be particularly sensitive to the disturbance created by a development. Such a decision will be based on a City review of the report as prepared by a qualified geotechnical consultant and by a site visit. 18.45.060 Procedures General: When an applicant submits an application for any building permit, subdivision, short subdivision or any other land use review which approves a use, development or future construction, the location of any sensitive areas and buffers on the site shall be indicated on the plans submitted. When a sensitive area is identified, the following procedures apply. The DCD Director may waive item numbers 1, 4 and 5 of the following if the size and complexity of the project does not warrant that step in the procedures. 1. Sensitive Areas Study and Geotechnical Report: The applicant shall submit the relevant study as required in TMC 21.04.140 and this chapter. It is intended that sensitive areas studies and information be utilized by applicants in preparation of their proposals and therefore shall be undertaken early in the design stages of a project. 2. Any new subdivision, short subdivision, boundary line adjustment, or multiple family residential proposal which includes a sensitive area or its buffer on the site shall apply for a Planned Residential Development permit and meet the requirements of Chapter 18.46 of the Tukwila Zoning Code. 3. Denial of Use or Development: A use or development will be denied if it is determined by the DCD Director that the applicant cannot ensure that potential dangers and costs to future inhabitants of the development, adjacent and local properties, and Tukwila are minimized and mitigated to an acceptable level. 4. Pre - development Conference: The applicant, specialist(s) of record, contractor, and Department representatives will be required to attend pre- construction conferences prior to any work on the site. 5. Construction Monitoring: The specialist(s) of record shall be retained to monitor the site during construction. 6. The DCD Director may require the boundary between a sensitive area and its buffer and any development or use to be permanently identified with fencing, or with a wood or metal sign with treated wood, concrete or metal posts. Size will be determined at the time of permitting, and wording shall be as follows: "Protection of this natural area is in your care. Alteration or disturbance is prohibited pursuant to TMC 18.45. Please call the City of Tukwila for more information." 18.45.080 Uses and Standards A. General. The following general uses may be located within a sensitive area or buffer, subject to the provisions of TMC 21.04. Each permitted use is subject to the standards of this section. Sensitive Areas Ordinance Page 10 1. Maintenance and repair of existing uses and facilities provided no alteration or additional fill materials will be placed or heavy construction equipment used in the sensitive area or buffer. 2. Non - destructive education and research. 3. Passive recreation and open space. 4. Maintenance and repair of essential streets, roads, rights -of -way, or utilities. 5. Actions to remedy the effects of emergencies that threaten the public health, safety or welfare. 6. Other uses may be allowed pursuant to TMC 18.45.080 B -H. B. Permitted Uses Subject to Administrative Review. The following uses may be permitted only after administrative review and approval by the DCD Director. 1. Maintenance and repair of existing uses and facilities where alteration or additional fill materials will be placed or heavy construction equipment used. 2. Construction of new essential streets and roads, rights -of -way and utilities. 3. New surface water discharges to wetlands or watercourses or their buffers from detention facilities, pre - settlement ponds, or other surface water management structures may be allowed provided that the discharge meets the clean water standards of RCW 90.48 and WAC 173.200 and 173.201 as amended, and does not increase the rate of flow to the wetland or watercourse beyond the level of the existing rate. 4. Regional stormwater detention areas may be allowed if use results in no decrease in rating of resource and enhances existing values and functions. Design shall be subject to the standards of this section and other applicable City of Tukwila standards. 5. Enhancement or other mitigation including landscaping. C. Wetlands. 1. General: a. No use or development may occur in a Type 1 and Type 2 wetland or its buffer except as specifically allowed by TMC 18.45.080 (A, B and H). Any use or development allowed is subject to the standards of this section. b. Only isolated Type 3 wetlands can be altered or relocated , and then only with the permission of the DCD Director. A mitigation or enhancement plan must be developed and must comply with the standards of compensatory mitigation required in this chapter. c. Mitigation plans shall be completed for any proposals for dredging, filling, alterations, and relocation of wetland habitat allowed in TMC 18.45.080 (A, B and H). 2. Compensatory Mitigation: a. The mitigation plan shall be developed as part of a sensitive area study by a specialist approved by the DCD Director. Wetland and /or buffer alteration or relocation may be allowed only when a mitigation plan clearly demonstrates that the changes would be an improvement of wetland and buffer quantitative and qualitative functions. The plan shall follow the performance standards of this chapter and show how water quality, wildlife and fish habitat, and general wetland quality would be improved. b. In order to achieve the City's goal of no- net -loss of wetland functions and acreage, alteration of wetlands will require the applicant to provide a restoration, enhancement or creation plan to compensate for the impacts to the wetland and will compensate at a ratio of 1.5:1. c. Mitigation Location. (1) On -site compensation shall be provided except where the applicant can demonstrate that: (a) the hydrology and ecosystem of the original wetland and those who benefit from the hydrology and ecosystem will not be damaged by the on -site loss; and (b) on -site compensation is not scientifically feasible due to problems with hydrology, soils, waves, or other factors, or (c) compensation is not practical due to potentially adverse impact from surrounding land uses; or (d) existing functional values at the site of the proposed restoration are significantly greater than lost wetland functional values; or Sensitive Areas Ordinance Page 11 (e) that established regional goals for flood storage, flood conveyance, habitat or other wetland functions have been established and strongly justify location of compensatory measures at another site. (2) Off -site compensation shall occur within the same watershed where the wet- land loss occurred. (3) In selecting compensation sites, applicants shall pursue siting in the following order of preference: (a) upland sites which were formerly wetlands; (b) idled upland sites generally having bare ground or vegetative cover consisting primarily of exotic introduced species, weeds, or emergent vegetation; (c) other disturbed upland. d. Mitigation Standards: The scope and content of a mitigation plan shall be decided on a case -by -case basis. As the impacts to the sensitive area increase, the mitigation measures to offset these impacts will increase in number and complexity. The components of a complete wetlands mitigation plan are as follows: (1) Baseline information of quantitative data collection or a review and synthesis of existing data for both the project impact zone and the proposed mitigation site. (2) Environmental goals and objectives that describe the purposes of the mitigation measures. This should include a description of site selection criteria, identification of target evaluation species and resource functions. Performance standards of the specific criteria for fulfilling environmental goals, and for beginning remedial action or contingency measures. They may include water quality standards, species richness and diversity targets, habitat diversity indices, or other ecological, geological or hydrological criteria. (4) Detailed construction plan of the written specifications and descriptions of mitiga- tion techniques. This plan should include the proposed construction sequence and construction management, and be accompanied by detailed site diagrams and blueprints that are an integral requirement of any development proposal. Monitoring and /or evaluation program that outlines the approach for assessing a completed project. An outline shall be included that spells out how the monitor- ing data will be evaluated by agencies that are tracking the mitigation project's progress. (6) Contingency plan identifying potential courses of action, and any corrective mea- sures to be taken when monitoring or evaluation indicates project performance standards have not been met. Performance security or other assurance devices as described in TMC 18.45.135. (3) (5) ( e. Mitigation Timing: Where feasible, compensatory mitigation projects shall be completed prior to activities that will permanently disturb wetlands and immediately after activities that will temporarily disturb wetlands. Construction of compensatory projects shall be timed to reduce impacts to existing wildlife, flora and water quality, and shall be completed prior to use or occupancy of the activity or development. 3. Essential Utilities a. Essential utilities must be constructed to minimize or where possible avoid wetland disturbance; and b. All construction must be designed to protect the wetland and its buffer against erosion, uncontrolled drainage, restriction of groundwater movement, slides, pollution, habitat disturbance, any loss of flood carrying and storage capacity and excavation or fill detrimental to the environment; and c. Upon completion of installation of essential utilities, wetlands must be restored to pre - project configuration, replanted as required and provided with maintenance care until newly planted vegetation is established; and d. All crossings must be designed for shared facilities in order to minimize adverse impacts and reduce the number of crossings. 4. Essential Streets, Roads and Rights -of -Way a. Essential streets, roads and rights -of -way must be designed and maintained to prevent erosion and avoid restricting the natural movement of groundwater; and Sensitive Areas Ordinance Page 12 b. Essential streets, roads and rights-of-way must be located to conform to the topography so that minimum alteration of natural conditions is necessary. The number of crossings shall be limited to those necessary to provide essential access; and c. Essential streets, roads and rights -of -way must be constructed in a way which does not adversely affect the hydrologic quality of the wetland or interrelated stream habitat. Where feasible, crossings must allow for combination with other essential utilities; and d. Upon completion of construction, the area affected must be restored to an appropriate grade, replanted according to a plan approved by the Director of DCD and provided with care until newly planted vegetation is established. 5. Public Use and Access: a. Public access shall be limited to trails, boardwalks, covered or uncovered viewing or seating areas, and displays and must be located in areas which have the lowest sensitivity to human disturbance or alteration; and b. Public access must be specifically developed for interpretive, educational or research purposes by, or in cooperation with, the City or as part of the adopted Tukwila Parks and Open Space Plan; and c. No motorized vehicle is allowed within a wetland or its buffer except as required for necessary maintenance, agricultural management or security; and d. Any public access or interpretive displays developed in a wetland and its buffer must, to the extent possible, be connected with a park, recreation or open -space area; and e. Vegetative edges, structural barriers, signs or other measures must be provided wherever necessary to protect Sensitive Areas by limiting access to designated public use or interpretive areas; and f. Access trails must incorporate design features and materials which protect water quality and allow adequate surface and ground water movement; and Must be located where they do not disturb nesting, breeding, and rearing areas and buffer .areas, and must be designed so that sensitive plant and critical wildlife species are protected. 6. Dredging, digging or filling: a. Dredging, digging or filling within a wetland and its buffer may occur only with the permission of the DCD Director and only for the following purposes: (1) Uses permitted by Section 18.45.080A, B and H; or (2) Maintenance of an existing wetland; or (3) Enhancement or restoration of habitat in conformance with an approved mitigation plan identified in a sensitive area study; or (4) Natural system interpretation, education or research when undertaken by, or in cooperation with, the City of Tukwila; or (5) Flood control or water quality enhancement by the City of Tukwila; or (6) Maintenance of existing water quality controls, for normal maintenance needs and for any diversion, rerouting, piping, or other alteration permitted by this chapter. b. Any dredging, digging or filling shall be performed in a manner which will minimize sedimentation in the water. Every effort will be made to perform such work at the time of year when the impact can be lessened. c. Upon completion of construction, the area affected must be restored to an appropriate grade, replanted according to a plan approved by the Director of DCD and provided with care until newly planted vegetation is established. D. Watercourses. 1. General: a. No use or development may occur in a watercourse or its buffer except as specifically allowed by TMC 18.45 080. Any use or development allowed is subject to the standards of this Section. b. Diverting or rerouting may only occur with the permission of the DCD Director and an approved mitigation plan. c. Any watercourse which has critical wildlife habitat or is necessary for the life cycle or spawning of salmonids, shall not be rerouted unless it can be shown that the habitat will be improved for the benefit of the species. g. Sensitive Areas Ordinance ` Page 13 d. Any watercourse which has no critical wildlife habitat may be rerouted if the waters flowing from the new configuration can be shown to do so in a manner that does not - in any way adversely affect the habitat of a downstream salmonid bearing water. 2. Mitigation: a. Mitigation plans shall be completed for any proposals of dredging, filling, diverting, and rerouting of watercourses. b. The mitigation plan shall be developed as part of a sensitive area study by a specialist approved by the DCD Director. The plan must show how water quality, treatment, erosion control, pollution reduction, wildlife and fish habitat, and general watercourse quality would be maintained or improved. All such plans must be approved by the DCD Director. c. Mitigation Standards. The scope and content of a mitigation plan shall be decided on a case -by -case basis. As the impacts to the sensitive area increase, the mitigation measures to offset these impacts will increase in number and complexity. The components of a complete mitigation plan are as follows: (1) Baseline information of quantitative data collection or a review and synthesis of existing data for both the project impact zone and the proposed mitigation site. (2) Environmental goals and objectives that describe the purposes of the mitigation measures. This should include a description of site selection criteria, identification of target evaluation species and resource functions. Performance standards of the specific criteria for fulfilling environmental goals, and for beginning remedial action or contingency measures. They may include water quality standards, species richness and diversity targets, habitat diversity indices, or other ecological, geological or hydrological criteria. The following shall be considered the minimum performance standards for approved stream alter- ations: (a) Maintenance or improvement of stream channel dimensions, including the components of depth, width, length and gradient of the original location; (b) Bank and buffer configuration should be restored to an equal or enhanced state of the original stream; (c) The channel, bank and buffer areas shall be replanted with native vegetation which replicates or improves the original in species, sizes and densities. (dj The stream channel bed and the biofiltration systems shall be equivalent to or better than in the original stream. (e) The original fish and wildlife habitat shall be maintained or enhanced. (f) Relocation of a watercourse shall not result in the new sensitive area or buffer extending beyond the development site and onto adjacent property without the agreement of the affected property owners. A watercourse may be rerouted. (3) (4) Detailed construction plan of the written specifications and descriptions of mitiga- tion techniques. This plan should include the proposed construction sequence and construction management, and be accompanied by detailed site diagrams and blueprints that are an integral requirement of any development proposal. Monitoring and /or evaluation program that outlines the approach for assessing a completed project. An outline shall be included that spells out how the monitor- ing data will be evaluated by agencies that are tracking the mitigation project's progress. (6) Contingency plan identifying potential courses of action, and any corrective mea- sures to be taken when monitoring or evaluation indicates project performance standards have not been met. (7) Performance security or other assurance devices as described in TMC 18.45.135. d. Mitigation Timing: DCD approved plans must have the mitigation construction completed before the existing watercourse can be modified. 3. Essential Utilities a. Essential utilities must be constructed to minimize, or where possible avoid, disturbance of the watercourse and its buffer; and (5) (g) Sensitive Areas Ordinance Page 14 b. All construction must be designed to protect the watercourse and its buffer against erosion, uncontrolled drainage, restriction of groundwater movement, slides, pollution, habitat disturbance, any loss of flood carrying and storage capacity and excavation or fill detrimental to the environment; and c. Upon completion of installation of essential utilities, watercourses and their buffers must be restored to pre - project configuration, replanted as required and provided with maintenance care until newly planted vegetation is established; and d. All crossings must be designed for shared facilities in order to minimize adverse impacts and reduce the number of crossings. 4. Essential Streets, Roads and Rights -of Way a. Essential streets, roads and rights -of -way must be designed and maintained to prevent erosion and avoid restricting the natural movement of groundwater; and b. Essential streets, roads and rights-of-way must be located to conform to the topography so that minimum alteration of natural conditions is necessary. The number of crossings shall be limited to those necessary to provide essential access; and c. Essential streets, roads and rights -of -way must be constructed in a way which does not adversely affect the hydrologic quality of the watercourse and its buffer. Where feasible, crossings must allow for combination with other essential utilities; and d. Upon completion of construction, the area affected must be restored to an appropriate grade, replanted according to a plan approved by the Director of DCD and provided with care until newly planted vegetation is established. S. Public Use and Access: a. Public access shall be limited to trails, boardwalks, covered or uncovered viewing and seating areas, and displays and must be located in areas which have the lowest sensitivity to human disturbance or alteration; and b. Public access must be specifically developed for interpretive, educational or research purposes by, or in cooperation with, the City or as part of the adopted Tukwila Parks and Open Space Plan; and c. No motorized vehicle is allowed within a watercourse or its buffer except as required for necessary maintenance, agricultural management or security; and d. Any public access or interpretive displays developed along a watercourse and its buffer must, to the extent possible, be connected with a park, recreation or open -space area; and e. Vegetative edges, structural barriers, signs or other measures must be provided wherever necessary to protect watercourses and their buffers by limiting access to designated public use or interpretive areas; and f. Access trails must incorporate design features and materials which protect water quality and allow adequate surface and ground water movement; and Must be located where they do not disturb nesting, breeding and rearing areas and must be designed so that sensitive plant and critical wildlife species are protected. 6. Piping: a. Piping of any watercourse should be avoided. Piping may be allowed in any watercourse if it is necessary for access purposes. Piping may be allowed in Type III watercourses if the applicant complies with the conditions of this section, including: (1) excess capacity to meet needs of the system during a 100 -year flood event, and (2) flow restrictors, and water quality and existing habitat enhancement procedures. b. No process that requires maintenance on a regular basis will be acceptable unless this maintenance process is part of the regular and normal facilities' maintenance process or unless the applicant can show funding for this maintenance is ensured; and c. Piping in a watercourse sensitive area shall be limited and shall require approval of the DCD Director. Piping projects shall be performed pursuant to the following applicable standards: (1) The conveyance system shall be designed to comply with the standards in current use and recommended by the Department of Public Works. (2) Where allowed, piping shall be limited to the shortest length possible as determined by the Director of DCD to allow access onto a property. Where water is piped for an access point, those driveways or entrances shall be consolidated to serve multiple properties where possible, and to minimize the length of piping. g. (3) Sensitive Areas Ordinance (6) (7) (8) (9) Page 15 (4) When required by the Director of DCD, watercourses under drivable surfaces shall be contained in an arch culvert using oversize or superspan culverts for rebuilding of a stream bed. These shall be provided with check dams to reduce flows, and shall be replanted and enhanced according to a plan approved by the Director of DCD. (5) When necessary to provide for fish passage, fish ladders shall be one foot vertical rise to ten foot horizontal distance, or as approved by the Washington State Department of Fisheries. Stormwater runoff shall be detained and infiltrated to preserve the watercourse channel's dominant discharge. All construction shall be designed to have the least adverse impact on the watercourse, buffer and surrounding environment. Piping shall be constructed during periods of low flow, or as specified by the State Department of Fisheries. Water quality must be as good or better for any water exiting the pipe as for the water entering the pipe, and flow must be comparable. 7. Dredging, digging or filling a. Dredging, digging or filling within a watercourse or its buffer may occur only with the permission of the DCD Director and only for the following purposes: (1) Uses permitted by Section 18.45.080(1), (2) and (3); or (2) Maintenance of an existing watercourse; or (3) Enhancement or restoration of habitat in conformance with an approved mitigation plan identified in a sensitive area study; or (4) Natural system interpretation, education or research when undertaken by, or in cooperation with, the City of Tukwila; or (5) Flood control or water quality enhancement by the City of Tukwila; or (6) Maintenance of existing water quality controls, for normal maintenance needs and for any diversion, rerouting, piping, or other alteration permitted by this chapter. b. Any dredging, digging or filling shall be performed in a manner which will minimize sedimentation in the water. Every effort will be made to perform such work at the time of year when the impact can be lessened. c. Upon completion of construction, the area affected must be restored to an appropriate grade, replanted according to a plan approved by the Director of DCD and provided with care until newly planted vegetation is established. E. Areas of Potential Geologic Instability. 1. General: The uses permitted in the underlying zoning district may be undertaken on sites which contain areas of potential geologic instability subject to the standards of this section and the requirements of a geotechnical study. 2. Exemptions: Any temporary slope which has been created through legal grading activities may be regraded without application of this chapter under an approved permit. 3. Alterations: a. Prior to permitting alteration of an area of potential geologic instability, the applicant must demonstrate one of the following: (1) There is no evidence of past instability or earth movement in the vicinity of the proposed development, and quantitative analysis of slope stability indicates no significant risk to the proposed development or surrounding properties; or (2) The area of potential geologic instability can be modified or the project can be designed so that any potential impact to the project and surrounding properties is eliminated, slope stability is not decreased, and the increase in surface water discharge or sedimentation shall not decrease slope stability. b. Where any portion of an area of potential geologic instability is cleared for development, a landscaping plan for the site shall include tree replanting with an equal mix of evergreen and deciduous trees, preferably native, and approved by the Director of DCD. Replacement vegetation shall be sufficient to provide erosion and stabilization protection. Sensitive Areas Ordinance Page 16 4. Geotechnical Report: a. The applicant shall submit a Geotechnical Report appropriate to both the site conditions and the proposed development. A geotechnical investigation shall be required for development in Class 2, Class 3, Class 4 areas, and any areas identified as seismic or coal mine hazard areas. This requirement may be waived by the Director of the Department of Community Development for sites in Class 2 areas that are at least 200 feet from the nearest adjacent Class 3 or Class 4 hazard area, and which do not show any erosion or sedimentation problems. b. Geotechnical reports for Class 2 areas shall include at a minimum a site evaluation review of available information regarding the site and a surface reconnaissance of the site and adjacent areas. Subsurface exploration of site conditions is at the discretion of the geotechnical consultant. c. Geotechnical reports for Class 3, Class 4 and Coal Mine Hazard areas shall include a site evaluation review of available information about the site, a surface reconnaissance of the site and adjacent areas, and a subsurface exploration of soils and hydrology conditions. Detailed slope stability analysis shall be done if the geotechnical consultant recommends it in Class 3 or Coal Mine Hazard areas, and must be done in all Class 4 areas. d. Seismic hazard areas shall include an evaluation of site response and liquefaction potential for the proposed development area. For one or two story single family dwellings this evaluation may be based on the performance of similar structures under similar foundation conditions. For proposed developments including occupied structures other than one and two story single family dwellings, the evaluation shall include sufficient subsurface exploration to provide a site coefficient (S) for use in the static lateral force procedure described in the Uniform Building Code. e. Applicants shall retain a Geotechnical Engineer to prepare the reports and evaluations required in this Section. The Geotechnical Report and completed Site Evaluation checklist shall be prepared in accordance with the generally accepted geotechnical practices, under the supervision of and signed and stamped by the Geotechnical Engineer. The report shall be prepared in consultation with the appropriate City department. Where appropriate, a Geologist must be included as part of the geotechnical consulting team. The report shall make specific recommendations concerning development of the site. f. The geotechnical engineers required under this section must meet the qualification standards approved by the Director of DCD. Applicants shall provide a list of qualifications of the firm or individuals who will be doing the technical studies, and those shall be approved by the Director of DCD. If the engineers' credentials are not sufficient, the City may require applicants to use a different engineer or firm which does meet the City's standards. The opinions and recommendations contained in the report shall be supported by field observations and, where appropriate or applicable, by literature review, conducted by the Geotechnical Engineer which shall include appropriate explorations, such as borings or test pits, and an analysis of soil characteristics conducted by or under the supervision of the engineer in accordance with standards of the American Society of Testing and Materials or other applicable standards. If the evaluation involves geologic evaluations or interpretations, the report shall be reviewed and approved by a Geologist. h. An independent review of geotechnical reports will be required per TMC 21.04.140. S. Disclosures, Declarations and Covenants. a. It shall be the responsibility of the applicant to submit, consistent with the findings of the geotechnical report, structural plans which were prepared and stamped by a Structural Engineer. The plans and specifications shall be accompanied by a letter from the Geotechnical Engineer who prepared the Geotechnical Report stating that in his /her judgment, the plans and specifications conform to the recommendations in the Geotechnical Report and that the risk of damage to the proposed development site, from soil instability will be minimal subject to the conditions set forth in the report; and the proposed development will not increase the potential for soil movement. b. Further recommendations signed and sealed by the Geotechnical Engineer shall be provided should there be additions or exceptions to the original recommendations based on the plans, site conditions, or other supporting data. If the Geotechnical Engineer who reviews the plans and specifications is not the same engineer who prepared the geotechnical Report, the new engineer shall, in a letter to the City accompanying the plans and specifications, express his or her agreement or disagreement with the recommendations in the Geotechnical Report and state that the plans and specifications conform to his or her recommendations. g. Sensitive Areas Ordinance Page 17 c. The Architect or Structural Engineer shall submit to the City, with the plans and specifications, a letter of notation on the design drawings at the time of permit application stating that he or she has reviewed the Geotechnical Report, understands its recommendations, has explained or has had explained to the owner the risks of loss due to slides on the site, and has incorporated into the design the recommendations of the Report and established measures to reduce the potential risk of injury or damage that might be caused by any earth movement predicted in the Report. d. The applicant, or the owner of the site if the applicant is not the owner, shall submit a letter to the City, with the plans and specifications, stating that he or she understands and accepts the risk of developing in an area with potential unstable soils and that he or she will advise, in writing, any prospective purchasers of the site, or any prospective purchasers of structures or portions of a structure on the site, of the slide potential of the area. e. The owner shall execute a covenant, running with the land, on a form provided by the City. The City will file the completed covenant with the King County Department of Records and Elections at the expense of the applicant or owner. A copy of the recorded covenant will be forwarded to the owner. This covenant shall include: (1) The legal description of the Property; (2) A statement explaining that the site is in an area of potential instability; of the risks associated with development on the site, of any conditions or prohibitions on development, and of any features in this design which will require maintenance or modification to address anticipated soil changes; A statement waiving any claims the owner or his /her successors or assigns may have against the City of Tukwila for any loss, or damage to people or property either on or off the site resulting from soil movement arising out of the issuance of any permit(s) authorizing development on the site; (4) The date of issuance and number of the permit authorizing the development. 6. Assurance Devices: Whenever the City determines that the public interest would not be served by the issuance of a permit in an area of potential geologic instability without assurance of a means of providing for restoration of areas disturbed by and repair of property damage caused by slides arising out of or occurring during construction, the DCD Director may require assurance devices pursuant to Section 18.45.135. 7. Construction Monitoring: a. The applicant shall retain a Geotechnical Engineer to monitor the site during construction. The applicant shall preferably retain the Geotechnical Engineer who prepared the final Geotechnical recommendations and reviewed the plans and specifications. If a different consultant is retained by the owner, the new Geotechnical Engineer shall submit a letter to the City stating whether or not he /she agrees with the opinions and recommendations of the original Geotechnical Engineer. Further recommendations, signed and sealed by the Geotechnical Engineer, and supporting data shall be provided should there be exceptions to the original recommendations. b. The Geotechnical Engineer shall monitor, during construction, compliance with the recommendations in the Geotechnical Report, particularly site excavation, shoring, soil support for foundations including piles, subdrainage installations, soil compaction and any other geotechnical aspects of the construction. Unless otherwise approved by the City, the specific recommendations contained in the soils report must be implemented by the owner. The Geotechnical Engineer shall make written, dated monitoring reports on the progress of the construction to the City at such timely intervals as shall be specified. Omissions or deviations from the approved plans and specifications shall be immediately reported to the City. The final construction monitoring report shall contain a statement from the Geotechnical Engineer that, based upon his or her professional opinion, site observations and testing during the monitoring of the construction, the completed development substantially complies with the recommendations in the Geotechnical Report and with all geotechnical- related permit requirements. Occupancy of the project will not be approved until the report has been reviewed and accepted by the DCD Director. 8. Conditioning and Denial of Use or Developments: a. Substantial weight shall be given to ensuring continued slope stability and the resulting public health, safety and welfare in determining whether a development should be allowed. b. The City may impose conditions that address site work problems; which could include but are not limited to limiting all excavation and drainage installation to the dryer season, or sequencing activities such as installing erosion control and drainage systems well in advance of construction. (3) Sensitive Areas Ordinance Page 18 A permit will be denied if it is determined by the DCD Director that the development will increase the potential of soil movement that results in an unacceptable risk of • damage to the proposed development, its site, or adjacent properties. F. Abandoned Mine Areas. 1. Development of a legal lot of record containing an abandoned coal mine area may be permitted when a geotechnical report shows that significant risks associated with the abandoned mine workings can be eliminated or mitigated so that the site is safe. Approval shall be obtained from the DCD Director before any building or land altering permit processes begin. 2 Any building setback or land alteration shall be based on the geotechnical report. 3. The City may impose conditions that address site work problems, which could include but are not limited to limiting all excavation and drainage installation to the dryer season, or sequencing activities such as installing drainage systems or erosion controls well in advance of construction. A permit will be denied if it is determined that the development will increase the potential of soil movement or result in an unacceptable risk of damage to the proposed development or adjacent properties. G. Areas of important geological or archaeological evidence. 1. Development on a legal lot of record determined to have historic or prehistoric geological or archaeological evidence, shall be prohibited until that evidence has been studied or researched for any valuable information about our history. Removal or salvage of the evidence shall be done in accordance with RCW 27.53, and shall be performed in a timely manner. 2. Once the geologic or archaeological evidence or articles have been studied or researched, or the importance of the site is declared to be marginal or not of use to the scientific community, development shall be allowed on the site. Development shall not begin on such a site until the DCD Director gives approval. H. Permitted Uses Subject to Exception Approval. Other uses may be permitted upon receiving a reasonable use exception pursuant to TMC 18.45.115. A use permitted through a reasonable use exception shall conform to the procedures of this chapter and be consistent with the underlying zoning. 18.45.090 Sensitive Areas Tracts A. In development proposals for planned residential or mixed area use developments, short subdivisions or subdivisions, boundary line adjustments and binding site plans, applicants shall create sensitive areas tracts, in lieu of an open space tract, per the standards of TMC 18.46.080. B. Applicants proposing development, involving uses other than those listed in TMC 18.45.090A, on parcels with sensitive areas or their buffers, may elect to establish a sensitive area tract which shall be: 1. If under one ownership, owned and maintained by the ownership, which assures the protection of the tract; or 2. Held in common ownership by multiple owners who shall collectively be responsible for maintenance of the tract; or 3. Dedicated for public use if acceptable to the City or other appropriate public agency. 18.45.115 Exceptions A. General. With the approval of the Director of DCD, isolated wetlands that are 400 square feet or smaller in area, and which are low value according to the rating methodology used in the City's Water Resource Rating and Buffer Study, may not require the compensatory mitigation standards of this chapter. B. Piping. Piping will be allowed in Type 1 and Type 2 watercourses only where relocation or alteration of a watercourse is denied and would result in denial of all reasonable use. C. Reasonable Use Exceptions, 1. If application of this Chapter would deny all reasonable use of the property containing wetlands, watercourses or their buffers, the property owner or the proponent of a development proposal may apply for a reasonable use exception. 2. The application for a reasonable use exception shall be in a format specified by and filed with the Department of Community Development. Requirements may include an environmental impact statement pursuant to Washington Administrative Code 197 -11 -400. l n Sensitive Areas Ordinance Page 19 Reasonable use exceptions shall be decided by the Planning Commission following a public hearing noticed as specified in 18.92. 3. If• the applicant demonstrates to the satisfaction of the Planning Commission that application of this Chapter would deny all reasonable use of the property, development may be allowed which is consistent with the general purposes of this ordinance and the public interest. 4. The Commission, in granting approval of the reasonable use exception, must determine that: a. No reasonable use with less impact on the sensitive area and its buffer is possible; b. There is no feasible on -site alternative to the proposed activities, including reduction in size or density, phasing of project implementation, change in timing activities, revision of road and lot layout, and /or related site planning activities that would allow a reasonable economic use with fewer adverse impacts to the sensitive area and its buffer; c. As a result of the proposed development there will be no increased or unreasonable threat of damage to off -site public or private property and no threat to the public health, safety or welfare on or off the development proposal site; d. Alterations permitted shall be the minimum necessary to allow for reasonable use of the property; e. The proposed development is compatible in design, scale and use with other development with similar site constraints in the immediate vicinity of the subject property; f. Disturbance of sensitive areas has been minimized by locating the necessary alterations in the buffers to the greatest extent possible; The inability to derive reasonable use of the property is not the result of actions by the applicant in segregating or dividing the property and creating the undevelopable condition after the effective date of this Chapter; and h. Any approved alteration of a sensitive area under this section shall be subject to conditions as established by this chapter and will require mitigation under an approved mitigation plan. If a development is approved as a reasonable use, Board of Architectural process, review and standards shall be applied. g. 18.45.120 Variances A. The Board of Adjustment shall review requests pursuant to TMC 18.72 for variance from the standards of this chapter unless excepted by Section 18.45.115. B. If a variance is granted, it shall be the minimum necessary to accommodate the permitted uses of the underlying zoning district, proposed by the application and the scale of the use may be reduced as necessary to meet this requirement. 18.45.125 Appeals A. Any aggrieved party who objects to or disagrees with Department of Community Development decisions or conditions for development in a sensitive area, shall appeal to the Planning Commission. Any such appeal shall be made in writing within ten days of the interpretation, condition or decision being appealed, and shall set forth the basis for the appeal. B. In considering appeals of decisions or conditions, the following shall be considered: 1. The intent and purposes of the sensitive areas ordinance; 2. Technical information and reports considered by the Department of Community Development; and 3. Findings of the DCD Director shall be given substantial weight. 18.45.130 Recording Required The property owner receiving approval of a use or development pursuant to this chapter shall record the City- approved site plan clearly delineating the wetland, watercourse, areas of potential geologic instability or abandoned mine and their buffer designated by section 18.45.020 and 18.45.040 with the King County Division of Records and Election. The face of the site plan must include a statement that the provision of this chapter, as now or hereafter amended, control use and development of the subject property and provide for any responsibility of the property owner for the maintenance or correction of any latent defects or deficiencies. 18.45.135 Assurance Device A. In appropriate circumstances, the Department of Community Development Director may require a letter of credit or other security device acceptable to the City, to guarantee performance and maintenance requirements of this Chapter. All assurances shall be on a form approved by the City Attorney. Sensitive Areas Ordinance Page 20 B. When alteration of a sensitive area is approved, the Director of the Department of Community Development may require an assurance device, on a form approved by the City Attorney, to cover the monitoring costs and correction of possible deficiencies. Monitoring of alterations may be required for up to five (5) years. C. Release of the security does not absolve the property owner of responsibility for maintenance or correcting latent defects or deficiencies. 18.45.140 Assessment Relief A. Fair Market Value. The King County Assessor shall consider sensitive area regulations in determining the fair market value of land under RCW 84.34. B. Current Use Assessment. Established sensitive area tracts, as defined in TMC 18.06.698 and provided for in TMC 18.45.090, shall be classified as open space and owners thereof may qualify for current use taxation under RCW 18.34; provided such landowners have not received density credits, or setback or lot size adjustments as provided in TMC Chapter 18.46. C. Special Assessments. Landowners who qualify under Section 18.45 140B shall also be exempted from special assessments on the sensitive area tract to defray the cost of municipal improvements such as sanitary sewers, storm sewers and water mains. SECTION 4. ORDINANCE NOS. 1247 AND 1249 AND TMC 18.46 AMENDED. TMC 18.46 is hereby amended as follows: 1. TMC 18.46.010 is hereby amended to read In its entirety as follows: 18.46.010 Purpose. It is the purpose of this chapter to encourage imaginative site and building design and to create open space in residential developments by permitting greater flexibility in zoning requirements than is permitted by other sections of this title. Furthermore, it is the purpose of this chapter to: 1. Promote the retention of significant features of the natural environment, including topography, vegetation, watercourses, wetlands, and views; 2. Encourage a variety or mixture of housing types; 3. Encourage maximum efficiency in the layout of streets, utility networks, and other public improvements; and 4. Create and /or preserve usable open space for the enjoyment of the occupants and the general public. 2. TMC 18.46.030 is hereby amended to read in its entirety as follows: 18.46.030 Permitted uses. The following uses are allowed in planned residential development: 1. In R -1 districts, dwellings may be permitted which are harmonious with the surrounding residential character and built environment. Single unit detached dwellings will be preferable to attached units; however, attached two -unit dwellings will be considered if necessary to accommodate interior zero lot lines for projects with sensitive areas and /or sensitive area buffers. 2. In R -2, R -3, R -4, and RMH districts, residential developments of all types regardless of the type of building in which such residence is located, such as single - family residences, duplexes, triplexes, fourplexes, rowhouses, townhouses or apartments; provided, that all residences are intended for permanent occupancy by their owners or tenants. Hotels, motels, and travel trailers and mobile homes and trailer parks are excluded; 3. Accessory uses specifically designed to meet the needs of the residents of the PRD such as garages and recreation facilities of a noncommercial nature; 4. In planned residential developments of ten acres or more, commercial uses may be permitted. Commercial uses shall be limited to those which are of a neighborhood convenience nature such as beauty or barber shops, drugstores, grocery stores and self - service laundries. 3. TMC 18.46.040 is hereby amended to read In its entirety as follows: 18.46.040 Site acreage minimum. The minimum site for a planned residential development shall be one acre, except sites con- taining sensitive areas and their buffers. Sensitive Areas Ordinance Page 21 4. TMC 18.46.050 is hereby repealed 5. TMC 18.46.060 is hereby amended to read in its entirety as follows: 18.46.060 Relationship of this chapter to other sections and other ordinances. A. 1. Lot Size. The minimum lot size provisions of other sections of this code are waived within the planned residential development. The number of dwelling units per net acre permitted in the underlying zone shall serve as the criteria to determine basic PRD density. 2. Building Height. Building heights may be modified within a PRD when it assists in maintaining natural resources, significant vegetation, and enhances views within the site without interfering with the views of adjoining property. For increases in building height, there shall be a commensurate decrease in impervious surface. 3. Setbacks. Yard requirements of TMC. 18.50 shall be waived within the PRD; however, setbacks and design of the perimeter of the PRD shall be comparable to or compatible with the bulk and streetscape of the existing development of adjacent properties or the type of development which may be permitted. B. Off -Street Parking. Off -street parking shall be provided in a PRD in the same ratio for types of buildings and uses as required in Chapter 18.56. However, for multiple family zoned sites with sensitive areas, a minimum of 2 parking stalls per unit will be allowed, with a 50% compact stalls allowance, and parking stalls in front of carports or garages will be allowed if the design does not affect circulation. C. Platting Requirements. The standards of the subdivision code for residential subdivisions shall apply to planned residential developments if such standards are not in conflict with the provisions of this chapter. Upon final approval of the PRD, filing of the PRD shall be in accordance with procedures of the subdivision code if any lots are to be transferred. D. Impervious Surface. The maximum amount of impervious surface calculated for the total development allowed on sensitive areas sites will be 50% for each single family development and each multi - family development. E. Recreation Space Requirements. Sensitive areas and stands of significant trees may be counted as area required to meet the recreation space minimums if usable passive recreation opportunities within these areas are demonstrated. Opportunities could include connection and continuation of area -wide trail systems, wildlife or scenic viewing opportunities, or picnic areas. F. Landscape and Site Treatment for Sites with Class 2, Class 3 and Class 4 Geologic Hazard Areas. 1. Down slope and side yard buffers - Elevations and off -site perspectives shall show minimum landscape coverage of 25% of the structures at time of project completion with anticipated 40% coverage within 15 years. This standard may supplement or be in lieu of the applicable landscape yard requirement. 2. Any road or access drive which cuts approximately perpendicular to a slope to the ridgeline of a hill shall have minimum five foot planted medians. The tree shall be a species that provides a branch pattern sufficient to provide at maturity, 50 % coverage of the pavement area. Roads or drives which require retaining walls parallel to the topographic line shall plant roadside buffers of northwest native plant species. G. The Board of Architectural Review shall review guidelines for single- and multi- family developments. The design and review of the PRD shall also utilize the guidelines of TMC 18.60.050. H. For single- family developments, the site plans shall include placement and footprint of the residences, driveways and roads. 6. TMC 18.46.070 is hereby amended to read in its entirety as follows: 18.46.070 Density standards. A. The basic density shall be the same as permitted by the underlying zone district. The dwelling units per net acre for the residential zones are as provided in Chapter 18.50. B. Single family. 1. In R -I single - family residential districts, the planning commission may recommend, and the City Council may authorize, a minimum lot size not less than the yard requirements of the Sensitive Areas Ordinance Page 22 R -1 -7.2 district following findings that the amenities or design features listed in subsections a. through d. of 18.46.0708.2. below are substantially provided. 2. In R -1 single- family residential districts on sites containing sensitive areas or their buffers, the planning commission may recommend, and the City Council may authorize, a minimum lot size less than the yard requirements of the R -1 -7.2 district following findings that the amenities or design features listed below in subsections a. through d. are substantially provided: a. At least fifteen percent of the natural vegetation is retained (in cases where significant stands exist); and b. Advantage or enhancement is taken of unusual or significant site features such as views, watercourses, or other natural characteristics; and c. Separation of auto and pedestrian movement, especially in or near areas of recreation; and d. Development aspects of the PRD complement the land use policies of the compre- hensive plan. C. In multiple - family residential districts, the planning commission may recommend, and the City Council may authorize, a dwelling unit density not more than twenty percent greater than permitted by the underlying zones or an increase equal to the allowable density credits as set forth in 18.46.070(D), if the site contains sensitive areas or buffers following findings that the amenities or design features listed below are substantially provided: 1. A variety of housing types are offered; 2. At least fifteen percent of the natural vegetation is retained (in cases where significant stands exist); 3. Advantage is taken or enhancement is achieved of unusual or significant site features such as views, watercourses, wetlands or other natural characteristics; 4. Separation of auto and pedestrian movement, especially in or near areas of recreation; and 5. Developmental aspects of the PRD complement the land use policies of the comprehensive plan. D. Density Transfer 1. Density transfers are intended to provide for the protection of wetlands, watercourses, and associated buffers while allowing development which is consistent with existing zoning to the greatest extent possible. 2. Density transfers are the percentage credits to be used in calculating the number of dwelling units for a residential site containing undevelopable sensitive areas or buffers. The calculation of the maximum units per buildable acre of a site with protected areas shall be equal to: (DU = Dwelling Units) ((DU /acre)(Buildable Acres)) + ](DU /acre)(Sensitive Areas and Buffer)(Density Transfer)] 3. Density transfer credits shall be determined from the table below: PERCENTAGE OF SITE IN DENSITY SENSITIVE AREAS & BUFFER TRANSFER 1 -10 30% 11 -20 27% 21 - 30 24% 31 -40 21% 41 - 50 18% 51 -60 15% 61 - 70 12% 71 -80 9% 81 -90 6% 91- 100 3% 4. The density transfer can only be used within the development proposal site. Any such modifications shall be reviewed and approved through the site development process in TMC 18.60. 5. Development of the transferred density shall be confined to buildable areas of the site, and shall not intrude on sensitive areas or their buffers. Sensitive Areas Ordinance Page 23 7. TMC 18.46.080 is hereby amended to read in its entirety as follows: 18.46.080 Open space. A. Each planned residential development shall provide not less than twenty percent of the gross site area for common open space which shall: 1. Provide either passive or active recreation concentrated in large usable areas; and 2. Network with the trail and open space system of the city and provide a connection and extension, if feasible; 3. Be under one ownership, owned and maintained by the ownership; or be held in common ownership by all of the owners of the development by means of a home owners or similar association. Such association shall be responsible for maintenance of the common open space; or be dedicated for public use, if acceptable to the city or other appropriate public agency. B. Planned residential developments shall set aside sensitive areas and their buffers in a sensitive areas tract as required by Chapter 18.45.090, and will be exempted from other open space requirements of this section. 8. TMC 18.46.090 is hereby amended to read in its entirety as follows: 18.46.090 Relationship to adjacent areas. A. The design and layout of a planned residential development shall take into account the integration and compatibility of the site to the surrounding areas. The perimeter of the PRD shall be so designed as to minimize any undesirable impact of the PRD on adjacent properties. B. Setbacks from the property lines of the PRD shall be comparable to or compatible with, those of the existing development of adjacent properties or, if adjacent properties are undeveloped , the type of development which may be permitted. 9. TMC 18.46:110 is hereby amended to read in its entirety as follows: 18.46.110 Application procedure required for PRD approval. A. Filing of Application. Application for approval of the PRD shall be made on forms prescribed by the Department of Community Development and shall be accompanied by a filing fee as required in Chapter 18.88 and by the following: 1. Justification for the density bonus, if requested by the applicant, 2. Program for development including staging or timing of development, 3. Proposed ownership pattern upon completion of the project, 4. Basic content of any restrictive covenants, 5. Provisions to assure permanence and maintenance of common open space through a home owners association, or similar association, condominium development or other means acceptable to the city; 6. An application for rezone may be submitted with the PRD application if rezoning is necessary for proposed density. Fees for rezone request shall be in addition to those of the PRD application; 7. An application for preliminary plat may be submitted with the PRD application, if necessary. Fees for the subdivision shall be in addition to those of the PRD application. 8. Graphic images of development in any sensitive area or buffer, including photo- montage or computer - generated perspectives in a standardized format required by the Director of the Department of Community Development. 9. Ev ry reasonable effort shall be made to preserve existing trees and vegetation and integrate them into the subdivision's design by preparing a tree inventory of the significant vegetation on site as part of the preliminary plat application. A tree and vegetation retention/removal plan shall be part of any preliminary plat application. Such tree and vegetation retention/removal plan shall assure the preservation of significant trees and vegetation. B. Planning Commission Public Hearing. The planning commission shall hold at least one public hearing on the proposed PRD, and shall give notice thereof pursuant to Chapter 18.92 of this title. The public hearing shall not be held before completion of all necessary and appropriate review by city departments. This review shall be completed within a reasonable period of time. Sensitive Areas Ordinance Page 24 C. Planning Commission Recommendation. Following the public hearing, the planning commission shall make a report of its findings and recommendations with respect to the proposed PRD and the criteria of this chapter and forward the report to the City Council. D. City Council Public Hearing. 1. After receipt of the planning commission report, the City Council shall hold a public hearing on the proposed PRD as recommended by the planning commission. The City Council shall give approval, approval with modifications, or disapproval to the proposed PRD. 2. The PRD shall be an exception to the regulations of the underlying zoning district. The PRD shall constitute a limitation on the use and design of the site unless modified by ordinance. 10. TMC 18.46.112 is hereby amended to read in Its entirety as follows: 18.46.112 Review criteria. The Planning Commission and City Council shall find that the proposed development plans meet all of the following criteria in their decision making. 1. Requirements of the subdivision code for the proposed development have been met, if appropriate; 2. Reasons for density bonuses meet the criteria as listed in Section 18.46.070; 3. Adverse environmental impacts have been mitigated; 4. Compliance of the proposed PRD to the provisions of this chapter and Chapter 18.45; 5. Time limitations, if any, for the entire development and specified stages have been documented in the application; 6. Development in accordance with the comprehensive land use policy plan and other relevant plans; 7. Compliance with the BAR review guidelines (TMC 18.60.050);` and 8. Appropriate retention and preservation of existing trees and vegetation recommended by the Director of Community Development. 11. TMC 18.46.120 is hereby amended to read in its entirety as follows: 18.46.120 Application procedures for building permit. The following procedures are required for approval of construction for the proposed planned residential development: 1. Time Limitation. A complete application for the initial building permit shall be filed by the applicant within twelve months of the date on which the City Council approved the PRD. An extension of time for submitting an application may be requested in writing by the applicant, and an extension not exceeding six months may be granted by the Director of DCD. If application for the initial building permit is not made within twelve months or within the time for which an extension has been granted, the plan shall be considered abandoned, and the development of the property shall be subject to the requirements and limitations of the underlying zone and the subdivision code. 2. Application. Application for building permit shall be made on forms prescribed by the DCD and shall be accompanied by a fee as prescribed by the building code. 3. Documentation Required. All schematic plans either presented or required in the approved PRD plans shall be included in the building permit application presented in finalized, detailed form. These plans shall include but are not limited to landscape, utility, open space, circulation, and site or subdivision plans. Final plats and public dedication documents must be approved by the City Council before the issuance of any building permits. 4. Sureties Required for Staging. If the PRD is to be developed in stages, sureties, or other security device as shall be approved by the City Attorney, shall be required for the complete PRD. The various stages or parts of the PRD shall provide the same proportion of open space and the same overall dwelling unit density as provided in the final plan. 5. Department of Community Development Action. The Department of Community Development shall determine whether the project plans submitted with the building permit are in compliance with and carry out the objectives of the approved PRD. Following approval of the DCD, the city clerk shall file a copy of the approved PRD plan with the official records of the city and the originals shall be recorded with the King County department of records and elections. After all approvals, the official zoning map shall be amended to reflect the PRD by adding the suffix "PRD" to the designation of the underlying zone. Sensitive Areas Ordinance Page 25 SECTION 5. ORDINANCE NO. 1247 AND TMC 18.70.050 AMENDED. TMC 18.70.050 is hereby amended to add subsections (6) and (7) as follows: (6) In wetlands, watercourses and their buffers, existing structures that do not meet the requirements of Chapter 18.45 may be remodeled, reconstructed or replaced, provided that: (a) the new construction does not further intrude into or adversely impact an undeveloped sensitive area or the required buffer; and (b) the new construction does not threaten the public health, safety or welfare, and (c) the structure otherwise meets the requirements of this chapter. In areas of potential geologic instability, coal mine hazard areas, and buffers, as defined in TMC 18.45, existing structures may be remodeled, reconstructed or replaced, provided that: (a) the new construction is subject to the geotechnical report requirements and standards of TMC 18.45.080E and F; and (b) the new construction does not threaten the public health, safety or welfare; and (c) the new construction does not increase the potential for soil or result in unacceptable risk or damage to existing or potential development or to neighboring properties; and (d) the structure otherwise meets the requirements of this chapter. (7) SECTION 6. ORDINANCE NO. 1014 AND TMC TITLE 17 AMENDED. 1. TMC 17.08.030 is hereby amended to read in its entirety as follows: 17.08.030 Principles of acceptability. The following principles shall determine the acceptability of boundary line adjustments and short subdivisions: 1. Create legal building sites with respect to zoning and health regulations; 2. Establish access to a public road for each segregated parcel; 3. If adjacent to another municipality or King County, take into consideration the subdivision standards of that jurisdiction, as well as the requirements of this code; 4. Make adequate provision for: drainage ways, streets, alleys, other public ways, water supplies and sanitary wastes, as deemed necessary. 5. Comply with Chapter 17.20, Design standards for the subdivision of land, and Chapters 17.24 and Chapter 17.28 Minimum standards for Residential and Commercial Subdivision Design, respectively. 6. Actions by the applicant to get a boundary line adjustment or short subdivision shall not result in the inability to derive reasonable economic use of the property or create an undevelopable lot under Chapter 18.45.115 unless that lot is to be dedicated for exclusive use as open space or common tract. 2. TMC 17.08.040 is hereby amended to read in its entirety as follows: 17.08.040 Application requirements. A. Application for a short subdivision shall be made with the Department of Community Development on forms prescribed by that office. Said application shall be accompanied by ten copies of the short subdivision plat. B. If the subject site is within the sensitive area overlay zone, administrative review and approval of a Planned Residential Development (PRD) shall be required for the proposed short subdivision and boundary line adjustment. The standards and criteria for PRD design and review are those listed in TMC 18.46. The procedure shall be those listed in 17.08.060. C. The short subdivision plat and boundary line adjustment shall conform to the following requirements: 1. Shall be a neat and accurate drawing by a land surveyor on reproducible material at a decimal scale. The plat map shall measure between eight and one -half inches by eleven inches and eight and one -half inches by fourteen inches. 2. Shall show how the proposed subdivision will be served by streets and utilities. 3. Each application shall be accompanied by a preliminary title report dated within thirty calendar days of the submission date. Sensitive Areas Ordinance Page 26 3. TMC 17.08.060 is hereby amended to read in its entirety as follows: 17.08.060 Review Procedures. A. Referral to Other Departments. Upon receipt of an application for a short subdivision, the planning division of the Department of Community Development shall transmit one copy of the application to each member of the short subdivision committee, and one copy to any department or agency deemed necessary. The application shall be transmitted at least five working days prior to the short subdivision committee meeting. B. Notice to adjacent property owners. If a PRD is being processed as part of the short plat application per 17.08.040 (b), notice shall be mailed to all property owners within 300 feet, fifteen days prior to the Short Subdivision Committee meeting, notifying them of the pending proposal and requesting comments. C. Short Subdivision Committee. The short subdivision committee shall consist of the director of the office of community development, who shall be chairman; the public works director; and the fire chief; or their designated representatives. D. Short Subdivision Committee Meeting. A meeting of the short subdivision committee, attended by the applicant at his option, shall be held no later than twenty calendar days from receipt of a complete application. Said meeting shall be open to the public. 1. Quorum. All members of the short subdivision committee or their representative must be present in order for action to be taken. 2. Action. The short subdivision committee may approve, approve with modifications, or deny the application for a short subdivision. The decision of the short subdivision committee shall be made at the meeting and the applicant notified in writing of such decision within three working days. An additional meeting may be called if a decision is not reached at the first meeting. The second meeting should be no later than seven days after the first meeting. An applicant may request to have an application on which the short subdivision committee has taken action reopened by the committee if it is found by the director of the office of community development and the applicant that new information has come to light that might affect the action taken by the short subdivision committee. 3. Appeal. The decision of the short subdivision committee shall.be final, unless an appeal by any aggrieved party is made to the planning commission within ten calendar days of the date of decision of the short subdivision committee. Said appeal shall be in writing to the planning commission and filed with the office of community development. The planning commission shall act on said appeal within forty calendar days unless an extension thereto is agreed to, in writing, by the applicant. The decision of the planning commission shall be final and conclusive unless, within ten calendar days, any aggrieved party files with the city clerk a written appeal addressed to the City Council. The City Council shall act on said appeal within twenty days of the date of appeal. 4. TMC 17.12.030(a) and (b) are hereby amended to read in their entirety as follows: 17.12.030 Preliminary plat procedures. (a) Application. (1) Application for a preliminary plat shall be filed with the planning division on forms prescribed by that office. A complete application must be filed at least thirty calendar days prior to the date of the planning commission meeting at which it is to be considered. (2) The application shall be accompanied by a fee of eight hundred dollars plus seventy-five dollars for each proposed lot. (3) At least five copies of the preliminary plat shall be submitted, which shall be prepared by a land surveyor. (4) Fifteen copies of the preliminary plat, photographically reduced to eight and one-half inches by eleven inches or eight and one -half inches by fourteen inches, shall accompany the application. (5) A list of the names and addresses of all owners of record of property within three hundred feet of the external boundaries of the proposed subdivision. (6) Environmental information shall be prepared and submitted in accordance with the guidelines established under the State Environmental Policy Act of 1971, as amended, Title 21 of this code, as amended, and the Sensitive Areas Overlay District, as amended in Title 18.45 of this code, as may be amended thereafter. Said information is a part of and must accompany the preliminary plat application. Sensitive Areas Ordinance Page 27 (b) Preliminary Plat Requirements. The following shall be part of the preliminary plat: (1) Vicinity Map. Adequate to readily identify the location of the plat in relation to its surrounding vicinity. (2) Preliminary Plat. The preliminary plat shall include all of the following: (A) The subdivision name and number, and the name and address of the land surveyor; (B) The date of preparation, the true north point, a graphic scale and legal description of the property proposed for subdivision. Plats shall be drawn to an appropriate engineering (decimal) scale; (C) All existing conditions shall be delineated. The location, width and names of all existing or prior platted streets or other public open spaces, permanent buildings and structures, and section and municipal corporation lines within or adjacent to the property proposed for subdivision shall be shown. In the case of a resubdivision, the lots, blocks, streets, alleys, easements and parks of the original subdivision being vacated, shall be shown by dotted lines in their proper position in relation to the new arrangement of the subdivision; the new subdivision being clearly depicted in solid lines so as to avoid ambiguity. Existing sewer and water lines, culverts, or other underground facilities within the property proposed for subdivision indicating pipe sizes, grades and exact location as obtained from public records shall be shown. Boundary lines of adjacent lands, whether subdivided or unsubdivided shall be indicated by dotted lines for a distance of three hundred feet from the external boundary of the property proposed for subdivision and shall include the existing land use classification. (D) A survey of existing trees and vegetation with a retention /removal plan which assures the preservation of significant trees and vegetation. (E) Existing contours (solid) and proposed contours (dotted) at intervals of five feet or less and referenced to the United States Coast and Geodetic Survey (USC & GS) datum. All contour lines shall be extended at least one hundred feet beyond the external boundaries of the property proposed for subdivision; (F) The names, locations, widths, and other dimensions of proposed streets, alleys, easements, parks and other open spaces, reservations, and utilities together with the purpose and any conditions or limitations of such reservations clearly indicated; (G) Clearly indicate the source of water supply, method of sewage disposal, and manner of surface runoff control; (H) Indicate the approximate dimensions of each lot and all lot and block numbers; (I) Indicate the acreage of land to be subdivided, the number of lots and the area of the smallest lot; 5. TMC 17.20.010 is hereby amended to read in its entirety as follows: 17.20.010 Purpose. It is the purpose of this chapter to provide for the protection of valuable, irreplaceable envi- ronmental amenities and to make urban development as compatible as possible with the ecological balance of the area. Goals are to preserve sensitive areas and their buffers, protect groundwater supply, prevent erosion, and to preserve trees, vegetation, and drainage patterns. These are beneficial to the city in lessening the costs of development to the city as a whole, to the subdivider in creating an attractive and quality environment, and in attainment of the goals and objectives of the Tukwila comprehensive land use policy plan. 6. TMC 17.20.020 is hereby amended to read in its entirety as follows: 17.20.020 Environmental considerations. A. Unsuitable Land. Land which meets the definition of a sensitive area or its buffer as defined in TMC 18 or is subject to the Flood Zone Control Ordinance as defined in TMC 16.52, shall be platted to reflect the standards and requirements of the Sensitive Areas Overlay zone, TMC 18.45, 18.46, the Planned Residential Development, and the Flood Zone Control Ordinance, TMC 16.52. B. Trees. Every reasonable effort shall be made to preserve existing trees and vegetation and integrate them into the subdivision's design by preparing a tree inventory of the significant vegetation on site as part of the preliminary plat application. Sensitive Areas Ordinance Page 28 7. TMC 17.20.040 is hereby amended to read in its entirety as follows: 17.20.040 Grading. Prior to any grading within a proposed or approved subdivision, a land alteration permit shall be obtained in accordance with the provisions of Chapter 70 of the Uniform Building Code. 8. TMC 17.20.050 is hereby amended to read in its entirety as follows: 17.20.050 Streets. A. Extension. Proposed street systems shall extend existing streets at the same or greater width, unless otherwise approved by the department of public works and authorized by the City Council in approval of the plat. Where appropriate, streets shall be extended to the boundaries of the plat to insure access to neighboring properties. The City's goal is to have an integrated system of local streets rather than a system of cul -de -sacs. Grading of steep topography may be necessary to achieve this objective. However, in sensitive areas, the layout and construction of streets shall follow the standards and procedures of the sensitive areas overlay zone. B. Names. All proposed street names or numbers shall be subject to approval by the Department of community development. C. Intersections. Any intersection of public streets, whatever the classification, shall be at right angles as nearly as possible and not be offset insofar as practical. 9. TMC 17.24.020 is hereby amended to read in its entirety as follows: 17.24.020 Street layout. Street layout shall provide for the most advantageous development of the subdivision, adjoining areas, and the entire neighborhood. Evaluation of street layout shall take into consideration potential circulation solutions. While it is important to minimize the impact to the topography from creating an integrated road system, improved site development and circulation solutions shall not be sacrificed to minimize the amount of cut and fill requirements of the proposal. Where sensitive areas are impacted, the standards and procedures for rights -of -way in the sensitive areas overlay zone shall be followed. 10. TMC 17.24.040 is hereby amended to read in its entirety as follows: 17.24.040 Public rights -of -way. A. Right -of -way Width. Street widths may vary according to function, traffic generated and topography. The following minimum street widths for streets, as defined in the Tukwila comprehensive land use policy plan, shall apply unless otherwise approved by the department of public works and authorized by the City Council in approval of the preliminary plat or by the short subdivision committee in the case of short plats. TYPE OF STREET RIGHT -OF -WAY PAVEMENT Major Arterial 80 60 feet Secondary Arterial 75 feet 48 feet Collector 60 feet 36 feet Local Street 50 feet * 30 feet Cul -De -Sac Roadway 40 feet 26 feet Turnaround 80 feet diameter 60 feet diameter Alley 20 feet 15 feet * Right -of -way may be reduced to 40 feet with five foot easements on each side if the subject roadway will be traversing or adjacent to wetlands and watercourses. B. Design. The design and alignment of all public streets shall conform to the following standards unless otherwise approved by the department of public works: Sensitive Areas Ordinance Page 29 1. Street Intersection Offsets. Where street intersections must be offset, such offsets shall not measure less than two hundred fifty feet from centerline to centerline. 2. Cul -de -sacs. Cul -de -sacs shall not exceed a length of six hundred feet unless authorized in accordance with Section 17.32.010. 3. Street Grades. Street grades shall not exceed 15 percent. However, provided there are no vehicular access points, grades may be allowed up to 18 percent, for not more than 200 feet when: a. exceeding the grades would facilitate a through street and connection with the larger neighborhood; and b. the greater grade would minimize disturbance of sensitive slopes;and c. the Fire Marshal grants approval. 4. Tangents. Minimum tangents shall conform to department of public works standards. 5. Horizontal Curves. Minimum curve radii shall conform to department of public works standards. 6. Vertical Curves. Changes in grade shall conform to department of public works standards. C. Right -of -way Improvement. All right -of -way improvements shall conform to department of public works standards. D. Utilities. All utilities designed to serve the subdivision shall be placed underground and, if located within a sensitive area, shall be designed to meet the standards of the sensitive areas overlay zone. Those utilities to be located beneath paved surfaces shall be installed, including all service connections, as approved by the department of public works; such installation shall be completed and approved prior to application of any surface materials. 1. Sanitary Sewers: Unless septic tanks are specifically approved by the appropriate health agencies, sanitary sewers shall be provided at no cost to the city and designed in accordance with city standards. 2. Storm Drainage: An adequate drainage system shall be provided for the proper drainage of all surface water; the amount of runoff shall be determined by the rational method. Cross drains shall be provided to accommodate all water flow and shall be of sufficient length to permit full width roadway and required slopes. The diameter to be provided shall be determined by Manning's Equation, but in no case shall the inner diameter be less than twelve inches. 3. Water System: The water distribution system including the locations of fire hydrants shall be designed and installed in accordance with city standards. E. Public Use and Service Areas. 1. Due consideration shall be given by the subdivider to the allocation of adequately sized areas for public service or usage. 2. Easements. Easements may be required for the maintenance and operation of utilities as specified by the public works department. F. Blocks. 1. Length. Blocks should not be less than three hundred feet nor more than one thousand feet in length. Where circumstances warrant, the planning commission may require one or more public pathways of not less than six feet nor more than fifteen feet in width dedicated in the city to extend entirely across the width of the block at locations deemed necessary. 2. Width. Blocks shall be wide enough to allow two tiers of lots, except where abutting a major street or prevented by topographical conditions or size of the property, in which case the planning commission may approve a single tier. G. Lots. 1. Arrangement. Insofar as practical, side lot lines shall be at right angles to street lines or radial to curved street lines. Each lot must have access to a public street that is approved at the time of plat review; however rather than designing flag lots, access shall be accomplished with common drive easements. Location of yards shall reflect the prevailing pattern within the neighborhood. For example, if adjacent developed lots front on the street the subdivision's lots fronting the street should also establish front yards for those lots. 2. Minimum Size. The size, shape, and orientation of lots shall meet or exceed the minimum area and width requirements of the applicable zoning classification and shall be appropriate for the type of development and use contemplated. Sensitive Areas Ordinance Page 30 3. Corner Lots. Corner lots may be required to be platted with additional width to allow for the additional side yard requirements. 4. Through Lots. Residential through lots are not encouraged and shall only be approved if there is a topographic or traffic safety concern preventing double tiered lots. Approved through lots shall be permitted access to only one street, unless otherwise approved by the department of public works and shall provide a fifteen foot rear yard buffer of native vegetation. 5. Property Corners at Intersections. All lot corners at intersections of dedicated public rights -of- way shall have a minimum radius of twenty-five feet. H. Trees. Each lot within a new subdivision shall be landscaped with at least one tree in the front yard to create a uniform streetscape. Installation shall be required per 17.12.040(3) I. Other Improvements. 1. Monuments. a. Concrete permanent control monuments shall be established at each and every controlling corner of the subdivision. Interior monuments shall be located as determined by the department of public works. b. All other lot corners shall be marked with suitable metal or wood markers. 2. Street Signs. The subdivider shall be responsible for the initial cost of any street name or number signs, or street markings, including installation thereof, necessary in the subdivision as required by the department of public works. SECTION 7. ORDINANCE NOS. 1331 AND 1344 AND TMC 21.04 AMENDED. 1. TMC 21.04.040 is hereby amended to read in its entirety as follows: 21.04.040 Definitions -- Additional. In addition to those definitions contained within WAC 197 -11 -700 through 799, when used in this chapter the following terms shall have the following meanings, unless the content indicates otherwise: 1. "Department" means any division, subdivision or organizational unit of the city established by ordinance, rule or order. 2. "Early notice" means the city's response to an applicant stating whether it considers issuance of the determination of significance likely for the applicant's proposal. 3. "Environmentally sensitive area" — see 21.04.300. 4. "Notice of action" means the notice of the time for commencing an appeal of a SEPA determination that the city or the applicant may give following final city action upon an application for a permit or approval when said permit or approval does not have a time period set by statute or ordinance for commencing an appeal. 5. "Official notice" means the notice that the city shall give of the date and place for commencing an appeal of final city action upon an application for a permit or approval where said permit or approval has a time period set by statute or ordinance for commencing appeal. 6. "SEPA Rules" means WAC Chapter 197 -11 adopted by the Department of Ecology. 2. TMC 21.04.130 is hereby amended to read in its entirety as follows: 21.04.130 Threshold determination -- Review at conceptual stage. A. If the city's only action on a proposal is a decision on a building permit or other license that requires detailed project plans and specifications, the applicant may request in writing that the city conduct environmental review prior to submission of the detailed plans and specifications. B. In addition to the environmental documents an applicant may be required to submit the following information: 1. Conceptual site plans and building plans; 2. Other information as the responsible official may determine. 3. Environmentally sensitive areas studies as described in TMC 21.04.140 for sensitive areas. Sensitive Areas Ordinance Page 31 3. TMC 21.04.140 is hereby amended to read In its entirety as follows: 21.04.140 Threshold determinations -- Environmental checklist. A. A completed environmental checklist shall be filed at the same time as an application for a permit, license, certificate or other approval not exempted by this chapter. The checklist shall be in the form of WAC 197 -11 -960 with the following additions: 1. If the site is an environmentally sensitive area, a sensitive area study that meets the requirements of the SEPA official may be required. The SEPA official may waive any study requirements determined to be unnecessary for review of a particular use or application. Environmentally sensitive area studies shall have three components: a site analysis, an impact analysis, and proposed mitigation measures. More or less detail may be required for each component depending on the size of the project, severity of potential impacts, and availability of information. Funding for a qualified professional, selected and retained by the City shall be paid for by the applicant, to review the geotechnical reports on Class 2 and 3 Landslide, Seismic and Coal Mine Hazard areas if the geotechnical report indicates Class 3 or 4 characteristics; and will be required in all Class 4 Landslide Hazard areas. 2. Identification of conflicts with the policies of the comprehensive land use policy plan and proposed measures to reduce the conflicts; 3. Description of the objectives of the proposal, the alternative means of accomplishing these objectives, comparison of the alternatives and indication of the preferred course of action. B. A checklist is not needed if the city and the applicant agree an EIS is required, SEPA compliance has been completed, or SEPA compliance has been initiated by another agency. C. The city shall use the environmental checklist to determine the lead agency and, if the city is the lead agency, for making the threshold determination. D. For private proposals, the applicant is required to complete the environmental checklist. The city may provide information as necessary. For city proposals, the department initiating the proposal shall complete the environmental checklist for that proposal. E. The city may decide to complete all or part of the environmental checklist for a private proposal, if either of the following occurs: 1. The city has technical information on a question or questions that is unavailable to the private applicant; or 2. The applicant has provided inaccurate information on previous proposals or on proposals currently under consideration. 4. TMC 21.04.150 is hereby amended to read in its entirety as follows: 21.04.150 Threshold determinations-Mitigated DNS. A. The responsible official may issue a determination of nonsignificance (DNS) based on conditions attached to the proposal by the responsible official or on changes to, or clarifications of, the proposal made by the applicant. B. An applicant may request in writing early notice of whether a Determination of Significance (DS) is likely. The request must: 1. Follow submission of a permit application and environmental checklist for a nonexempt proposal for which the department is lead agency; and 2. Precede the city's actual threshold determination for the proposal. C. The responsible official's written response to the request for early notice shall: 1. State whether the city currently considers issuance of a DS likely and, if so, indicate the general or specific areas of concern that are leading the city to consider a DS; and 2. State that the applicant may change or clarify the proposal to mitigate the indicated impacts, and may revise the environmental checklist and /or permit application as necessary to reflect the changes or clarifications. D. When an applicant submits a changed or clarified proposal, along with a revised environmental checklist, the city shall base its threshold determination on the changed or clarified proposal. 1. If the city indicated specific mitigation measures in its response to the request for early notice, and the applicant changed or clarified the proposal to include those specific mitigation measures, the city shall issue and circulate a determination of nonsignificance if the city determines that no additional information or mitigation measures are required. 2. If the city indicated areas of concern, but did not indicate specific mitigation measures that would allow it to issue a DNS, the city shall make the threshold determination, issuing a DNS or DS as appropriate. Sensitive Areas Ordinance Page 32 3. The applicant's proposed mitigation measures, clarifications, changes or conditions must be in writing and must be specific. 4. Mitigation measures which justify issuance of a mitigated DNS may be incorporated in the DNS by reference to agency staff reports, studies or other documents. E. The city shall not act upon a proposal for which a mitigated DNS has been issued for fifteen days after the date of issuance. F. Mitigation measures incorporated in the mitigated DNS shall be deemed conditions of approval of the licensing decision and may be enforced in the same manner as any term or condition of the permit or enforced in any manner specifically prescribed by the city. Failure to comply with the designated mitigation measures shall be grounds for suspension and /or revocation of any license issued. G. If the city's tentative decision on a permit or approval does not include mitigation measures that were incorporated in a mitigation DNS for the proposal, the city should evaluate the threshold determination to assure consistency with WAC 197- 11- 340(3)(a) relating to the withdrawal of a DNS. H. The city's written response under subsection (c) of this section shall not be construed as a determination of significance. In addition, preliminary discussion of clarification or changes to a proposal, as opposed to a written request for early notice, shall not bind the city to consider the clarifications or changes in its threshold determination. 5. TMC 21.04.270 is hereby amended to read in its entirety as follows: 21.04.270 SEPA -- Policies. A. The policies and goals set forth in this chapter are supplementary to those in the existing authorization of the city. B. The city adopts by reference the policies in the following city codes, ordinances, resolutions and plans as now existing or as may be amended hereafter: 1. Zoning Cod' -TMC Chapter 18; 2. Shoreline Master Plan - Ordinance 898; 3. Comprehensive Land Use Policy Plan- Ordinance 1246; 4. Long Range Parks and Open Space Plan - Ordinance 1315; 5. Subdivision Ordinance -TMC Chapter 17.04; 6. Comprehensive Sewer Plan - Resolution 904; 7. Comprehensive Water Plan- Resolution 873; 9. Uniform Building Code -1982 Edition - Ordinance 1287; 9. Transportation Improvement Plan- Resolution 917; 10. Annexation Policy Plan - Resolution 626; 11. Sidewalk Ordinance - Ordinance 1233; 12. Standard Specifications for Municipal Construction - Ordinance 1250. 6. TMC 21.04.300 is hereby amended to read in its entirety as follows: 21.04.300 Environmentally sensitive areas. A. Environmentally sensitive areas designated on the zoning maps and /or as defined in Zoning Code TMC 18.06 and pursuant to 18.45.020 or hereinafter amended, designate the locations of environmentally sensitive areas within the city and are adopted by reference. In addition to those areas identified in WAC 197 -11 -908 and for purposes of this chapter environmentally sensitive areas shall also include wooded hillsides, and the Green /Duwamish River and its shoreline zone as defined by the Tukwila Master Program. For each environmentally sensitive area, the categorical exemptions within WAC 197 -11 -800 that are inapplicable for these areas are: WAC 197 -11- 800(1), (2)(a) through (h), (3), (5), (6)(a), (14(c), (24)(a) through (g), and (25)(d), (f), (h) and (i). Unidentified exemptions shall continue to apply within environmentally sensitive areas of the city. B. The city shall treat proposals located wholly or partially within an environmentally sensitive area no differently than other proposals under this chapter, making a threshold determination for all such proposals. The city shall not automatically require an EIS for a proposal merely because it is proposed for location in an environmentally sensitive area. C. Certain exemptions do not apply on lands covered by water, and this remains true regardless of whether or not lands covered by water are mapped. Sensitive Areas Ordinance Page 33 SECTION 8. SEVERABILITY. If any portion of this Ordinance, as now or hereafter amended, its application to any person or circumstances is held invalid or unconstitutional, such adjudication shall not affect the validity of the Ordinance as a whole, or any section, provision, or part thereof not adjudicated to be invalid or unconstitutional and its application to other persons or circumstances shall not be affected. SECTION 9. EFFECTIVE DATE. This Ordinance shall take effect five (5) days from the date of publication of the attached summary which is hereby approved. PASSED BY THE CITY UNCIL OF THE CITY OF TUKWILA, WASHINGTON, at a Regular Meeting thereof this /0 day o , 1991. In accordance with RCW 35A.12.130 this ordinance shall become valid without the Mayor's approval. ATTEST /AUTHENTICATED: Jane E. Cantu, City Clerk APPROVED AS TO FORM: OFFICE OF THE CITY ATTORNEY: / By: i� �-I da C )i T 71 ( J • FILED WITH THE CITY CLERK: C - / — 9/ PASSED BY THE CITY COUNCIL: 6 -/° PUBLISHED: 6 -/ - 7/ EFFECTIVE DATE: �? ' _.. 9/ ORDINANCE NO.: /5 � Gary L. Van Dusen, Mayor • w' r. SUMMARY OF ORDINANCE NO. / �� 9 AN ORDINANCE OF THE CITY OF TUKWILA, WASHINGTON, REGULATING DEVELOPMENT ON SENSITIVE AREAS AND BUFFERS; AMENDING ORDINANCE NOS 1247 AND 1289 AND TWCWILA MUNICIPAL CODE (TMC) TITLE 18; AMENDING ORDINANCE NOS. 1331 AND 1334 AND TMC TITLE 21.04; AMENDING ORDINANCE NO 1014 AND TMC TITLE 17; AND PROVIDING FOR AN EFFECTIVE DATE. On to /0V9/ , the City Council of the City of Tukwila passed Ordinance No. 5"99 f ovidin for the regulation of development their , p g gul pment on sensitive areas and they. buffers; amending Tukwila Municipal Code Titles 17, 18 and 21; and providing for severability an effective date. The full text of this ordinance will be mailed without charge to anyone who submits a written request to the City Clerk of the City of Tukwila for a copy of the text. APPROVED by the City Council at its meeting of 4 ,x l r / 1 9/ . /i Published Valley Daily News: —/.3 - 9/ /A4_, • e E. Cantu, City Clerk TO: Mayor Van Dusen DATE: August 26, 1991 MEMORANDUM FROM: Moira Bradshaw, Associate Planner - DCD Gary Schulz, Urban Environmentalist - DCD SUBJECT: Proposed Amendments to the Sensitive Areas Ordinance No.1599. Planning staff has reviewed the draft ordinance that would amend the SAO and recommends the addition of two amendments. Both of these amendments may need some refinement but are listed below for your review and approval. 1) Problem: Chapter 18.45.080 Uses and Standards (A) & (B) are not clear regarding the need for SEPA. As written General Uses under (A) are subject to SEPA; however, without impacts these actions may be defined as categorical exemptions from SEPA. Actions listed under (B) have significant impacts but appear subject only to administrative review. Solution: Present the possible conflict to the City Attorney for review and revision if necessary. 2) Problem: Chapter 18.45.060 Procedures section allows DCD Director to waive 1. Sensitive Areas Study and Geotechnical Report after consideration of the size and complexity of a project. However, in the Chapter 18.45.080 E. (4) (a) Uses and Standards section the Director's discretion to waive reports is limited to properties that have Class 2 slopes. Effect: As an example, above Interurban Avenue there are Class 3 areas that abut Class 1. Development has occurred and is proposed on relatively flat portions of the lot. A full geotechnical study is required because the lot contains Class 3 areas. There are occasions when the applicant wants to build on relatively flat, non - sensitive portions of the lot but are required to conduct a detailed investigation just because a sensitive area, which is to remain undisturbed, is located on the lot. Solution: Allow discretion in the Uses and Standards section consistent with discretion in Procedures section to waive the geotechnical report requirement. Si sao822 August 22, 1991 Ga L. VanDusen Mayor GLVD /JM:so CITY OF T Uli 14'ILA .6200 SOUTHCEV7'ER HO('l.E'I.4/W. 7'1 WASHINGTON !8188 Mr. Jack Flesher Chairman, Tukwila Planning Commission c/o City of Tukwila 6200 Southcenter Boulevard Tukwila, WA 98188 Dear Mr As you are awa e, I allowed the Sensitive Areas Ordinance 'to become law without my signature. I had severe concerns regarding the impacts of the ordinance on our single family property owners. Among those concerns is the existing burden of requiring expensive and time consuming reviews for minor developments that in no way would affect any environmentally sensitive portion of a parcel. With approximately three months of operational experience with the ordinance, we now have a clearer picture of the specific areas in need of modification. On August 19 I presented the attached draft amendments to the City Council and advised them that I would directly refer to the Planning Commission those elements that require Commission review. In light of the hardship that the ordinance is creating for several of our residential citizens, I am requesting the Commission expedite review and public hearing of those elements within your jurisdiction. It is my desire to see adoption of these amendments as quickly as possible. Your excellent work in the review of the existing document was greatly appreciated. I realize that this request is disruptive to your on -going work plan and adds to your already heavy work load, however, your review is critical to the amendment process. Thank you for your consideration of this matter. cc: Director, Dept. of Community Development I'IIONE # (206) 433.1800 Gary l.. Van f)nsrn. Mayor A // J CITY OF T UIi WILA 62nn SOUTHCENTER130U1.1i1:4RU, TUKWIL:1, IMSH /NC1'0,V!) I88 To: City Council Fr: Mayor VanDus Re: SAO Date: August 19, 1991 GLVD /so sao8lS PHONE r t2061.133.180n Caryl.. ISu,Dnse n..1Ja or In June I advised the Council that, while I allowed the Sensitive Areas Ordinance to become law without my signature, serious concerns existed over the impacts of the ordinance on single family property owners. The past three months have given us several examples of the unreasonable requirements for SEPA reviews, geo- technical studies and long delays in the permit review process for building activity as minor as extending the roof on an existing carport. The result has been seen at the service counter of the Department of Community Development. Our citizens are confused, angry and frustrated over what they see as unfair and unnecessary requirements. The ordinance was well intended. The creation of controls to protect our environmentally sensitive areas is appropriate as well as a matter of law as required by the Growth Management Act. It lacks, however, an element of common sense. It is too broad reaching in the triggering of mandatory reviews that are both expensive and time consuming and unfortunately, in many cases, unnecessary. Now that we have sufficient experience behind us in the actual administration of the ordinance, it is time to make some modifications that will preserve the intent of the law while eliminating those elements that run counter to our mission statement of providing caring, efficient and effective service. On Monday evening I will present the Council with a series of amendments to the Sensitive Areas Ordinance that are designed to correct the problems we have encountered to date. I would hope that the Council sees both the appropriateness and urgency of these amendments and takes action as quickly as possible. To expedite review of those portions of the ordinance that pertain to the Zoning Code, I have asked the Department of Community Development to arrange for immediate consideration by the Planning Commission. CITY OF TUKWILA 6200 SOUTIICENTER BOULEVARD, 7 UK VILA, WASHINGTON 98188 August 16, 1991 Mr. Lee Feng c/o Bill Vance 31735 48th S.W. Federal Way, WA 9 :023 Dear Mr. Feng: I have been advised b for a building permit the recently passed S As you may or may n I expressed serious residents. The presu expensive and time c protecting our fragi administration of thi Sincerely, e/ 'Lf6e/ f PHONE q (2061 433.1800 Cary L. VanDnscn, Mayor AUG ? 9 1991 c,i i'i tJi' . i uir.vvILA r- r..ANNNING DEPT. . the Department of Community Development, that you either have made an application or have received a building permit from the City of Tukwila that has been affected by nsitive Areas Ordinance. t be aware, earlier this summer I allowed the SAO to become law without my signature. ncerns to the City Council regarding the impact of the ordinance on our single family ption that any development on a parcel containing a sensitive area should trigger an nsuming environmental review is inappropriate. While I fully support the notion of c and diminishing environment, a measure of common sense is needed in the ordinance. I have asked my sta to prepare a series of amendments to the SAO that would allow for the exercise of discretion by the Ad inistration in determining when the State Environmental Policy Act (SEPA) checklist and gco- technical studies are required for single family development. The fees for these actions range from $250 to thousands of dollars. It is hoped that we will be able to eliminate those requirements when it can be demonstrated that the development will in no way infringe upon any portions of the property designated as sensitive areas. If you have any questions concerning this matter in general, or your permit specifically, please feel free to contact the staff in t e Department of Community Development (431 -3654) or my office (433- 1805). Gary VanDusen Mayor GLVD:JM/so sao816 WAIVERS Name Poirer, Joanne John Newell, Inc. (Floyd Hunt) Leschi Trading Co. (David Hawkins) Louden Real Estate (Scott Clark) Hegyi, Beno Hittle, Craig City of Tukwila 6200 Southcenter Boulevard Tukwila Washington 98188 (206) 433.1800 Gary L. VanDusen, Mayor MEMORANDUM TO: Rick Beeler, Director Department of Community Development FROM: Ann Siegenthaler, Assistant Planner RE: Residential permits affected by SAO DATE: August 12, 1991 Below is a listing of permit applications for single- family residential development which are affected by the Sensitive Areas Ordinance (as of 8/12/91). Type Remodel (slopes) Fill (slopes) Short plat (slopes) Short plat (watercourse) New residence (slopes) House move (slopes) Shaver, Jeff & Melodie New residence (slopes) Easter, Mike & C. Short plat (slopes) Address 13413 43rd Ave. S. ? 13800 Macadam Rd. ? 14116 56th Ave. S. ? 4637 S. 138th ? 14251 58th Ave. S. ? 4820 S. 150th ? Phone Approved Y N S. 144th & Macadam 323 -0372 Y 14811 42nd Ave. S. 243 -8000 Y Y Memo R. Beeler SAO Permits, 8/12/91 Page 2 WAIVERS. cont. Name Type Koyamatsu, Keith New residence (slopes) Bates, Dwight & Linda Short plat (slopes) Mott, Lillian No devel. plans (slopes) BUILDING PERMITS Name Kendall, Roy Alexander, Chas. (Ewan Willis) Wood, James Lee, Feng (Bill Vance) Lang, C.W. ' Type Addition (Coal mine, slopes, setbacks) Garage (slopes, setbacks) Carport (slopes) Addition (res. in C2) (slopes, setbacks) Carport (slopes) Address Address 139xx 56th Place S. ? 4440 S. 160th 3521 S. 154th Phone 246 -6455 Y Lots 6, 7, Block 2 850 -3748 ? Adams Home Tracts Phone 13941 56th Place S. 246 -8016 11211 51st Avenue S. 14305 Interurban 242 -6514 622 -3990 246 -2417 14920 62nd Ave. S. 243 -4862 Y