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CRA-2010-0049 ESLHA-landslide-erosion-stream-habitat.pdfCITY OF EDMONDS CRITICAL AREAS RECONNAISSANCE REPORT Site Location: 7316 164th Street SW Tax Acct. Number: 00513100006301 Determination: Study Required Determination #: CRA -2010-0049 Applicant: Michael Kerr Owner: Michael Kerr/Diana Clay BACKGROUND During review and inspection of the subject site, it was found that the site contains and/or is adjacent to critical areas, including Geologically Hazardous Areas and Fish and Wildlife Habitat Conservation Areas, pursuant to Chapters 23.40, 23.80 and 23.90 of the Edmonds Community Development Code (ECDC). There is an existing house on the eastern -most edge of the subject parcel where it is relatively level. West of the developed area, however, the parcel falls very steeply towards Puget Sound. According to the City's LIDAR data, the steepness of the western slope varies from 60% to more than 80%, which qualifies it as a landslide hazard area. In fact, the parcel is located within the North Edmonds Earth Subsidence and Landslide Hazard Area and its buffer. The owner also indicated that there is a year-round stream present on the parcel. This study applies to the entire subject parcel. Depending on the location and type of project proposed relative to the identified critical areas, certain studies and reports may be required. ALLOWED ACTIVITIES AND EXEMPT DEVELOPMENT PROPOSALS Certain activities are allowed in or near critical area buffers as specified in ECDC 23.40.220. Similarly, certain development proposals may be exempt from Critical Areas Requirements (ECDC 23.40.230). If you have any questions about whether your proposed development qualifies as an allowed or exempt activity, please contact a Planner for more information. NORTH EDMONDS EARTH SUBSIDENCE LANDSLIDE HAZARD AREA The subject site is located within the North Edmonds Earth Subsidence Landslide Hazard Area (ESLHA). Contact the Building Division for requirements related to the ESLHA. GENERAL CRITICAL AREAS REPORT REQUIREMENTS Critical Areas Reports identify, classify, and delineate any areas on or adjacent to the subject property that may qualify as critical areas. They also assess these areas and identify any potential impacts resulting from your specific development proposal. If a specific development proposal results in an alteration to a critical area, the critical areas report will also contain a mitigation plan. You have the option of completing the portion of the study that classifies and delineates the critical areas and waiting until you have a specific development proposal to complete the study. You may also choose to submit the entire study with your specific development application. • Please review the minimum report requirements for all types of Critical Areas that are listed in ECDC 23.40.090.D. There are additional report requirements for different types of critical areas (see below). • Note that it is important for the report to be prepared by a qualified professional as defined in the ordinance. There are options on how to complete a critical areas study, and there is an approved list of consultants that you may choose from. You may contact the Planning Division for more information. • General Mitigation Requirements for all Critical Areas are discussed in ECDC 23.40.110 through 23.40.140. STUDY REQUIREMENT — EROSION HAZARD AREA It appears that this property contains or is adjacent to an Erosion Hazard Area. Erosion Hazard Areas include: • Those areas with Alderwood and Everett series soils on slopes of 15 percent or greater. • Any area with slopes of 15 percent or greater and impermeable soils interbedded with granular soils and springs or ground water seepage. • Areas with significant visible evidence of ground water seepage, and which also include existing landslide deposits regardless of slope. DEVELOPMENT PROPOSALS ASSOCIATED WITH EROSION HAZARD AREAS Development within an Erosion Hazard Area must meet additional criteria. • For erosion hazard areas with suitable slope stability, the only critical area study needed is an erosion and sediment control plan prepared in compliance with the requirements set forth in Chapter 18.30 ECDC as part of the construction documents. This option is at the director's discretion, per Edmonds Community Development Code section 20.80.050.G. • In areas where the slope stability is not suitable, projects within Erosion Hazard Areas will require a report by a licensed Geotechnical Engineer or other qualified professional. Note that it is important for the report to be prepared by a qualified professional as defined in the ordinance. • Report requirements are given in ECDC 23.80.050, and more generally in ECDC 23.40.090. D. • Development standards are given in ECDC 23.80.060 and 23.80.070. STUDY REQUIREMENT — LANDSLIDE HAZARD AREA It appears that this property contains or is adjacent to a Landslide Hazard Area. • A Landslide Hazard Area is any area with a slope of forty percent (40%) or steeper and with a vertical relief of ten (10) or more feet (except areas composed of consolidated bedrock). • Landslide Hazard Areas are further defined and illustrated in ECDC 23.80.020.6. • In addition to the general requirements for Critical Areas reports referenced above, specific Critical Area report requirements for Landslide Hazard Areas are provided in ECDC 23.80.050. DEVELOPMENT PROPOSALS ASSOCIATED WITH LANDSLIDE HAZARD AREAS Development is restricted within a Landslide Hazard Area and its buffer. • Projects that will intrude into these areas will require a report by a licensed Geotechnical Engineer. 2 • The criteria that are applied depend on the amount that the buffer is reduced. • The buffer can be reduced to a minimum of ten (10) feet (with an additional 15' building setback per ECDC 23.40.280) if a report is prepared that meets the standards listed in ECDC 23.80.050. The alteration must also meet the requirements listed in ECDC 23.80.060. • In addition, proposals to reduce the buffer to less than ten (10) feet must comply with the design standards listed in ECDC 23.80.070.A.3. STUDY REQUIREMENTS — STREAMS • Streams are areas where surface waters produce a defined channel or bed which demonstrates clear evidence of the passage of water. Streams need not contain water year-round. • Streams are regulated as types of Fish and Wildlife Habitat Conservation Areas. • Streams are classified according to whether or not they run year round and whether or not they support fish populations according to the classification system listed in ECDC 23.90.010.A.1. • The minimum buffer widths for streams vary depending on the type of stream and are listed in ECDC 23.90.040.D.1. • In addition to the general requirements for Critical Areas reports referenced above, specific Critical Areas report requirements for Fish and Wildlife Habitat Conservation Areas are provided in ECDC 23.90.020.A to C and additional technical information requirements for streams are listed in ECDC 23.90.020.D. DEVELOPMENT PROPOSALS ON A SITE WITH A STREAM Development proposals that encroach into streams or their buffers or building setbacks may be allowed through the approval of certain processes. The width of a stream buffer may be reduced through the approval of a Stream Buffer Enhancement Plan that meets the specific requirements referenced in ECDC 23.90.040.D.2. The maximum amount that a buffer can be reduced through buffer enhancement is 50%. A buffer may also be modified through a process called buffer averaging. The criteria applied to buffer averaging are listed in 23.90.040.D.2. The maximum amount that the buffer width can be reduced at any single location through buffer averaging is 50%. Development proposals that propose encroachments into buffers beyond what is allowed through the above methods require a Critical Areas Variance. If you think that you have a proposal that may require one of these processes, please contact a Planner for more information. STUDY REQUIREMENT — FISH AND WILDLIFE HABITAT CONSERVATION AREAS Since the site is located within a mapped fish and wildlife habitat conservation area, the City would like to preserve as much of the native vegetation as possible. DEVELOPMENT PROPOSALS ON A SITE WITH FISH AND WILDLIFE HABITAT CONSERVATION AREAS The applicant must submit a clearing/tree cutting plan with any development permit, if applicable. Tree cutting and clearing of native vegetation shall be limited to the footprint of development. If you have any questions about this determination, please contact a Planner for more information. Name Signatu Date NOTE: Cited sections of the Edmonds Community Development Code (ECDC) can be found on the City of Edmonds website at www.ci.edmonds.wa.us. 11