CA-07-0055 Landslide and Erosion Hazard Areas and Potential Wetland.pdf
CITY OF EDMONDS
CRITICAL AREAS RECONNAISSANCE REPORT
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Site Location:Tax Acct. Number:
7403 – 175 Street SW 00713100000100
Determination:Determination #:
Study Required CRA-2007-0055
Applicant:Owner:
Patricia Black Dave Mills
CRITICAL AREAS RECONNAISSANCE REPORT:STUDY REQUIRED
During review and inspection of the subject site, it was found that the site contains and is adjacent to
critical areas, including Landslide Hazard and Erosion Hazard Areas, pursuant to Chapters 23.40
and 23.80 of the Edmonds Community Development Code (ECDC). Additionally, review of various
City resources indicated that the site may contain or be adjacent to wetlands and/or drainage areas,
pursuant to Chapters 23.40 and 23.50 of the Edmonds Community Development Code (ECDC).
During our field visit, staff was unable to confirm if the site contains or is adjacent to wetlands and/or
drainage areas; a qualified biologist will need to conduct a site visit to make this determination.
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 – 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.B.
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.
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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.
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 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.
REPORT REQUIREMENTS – WETLANDS
The site investigation has shown that the site may contain a wetland; this is subject to confirmation
by a qualified biologist. Wetlands are areas inundated or saturated by ground or surface water that
support, under normal circumstances, vegetation adapted for life in saturated soil.
Wetlands are generally rated according to their size, condition, function, and vegetation
types into four (4) different categories described in ECDC 23.50.010 and by use of the “City
of Edmonds Wetland Field Data Form” by the critical areas consultant.
Buffer widths for wetlands vary depending on the category of the wetland as listed in ECDC
23.50.040.F.
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In addition to the general requirements for Critical Areas reports referenced above, there are
specific Critical Areas report requirements for wetlands that are provided in ECDC
23.50.030.
Note for Lake Ballinger: See ECDC 23.50.010 regarding delineating wetlands around Lake
Ballinger. Provisions for protection of Lake Ballinger shorelines not meeting criteria for
jurisdictional wetlands are provided in the City of Edmonds Shoreline Master Program,
which requires a 35-foot setback from the Ordinary High Water Mark.
DEVELOPMENT PROPOSALS ASSOCIATED WITH WETLANDS
Development proposals that encroach into wetlands or their buffers or building setbacks may be
allowed through the approval of certain processes.
The width of a wetland buffer may be reduced through buffer enhancement if the criteria
described in ECDC 23.50.040.F.3 can be met. 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 ECDC 23.50.040.F.4. The maximum amount that
the buffer width can be reduced at any single location through buffer averaging is 50%.
Development proposals that proposed encroachments into buffers beyond what is allowed
through the above methods require a Critical Areas Variance, or a Reasonable Use
Exception. If you think that you have a proposal that may require one of these processes,
please contact a Planner for more information.
Any time a development proposal requires an alteration to a wetland, a mitigation plan is
required as part of the Critical Areas report. In addition to the General Mitigation
requirements referenced above, mitigation requirements specific to wetlands are provided in
ECDC 23.50.050.
NOTE: There are specific performance standards for the subdivision of lands in wetlands
and wetland buffers. These are listed in ECDC 23.50.060.
ALLOWED ACTIVITIES
Certain activities are allowed in or near critical area buffers as specified in ECDC 23.40.20. If you
have any questions about whether your proposed development qualifies as an allowed activity,
please contact a Planner for more information.
EXEMPT DEVELOPMENT PROPOSALS
Certain development proposals may be exempt from Critical Areas Requirements (ECDC 23.40.230).
If you think that a specific development proposal may be exempt, contact a Planner for more
information.
Jen Machuga, Planner May 1, 2007
Name Signature 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.
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