CA-08-0099 Erosion-Landslide-Stream.pdf
CITY OF EDMONDS
CRITICAL AREAS RECONNAISSANCE REPORT
Site Location: 7418 Soundview Drive Tax Acct. Number: 00513600001200
Determination: Study Required Determination #: CRA-2008-0099
Applicant: Derek Platt Owner: Derek Platt
BACKGROUND
During review and inspection of the subject site, it was found that the site contains and/or
is adjacent to critical areas, including Erosion and Landslide Hazard areas as well as a
Fish and Wildlife Habitat Conservation Area, pursuant to Chapters 23.40, 23.80 and 23.90
of the Edmonds Community Development Code (ECDC).
The hilly site is characterized by a general southeast-northwest trending grade with a more
level developed bench in the south-central portion of the parcel. Slopes are in excess of
40% at the extreme southeastern corner of the parcel and the western half of the parcel
falls away at greater than 40% slope. Site inspection also revealed the presence of a
small stream which runs along the eastern boundary of the parcel, under the approach
drive to the subject parcel, and off to the west on the adjacent parcel to the north.
This report applies to the entire subject parcel. Depending on the location and type of
project proposed relative to the identified critical areas, certain additional 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.
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
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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
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defined in the ordinance. There are options on how to complete a critical areas
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study, and there is an approved list of consultants that you may choose from.
Please contact the Planning Division for more information.
General Mitigation Requirements for all Critical Areas are discussed in ECDC
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23.40.110 through 23.40.140.
STUDY REQUIREMENT EROSION HAZARD AREA
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
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greater.
Any area with slopes of 15 percent or greater and impermeable soils interbedded
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with granular soils and springs or ground water seepage.
Areas with significant visible evidence of ground water seepage, and which also
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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
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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 directors discretion, per Edmonds Community
Development Code section 20.80.050.G.
In areas where the slope stability is not suitable, projects within Erosion Hazard
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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
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23.40.090.D.
Development standards are given in ECDC 23.80.060 and 23.80.070.
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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
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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.
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In addition to the general requirements for Critical Areas reports referenced above,
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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
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Geotechnical Engineer.
The criteria that are applied depend on the amount that the buffer is reduced.
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The buffer can be reduced to a minimum of ten (10) feet (with an additional 15
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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
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with the design standards listed in ECDC 23.80.070.A.3.
REPORT REQUIREMENTS STREAMS
A portion of an unnamed stream runs parallel to the eastern boundary of the subject
property.
Streams are areas where surface waters produce a defined channel or bed which
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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.
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Streams are classified according to whether or not they run year round and whether
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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
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are listed in ECDC 23.90.040.D.1.
In addition to the general requirements for Critical Areas reports referenced above,
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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 NEAR 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 buffer enhancement through
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the review 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
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criteria applied to buffer averaging are listed in 23.90.040.D.2The maximum
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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
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allowed through the above methods require a Critical Areas Variance. If you think
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that you have a proposal that may require a variance, please contact a Planner for
more information.
If you have any questions about this determination, please contact a Planner for more
information.
Michael Clugston, AICP September 9, 2008
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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