CA-09-0011 Erosion-Landslide.pdfCRITICAL AREAS RECONNAISSANCE REPORT
Site Location:
7412 178' P1 SW
Tax Acct. Number:
00748100000700
Determination:
Study Required
Determination #:
CRA -2009-0011
Applicant:
David & Jessica Snyder
Owner:
David & Jessica Snyder
CRITICAL AREAS RECONNAISSANCE REPORT: STUDY REQUIRED
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, pursuant to Chapters 23.40 and 23.80 of the
Edmonds Community Development Code (ECDC).
The subject property lies at the top at the eastern end of 178`h PI SW off of 76`h Ave W. The driveway
leading up to the property slopes to the west at approximately 22 percent according to the City's LIDAR
data. The property generally slopes to the west. The site where the residence sit is relatively flat and the
landscaped yard is terraced. There is a gully the runs between the subject property and adjacent properties
also sloping to the west. The slope from the subject property (approximately starting at an existing retaining
wall) into the gully is approximately 40% according to the City's LIDAR data. This qualifies the slope as
an erosion hazard and portions toward the southwest corner of the parcel as a possible landslide hazard.
This review 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.
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.
• PIease 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.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.
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 th uffer to less than ten (10) feet must comply with the design
standards listed in ECDC 23.80 0 .A.3. Jb
,ien, Associate
Name
NOTE: Cited sections of the Edmonds Comr
Edmonds website at www.ci.edmonds.wa.us.
Date
Development Code (ECDC) can be found on the City of