CRA-12-0035 Erosion-Landslide.pdfCITY OF EDM®NDS
121 51h Avenue North, Edmonds WA 98020
Phone: 425.771.0220 • Fax: 425.771.0221 • Web: www.edmondswa.g}ov
DEVELOPMENT SERVICES DEPARTMENT • PLANNING DIVISION
filo. 1890
Critical Areas File Number
CRA20120035
Determination
Study Required
Site Location
9115 Park Rd., Edmonds
Tax Account Number
00648100000300
Property Owner
Lance Horton
Applicant
Same as owner
Critical Areas Present
Q Geologically Hazardous Areas
Q Erosion Hazard Areas
0 Landslide Hazard Areas
During review and inspection of the subject site, it was found that the site may contain (or be adjacent to)
critical areas, including Geologically Hazardous Areas (Erosion Hazard Areas and Landslide Hazard Areas),
pursuant to Chapters 23.40 and 23.80 of the Edmonds Community Development Code (ECDC). Cited sections
of the Edmonds Community Development Code (ECDC) can be found on the City of Edmonds website at
www.edmondswa.gov.
The majority of the portion of the site surrounding the existing residence is relatively level. However, near
the northern side of the residence, the site begins sloping downwards steeply to the north. This slope
continues from the subject site onto the adjacent property to the north. The steepest portion of the slope is
where there is an existing series of stepped retaining walls located near the northern side of the existing
residence. These stepped retaining walls have an overall change in elevation of over 10 feet and an overall
slope in excess of 40%. Due to the degree of the slopes on and adjacent to the northern portion of the
property, it was found that the site contains and is adjacent to slopes that are steep enough to be considered
both an Erosion Hazard Area (over 15% slope) and a Landslide Hazard Area (over 40% slope).
Allowed•Exempt
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.
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 submit the entire study with your specific
development application. Please review the minimum report requirements for all types of Critical Areas
which 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 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.
It appears that this property contains or is adjacent to an Erosion Hazard Area. Geologically hazardous areas
include areas susceptible to erosion, land sliding, earthquake, or other geological events. They pose a threat
to the health and safety of citizens when incompatible development is sited in areas of significant hazard.
Such incompatible development may not only place itself at risk, but also may increase the hazard to
surrounding development and use.
Erosion Hazard areas include Alderwood and Everett series soils on slopes of 15 percent or greater, among
others. Landslide Hazard Areas are further defined in ECDC 23.80.020.A. In addition to the general
requirements for Critical Areas reports referenced above, specific Critical Area report requirements for
Erosion Hazard Areas (which are one of the Geologically Hazardous Areas) are provided in ECDC 23.80.050.
Note that Stable Erosion Hazard Areas may have limited report requirements at the director's discretion.
At a minimum, an erosion and sediment control plan prepared in compliance with the requirements in
ECDC Chapter 18.30 shall be required.
Development is restricted within an Erosion Hazard Area and must meet additional criteria. For erosion
hazard areas with suitable slope stability, an erosion and sediment control plan prepared in compliance ECDC
18.30 will be considered to meet the Critical Areas "Study Required" determination. The determination of
"suitable slope stability" will be made by both the Planning and Engineering divisions of the City of Edmonds.
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.
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It appears that this property contains or is adjacent to a Landslide Hazard Area. Geologically hazardous areas
include areas susceptible to erosion, land sliding, earthquake, or other geological events. They pose a threat
to the health and safety of citizens when incompatible development is sited in areas of significant hazard.
Such incompatible development may not only place itself at risk, but also may increase the hazard to
surrounding development and use.
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 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.
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This review applies to the entire subject parcel. Depending on the location and project proposed relative to
the identified critical areas, certain studies and reports may be required. Please contact the Planning
Division at 425.771.0220 if and when you have a specific development proposal for this site in order to
discuss the various permits that will be required. Please note that tree removal on sites containing critical
areas may first require a tree cutting permit, and the illegal removal of trees may result in penalties and
steep fines (ECDC 18.45.070, ordinance #3828).
Jen Machuga, Associate Planner
Name, Title
June 19, 2012
Date
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