2006-0673_ZiedalskiDeck.doc
CE
ITY OF DMONDS
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121 5 Avenue North • Edmonds, WA 98020
Phone: 425.771.0220 • Fax: 425.771.0221 • Web: www.ci.edmonds.wa.us
DSD: P•E•B
EVELOPMENT ERVICES EPARTMENTLANNING NGINEERING UILDING
Plan Review Comments – Planning Division
Plan Check #: 2006-0673
Project Name: Tom Ziedalski Deck
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Project Address: 15900 70 Avenue West – RS-12 Zone
June 12, 2006
Dave Kleven
The Deck Connection, Inc.
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16410 84 Street NE #D232
Lake Stevens WA 98258
Phone: 425.531.4193 / Fax: 425.491.7800
Dear Mr. Kleven,
I have reviewed the above building permit application for the Planning Division and it was found
that the following information, corrections, or clarifications will need to be addressed before
review can continue:
1.Setbacks: The minimum side setback in the RS-12 zone is 10 feet. However, as shown, the
proposed deck is located 8 feet from the south property line. Please revise the plans and
site plan to meet the minimum 10-foot setback requirement.
2.Height: The plans show that the proposed deck has a height of 6 inches to 8 feet. Please
revise this figure (if it changes) due to the new location of the deck. Accessory structures
cannot exceed 15 feet in height, as measured from average original grade. Please clarify:
was the height figure provided measured from average original grade?
3.Geotechnical Report: Thank you for providing a geotechnical report, required because this
site is on/adjacent to a landslide hazard area. However, there is information missing that is
required by the Edmonds Community Development Code, Chapter 23.80 (Geologically
Hazardous Areas). Please review the following code sections (attached and available
online) and have the geotechnical engineer touch on the following areas:
a.ECDC 23.80.050.C: The geotechnical engineer needs to make a statement that they
have reviewed the deck plans and the site plan (a copy of these needs to be included in
their report). Please review attached code section…
b.ECDC 23.80.070.A.2: This section deals with the alteration of critical areas. Because
your plans are IN the critical area, the geotechnical engineer needs to make statements
regarding items in this section of the code, assuring that as designed and sited, there will
be no impact to the critical area and to neighbors. Please review attached code section…
Thank you for your cooperation. Please redline plans or submit three sets of revised
plans/documents (affected sheets only) with a written response to each of the above items.
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Please make all submittals to the Development Services Permit Coordinator Monday through
Friday, 9am to noon or 1pm to 4pm. If you have any questions, please do not hesitate to contact
me at (425) 771-0220, extension 1778. I look forward to working with you on this project.
Sincerely,
CITY OF EDMONDS
Gina Coccia, Planner
ECDC 23.80.050 Special study and report requirements – Geologically hazardous areas.
Critical area report requirements for geologically hazardous areas are generally met through submission
to the director of one or more geotechnical engineering reports. In addition to the general critical areas
report requirements of ECDC 23.40.090, critical areas reports for geologically hazardous areas must
meet the requirements of this section and Chapters 18.30 and 19.10 ECDC as applicable. Critical areas
reports for two or more types of critical areas must meet the report requirements for each relevant type of
critical area. Geotechnical report(s) submitted for the purpose of critical areas review are required as
necessary in addition to reports, data and other information mandated per ECDC Titles 18 and 19.
A. Preparation by a Qualified Professional. A critical areas report for a geologically hazardous area shall
be prepared by an engineer or geologist licensed in the state of Washington, with experience analyzing
geologic, hydrologic, and ground water flow systems, and who has experience preparing reports for the
relevant type of hazard. Critical areas studies and reports on geologically hazardous areas shall be
subject to independent review pursuant to ECDC 23.40.090(B).
B. Area Addressed in Critical Areas Report. The following areas shall be addressed in a critical areas
report for geologically hazardous areas:
1. The project area of the proposed activity; and
2. All geologically hazardous areas within 200 feet of the project area or that have the potential to be
affected by the proposal.
C. Geological Hazards Assessment. A critical areas report for a geologically hazardous area shall contain
an assessment of geological hazards including the following site- and proposal-related information at a
minimum:
1. Site and Construction Plans. The report shall include a copy of the site plans for the proposal showing:
a. The type and extent of geologic hazard areas, any other critical areas, and buffers on,
adjacent to, within 200 feet of, or that are likely to impact the proposal;
b. Proposed development, including the location of existing and proposed structures, fill,
storage of materials, and drainage facilities, with dimensions indicating distances to the
floodplain, if available;
c. The topography, in two-foot contours, of the project area and all hazard areas addressed
in the report; and
d. Clearing limits;
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2. Assessment of Geological Characteristics. The report shall include an assessment of the geologic
characteristics of the soils, sediments, and/or rock of the project area and potentially affected adjacent
properties, and a review of the site history regarding landslides, erosion, and prior grading. Soils analysis
shall be accomplished in accordance with accepted classification systems in use in the region. The
assessment shall include, but not be limited to:
a. A description of the surface and subsurface geology, hydrology, soils, and vegetation
found in the project area and in all hazard areas addressed in the report;
b. A detailed overview of the field investigations, published data, and references; data and
conclusions from past assessments of the site; and site-specific measurements, tests,
investigations, or studies that support the identification of geologically hazardous areas; and
c. A description of the vulnerability of the site to seismic and other geologic events;
3. Analysis of Proposal. The report shall contain a hazards analysis including a detailed description of the
project, its relationship to the geologic hazard(s), and its potential impact upon the hazard area, the
subject property, and affected adjacent properties; and
4. Minimum Buffer and Building Setback. The report shall make a recommendation for the minimum no-
disturbance buffer and minimum building setback from any geologic hazard based upon the geotechnical
analysis.
D. Incorporation of Previous Study. Where a valid critical areas report has been prepared within the last
five years for a specific site, and where the proposed land use activity and surrounding site conditions are
unchanged, said report may be incorporated into the required critical areas report. The applicant shall
submit a hazards assessment detailing any changed environmental conditions associated with the site.
E. Mitigation of Long-Term Impacts. When hazard mitigation is required, the mitigation plan shall
specifically address how the activity maintains or reduces the preexisting level of risk to the site and
adjacent properties on a long-term basis (equal to or exceeding the projected lifespan of the activity or
occupation). Proposed mitigation techniques shall be considered to provide long-term hazard reduction
only if they do not require regular maintenance or other actions to maintain their function. Mitigation may
also be required to avoid any increase in risk above the preexisting conditions following abandonment of
the activity.
F. Additional Technical Information Requirements for Erosion and Landslide Hazard Areas. In addition to
the basic critical areas report requirements for geologically hazardous areas provided in subsections A
through E of this section, technical information for erosion and landslide hazard areas shall meet the
requirements of Chapter 19.10 ECDC and include the following information at a minimum:
1. Site Plan. The critical areas report shall include a copy of the site plan for the proposal showing:
a. The height of slope, slope gradient, and cross-section of the project area;
b. The location of springs, seeps, or other surface expressions of ground water on or within
200 feet of the project area or that have the potential to be affected by the proposal; and
c. The location and description of surface water runoff features;
2. Hazards Analysis. The hazards analysis component of the critical areas report shall specifically include:
a. A description of the extent and type of vegetative cover;
b. A description of subsurface conditions based on data from site-specific explorations;
c. Descriptions of surface and ground water conditions, public and private sewage disposal
systems, fills and excavations, and all structural improvements;
d. An estimate of slope stability and the effect construction and placement of structures will
have on the slope over the estimated life of the structure;
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e. An estimate of the bluff retreat rate that recognizes and reflects potential catastrophic
events such as seismic activity or a 100-year storm event;
f. Consideration of the run-out hazard of landslide debris and/or the impacts of landslide
run-out on down-slope properties;
g. A study of slope stability including an analysis of proposed cuts, fills, and other site
grading;
h. Recommendations for building siting limitations; and
i. An analysis of proposed surface and subsurface drainage, and the vulnerability of the site
to erosion;
3. Geotechnical Engineering Report. The technical information for a project within a landslide hazard area
shall include a geotechnical engineering report prepared by a licensed engineer that presents engineering
recommendations for the following:
a. Parameters for design of site improvements including appropriate foundations and
retaining structures. These should include allowable load and resistance capacities for bearing
and lateral loads, installation considerations, and estimates of settlement performance;
b. Recommendations for drainage and subdrainage improvements;
c. Earthwork recommendations including clearing and site preparation criteria, fill placement
and compaction criteria, temporary and permanent slope inclinations and protection, and
temporary excavation support, if necessary; and
d. Mitigation of adverse site conditions including slope stabilization measures and
seismically unstable soils, if appropriate;
4. Erosion and Sediment Control Plan. For any development proposal on a site containing an erosion
hazard area, an erosion and sediment control plan shall be required. The erosion and sediment control
plan shall be prepared in compliance with requirements set forth in Chapter 18.30 ECDC.
G. Limited Report Requirements for Stable Erosion Hazard Areas. At the director’s discretion, detailed
critical areas report requirements may be waived for erosion hazard areas with suitable slope stability.
Report requirements for stable erosion hazard areas may be met through construction documents that
shall include at a minimum an erosion and sediment control plan prepared in compliance with
requirements set forth in Chapter 18.30 ECDC.
H. Seismic Hazard Areas. In addition to the basic critical areas report requirements for geologically
hazardous areas provided in subsections A through E of this section, a critical areas report for a seismic
hazard area shall also meet the following requirements:
1. The site map shall show all known and mapped active faults within 200 feet of the project area or that
have the potential to be affected by the proposal.
2. The hazards analysis shall include a complete discussion of the potential impacts of seismic activity on
the site (for example, forces generated and fault displacement).
3. A geotechnical engineering report shall evaluate the physical properties of the subsurface soils,
especially the thickness of unconsolidated deposits and their liquefaction potential. If it is determined that
the site is subject to liquefaction, mitigation measures appropriate to the scale of the development shall
be recommended and implemented. \[Ord. 3527 § 2, 2004\].
ECDC 23.80.070 Development standards – Specific hazards.
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A. Erosion and Landslide Hazard Areas. Activities on sites containing erosion or landslide hazards shall
meet the requirements of ECDC 23.80.060, Development Standards – General Requirements, and the
specific following requirements:
1. Buffer Requirement. A buffer shall be established from all edges of landslide hazard areas. The size of
the buffer shall be determined by the director consistent with recommendations provided in the
geotechnical report to eliminate or minimize the risk of property damage, death, or injury resulting from
landslides caused in whole or part by the development, based upon review of and concurrence with a
critical areas report prepared by a qualified professional.
a. Minimum Buffer. The minimum buffer shall be equal to the height of the slope existing
within the project area or 50 feet, whichever is greater;
b. Buffer Reduction. The buffer may be reduced to a minimum of 10 feet when a qualified
professional demonstrates to the satisfaction of the director that the reduction will adequately
protect the proposed development, adjacent developments and uses and the subject critical
area;
c. Increased Buffer. The buffer may be increased where the director determines that a larger
buffer is necessary to prevent risk of damage to proposed and existing development;
2. Alterations. Alterations of an erosion or landslide hazard area and/or buffer may only occur for activities
for which a hazards analysis is submitted and certifies that:
a. The development will not increase surface water discharge or sedimentation to adjacent
properties beyond predevelopment conditions;
b. The development will not decrease slope stability on adjacent properties; and
c. Such alterations will not adversely impact other critical areas;
3. Design Standards. Development within an erosion or landslide hazard area and/or buffer shall be
designed to meet the following basic requirements unless it can be demonstrated that an alternative
design that deviates from one or more of these standards provides greater long-term slope stability while
meeting all other provisions of this title. The requirement for long-term slope stability shall exclude
designs that require regular and periodic maintenance to maintain their level of function. The basic
development design standards are:
a. The proposed development shall not decrease the factor of safety for landslide
occurrences below the limits of 1.5 for static conditions and 1.2 for dynamic conditions. If
stability at the proposed development site is below these limits, the proposed development
shall provide practicable approaches to reduce risk to human safety and improve the factor of
safety for landsliding. In no case shall the existing factor of safety be reduced for the subject
property or adjacent properties;
b. Structures and improvements shall be clustered to avoid geologically hazardous areas
and other critical areas;
c. Structures and improvements shall minimize alterations to the natural contour of the
slope, and foundations shall be tiered where possible to conform to existing topography;
d. Structures and improvements shall be located to preserve the most critical portion of the
site and its natural landforms and vegetation;
e. The proposed development shall not result in greater risk or a need for increased buffers
on neighboring properties;
f. The use of retaining walls that allow the maintenance of existing natural slope area is
preferred over graded artificial slopes; and
g. Development shall be designed to minimize impervious lot coverage;
4. Vegetation Retention. Unless otherwise provided or as part of an approved alteration, removal of
vegetation from an erosion or landslide hazard area or related buffer shall be prohibited;
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5. Seasonal Restriction. Clearing shall be allowed only from May 1st to October 1st of each year;
provided, that the director may extend or shorten the dry season on a case-by-case basis depending on
actual weather conditions, except that timber harvest, not including brush clearing or stump removal, may
be allowed pursuant to an approved forest practice permit issued by the city of Edmonds or the
Washington State Department of Natural Resources;
6. Point Discharges. Point discharges from surface water facilities and roof drains onto or upstream from
an erosion or landslide hazard area shall be prohibited except as follows:
a. Conveyed via continuous storm pipe downslope to a point where there are no erosion
hazard areas downstream from the discharge;
b. Discharged at flow durations matching predeveloped conditions, with adequate energy
dissipation, into existing channels that previously conveyed storm water runoff in the
predeveloped state; or
c. Dispersed discharge upslope of the steep slope onto a low-gradient, undisturbed buffer
demonstrated to be adequate to infiltrate all surface and storm water runoff, and where it can
be demonstrated that such discharge will not increase the saturation of the slope; and
7. Prohibited Development. On-site sewage disposal systems, including drain fields, shall be prohibited
within erosion and landslide hazard areas and related buffers.
B. Earth Subsidence and Landslide Hazard Area. In addition to the requirements of this chapter,
development proposals for lands located within the earth subsidence and landslide hazard area as
indicated on the critical areas inventory shall be subject to the provisions of Chapter 19.10 ECDC.
C. Seismic Hazard Areas. Activities proposed to be located in seismic hazard areas shall meet the
standards of ECDC 23.80.060, Development Standards – General Requirements. \[Ord. 3527 § 2, 2004\].
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