20070820132800.pdfLANDAU
ASSOCIATES
TECHNICAL MEMORANDUM L,,NAMA W_"RM
TO: Jeannine Graf, Building Official RECEIVED
City of Edmonds Development Services Department, Building Division G 2 0 200
FROM: Dennis R. Stettler, F.E, t�
BUILDING
DATE: August 20, 2007
RE: COMPLETENESS REVIEW FOR EARTH SUBSIDENCE AND LANDSLIDE HAZARD AREA
SUBMITTAL PACKAGE — PLAN REVIEW N05. BLD2007-0833, BLD2007-0834
ISAACSON GRADING AND DRAINAGE —16007 73r`O PLACE WEST
EDMONDS, WASHINGTON
This technical memorandum provides our assessment of the completeness of the geotechnical
portions of the permit package for Grading and Drainage submitted to the City of Edmonds for the
proposed referenced development within the Earth Subsidence and Landslide Hazard Area (ESLHA) of
North Edmonds. This completeness review was accomplished in accordance with Landau Associates'
On -Call Geotechnical Engineering Services Agreement with the City of Edmonds.
The completeness review is not intended to be a thorough review of the submittal package.
Instead, it is intended to be a cursory review to assess whether the submittal appears to contain the
necessary information in order to complete a geotechnical peer review in accordance with Edmonds
Community Development Code Chapter ECDC 19.10.
The submittal package provided to us included:
• An Erosion and Sediment Control Flan, an Existing Condition and Tree Plan, and a Drainage
Flan. All three plan sheets were prepared by Western Engineers, Inc. and printed June 18,
2007.
• A copy of the City of Edmonds Plan Review Corrections form for the project prepared by
Jeannine Graf of the Building Department, dated August 15, 2007.
On the basis of our cursory review, it appears that the submittal package is missing a number of
items that are required for Building Department submittals for projects within the North Edmonds Earth
Subsidence and Landslide Hazard Area. ECDC 19, 10, and by reference ECDC 23.80, identify a number
of specific submittal requirements. We are aware that this property was previously the subject of a tree
clearing permit through the Planning Department. Although certain documents were provided as a part of
that previous permit application, the current application for grading and drainage through the Building
Department is a separate application and needs to be a complete submittal package.
The applicant is referred to ECDC 19.10 and ECDC 23.80 for a complete outline of the required
plan review submittal materials. The key missing elements are outlined in the Plan Review Corrections
form prepared by the City of Edmonds for this submittal. In later peer review for this project, we will be
130 2nd Avenue South . Edmonds, WA 98020 • (425) 778-0907 • fax (425)778-6409 • www.landauinc.com
looking at the required geotechnical report to see that it addresses the slope stability and related site
development issues that are identified in ECDC 19.10 and ECDC 23.80.
On the Erosion and Sediment Control Plan is a note that states "Proposed grading based on
existing site features. Base survey not accurate with current conditions." It is not known what is meant
by that statement. The applicant is required to furnish a topographic map showing current conditions and
contour lines on at least two foot intervals. If the existing base map does not accurately show the current
conditions, then the base map should be redone prior to resubmittal.
Proposed drainage features are shown on the Drainage Plan. Other features are shown without
sufficient detail. For example, the Drainage Plan also shows a proposed footprint for a house, garage,
retaining wall, along with what appears to be drains and drain pipes around the proposed house and
garage. We assume that these features are not a part of the current permit submittal, since there are no
details provided on these features. It should be made very clear what elements of the proposed plans are
included in the current grading and drainage permit application and which are not.
It would be appropriate to point out to the applicant that providing an application for only limited
grading and drainage at this time, but not other elements of the planned property development, presents
certain risks to the applicant. Review of development plans are benefited when the reviewer has a
complete understanding of the overall development. This is particularly critical in the Earth Subsidence
and Landslide Hazard Area where an appreciation of the planned overall site grading, retaining walls,
foundations, and drainage is an integral part of understanding whether the proposed overall site
improvements appropriately benefit or detract from long-term slope stability. Reviews that are conducted
on a piecemeal basis run the risk that subsequent permit applications for the proposed additional grading,
drainage, retaining walls, and structures that will be a part of the overall property development may
disclose issues that would require rework of the drainage features that are a part of the current application.
Please contact us if you have any questions regarding this completeness review and when you are
ready for us to commence with our geotechnical peer review.
DRS/rgm
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