Engineering-pln20150001-WoodwayCourt-Memo-2.pdf
MEMORANDUM
Date:July 23, 2015
To:
Kernen Lien,SeniorPlanner
From:
JoAnne Zulauf, Engineering Technician
Subject:
PLN20150001,Woodway Court4-lot short plat
23920 104th St SW
The comments provided below are based upon review of the preliminary civil plans &
documents for the subject short plat. Additional informationis requested from the applicant
at this time in order to continue review of the application and provide preliminary approval of
the short plat. Please ask the applicant to provide a written response to each of the
outstanding comments below and revise and resubmit plans accordingly.
Please also note, after receiving preliminary short plat approval from the Planning Division,
the applicant will be required to submit civil engineering plans to the City for review and
approval after receiving preliminary short plat approval from the Planning Division.
1)Please providea description ofTracts 998 and 999 and the easements allocated to eachof
the proposed lots.
2)The submitted arborist reportfrom Shoffner Consultingfinds that the reduced viability of
retaining all four trees located in the right of way is not an existing condition but is a
condition that will be created by the clearing of the land for development. Pursuant to
Edmonds Community Development Code Chapter 18.45, please revisit the development
proposal and show that utilities and other improvements have been located such that a
reasonable attempt has been made to retain as many trees aspossible.
3)Provide a letter of preliminary approval from Olympic View Water and Sewer District
allowing connection to the water and sewer system as they are the utility purveyor for the
subject property.
The following is provided as information onlyfor future civil construction plan submittal:
1)The applicant proposes infiltration of stormwaterrunoff for the project .The geotechnical
report indicates advance outwash soils 2 to 3 feet below ground surface.These soils are
suitable for infiltration of stormwater runoff.
City of Edmonds
2)The project appears to have one acre or more of land disturbing activity and would,
therefore, qualify as a Large Site Project. Please confirm.If so, the applicant must file a
Notice of Intent (NOI) with the Department of Ecology for their Stormwater Pollution
Prevention Plan (SWPP).Include the NOI in the drainage report.Also, Large Site
Projects cannot use the pre-sizing tables in Engineering Handout E72B to size individual
infiltration trenches on the lots.They must be modeled to the Ecology duration standard
(100% infiltration meets that standard).
3)The design submittalshould include characterization of the subsurface soil directly below
the proposed infiltration facilities per the 2005 Ecology Stormwater Management Manual
for Western Washington.This should include, but not be limited to, Volume II, Chapter
3.3.5.
4)Thepreliminary plan shows an infiltration trench along the south side of the private
road.This is a non-standard design.These gravel shoulders tend to clog or sometimes
residents will pave over them.Catch basins that drain to infiltration trench or a trench
drain at the west end of the private road that flows to an infiltrate trench would be a more
permanent solution.The system would need to take into account treatment of the runoff
from the private road.
5)The modeling in Section E uses the “Vault” element for the infiltration trench.The
“Gravel Trench/Bed” element is more appropriate for these systems.
Thank you.