Engineering-Storm Request for Info-PLN20190052-Jodar.docx.pdfMEMORANDUM
REQUEST FOR ADDITIONAL INFORMATION
Date: October 25, 2019
To: Kernen Lien, Environmental Programs Manager
From: Jeanie McConnell, Engineering Program Manager
Subject: PLN201900552, Jodar 4 lot short plat
8717 — 2401" St SW
The comments provided below are based upon review of the preliminary civil plans &
documents for the subject short plat. Additional information is 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 comments
below and revise and resubmit plans accordingly.
1. Show existing and proposed driveway approaches. Clearly indicate proposed points of
access for each lot.
2. Add note that along with the removal of the existing single-family residence, all
associvated impervious surface areas (ex. driveway) will be removed.
3. Show existing access easement areas and existing pavement areas on one plan sheet. Will
the existing and proposed pavement areas fall within existing easement areas?
4. In accordance with Edmonds Community Development Code (ECDC) Chapter 18.90,
sidewalks are required as a condition of short plat approval. Please resubmit plans
showing the proposed sidewalk along the 241h St SW property frontage..
5. The Edmonds Community Development Code does not allow for driveway/access road
slopes to exceed 14% without first obtaining approval from the City Engineer. This is not
an average of the overall slope and at no point shall the proposed access road exceed 14%.
Given it appears feasible to achieve a slope of less than 14%, please revise proposed
grading as needed and add note to this effect.
6. Update cross section of 240th St SW to callout full ROW width, pavement center line and
a west bound lane of 12' from center of pavement to the face of the proposed curb. Also
include proposed sidewalk.
City of Edmonds
7. The following comments pertain to stormwater aspects of the project and may overlap
with comments provided by Stormwater Engineer, Zachary Richardson. Please address
the following:
a. An easement shall be provided to the public for the continued use of the property
for the stormwater swale that exists along the west property line. The limits of the
easement will be determined once additional information has been provided on the
limits of the swale. Please note, this project is only responsible for establishing an
easement across the subject property. The retaining wall shall not be located
within the easement.
b. The currently proposed stormwater outfall is shown to cross an adjacent parcel to
the north. A note has been added that an easement is to be obtained from the
adjoining property owner. At a minimum, provide the City with a copy of a
written agreement or granting of permission from the adjacent property allowing
for this stormwater improvement to occur on their site. In addition, provide invert
elevations for the storm connection on Edmonds Way. Currently the public storm
system does not exist in the location of the proposed outfall.
8. Please note the requirement for a street light along the property frontage, near the
intersection of 87th Ave W. A street light could be placed on the existing power pole if
approved by PUD.
9. Show the location of existing and proposed dry utilities.
STORMWATER ENGINEER REVIEW
Refer to attached plan review comments by City Stormwater Engineer, Zachary Richardson. Please
contact Zack directly at 425-771-0220 or by email at zachary.richardsonkedmondswa.gov with any
specific questions you may have regarding his comments.
Thank you.
of EDM STO RM WATE R REVIEW COMMENTS
City of Edmonds
Engineering Division
To: Applicant
Date: Revised October 24, 2019
Project Name: Adamant Homes 4 Lot SP
Permit Number: PLN20190052
Address: 8717 240'" St SW
Review Type: Preliminary Plat (Feasibility)
Submittal Date: 9/23/2019
Reviewer: Zack Richardson, PE
City of Edmonds, Stormwater Engineer
Recommendation: I recommend that PLN20190052 be withheld until the comments
below are adequately addressed. The project involves several off -site storm elements;
stormwater review is limited to function of the facilities. See Engineering Reviewer
comments for direction on long-term protection of facilities, easements,
timing/coordination, and procedures.
Review Comments:
Geotech report: Revise boring/test/auger logs and/or infiltration feasibility section
to better align with each other, or revise BMP recommendations accordingly:
a. Text section states sand layers are insufficient to serve as receptors, but
test pits show sand or loam to at least 7' depth; explain further.
b. Text section states till deposits are a concern, but no test pit appears to
clearly identify a till or hardpan layer; explain further.
2. Drainage Report: Update report to address frontage improvements:
a. It appears all frontage improving will not drain to the proposed detention
system and therefore need to be considered as by-pass (unless in
separate TDA); update model as needed to show compliance with by-pass
flows.
b. Update text to describe impacts to adjacent property to west as result of
new curb.
3. Drainage report: Add text explaining how the engineer has ensured the project
will not impact the capacity of the existing ditch to the west (with the proposed
wall).
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4. Sheet 3: Add a reference to the corresponding permit number for the storm drain
improvements by others.
5. Sheet 3: Add callout for the existing swale to the west: "Maintain swale flow line
and capacity"
6. Sheet 3: Show footing drain locations and discharge point; show easements as
needed.
7. Sheet 3: Show the outfall for the existing CB in 240t" (to remain) in greater detail;
it appears the proposed fire hydrant would conflict with this outfall.
8. Sheet 3: Add to the private road cross section, notation indicating location of
existing ditch flow line; address concern for placing block (i.e non-solid/non-
watertight) wall along potential flowing water, or explain why this is not a concern.
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