2856_001RAM Engineering
City of Edmonds Development Services Department
1215 th Avenue North
Edmonds, WA 98020
RE: Select Lot 9 of Westhaven Plat
Plan Check BLD20191175
1't Engineering Site Plan Review Comment Response
RAM Job No. 17-038
Staff:
qcaoneo,
November 7, 2019
This letter outlines the revisions and corrections made per Staff review. Below is a list of the comment
response documents addressing the comments and requests:
Engineering Comments: JoAnne Zulauf letter dated October 10, 2019
GENERAL
1) Please submit a Side Sewer Permit Application form.
Response: Application Attached
TESC
1) Please add note that plat tesc will be maintained during sfr construction or provide a tesc
plan for the sfr.
Response: Added note to plan.
SEWER
1) Provide invert elevation at the sewer stub.
Response: Added invert to pion.
STORM
1) Show where the retaining wall drainage will discharge to.
Response: Added retaining wall drywell to plan.
2) Provide invert elevation for storm stub.
Response: Added invert to plan.
3) It appears that the storm invert at the house is lower than the invert at the outfall of
the perforated stub.
Response: adjusted inverts to provide positive flow.
RESUB
NOV I Z 2019
BUILDING DEPARTMENI
01-TY OF EDMONDS
RAM Engineering 1653113" Ave W, Suite A108 Lynnwood WA 98037 (425) 678-6960 RAMengineeringinc.com
Select Westhaven- Lot 9
Plan Check BLD20191175
1st Engineering Site Plan Review Comment Response
Stormwater Engineering Comments: Zack Richardson, PE letter dated October 21, 2019
Review Comments:
Page 2 of 2
RAMJob No. 17-038
1. It is unclear that the driveway runoff is adequately controlled and collect in a manner
that will not negatively impact adjacent properties or the public sidewalk; provide
additional grading information, cross-section (inverse crown, thickened edge, etc),
and/or drain collection points as needed to demonstrate how driveway flow is
controlled as currently shown with arrows.
a. It appears an area drain or trench drain could easily be added to the
connection point with the plat improvements (or anywhere along the
proposed pipe) to reduce impacts to the sidewalk with negligible impacts to
the project; address as needed
Response: The driveway area is mi . ni . mal (less than Z 069 sf) and will sheet flow to the catch basin system
in 215 th P1 SW (design slopes shown on plans). Some runoff may dissipate off the edge of the driveway
within lawn and landscape areas (this is ideal). Concentration offlows with a thickened edge or inverted
crown is not necessary. The de minimus flows from the driveway area will have no adverse impacts to
the surrounding properties or adjacent sidewalk areas.
If there are any questions regarding the items above, please contact me at your earliest convenience; I
can be reached at (425)678-6960 or RobL@RAMengineeringinc.com.
Thank you,
Rob Long, PE
Principal
RAM Engineering 16531 13" Ave W, Suite A108 Lynnwood WA 98037 (425) 678-6960 RAMengineeringinc,corn
RAM Engineering
To: City of Edmonds Engineering Division
c/o Zach Richardson, PE Stormwater Engineer
121 5th Avenue North
Edmonds, WA 98020
From: Rob Long, PE
RAM Engineering
16531 13th Ave W, Suite A108
Lynnwood WA 98037
Subject: Select Homes: Westhaven Plat, Plan Check PLN20180034
Project Allowable Lot Impervious Allocation Revision
RAM Job No. 17-038
Memorandum
Date: November 7, 2019
This letter provides a revision to the allowable lot hard (impervious) surface allocation for the Westhaven plat. The
original plat design included a total new and replaced hard surface of the project at 51,200 sf, of which 42,000 sf of the
area was allocated to impervious on the lots. The applicant would like to revise the hard surface allocation for each
individual lot to support the building permit application for each lot. The following table provides the requested
reallocation and demonstrates that then revised numbers will not exceed the original approved hard surface allocation
of 42,000 sf for the lots. The new revised lot allocation will be 500 sf less than the original 42,000 sf design.
Westhaven Individual Lot Hard Surface Allocation:
Lot
Impervious
Lot
Imnervious
1
4,200
6
4,750
2
4,100
7
3,850
3
4,200
8
3,500
4
4,000
9
4,800
5
3,900
10
4,200
Total Lot Impervious
Allocation
= 41,500 sf
If you have any questions or need additional information, please contact me at RobL@RAMengineeringinc.com or call me
at (425) 678-6960.
Thank you.
111-7119
RAM Engineering 16531 131h Ave W, Suite A108 Lynnwood WA 98037
RESUB
NOV I Z 2019
BUILDING DEPARTMENT
G1TY OF EDMONDS
(425) 678-6960 RAMengineeringinc.com