2860_001'-'canne
RAM Engineering
ftevember7,2019'- �-
City of Edmonds Development Services Department
1215 1h Avenue North
Edmonds, WA 98020
RE: Select Lot 10 of Westhaven Plat
Plan Check BLD20191177
Vt Engineering Site Plan Review Comment Response
RAM Job No. 3.7-038
Staff:
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 Pert -nit Application form.
Response: Application attached.
TESC
1) Please add note that plat tesc will be maintained during Or construction or provide a tesc
plan for the sfr.
Response: Added note to plan.
SEWE
1) Provide invert elevation at the sewer stub.
Response: Added invert to plan.
STORM
1) Show where the retaining wall drainage will discharge to
Added retaining wall drywell to plan.
2) It appears that the storrn invert at the house and the invert at the outfall of the perforated
stub are the same.
Response: revised inverts to show positiveflow.
RESUB
NOV 12 2019
BUILDING DEPARTMENT
CITY OF EDMONDS.'
RAM Engineering 16531 131h Ave W, Suite A108 Lynnwood WA 98037 (425) 678-6960 RAMengineeringinc.corn
Select Westhaven Lot 10
Plan Check BLD20191177
1st Engineering Site Plan Review Comment Response
Stormwater Engineering Comments: Zack Richardson, PIE letter dated October 21, 2019
Review Comments:
Page 2 of 2
RAMJob No. 17-038
1. The lot impervious coverage appears to exceed the typical lot assumptions from
the plat drainage design, however, it generally appears that the plat total
impervious may still be balanced against other lots which run under allotments.
Engineer shall provide written explanation or documentation of impervious
distribution varying form the reviewers Interpretation below:
a. The plat drainage report generally assume 4,000 SF per lot of impervious.
b. An extra 2,000 was allotted for "panhandle driveways" which were
assumed to be limited to Lot 9 and Lot 6
c. The effective result was 4,000 SF allotment per lot, except that Lot 6 and 9
could go up to 5,000 SF.
d. This documentation shall be included with all drainage submittals for SFRs.
associated with this plat, including lots which are under the allotment, In
order to correctly assess the re -distribution to all lots correctly.
Total Hard Surface New/Replaced Prop sed = 51,200 sf (1,175 ac)
Building Rooftop = 30,OC , -10"ts @ 3,000 sf ea.)
Uncovered Patio and Walk = 2,000 sf (10 lots @ 200 sf ea.)
Individual Driveways = 8,000 sf (10 lots @ 800 if eaj
Additional Panhandle Driveways =IM21-
Vault Access Road = 1,800 sf
ROW Frontage and Cul-de-sac - 6,300 sf
ROW Sidewalk = 1,100 sf
Response: Attached is a letter with an updated allocation for the lot hard (impervious) surface areas for
theproject. The letter lists the hard surface areas for each lot and demonstrates that the overall lot hard
surface area is not exceeded This letter will be submitted with all lot building permitsfor reference.
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 131h Ave W, Suite A108 Lynnwood WA 98037 (425) 678-6960 RAM engineeringinc, com
RAM Engineering
A '�'
To: City of Edmonds Engineering Division
c/o Zach Richardson, PE Stormwater Engineer
121 5th Avenue North
Edmonds, WA 98020
From: Rob Long, PE
PEAM 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
Imvervious
Lot
Impervious
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.
L * to
13�
36508
ISTO
RESUB
111-7119
NOV 12 2019
BUILDING DEPARTMENT
CITY OF EDMONW
RAM Engineering 1653113 1h Ave W, Suite A108 Lynnwood WA 98037 (425) 678-6960 RAMengineeringinc.com