APPROVED STM BLD2023-0686+Storm_Drainage_Memo+6.2.2023_4.02.29_PM+3585531RAM Engineering
To: City of Edmonds
Engineering Division
From: Rob Long, PE
RAM Engineering
Memorandum
Date: June 2, 2023
ENGINEERING DIVISION
---_ -- — .JTED
Subject: 23907 9111 PI W, Lot 3 Brackett's Reserve _ p(�� (j 16/29/2022
Stormwater Memo
RAM Job No. 20-024
RECEIVED
Jun 08 2023
1■.ylIM0161:I:6
This memo provides a summary of the stormwater drainage control system for Lot 3 of the Brackett's Reserve
Plat (PLN 2021-0037). A site -specific geotechnical evaluation recommends one stormwater BMP for the site;
BMP T5.13: Post -Construction Soil Quality and Depth based on the site's soil conditions. In accordance with
Edmonds Code, lawn and landscape areas will be managed by post -construction soil quality and depth (soil
amendments). The roof top, driveway, walk and patio areas will be managed by the Brackett's Reserve
detention vault located in Track 999 of the plat. The plat design has allocated 2,900 sf (base 2,800 sf and 100 sf
transferred from Lot 2) of hard surface for Lot 3 hard surface areas.
Below is a stormwater control summary table for Lot 3:
Stormwater Control Summary:
Project Site Category: Category 2 (part of the Brackett's Reserve Plat)
Discharge Location: City's Municipal Separate Storm Sewer System (MS4)
Type of Area
Square Footage
Storm water Facility
Lawn and Landscape
2,195 sf
Soil Amendments (BMP T5.13)
Roof
2,268 sf
Plat Detention Vault
Hard Surfaces
590 sf
Plat Detention Vault
(Driveway/Apron, Walk and Patio)
25% Retrofit
0 SF
None
P M Engineering 19109 36"Ave W, Suite 100 Lynnwood WA 98036 (425) 678-6960 RAMengineeringinc.com
23907 91st PI W, Lot 3 Brackett's Reserve Page 2 of 2
Stormwater Memo
RAM lob No. 20-024
23907 91st PI W, Lot 3 Brackett's Reserve Hard Surface Summary:
Roof = 2,268 sf
Driveway = 460 sf
Sidewalk/Patio = 130 sf
Total = 2,858 sf
Allowed/Allocated = 2,900 sf (base 2,800 sf and 100 sf transferred from Lot 2)
I
I
ID' JOINT
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CONSTRUCT STABIL12ED 7EMPORARY
�, I / i • i I CONS7RUC770N ENTRANCE PER CITY
OF EDMONDS S7D DWG NO ER-901
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ALONG BUILDING PERIMETER FOOTINGS
PER FOORNC DRAIN DETAIL BY EAR7H
r zz EE ` SOLUTIONS NW ONSHEET CN-Of — — — — — APPROVED LANDSCAPING LOCA77ON (TYP)
C==�=G == _= E ♦ SEE LANDSCAPE PLAN APPROVED AS
— — — — — — — N69 45'00R 10OW- — — — — — — — — — — — — — — — — PART OF PLAT BRACKETS RESERVE PLAT
45*17 (PLN2021-0037)
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i' INSTALL 7EMPORARY 2 (PLN2021-0037)
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RAM Engineering 19109 3611 Ave W, Suite 100 Lynnwood WA 98036 (425)678-6960 RAMengineeringinc.com