APPROVED STM_BLD2023-0071+Storm_Drainage_Report+1.17.2023_2.53.26_PM+3318818RAM Engineering
To: City of Edmonds
RECEIVED
Engineering Division
Feb 08 2023
From: Rob Long, PE
CITY OFEDMONDS
RAM Engineering
DEVELOPMENT SERVICES
DEPARTMENT
Subject: 23902 9111 PI W, Lot 7 Brackett-s Reserve
Stormwater Memo
RAM Job No. 20-024
Memorandum
Date: December 9, 2022
BLD2023-0071
COMPLIES WITH APPLICABLE
CITY STORM CODE
.PE.
03/07/2023
This memo provides a summary of the stormwater drainage control system for Lot 7 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 2,800 sf of hard surface for Lot 7
hard surface areas.
Below is a stormwater control summary table for Lot 7:
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
1,805 sf
Soil Amendments (BMP T5.13)
Roof
1,877 sf
Plat Detention Vault
Hard Surfaces
900 sf
Plat Detention Vault
(Driveway/Apron, Walk and Patio)
25% Retrofit
0 SF
None
PKAM Engineering 19109 3611 Ave W, Suite 100 Lynnwood WA 98036 (425)678-6960 RAMengineeringinc.com
23902 91st PI W, Lot 7 Brackett's Reserve
Stormwater Memo
RAM lob No. 20-024
Page 2 of 2
23911 91st PI W, Lot 7 Brackett's Reserve Hard Surface Summary:
Roof = 1,877 sf
Driveway = 800 sf
Sidewalk/Patio = 100 sf
Total = 2,777 sf
Allowed/Allocated = 2,800 sf
100 SF
F//SA
IDEWALK/PATIO
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4,537 Sly TOP 354.00 (NORTH END)
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RAM Engineering 19109 3611 Ave W, Suite 100 Lynnwood WA 98036 (425)678-6960 RAMengineeringinc.com