APPROVED ENG RESUB1 BLD2023-0292+STORMWATER MEMO+5.18.2023_1.09.35_PM+3554359RAM Engineering BLD2023-0292
Memorandum
To: City of Edmonds
RESU B Date: March 6, 2023
Engineering Division
Update: May 15, 2023
May 18 2023
From: Rob Long, PE
CITY OFEDMONDS
RAM Engineering
DEVELOPMENT SERVICES
DEPARTMENT
Subject: Select Homes 8929 220t"
St SW Short Plat- Lot 1
Stormwater Memo
RAM Job No. 20-016
This memo provides a summary of the stormwater drainage control system for Lot 1 of the 2201h St SW. Short
Plat (PLN 2020-016). 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 a detention pipe designed in
accordance with the Edmonds Stormwater Addendum.
The Lot 1 roof, driveway/apron, walk and patio, as well as half the ROW areas (460 sf) will create 4,932 sf hard
surface and require 40 ft of 36" pipe (4,932 sf x 0.008) for BMP mitigation. The detention pipe will be
constructed (as part of the short plat improvements) along the lower southerly boundary of Lot 1.
Below is a stormwater control summary table for Lot 1:
Stormwater Control Summary:
Project Site Category: Category 2 (part of the 2201h St SW 2-Lot Short Plat)
Discharge Location: City's Municipal Separate Storm Sewer System (MS4)
Type of Area
Square Footage
Storm water Facility
Lawn and Landscape
5,184 sf
Soil Amendments (BMP T5.13)
Roof
2,575 sf
Detention Pipe (ECDC 18.30.030.D.5.d)
• 40 ft of 36" pipe (4,932 sf x 0.008)
Hard Surfaces
2 357 sf
Detention Pipe (ECDC 18.30.030.D.5.d)
(Driveway/Apron, Walk and Patio)
40 ft of 36" pipe (4,932 sf x 0.008)
25% Retrofit
0 SF
None
ENGINEERING DIVISION
APPROVED
p�A_� 06/06/2023
R/ M Engineering 19109 361h Ave W, Suite 100 Lynnwood WA 98036 (425) 678-6960 RAMengineeringinc.com
Select Homes 8929 200fh ST SW Shot Plat- Lot 1
Stormwater Memo
RAM Job No. 20-016
Page 2 of 2
Select Homes 220t" St SW Short Plat Lot 1 Hard Surface Summary:
Roof = 2,575 sf
Driveway = 1,847 sf
Sidewalk/Patio = 50 sf
Half of Row Improvements = 460 sf
Total = 4,932 sf
ANT � i
I
AS PART OF E 220TH ST SW - ,
SNORT PLAT. SEE APPROVED ----
LANDSCAPE PLAN (PLN202f-00JB) I
�I
au, •��__ N8926'16"
RETAWNG WALL TO BE
CONSTRUCTED AS PART OF�
THE 22o7N sr sW SHORT
PLAT (PLN202f-0038)
INSTALL FOLNIDATIOM/FGOTING DRAIN
ALONG BUILDING PERIMETER
Roof _2,575 SF
f0' PRIVATE -�
SIDE SEWER
EASEMENT
23'-4' P4C(3034)-" SEAR SERWCE
IA
FG
UTNJIAES
:RA
21`
FF 4J5.�
SD CO
DWWW
✓F All of
1s,
COVF7JFD
PORCH'
\PROPOSED
C
HOUSE
MAIN FF 43580
1
r £ A72.D..
i
SHORT PLAT IMPROVEMENTS
—' �
CONSTRUCTED
TO BE OF 2201H AS
PAR OF 17fE 220JH Sr SW
SHORT PLAT (PLN2M-0038)
DRIVEWAY = 1,847 SF
1 CHANNEL DRAIN
TOP 4J8.20
NOS PRO CHANNEL DRAIN
U
OR APPROVED £OVAL
M
(SET DETAIL ON SHT GN-OT)
~
�$
�•�
INSTALL 1-IA- RE (160 PSI)
FROM WATER METER TO HOUSE
DETAILS (TRACER WERE TO BE
INSTALLED WI7H WATER LW)
1-1/� WATER
4 A725 ''°° CF. 431-6 WALK= 50 SF
o 2OT MIN
r. DcoL4•Rm _
PA DO TF �.3ZSf
I 28'ORAINACE d'.t7bNT
I UTILITY EASEMENT (TYP)
CONNECTED 7b SEWER STUB�l
INSTALL 6' CLEANOUT WOTN
12"CAST PON LAMPHCLE
-
_ -
1 C
44' - 4" PVC STORM
DRAIN 1 1.OT MNV
_ COVE'RtWTH 1/2-HEX BOL TS
L ROOF
DRAIN
j
i6• PRIVATE ACCESS EASEMENT
& PXK HOLE
SSCO IE - 4285t
RCHRINE
HEAT
4' PVC F-007WG
: - 1 PUMP
I' WATER SERWC£ INSTALLEDT.DRAM
C I.OT MIN
1
! AS PART OF SHORT PLA10'
I I , • INSTALL 1' WATER METER
WIN LENGTH FOOFWO
DRAIN DRYWELL TRENCH
CONNECT�7.7. __�
Slow Sne
_
(PER G-OTEGI
-
IE Amf •
EX F7RE HYDRANT
RECOMM.A?1.1S
I
N6978'18 88-6"""
..._....................W
... ...... __"
- i.i
...... .......................
5X15' U7NJTY EASEMENT
_....__
...................-
- .- 1.44W 200I413W)
20' PRIVATE - -
50% FRONTAL = 460 SF
CASE T ;g
—�— -
I
220TH sr,
nv
£X F7Rf HYDRANT
TAM A"
V
Q
TOP CONCRETE MON
IN CASE
_
WIN 2" BRASS DISC W/PUNCH
ELEV 427.46
0
to
d
36508 W�
OA �IST
\` I0
5/15/2023
RAM Engineering 19109 3611 Ave W, Suite 100 Lynnwood WA 98036 (425) 678-6960 RAMengineeringinc.com