20221160 Ver 1_Post Hydrology_20221026

BAYBERRY
DRB21001
HYDROLOGY
Culvert #1 Drainage Area
S. SARMADI
10/27/2022
I. SCS CURVE NUMBERS
HSG Commercial 1/8 acre 1/6 acre 1/3 acre
A 89 77 72 57
B 92 85 82 72
C 94 90 88 81
D 95 92 90 86
Assume:HSG 'A' =10.2%
HSG 'B' =15.7%
HSG 'C' =0.0%
HSG 'D' =74.1%
Cover Condition SCS CN
Commercial 94
Residential -1/8 acre 89
Residential - 1/6 acre 87
Residential - 1/3 acre 81
II. POST-DEVELOPMENT
A. Watershed Breakdown
Contributing Area SCS CN Area [sf]Area [acres]
Commercial 94 0 0.00
Residential - 1/8 acre 89 0 0.00
Residential - 1/6 acre 87 0 0.00
Residential - 1/3 acre 81 1,380,325 31.69
Total area =31.69 acres
1,380,325 sq.ft.
Composite SCS CN =81
B. Time of Concentration Information
Time of concentration is calculated using the Kirpich Method.
Length =1129.32 ft
Top Elev =526
Bot Elev =494
Height =32 ft
Slope =0.0283 ft/ft
Surface Roughness Factor =1.00
Segment Time =6.90 minutes
Time of Concentration =6.90 minutes
SCS Lag Time =4.14 minutes (SCS Lag = 0.6* Tc)
Time Increment =1.20 minutes (= 0.29*SCS Lag)
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Residential
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Comments
Comments
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BAYBERRY
DRB21001
HYDROLOGY
Culvert #1 Drainage Area
S. SARMADI
10/27/2022