SW6210503_Design Calculations (CN)_20211222

1651 Townsend Estates
Wet Pond #1
SCS curve number
Hydraulic Soi Group: A
Area
SCS CN
Used 54.5 lots within DA @ 4100 per lot
Building (sf)
223,450
98
Sidewalk (sf)
15,433
98
1 mpervious
344,472
Pavement (sf)
90,844
98
Total DA
735,826
Pond (sf)
14,745
98
% Imper
46.81%
Open space (sf)
391,354
54
Offsite -open space (sf)
0
54
Total (sf)
735826
75
Total (ac)
16.89
Rational Coefficient
Pre -development
Post -development
Area
C
Area
Building (sf)
60,588
0.95
Building (sf)
223,450
Sidewalk (sf)
0
0.95
Sidewalk (sf)
15,433
Pavement (sf)
0
0.95
Pavement (sf)
90,844
Open space (sf)
675,238
0.30
Pond (sf)
14,745
Offsite -open space (sf)
0
0.40
Open space (sf)
391,354
Offsite -open space (sf)
0
Total (sf)
735826
0.35
Total (ac)
16.89
Total (sf)
735826
Total (ac)
16.89
C
0.95
0.95
0.95
0.95
0.36
0.40
0.64
1651 Coefficient.xls Printed 12/22/2021