SW6240102_Design Calculations_20240507 (6)

Raeford Vass Rd DG
Infiltration Basin
SCS curve number
Hydraulic Soil Group : A
Area SCS CN
Building(sf) 10,831 98 10,831
Sidewalk(sf) 98
Pavement(sf) 27,230 98 35,368
Pond(sf) 98
Open space(sf) 25,398 49 30,599
Offsite-open space(sf) 69
Offsite-impervious(sf) 9,897 98
Total(sf) 73356 81 76798
Total(ac) 1.68 1.76
Rational Coefficient
Pre-development Post-development
Area C Area C
Building(sf) 0.95 Building(sf) 10,831 0.95
Sidewalk(sf) 0.95 Sidewalk(sf) 0.95
Pavement(sf) 0.95 Pavement(sf) 27,230 0.95
Open space(sf) 63,459 0.25 Pond(sf) 0.95
Offsite-open space(sf) 0.40 Open space(sf) 25,398 0.30
Offsite-impervious(sf) 9,897 0.95 Offsite-open space(sf) 0.30
Offsite-impervious(sf) 9,897 0.95
Total(sf) 73356 0.34
Total(ac) 1.68 Total(sf) 73356 0.72
Total(ac) 1.68
2019-Runnoff coefficient calcs.xls Printed 5/7/2024