OCSCD NOAA 24-hr D 2 YEAR Rainfall=3.42" Prepared by Professional Design Services Printed 12/31/2025 HydroCAD® 10.20-6a s/n 02223 © 2024 HydroCAD Software Solutions LLC Page 9
Summary for Subcatchment 5S: IMPERVIOUS
Runoff = 0.93 cfs @ 12.08 hrs, Volume= 0.066 af, Depth> 2.92" Routed to Pond 8P : SSIB #2 UNDERGROUND
Runoff by SCS TR-20 method, UH=Delmarva, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs NOAA 24-hr D 2 YEAR Rainfall=3.42"
Area (ac) CN Description
0.270 98 Roofs, HSG A
0.270 100.00% Impervious Area
Tc (min) Length (feet) Slope (ft/ft) Velocity (ft/sec) Capacity (cfs) Description
0.9 50 0.0100 0.94 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.42"
0.7 130 3.00 Direct Entry, PIPE FLOW
1.6 180 Total
Subcatchment 5S: IMPERVIOUS