POST DEV NOAA 24-hr D 10 YEAR Rainfall=5.38" Prepared by Professional Design Services Printed 12/31/2025 HydroCAD® 10.20-6a s/n 02223 © 2024 HydroCAD Software Solutions LLC Page 30
Summary for Subcatchment 1S: POROUS
Runoff = 0.03 cfs @ 13.03 hrs, Volume= 0.010 af, Depth> 0.21" Routed to Pond 3P : SSIB #1 SURFACE BASIN
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 10 YEAR Rainfall=5.38"
Area (ac) CN Description
0.570 39 >75% Grass cover, Good, HSG A
0.570 100.00% Pervious Area
Tc (min) Length (feet) Slope (ft/ft) Velocity (ft/sec) Capacity (cfs) Description
11.7 100 0.0300 0.14 Sheet Flow, Grass: Dense n= 0.240 P2= 3.42"
0.3 50 0.0350 2.81 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps
0.9 160 3.00 Direct Entry, PIPE FLOW
12.9 310 Total
Subcatchment 1S: POROUS