POST DEV NOAA 24-hr D 100 YEAR Rainfall=9.48" Prepared by Professional Design Services Printed 12/31/2025 HydroCAD® 10.20-6a s/n 02223 © 2024 HydroCAD Software Solutions LLC Page 79
Summary for Subcatchment 6S: POROUS
Runoff = 0.18 cfs @ 12.27 hrs, Volume= 0.025 af, Depth> 1.57" 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 100 YEAR Rainfall=9.48"
Area (ac) CN Description
0.190 39 >75% Grass cover, Good, HSG A
0.190 100.00% Pervious Area
Tc (min) Length (feet) Slope (ft/ft) Velocity (ft/sec) Capacity (cfs) Description
11.3 90 0.0270 0.13 Sheet Flow, Grass: Dense n= 0.240 P2= 3.42" Shallow Concentrated Flow, Paved Kv= 20.3 fps
1.1 160 0.0150 2.49
12.4 250 Total
Subcatchment 6S: POROUS