Runoff = 0.01 cfs @ 17.02 hrs, Volume= 0.004 af, Depth= 0.05" Routed to Link 5L : Ex Study Area West (Total)
Runoff by SCS TR-20 method, UH=Delmarva, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 2-Year-Projected Rainfall=4.04"
Area (ac) CN Description
0.930 39 >75% Grass cover, Good, HSG A
0.930 39 100.00% Pervious Area
Tc (min) Length (feet) Slope (ft/ft) Velocity (ft/sec) Capacity (cfs) Description
8.4 47 0.0350 0.09 Sheet Flow, A-B Woods: Light underbrush n= 0.400 P2= 4.04" Using McCuen-Spiess flow length
0.4 51 0.0200 2.28 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps
8.8 98 Total, Increased to minimum Tc = 10.0 min
Subcatchment 3S: Ex. Study Area West (Perv)
| 2026-02 Existing and Proposed | NOAA 24-hr D 2-Year-Projected Rainfall=4.04" |
|---|---|
| Prepared by Dynamic Engineering | Printed 2/10/2026 |
| HydroCAD\circledR 10.20-8a s/n 08640\circledC 2025 HydroCAD Software Solutions LLC | Page 32 |
Runoff = 0.23 cfs @ 12.19 hrs, Volume= 0.029 af, Depth= 3.81" Routed to Link 5L : Ex Study Area West (Total)
Runoff by SCS TR-20 method, UH=Delmarva, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 2-Year-Projected Rainfall=4.04"
Area (ac) CN Description
0.040 98 Paved parking, HSG A
0.050 98 Roofs, HSG A
0.090 98 Weighted Average
0.090 98 100.00% Impervious Area
Tc (min) Length (feet) Slope (ft/ft) Velocity (ft/sec) Capacity (cfs) Description
0.9 100 0.0300 1.82 Sheet Flow, A-B
1.1 148 0.0200 2.28 Smooth surfaces n= 0.011 P2= 4.04"
Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps
2.0 248 Total, Increased to minimum Tc = 10.0 min
Subcatchment 4S: Ex. Study Area West (Imp)