2026-02 Existing and Proposed Prepared by Dynamic Engineering HydroCAD\circledR 10.20-8a s/n 08640 © 2025 HydroCAD Software Solutions LLC NOAA 24-hr D 2-Year-Current Rainfall=3.42" Printed 2/10/2026 Page 9
Link 18L: Study Area Road Undetained (Total) Inflow=0.06 cfs 0.008 af Primary=0.06 cfs 0.008 af
Total Runoff Area = 2.340 ac Runoff Volume = 0.232 af Average Runoff Depth = 1.19' 62.82% Pervious = 1.470 ac 37.18% Impervious = 0.870 ac
2026-02 Existing and Proposed Prepared by Dynamic Engineering HydroCAD\circledR 10.20-8a s/n 08640 © 2025 HydroCAD Software Solutions LLC NOAA 24-hr D 2-Year-Current Rainfall=3.42" Printed 2/10/2026 Page 10
| Summary for Subcatchment 3S: Ex. Study Area West (Perv) | ||
| Runoff = | 0.00 cfs @ | 24.00 hrs, Volume= |
|---|---|---|
| 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-Current Rainfall=3.42"
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)