2026-02 Existing and Proposed NOAA 24-hr D 100-Year-Current Rainfall=9.48" Prepared by Dynamic Engineering Printed 2/10/2026 HydroCAD® 10.20-8a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 95
Summary for Subcatchment 4S: Ex. Study Area West (Imp)
Runoff = 0.54 cfs @ 12.19 hrs, Volume= 0.069 af, Depth= 9.24" 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 100-Year-Current Rainfall=9.48"
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
2.0 248 Total. Increased to minimum Tc = 10.0 min
Subcatchment 4S: Ex. Study Area West (Imp)
2026-02 Existing and ProposedNOAA 24-hr D100-Year-CurrentRainfall=9.48''
Prepared by Dynamic EngineeringPrinted2/10/2026
HydroCAD\circledR 10.20-8a s/n 08640© 2025 HydroCAD Software Solutions LLCPage 96
Summary for Subcatchment 6S: Ex. Study Area Road (Imp)
Runoff = 0.18 cfs @ 12.19 hrs, Volume= 0.023 af, Depth= 9.24" Routed to Link 8L : Existing Study Area Road (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 100-Year-Current Rainfall=9.48"
Area (ac) CN Description
0.030 98 Paved parking, HSG A
0.030 98 100.00% Impervious Area
Tc (min) Length (feet) Slope (ft/ft) Velocity (ft/sec)
1.0 82 0.0150 1.32
Sheet Flow, A-B
Smooth surfaces n= 0.011
P2= 4.04"
1.0 82 Total, Increased to minimum Tc = 10.0 min
Subcatchment 6S: Ex. Study Area Road (Imp)