J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 19 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 21S: PO-DA 1 Runoff = 4.81 cfs @ 12.11 hrs, Volume= Routed to Pond 21P : O-2 0.327 af, Depth> 3.24" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" * Area (sf) 7,888 19,498 2,304 23,117 52,807 44,919 7,888 CN 98 80 85 73 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Brush, Good, HSG D Weighted Average 85.06% Pervious Area 14.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 23 0.0352 1.33 Sheet Flow, Sheet Flow Smooth surfaces n= 0.011 P2= 3.45" 0.2 31 0.2437 2.47 Shallow Concentrated Flow, Shallow Concentrated Flow Woodland Kv= 5.0 fps 3.2 287 0.0462 1.50 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 3.7 341 Total