J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 Prepared by TRC Engineers, Inc. NJ DEP 2-hr NJDEP Rainfall=1.25" Printed 3/4/2012 Page 69 HydroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EX-DA 3 Runoff = 3.97 cfs @ 1.12 hrs, Volume= Runoff by SCS TR-20 method, NJ DEP 2-hr NJDEP Rainfall=1.25" UH=SCS, Split 0.116 af, Depth= 0.49" Pervious/lmperv., Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Area (sf) CN Description * ★ * * 3,042 35,019 29,686 30,906 26,372 98 98 91 80 78 Impervious, HSG D Gravel road, HSG D Gravel, HSG D Grass, Good, HSG D Meadow, non-grazed, HSG D 125,025 86,964 38,061 88 83 98 Weighted Average 69.56% Pervious Area 30.44% Impervious Area Tc (min) Length (feet) 4.0 150 0.0070 0.63 1.6 350 0.0600 3.67 5.6 500 Total, Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Sheet Flow, Gravel Storage Area n= 0.020 P2= 3.42" Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps Increased to minimum Tc = 6.0 min Subcatchment 3S: EX-DA 3 Hydrograph I^RunoffJ 97 cfs 72 / _j / _ _ L _ J _ __ _L_J /■ i Flow Length=500’ ' - 0 1 2 3 f 4 56 7 8 r ; NJ DEP 2-hr NJDEP Rainfall=1.25" Runoff Area=125,025 sf Runoff Volume=0.116 af Runoff Depth=0.49" r Tc=6.0 min 4 - 4 4 - 4 CN=83/98 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours)