J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 NJ DEP 2-hr NJDEP Rainfall=1.25" Prepared by TRC Engineers, Inc. HydroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Printed 3/4/2012 Page 74 Summary for Subcatchment 7S: EX-DA 7 Runoff = 1.20 c f s @ 1.16 hrs, Volume= Runoff by SCS TR-20 method, NJ DEP 2-hr NJDEP Rainfall=1.25" UH=SCS, Split 0.040 af, Depth= 0.20" Pervious/lmperv., Area (sf) CN Description 805 2,198 10,157 86,177 5.402 98 98 85 80 73 Impervious, HSG D Gravel road, HSG D Yard stone, HSG D >75% Grass cover, Good, HSG D Brush, Good, HSG D 104,739 101,736 3,003 81 80 98 Weighted Average 97.13% Pervious Area 2.87% Impervious Area * ★ * Tc (min) Length (feet) 4.5 70 Slope Velocity Capacity (ft/ft) (ft/sec) Time Span= 0.00-30.00 hrs, Description (cfs) Sheet Flow, 0.1600 0.26 Grass: Dense n= 0.240 P2= 3.42" 0.8 70 0.0857 1.46 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 2.4 310 0.0200 2.12 7.7 450 Total Shallow Concentrated Flow, Grassed Waterwav Kv= 15.0 fps Subcatchment 7S: EX-DA 7 Hydrograph -— -—i------- 1—r ------- :----- 1---- 1---- r d .20 cfs NJ! DEP 2-hr NJDEP .-i-.jJ.-j-.j. Rainfall=1.25^' Runoff Area=104,739 sf Runoff Volume=0.040 af Runoff Depth=0.20" : Flow Length-450' iiiiii itii Tc=7L7 min CN=80/98 x / X 2 0 1 2 34 n 56 78 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) dt= 0.01 hrs