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 HvdroCAD Software Solutions LLC Printed 3/4/2012 Page 77 Summary for Subcatchment 9B: EX-DA 9B Runoff = 1.03 cfs @ 1.42 hrs, Volume= Runoff by SCS TR-20 method, NJ DEP 2-hr NJDEP Rainfall=1.25" UH=SCS, Split 0.061 af, Depth= 0.70" Pervious/lmperv., Time Span= 0.00-30.00 hrs, Area (sf) CN Description * * 24,703 670 20,336 98 Impervious, HSG D 91 Gravel, HSG D 85 Yard stone, HSG D 45,709 21,006 24,703 92 Weighted Average 85 45.96% Pervious Area 98 54.04% Impervious Area Tc (min) Length (feet) Slope Velocity Capacity (ft/ft) (ft/sec) 30.0 150 0.0070 0.08 Sheet Flow, Yard Stone 1.0 160 0.0190 2.80 Shallow Concentrated Flow, 31.0 310 Total h Description (cfs) n= 0.250 P2= 3.42" Paved Kv= 20.3 fps Subcatchment 9B: EX-DA 9B Hydrograph -i-------- 1----- i------ :----- •------ r -!—i---------- 1—r r 1.03 cfs NJ DEP 2-hr NJDEP ; Rainfall=1.25" Runoff Area=45,709 sf HuiddfHv'olume=0.0$1! af Runoff Depth=0.70V Flow Length=310' Tc=31.0 min CN=85/98 a 23 4 56 7 8 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