J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 Prepared by TRC Engineers, Inc. HydroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Type III 24-hr 100 yr Rainfall=8.72" Printed 3/4/2012 Page 53 Summary for Subcatchment 8S: EX-DA 8 Runoff = 5.04 cfs @ 12.37 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 100 yr Rainfall=8.72" UH=SCS, 0.665 af, Depth= 7.44" Split Pervious/lmperv., Time Span= 0.00-30.00 hrs, Area (sf) CN Description * * # 15,912 29,261 1.535 98 Impervious, HSG D 85 Yard stone, HSG D 80 Grass, Good, HSG D 46,708 30,796 15,912 89 Weighted Average 85 65.93% Pervious Area 98 34.07% Impervious Area Tc (min) Length (feet) 25.5 80 0.0030 0.05 Sheet Flow, Yard stone 0.5 80 0.0170 2.65 Shallow Concentrated Flow, 2.2 165 0.0060 1.25 Shallow Concentrated Flow, Yard Stone 0.2 60 0.0580 4.89 28.4 385 Total Slope Velocity Capacity (ft/ft) (ft/sec) Description (cfs) n= 0.250 P2= 3.42" Paved Kv= 20.3 fps Unpaved Kv= 16.1 fps Shallow Concentrated Flow, Paved Kv= 20.3 fps Subcatchment 8S: EX-DA 8 Hydrograph L I 5.04 Cfs I « 3 i 01 2 34 56 78 r - r i r r : Type ill 24-hr 100 yr : : Rainfall=8.72" Runoff Area=46,708 sf RunoffVolume=0.665 af I Runoff Depth=7.44" Flow Length=385‘ n : \ ; Tc=28.4min CN=85/98 “f'j i i 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