J_2024 05 09_West Orange Stormwater Management Plan

Type III 24-hr 2 yr Rainfall=3.42" Printed 3/4/2012 Page 5 Pre-Development West Orange with ponds 2 Prepared by TRC Engineers, Inc. HydroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EX-DA 3 Runoff = 7.09 cfs @ 12.09 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 2 yr Rainfall=3.42" UH=SCS, Split 0.530 af, Depth= 2.22" Pervious/lmperv., Time Span= 0.00-30.00 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-qrazed, 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) Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 4.0 150 0.0070 0.63 Sheet Flow, Gravel Storage Area 1.6 350 0.0600 3.67 Shallow Concentrated Flow, 5.6 500 Total, n= 0.020 P2= 3.42" Grassed Waterway Kv= 15.0 fps Increased to minimum Tc = 6.0 min Subcatchment 3S: EX-DA 3 Hydrograph —i—i—i—i---- i—i iitii• • j_- 9 cfs 7 !/ /' 2 01 2 34 56 78 Type III 24-hr 2 yr H ; J Rainfall=3.42" Runoff Area=125,025 sf Runoff Volume=0.530 af : : Runoff Depth=2.22M : Flow Length=500‘ • : :Tc=6.0 min 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) dt= 0.01 hrs