J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 Prepared by TRC Engineers, Inc. Type III 24-hr 10 yr Rainfall=5.21" Printed 3/4/2012 Page 31 HydroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: EX-DA 7 Runoff = 8.27 cfs @ 12.11 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 10 yr Rainfall=5.21" UH=SCS, Split 0.627 af, Depth= 3.13" Pervious/lmperv., Time Span= 0.00-30.00 hrs, dt= 0.01 Area (sf) CN Description * * * 805 2,198 10,157 86,177 5,402 98 Impervious, HSG D 98 Gravel road, HSG D 85 Yard stone, HSG D 80 >75% Grass cover, Good, HSG D 73 Brush, Good, HSG D 104,739 101,736 3,003 81 Weighted Average 80 97.13% Pervious Area 98 2.87% Impervious Area Tc (min) Length (feet) 4.5 70 0.1600 0.26 0.8 70 0.0857 2.4 310 0.0200 2.12 7.7 450 Total Slope Velocity Capacity (ft/ft) (ft/sec) Description (cfs) Sheet Flow, Grass: Dense n= 0.240 P2= 3.42" Shallow Concentrated Flow, 1.46 Woodland Kv= 5.0 fps Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps Subcatchment 7S: EX-DA 7 Hydrograph i—i—i—i—i—i—r A | ■ Runoff| 9- 8.27 cfs III■Iv 87- ---L _ J---I---•_ 6- I u. 4- 3- 21 _I . . Type III 24-hr 10 yr - : r Rainfall=5.21" Runoff Area=104,739 sf Runoff; Volumo=0.627 af Runoff Depth=3.13" : i Flow Length=450' Tc=7i7 min CN=80/98 i - J-----------1------I------ 1 o-H 0 1 2 3 4 5 6 7 8 9 tTTnrrrT, r™T 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) hrs