J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 Type III 24-hr 100 yr Rainfall=8.72" Prepared byTRC Engineers, Inc. HvdroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Printed 3/4/2012 Page 47 Summary for Subcatchment 3S: EX-DA 3 Runoff = 22.59 cfs @ 12.08 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 100 yr Rainfall=8.72" UH=SCS, 1.727 af, Depth= 7.22" Split Pervious/lmperv., Time Span= 0.00-30.00 hrs, dt= 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) 4.0 150 0.0070 0.63 1.6 350 0.0600 3.67 5.6 500 Total, Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Sheet Flow, Gravel Storage Area n= 0.020 P2= 3.42" Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps Increased to minimum Tc = 6.0 min Subcatchment 3S: EX-DA 3 Hydrograph I i - .I . t I l. . l. . J — I ---------E ---- I ---- 7 - — — J l. i - J - -•--1 2423r . _ i __ 22-: I __ I__ _____ I 21 i ;i: 20j _ _ L_____ I . . 1 . 22.59 cfs - r—r-*t - ri 19 i 18*: 17i 16-: 15-; , £ 143 13-: I 12i Li. 11- 10-; 9-i 94 L — -i - 7:. 6: ; • , _ J . 3-i - 1. .. L . J. ____ 3 4 5 67 8 .1 - - L _ J . _ _ L _ 1 . ________________________I ____L _ J _________ ............................. I' 2 III - - i — r - t --------------------1 — p - r — i ------------------- 1 — i — i - ~ i — 2i 1-1 1 L - J. J_. Type III 24-hr 100 yr : Rainfall=8.72" Runoff Area=125,025 sf Runoff Volume=1.727 af :i: Runoff Depth=7.22" Flow Length=^500' Tc=6.0 niin CN=83/98 . I--- 5-; 4i II -m-\ * 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) - 0.01 hrs