J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 Type III 24-hr 10yr Rainfall=5.21" Prepared byTRC Engineers, Inc. Printed 3/4/2012 Page 26 HydroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EX-DA 3 Runoff = 12.28 cfs @ 12.09 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 10 yr Rainfall=5.21" h * ★ * UH=SCS, Split 0.922 af, Depth= 3.85" Pervious/lmperv., 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 Time Span= 0.00-30.00 Tc (min) Length (feet) 4.0 150 0.0070 0.63 Sheet Flow, Gravel Storage Area 1.6 350 0.0600 3.67 Shallow Concentrated Flow, hrs, Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) n= 0.020 P2= 3.42" Grassed Waterway Kv= 15.0 fps 5.6 500 Total, Increased to minimum Tc = 6.0 min Subcatchment 3S: EX-DA 3 i--r 12 28 cfs i 12 Hydrograph I--i i------ i----- 1 "I / L- i__ J- _ 10 ✓ . 1. J _ J / —8 r r l 7- _ 1 ____ I ___ I ___• L . i— r 4 5 6 7 Type: III 24*hr 10 yr Rainfall=5.21V Runoff Area=125,025 sf Runoff; Volume=0.922 af : ! Runoff Depth=3.85':' "T tlow Length-500' Tc=6.0 min CN=83/98 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) ___ ■ _ L _ r - r —i — .. L _ ! _ I r-i dt= 0.01 hrs