7263 20190410 POSTDEV Type IA 24-hr Flood Control Rainfall=3.60" <br />Prepared by AKS Engineering & Forestry, LLC Printed 5/2/2019 <br />HydroCAD® 10.00-20 s/n 05097 © 2017 HydroCAD Software Solutions LLC Page 3 <br />Summary for Subcatchment Post-Dev: Post-Dev <br />Runoff = 0.60 cfs @ 7.92 hrs, Volume= 0.207 af, Depth= 2.37" <br />Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-36.00 hrs, dt= 0.05 hrs <br />Type IA 24-hr Flood Control Rainfall=3.60" <br />Area (sf) CN Description <br />31,305 <br />98 <br />Paved parking, HSG A <br />6,510 <br />49 <br />50-75% Grass cover, Fair, HSG A <br />7,850 <br />49 <br />50-75% Grass cover, Fair, HSG A <br />45,665 <br />83 <br />Weighted Average <br />14,360 <br />49 <br />31.45% Pervious Area <br />31,305 <br />98 <br />68.55% Impervious Area <br />Tc Length Slope Velocity Capacity Description <br />(min) (feet) (ft/ft) (ft/sec) (cfs) <br />6.0 Direct Entry, <br />Inflow Area = 1.048 ac, <br />Inflow = 0.60 cfs @ <br />Outflow = 0.60 cfs @ <br />Discarded = 0.06 cfs @ <br />Primary = 0.53 cfs @ <br />Summary for Pond RG: Raingarden <br />58.55% Impervious, Inflow Depth = 2.37" for Flood Control event <br />7.92 hrs, Volume= 0.207 of <br />7.96 hrs, Volume= 0.207 af, Atten= 0%, Lag= 2.6 min <br />7.96 hrs, Volume= 0.120 of <br />7.96 hrs, Volume= 0.086 of <br />Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs / 2 <br />Peak Elev= 407.59'@ 7.96 hrs Surf.Area= 1,383 sf Storage= 639 cf <br />Plug-Flow detention time= 76.0 min calculated for 0.207 of (100% of inflow) <br />Center-of-Mass det. time= 76.1 min ( 751.5 - 675.4 ) <br />Volume Invert <br />Avail.Storage Storage Description <br />#1 407.00' <br />1,307 cf Custom Stage Data (Irregular) Listed below (Recalc) <br />Elevation Su <br />rf.Area Perim. Inc.Store Cum.Store Wet.Area <br />(feet) <br />(sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) <br />407.00 <br />815 330.0 0 0 815 <br />408.00 <br />1,870 369.0 1,307 1,307 3,012 <br />Device Routing <br />Invert Outlet Devices <br />#1 Discarded <br />407.00' 2.000 in/hr Exfiltration over Surface area Phase-In= 0.01' <br />#2 Device 3 <br />407.50' 24.0" Horiz. Orifice/Grate C= 0.600 <br />Limited to weir flow at low heads <br />#3 Primary <br />406.11' 6.0" Round Culvert L= 22.3' RCP, sq.cut end projecting, Ke= 0.500 <br />Inlet/ Outlet Invert= 406.11'/405.14' S=0.0435'/' Cc= 0.900 <br />n=0.013, Flow Area= 0.20 sf <br />