2022 08 Drainage Report

2022-07-28 Proposed Hydrology NOAA 24-hr D 10-Year Rainfall=6,22" Prepared by Dynamic Engineering Printed 8/5/2022 HydroCAD® 10.20-2d_sin 08840 © 2021 HydroCAD Software Solutions LLC ‘Summary for Pond 4P: Basin B Inflow Area = 0.831 ac, 12.83% Impervious, Inflow Depth = 2.85" for 10-Year event Inflow = = 227 cfs@ 12.18hrs, Volume= 0.198 af Outflow = 0.30 cfs@ 13.18 hrs, Volume= 0.096 af, Atten= 87%, Lag= 58.7 min Primary = 0.30 cfs @ 13.15 hrs, Volume= 0.096 af Routed to Link 2L : Mt. Pleasant Ave. Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs. Peak Elev= 623.95 @ 13.15 hrs Surf.Area= 3,118 sf Storage= 4,910 cf Plug-Flow detention time= 314.2 min calculated for 0.096 af (48% of inflow) Center-of-Mass det. time= 177.5 min ( 1,005.2 - 827.7 ) Volume Invert___Avail.Storage Storage Description a 622.00" 8,561 of |Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Ine.Store Cum.Store (feet) {sq-ft) (cubic-feet) (cubic-feet) 622.00 1,951 0 0 623.00 2,519 2,235 2,235 624.00 3,150 2,835 5,070 625.00 3,833 3,492 8,561 Device Routing Invert__Outlet Devices #1 Primary 623.80' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads imary OutFlow Max=0.30 cfs @ 13.15 hrs HW=623.95' (Free Discharge) =Orifice/Grate (Weir Controls 0.30 cfs @ 1.26 fps) 2022-07-28 Proposed Hydrology NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Dynamic Engineering Printed 8/5/2022 HydroCAD® 10.20-2d sin 08640 © 2021 HydroCAD Software Solutions LLC Page 86 Pond 4P: Basin B Hydrograph es) Inflow Area=0.831 ac Peak Elev=623.95" Storage=4,910 cf Flow (fs) ° O° GG vO te Tato Wea a as 8 28-9: 6 3 98.40.4244 4 8 9 2 4 8 8 0 620460687072 Pond 4P: Basin B ‘Stage-Discharge Elevation (fest) Discharge (cfs)