2022 08 Drainage Report

2022-07-28 Proposed Hydrology NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Dynamic Engineering Printed 8/5/2022 HydroCAD® 10.20-2d s/n 08640 © 2021 HydroCAD Software Solutions LLC 4 Summary for Pond 3P: Basin A Inflow Area = 0.669 ac, 15.97% impervious, Inflow Depth= 5.98" for 100-Year event Inflow = 3.80 cfs @ 12.17 hrs, Volume= 0.334 af Outflow = 0.77 cfs @ 12.67 hrs, Volume= 0.217 af, Atten= 60%, Lag= 29.7 min Primary = 0.77 cfs@ 12.67 hrs, Volume= 0.217 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= 626.67’ @ 12.67 hrs Surf.Area= 3,608 sf Storage= 7,334 of Plug-Flow detention Center-of-Mass det. 2= 234.6 min caloulated for 0.217 af (65% of inflow) 1@= 122.5 min ( 929.3 - 806.8 ) Volume. Invert___Avail.Storage Storage Description ca] 624.00" 8,561 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store {feet) (sq-ft) (cubic-feet) (cubic-feet) 624.00 1,951 0 625.00 2.519 2,235 2,235 626.00 3,150 2,835 5,070 627.00 3,833 3,492 8,561 Device Routing invert__Outlet Ds #1 Primary 626.00' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads rimary OutFlow Max=0.77 cfs @ 12.67 hrs HW=626.67' (Free Discharge) '=Orifice/Grate (Orifice Controls 0.77 cfs @ 3.94 fps) 2022-07-28 Proposed Hydrology NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Dynamic Engineering Printed 8/5/2022 Hy 10.20-2d s/n 08640 © 2021 HydroCAD Software Solutions LLC Pond 3P: Basin A Hydrograph Flow (cts) O24 6 6 10.12 a a to 20204 0 28 2022 9 2838 40 244404 5 2 488 860 62 OH 686 70 72 ime (hour) Pond 3P: Basin A Stage-Discharge Elevation (Foot) 624- 0 00s O1 O01 O2 G2 03 035 O4 O45 O05 O85 06 OOS O7 OFS 00 ONS 09 Diacharge (fs)