POST DEV NOAA 24-hr D 2 YEAR Rainfall=3.42" Prepared by Professional Design Services Printed 12/31/2025 HydroCAD® 10.20-6a s/n 02223 © 2024 HydroCAD Software Solutions LLC Page 15
Summary for Pond 3P: SSIB #1 SURFACE BASIN
[82] Warning: Early inflow requires earlier time span
Inflow Area = 1.290 ac, 55.81% Impervious, Inflow Depth > 1.63" for 2 YEAR event Inflow = 1.36 cfs @ 12.22 hrs, Volume= 0.175 af Outflow = 0.28 cfs @ 13.18 hrs, Volume= 0.104 af, Atten= 79%, Lag= 57.6 min Discarded = 0.09 cfs @ 13.18 hrs, Volume= 0.081 af Primary = 0.19 cfs @ 13.18 hrs, Volume= 0.023 af Routed to Reach 10 : COMPOSITE Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 111.65' @ 13.18 hrs Surf.Area= 2,939 sf Storage= 3,983 cf Plug-Flow detention time= 167.6 min calculated for 0.104 af (59% of inflow) Center-of-Mass det. time= 81.6 min ( 831.1 - 749.5 )
VolumeInvertAvail.StorageStorage Description
#1110.00'12,950 cfCustom Stage Data (Prismatic)Listed below (Recalc)
Elevation (feet)Surf.Area (sq-ft)Inc.Store (cubic-feet)Cum.Store (cubic-feet)
110.002,00000
111.002,4502,2252,225
112.003,2002,8255,050
113.004,0003,6008,650
114.004,6004,30012,950
DeviceRoutingInvertOutlet Devices
#1Discarded110.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 106.00'
#2Primary111.50'12.0" W x 4.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads
#3Primary113.00'24.0" x 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads
Discarded OutFlow Max=0.09 cfs @ 13.18 hrs HW=111.65' (Free Discharge) 1=Exfiltration (Controls 0.09 cfs)
Primary OutFlow Max=0.19 cfs @ 13.18 hrs HW=111.65' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.19 cfs @ 1.25 fps) 3=Orifice/Grate (Controls 0.00 cfs)