POST DEV NOAA 24-hr D 10 YEAR Rainfall=5.38" Prepared by Professional Design Services Printed 12/31/2025 HydroCAD® 10.20-6a s/n 02223 © 2024 HydroCAD Software Solutions LLC Page 38
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 > 2.70" for 10 YEAR event
Inflow =2.16 cfs @ 12.22 hrs, Volume= 0.290 af
Outflow =1.05 cfs @ 12.67 hrs, Volume= 0.209 af, Atten= 51%, Lag= 26.5 min
Discarded =0.10 cfs @ 12.67 hrs, Volume= 0.089 af
Primary =0.95 cfs @ 12.67 hrs, Volume= 0.120 af
Routed to Reach 10 : COMPOSITE
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 112.02' @ 12.67 hrs Surf.Area= 3,217 sf Storage= 5,118 cf
Plug-Flow detention time = 129.4 min calculated for 0.208 af (72% of inflow) Center-of-Mass det. time = 59.2 min (812.0 - 752.7)
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=0.10 cfs @ 12.67 hrs HW=112.02' (Free Discharge) 1=Exfiltration (Controls 0.10 cfs)
Primary OutFlow Max=0.95 cfs @ 12.67 hrs HW=112.02' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.95 cfs @ 2.84 fps) 3=Orifice/Grate (Controls 0.00 cfs)