Analysis - Proposed Conditions NOAA 24-hr D 2 YR-C Rainfall=3.42" Prepared by Civil Core Consulting Printed 12/19/2025 HydroCAD® 10.20-8a s/n 13637 © 2025 HydroCAD Software Solutions LLC Page 61

Summary for Pond 33P: INFILTRATION BASIN 2

Inflow Area = 27,007 sf, 30.65% Impervious, Inflow Depth > 0.97" for 2 YR-C event

Inflow = 0.14 cfs @ 12.47 hrs, Volume= 2,194 cf

Outflow = 0.08 cfs @ 14.24 hrs, Volume= 2,194 cf, Atten= 41%, Lag= 106.1 min

Discarded = 0.08 cfs @ 14.24 hrs, Volume= 2,194 cf

Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf

Routed to Link 33L : POA 2

Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs

Peak Elev= 92.12' @ 14.24 hrs Surf.Area= 704 sf Storage= 286 cf

Plug-Flow detention time= 26.8 min calculated for 2,194 cf (100% of inflow)

Center-of-Mass det. time= 26.8 min ( 895.5 - 868.7 )

Volume Invert Avail.Storage Storage Description

#1 91.65' 4,378 cf Custom Stage Data (Prismatic)Listed below (Recalc)

Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet)

91.65 520 0 0

92.00 651 205 205

93.00 1,094 873 1,077

94.00 1,629 1,362 2,439

95.00 2,249 1,939 4,378

Device Routing Invert Outlet Devices

#1 Device 3 93.65' 2.5" Vert. Orifice C= 0.600 Limited to weir flow at low heads

L= 17.0' RCP, groove end projecting, Ke= 0.200

#2 Device 3 94.70' 48.0" x 48.0" Horiz. Grate C= 0.600

#3 Primary 93.65' 12.0" Round Culvert

Inlet / Outlet Invert= 93.65' / 93.50' S= 0.0088 ' /' Cc= 0.900

n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf

#4 Discarded 91.65' 4.950 in/hr Exfiltration over Surface area Phase-In= 0.01'

Discarded OutFlow Max=0.08 cfs @ 14.24 hrs HW=92.12' (Free Discharge)

4=Exfiltration (Exfiltration Controls 0.08 cfs)

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=91.65' TW=0.00' (Dynamic Tailwater)

3=Culvert ( Controls 0.00 cfs)

1=Orifice ( Controls 0.00 cfs)

2=Grate ( Controls 0.00 cfs)

Pond 33P: INFILTRATION BASIN 2