Analysis - Proposed Conditions NOAA 24-hr D 100 YR-C Rainfall=9.48" Prepared by Civil Core Consulting Printed 12/19/2025 HydroCAD® 10.20-8a s/n 13637 © 2025 HydroCAD Software Solutions LLC Page 327

Summary for Pond 8P: INFILTRATION BASIN 3

Inflow Area =38,333 sf,22.73% Impervious,Inflow Depth = 3.49" for 100 YR-C event
Inflow =1.59 cfs @12.15 hrs,11,133 cf
Outflow =0.34 cfs @13.49 hrs,11,133 cf,Atten= 79%, Lag= 80.4 min
Discarded =0.27 cfs @11.94 hrs,10,720 cf
Primary =0.07 cfs @13.49 hrs,413 cf
Routed to Link 34L : POA 3

Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 93.06' @ 13.49 hrs Surf.Area= 1,150 sf Storage= 2,655 cf

Plug-Flow detention time=77.2 min calculated for 11,133 cf (100% of inflow) Center-of-Mass det. time=77.2 min (944.1 - 866.9)

VolumeInvertAvail.StorageStorage Description
#190.75'4,888 cfCustom Stage Data (Prismatic)Listed below (Recalc)
Elevation (feet)Surf.Area (sq-ft)Inc.Store (cubic-feet)Cum.Store (cubic-feet)
90.75 95.001,150 1,1500 4,8880 4,888
DeviceRoutingInvertOutlet Devices
#1Device 392.75'2.5" Vert. Orifice C= 0.600 Limited to weir flow at low heads
#2Device 394.50'48.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads
#3Primary92.75'12.0" Round Culvert L= 7.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 92.75' / 92.65' S= 0.0143 ' / Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf
#4Discarded90.75'10.000 in/hr Exfiltration over Surface area Phase-In= 0.01'
Discarded OutFlow Max=0.27 cfs @ 11.94 hrs HW=90.80' (Free Discharge) 4=Exfiltration (Exfiltration Controls 0.27 cfs)
Primary OutFlow Max=0.07 cfs @ 13.49 hrs HW=93.06' TW=0.00' (Dynamic Tailwater) 3=Culvert (Passes 0.07 cfs of 0.37 cfs potential flow) 1=Orifice (Orifice Controls 0.07 cfs @ 2.18 fps) 2=Grate ( Controls 0.00 cfs)

Pond 8P: INFILTRATION BASIN 3 Grate

Cuffieat

Exfiltration