2026 05 Storm Water Management Report rcd 5 6 2026

2026-04 Proposed & Existing CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" 2026-04 Proposed & Existing CondiNOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" Prepared by Dynamic Engineering Printed 5/5/2026 Prepared by Dynamic Engineering Printed 5/5/2026 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 73 HydroCAD® 10.20-7a s/n 08640 © 2025 HydroCAD Software Solutions LLC Page 74 Summary for Pond 2P: BIO BASIN Pond 2P: BIO BASIN Hydrograph Inflow Area = 0.146 ac, 53.42% Impervious, Inflow Depth = 7.91" for 100-Year-Current event Inflow = 1.25 cfs @ 12.10 hrs, Volume= 0.096 af 1.25 cfs Inflow Primary Outflow = 0.85 cfs @ 12.11 hrs, Volume= 0.088 af, Atten= 32%, Lag= 0.8 min Primary = 0.85 cfs @ 12.11 hrs, Volume= 0.088 af Inflow Area=0.146 ac Routed to Link 4L : POI #1 Peak Elev=623.54' Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Peak Elev= 623.54' @ 12.11 hrs Surf.Area= 783 sf Storage= 816 cf

=623.54' Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.001 hrs Peak Elev= 623.54' @ 12.11 hrs Surf.Area= 783 sf Storage= 816 cf 1 0.85 cfs Storage=816 cf Plug-Flow detention time= 102.3 min calculated for 0.088 af (91% of inflow) Flow (cfs) Center-of-Mass det. time= 53.7 min ( 816.1 - 762.4 ) Volume Invert Avail.Storage Storage Description #1 622.00' 1,219 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 622.00 323 0 0 623.00 577 450 450 624.00 960 769 1,219 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Device Routing Invert Outlet Devices #1 Primary 619.05' 15.0" Round Culvert L= 35.0' RCP, rounded edge headwall, Ke= 0.100 Inlet / Outlet Invert= 619.05' / 618.93' S= 0.0034 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 622.86' 0.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #3 Device 1 623.70' 48.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at

6' 0.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #3 Device 1 623.70' 48.0" x 48.0" Horiz. Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.85 cfs @ 12.11 hrs HW=623.54' (Free Discharge) 1=Culvert (Passes 0.85 cfs of 13.04 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 0.85 cfs @ 2.69 fps) 3=Grate ( Controls 0.00 cfs)