21 Stormwater Mgmt Report_082025

NOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" NJA230139 - REV 0 Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Printed 8/6/2025 Page 31 Summary for Subcatchment P1p: Proposed Pervious Runoff = 0.12 cfs @ 12.20 hrs, Volume= Routed to Link P1 : PDA 1A 552 cf, Depth= 1.69" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.10 hrs NOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" Area (ac) 0.090 0.090 CN 39 39 Tc Length (min) (feet) 5.7 85 Description >75% Grass cover, Good, HSG A 100.00% Pervious Area Slope (ft/ft) 0.0500 Velocity (ft/sec) 0.25 0.2 15 0.0400 1.29 0.5 121 0.0400 4.06 2.0 287 0.0140 2.40 0.1 20 0.6600 4.06 8.5 528 Total Capacity (cfs) Description Sheet Flow, Grass: Short n= 0.150 P2= 3.47" Sheet Flow, Smooth surfaces n= 0.011 P2= 3.47" Shallow Concentrated Flow, Paved Kv= 20.3 fps Shallow Concentrated Flow, Paved Kv= 20.3 fps Shallow Concentrated Flow, Woodland Kv= 5.0 fps Subcatchment P1p: Proposed Pervious Hydrograph 0.13 NOAA 24-hr D 100-Year-Current Rainfall=9.18" P2=3.47" Runoff Area=0.090 ac Runoff Volume=552 cf Runoff Depth=1.69" Flow Length=528' Tc=8.5 min CN=39/0 0.12 0.11 0.1 0.09 Flow (cfs) Runoff 0.12 cfs 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 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)

NOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" NJA230139 - REV 0 Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Printed 8/6/2025 Page 32 Summary for Pond PP1: Pervious Pavement Inflow Area = 11,761 sf,100.00% Impervious, Inflow Depth = 8.94" for 100-Year-Current event Inflow = 2.07 cfs @ 12.04 hrs, Volume= 8,762 cf Outflow = 1.72 cfs @ 12.11 hrs, Volume= 7,737 cf, Atten= 17%, Lag= 4.6 min Primary = 1.72 cfs @ 12.11 hrs, Volume= 7,737 cf Routed to Link P1 : PDA 1A Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.10 hrs / 9 Peak Elev= 367.21' @ 12.11 hrs Surf.Area= 8,538 sf Storage= 1,916 cf Plug-Flow detention time= 132.4 min calculated for 7,726 cf (88% of inflow) Center-of-Mass det. time= 72.7 min ( 807.9 - 735.2 ) Volume #1 Invert 366.65' Elevation (feet) 366.65 367.65 Avail.Storage 3,415 cf Surf.Area (sq-ft) 8,538 8,538 Device #1 Routing Primary Invert 365.50' #2 Device 1 366.95' Storage Description Custom Stage Data (Prismatic)Listed below (Recalc) 8,538 cf Overall x 40.0% Voids Inc.Store (cubic-feet) 0 8,538 Cum.Store (cubic-feet) 0 8,538 Outlet Devices 15.0" Round RCP_Round 15" L= 273.0' RCP, groove end projecting, Ke= 0.200 Inlet / Outlet Invert= 365.50' / 364.15' S= 0.0049 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 1.23 sf 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=1.68 cfs @ 12.11 hrs HW=367.21' TW=0.00' (Dynamic Tailwater) 1=RCP_Round 15" (Passes 1.68 cfs of 5.52 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 1.68 cfs @ 1.66 fps)

NJA230139 - REV 0 NOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Printed 8/6/2025 Page 33 Pond PP1: Pervious Pavement Hydrograph Inflow Primary 2.07 cfs 2 Flow (cfs) 1.72 cfs Inflow Area=11,761 sf Peak Elev=367.21' Storage=1,916 cf 1 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)

NJA230139 - REV 0 NOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Printed 8/6/2025 Page 34 Summary for Link E1: EDA 1A Inflow Area = Inflow = Primary = 59,242 sf, 98.53% Impervious, Inflow Depth = 8.83" for 100-Year-Current event 11.80 cfs @ 12.09 hrs, Volume= 43,606 cf 11.80 cfs @ 12.09 hrs, Volume= 43,606 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.10 hrs Link E1: EDA 1A Hydrograph 11.80 cfs 11.80 cfs 13 12 Inflow Primary Inflow Area=59,242 sf 11 10 9 Flow (cfs) 8 7 6 5 4 3 2 1 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)

NJA230139 - REV 0 NOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Printed 8/6/2025 Page 35 Summary for Link P1: PDA 1A Inflow Area = Inflow = Primary = 59,242 sf, 93.38% Impervious, Inflow Depth = 8.25" for 100-Year-Current event 10.58 cfs @ 12.09 hrs, Volume= 40,739 cf 10.58 cfs @ 12.09 hrs, Volume= 40,739 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.10 hrs Link P1: PDA 1A Hydrograph 10.58 cfs 10.58 cfs 11 Inflow Primary Inflow Area=59,242 sf 10 9 Flow (cfs) 8 7 6 5 4 3 2 1 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)

NJA230139 - REV 0 NOAA 24-hr D 2-Year-Current Rainfall=3.47", P2=3.47" Printed 8/6/2025 Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Primary Comparison 4.41 cfs 4 3.80 cfs Primary (cfs) 3 2 1 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) Link E1 Link P1

NJA230139 - REV 0 NOAA 24-hr D 10-Year-Current Rainfall=5.38", P2=3.47" Printed 8/6/2025 Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Primary Comparison 6.89 cfs 7 6.07 cfs 6 Primary (cfs) 5 4 3 2 1 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) Link E1 Link P1

NJA230139 - REV 0 NOAA 24-hr D 100-Year-Current Rainfall=9.18", P2=3.47" Printed 8/6/2025 Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Primary Comparison 13 11.80 cfs 12 10.58 cfs 11 10 9 Primary (cfs) 8 7 6 5 4 3 2 1 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) Link E1 Link P1

B. PRE- vs. POST-DEVELOPMENT HYDROGRAPHS Future Adjusted Precipitation Depths      2-Year Storm Event 10-Year Storm Event 25-Year Storm Event 100-Year Storm Event Pre- vs. Post Comparison

E1i E1p P1i(pp) P1i P1p Existing Impervious Existing Pervious Proposed Impervious Proposed Impervious Proposed Pervious PP1 Pervious Pavement Subcat E1 P1 EDA 1A PDA 1A Reach Pond Link Routing Diagram for NJA230139 - REV 0 Prepared by Bohler, Printed 8/6/2025 HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC