21 Stormwater Mgmt Report_082025

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

NJA230139 - REV 0 Printed 8/6/2025 Page 2 Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# 1 2 3 Event Name Storm Type Curve Mode Duration (hours) B/B 2-Year-Current 10-Year-Current 100-Year-Current NOAA 24-hr NOAA 24-hr NOAA 24-hr D D D Default Default Default 24.00 24.00 24.00 1 1 1 Depth (inches) 3.47 5.38 9.18 AMC 2 2 2 P2 (inches) 3.47 3.47 3.47

NJA230139 - REV 0 Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 4,792 113,692 118,483 39 98 96 >75% Grass cover, Good, HSG A (E1p, P1p) Paved parking, HSG A (E1i, P1i, P1i(pp)) TOTAL AREA Printed 8/6/2025 Page 3

NJA230139 - REV 0 Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (sq-ft) Soil Group Subcatchment Numbers 118,483 0 0 0 0 118,483 HSG A HSG B HSG C HSG D Other E1i, E1p, P1i, P1i(pp), P1p TOTAL AREA Printed 8/6/2025 Page 4

NJA230139 - REV 0 Printed 8/6/2025 Page 5 Prepared by Bohler HydroCAD® 10.20-5c s/n 03478 © 2023 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (sq-ft) HSG-B (sq-ft) HSG-C (sq-ft) HSG-D (sq-ft) Other (sq-ft) Total (sq-ft) Ground Cover 4,792 0 0 0 0 4,792 113,692 118,483 0 0 0 0 0 0 0 0 113,692 118,483 >75% Grass cover, Good Paved parking TOTAL AREA Sub Num

NOAA 24-hr D 2-Year-Current Rainfall=3.47", 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 6 Time span=0.00-72.00 hrs, dt=0.10 hrs, 721 points x 9 Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=1.340 ac 100.00% Impervious Runoff Depth=3.24" Flow Length=441' Tc=3.2 min CN=0/98 Runoff=4.41 cfs 15,743 cf Subcatchment E1i: Existing Impervious Subcatchment E1p: Existing Pervious Runoff Area=0.020 ac 0.00% Impervious Runoff Depth=0.01" Flow Length=526' Tc=8.6 min CN=39/0 Runoff=0.00 cfs 1 cf Subcatchment P1i: Proposed Impervious Runoff Area=1.000 ac 100.00% Impervious Runoff Depth=3.24" Flow Length=443' Tc=3.1 min CN=0/98 Runoff=3.30 cfs 11,749 cf Runoff Area=0.270 ac 100.00% Impervious Runoff Depth=3.24" Flow Length=30' Slope=0.0150 '/' Tc=0.5 min CN=0/98 Runoff=0.77 cfs 3,172 cf Subcatchment P1i(pp): Proposed Subcatchment P1p: Proposed Pervious Runoff Area=0.090 ac 0.00% Impervious Runoff Depth=0.01" Flow Length=528' Tc=8.5 min CN=39/0 Runoff=0.00 cfs 2 cf Pond PP1: Pervious Pavement Peak Elev=367.07' Storage=1,436 cf Inflow=0.77 cfs 3,172 cf Outflow=0.54 cfs 2,148 cf Link E1: EDA 1A Inflow=4.41 cfs 15,744 cf Primary=4.41 cfs 15,744 cf Link P1: PDA 1A Inflow=3.80 cfs 13,899 cf Primary=3.80 cfs 13,899 cf Total Runoff Area = 118,483 sf Runoff Volume = 30,667 cf Average Runoff Depth = 3.11" 4.04% Pervious = 4,792 sf 95.96% Impervious = 113,692 sf

NOAA 24-hr D 2-Year-Current Rainfall=3.47", 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 7 Summary for Subcatchment E1i: Existing Impervious Runoff = 4.41 cfs @ 12.09 hrs, Volume= Routed to Link E1 : EDA 1A 15,743 cf, Depth= 3.24" 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 2-Year-Current Rainfall=3.47", P2=3.47" Area (ac) 1.340 1.340 CN 98 98 Tc Length (min) (feet) 0.9 100 Description Paved parking, HSG A 100.00% Impervious Area Slope (ft/ft) 0.0400 Velocity (ft/sec) 1.89 0.1 36 0.0400 4.06 2.1 285 0.0120 2.22 0.1 20 0.6600 4.06 3.2 441 Total Capacity (cfs) Description 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 E1i: Existing Impervious Hydrograph Runoff 4.41 cfs NOAA 24-hr D 2-Year-Current Rainfall=3.47" P2=3.47" Runoff Area=1.340 ac Runoff Volume=15,743 cf Runoff Depth=3.24" Flow Length=441' Tc=3.2 min CN=0/98 4 Flow (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)

NOAA 24-hr D 2-Year-Current Rainfall=3.47", 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 8 Summary for Subcatchment E1p: Existing Pervious Runoff = 0.00 cfs @ 24.00 hrs, Volume= Routed to Link E1 : EDA 1A 1 cf, Depth= 0.01" 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 2-Year-Current Rainfall=3.47", P2=3.47" Area (ac) 0.020 0.020 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 2.1 285 0.0120 2.22 0.1 20 0.6600 4.06 8.6 526 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 E1p: Existing Pervious Hydrograph NOAA 24-hr D 2-Year-Current Rainfall=3.47" P2=3.47" Runoff Area=0.020 ac Runoff Volume=1 cf Runoff Depth=0.01" Flow Length=526' Tc=8.6 min CN=39/0 0 0 0 0 0 0 Flow (cfs) Runoff 0.00 cfs 0 0 0 0 0 0 0 0 0 0 0 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 2-Year-Current Rainfall=3.47", 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 9 Summary for Subcatchment P1i: Proposed Impervious Runoff = 3.30 cfs @ 12.09 hrs, Volume= Routed to Link P1 : PDA 1A 11,749 cf, Depth= 3.24" 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 2-Year-Current Rainfall=3.47", P2=3.47" Area (ac) 1.000 1.000 CN 98 98 Tc Length (min) (feet) 0.9 100 Description Paved parking, HSG A 100.00% Impervious Area Slope (ft/ft) 0.0400 Velocity (ft/sec) 1.89 0.1 36 0.0400 4.06 2.0 287 0.0140 2.40 0.1 20 0.6600 4.06 3.1 443 Total Capacity (cfs) Description 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 P1i: Proposed Impervious Hydrograph Runoff 3.30 cfs NOAA 24-hr D 2-Year-Current Rainfall=3.47" P2=3.47" Runoff Area=1.000 ac Runoff Volume=11,749 cf Runoff Depth=3.24" Flow Length=443' Tc=3.1 min CN=0/98 Flow (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)

NOAA 24-hr D 2-Year-Current Rainfall=3.47", 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 10 Summary for Subcatchment P1i(pp): Proposed Impervious Runoff = 0.77 cfs @ 12.04 hrs, Volume= Routed to Pond PP1 : Pervious Pavement 3,172 cf, Depth= 3.24" 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 2-Year-Current Rainfall=3.47", P2=3.47" Area (ac) 0.270 0.270 CN 98 98 Tc Length (min) (feet) 0.5 30 Description Paved parking, HSG A 100.00% Impervious Area Slope (ft/ft) 0.0150 Velocity (ft/sec) 1.00 Capacity (cfs) Description Sheet Flow, Smooth surfaces n= 0.011 P2= 3.47" Subcatchment P1i(pp): Proposed Impervious Hydrograph 0.85 0.8 NOAA 24-hr D 2-Year-Current Rainfall=3.47" P2=3.47" Runoff Area=0.270 ac Runoff Volume=3,172 cf Runoff Depth=3.24" Flow Length=30' Slope=0.0150 '/' Tc=0.5 min CN=0/98 0.75 0.7 0.65 0.6 0.55 Flow (cfs) Runoff 0.77 cfs 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 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)