JMA02P003 262 270 Main Street Development Stormwater Management Report

Proposed Flows NOAA10 24-hr D 2-Year-Future Rainfall=4.04" Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 5/26/2026 HydroCAD® 10.20-8a Sampler s/n S05110 © 2025 HydroCAD Software Solutions LLC This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and educational use ONLY. For actual design or modeling applications you MUST use a full version of HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical support,training materials, and additional features which are essential for actual design work. Pond 5P: Porous Pavement B Hydrograph 1.67 cfs Inflow Outflow Inflow Area=16,284 sf Discarded Primary Peak Elev=97.32' Storage=1,820 cf Flow (cfs) 1 0.09 cfs 0.07 cfs 0.02 cfs 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)

Proposed Flows NOAA10 24-hr D 2-Year-Future Rainfall=4.04" Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 5/26/2026 HydroCAD® 10.20-8a Sampler s/n S05110 © 2025 HydroCAD Software Solutions LLC This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and educational use ONLY. For actual design or modeling applications you MUST use a full version of HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical support,training materials, and additional features which are essential for actual design work. Pond 5P: Porous Pavement B Stage-Discharge Total Discarded Primary 99 Elevation (feet) 98 Orifice/Grate Exfiltration 97 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 Discharge (cfs)

Proposed Flows NOAA10 24-hr D 2-Year-Future Rainfall=4.04" Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 5/26/2026 HydroCAD® 10.20-8a Sampler s/n S05110 © 2025 HydroCAD Software Solutions LLC This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and educational use ONLY. For actual design or modeling applications you MUST use a full version of HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical support,training materials, and additional features which are essential for actual design work. Pond 5P: Porous Pavement B Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 Surface Storage 99 Elevation (feet) 98 Custom Stage Data 97 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 11,000 12,000 13,000 14,000 Storage (cubic-feet)

Proposed Flows NOAA10 24-hr D 2-Year-Future Rainfall=4.04" Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 5/26/2026 HydroCAD® 10.20-8a Sampler s/n S05110 © 2025 HydroCAD Software Solutions LLC This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and educational use ONLY. For actual design or modeling applications you MUST use a full version of HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical support,training materials, and additional features which are essential for actual design work. Hydrograph for Pond 5P: Porous Pavement B Time Inflow Storage Elevation Outflow Discarded Primary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 97.00 0.00 0.00 0.00 2.50 0.01 22 97.00 0.01 0.01 0.00 5.00 0.03 54 97.01 0.02 0.02 0.00 7.50 0.04 77 97.01 0.04 0.04 0.00 10.00 0.06 122 97.02 0.06 0.06 0.00 12.50 0.16 1,723 97.30 0.08 0.07 0.02 15.00 0.06 1,704 97.30 0.08 0.07 0.02 17.50 0.04 1,410 97.25 0.07 0.07 0.00 20.00 0.03 1,120 97.20 0.07 0.07 0.00 22.50 0.02 770 97.14 0.07 0.07 0.00 25.00 0.00 289 97.05 0.07 0.07 0.00 27.50 0.00 6 97.00 0.00 0.00 0.00 30.00 0.00 0 97.00 0.00 0.00 0.00 32.50 0.00 0 97.00 0.00 0.00 0.00 35.00 0.00 0 97.00 0.00 0.00 0.00 37.50 0.00 0 97.00 0.00 0.00 0.00 40.00 0.00 0 97.00 0.00 0.00 0.00 42.50 0.00 0 97.00 0.00 0.00 0.00 45.00 0.00 0 97.00 0.00

0 97.00 0.00 0.00 0.00 42.50 0.00 0 97.00 0.00 0.00 0.00 45.00 0.00 0 97.00 0.00 0.00 0.00 47.50 0.00 0 97.00 0.00 0.00 0.00 50.00 0.00 0 97.00 0.00 0.00 0.00 52.50 0.00 0 97.00 0.00 0.00 0.00 55.00 0.00 0 97.00 0.00 0.00 0.00 57.50 0.00 0 97.00 0.00 0.00 0.00 60.00 0.00 0 97.00 0.00 0.00 0.00 62.50 0.00 0 97.00 0.00 0.00 0.00 65.00 0.00 0 97.00 0.00 0.00 0.00 67.50 0.00 0 97.00 0.00 0.00 0.00 70.00 0.00 0 97.00 0.00 0.00 0.00

Proposed Flows NOAA10 24-hr D 10-Year-Future Rainfall=6.31" Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 5/26/2026 HydroCAD® 10.20-8a Sampler s/n S05110 © 2025 HydroCAD Software Solutions LLC This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and educational use ONLY. For actual design or modeling applications you MUST use a full version of HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical support,training materials, and additional features which are essential for actual design work. Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Proposed Impervious Runoff Area=13,934 sf 100.00% Impervious Runoff Depth=6.07" Tc=1.0 min CN=98 Runoff=2.31 cfs 7,050 cf Subcatchment 3S: Proposed Pervious Runoff Area=907 sf 0.00% Impervious Runoff Depth=3.45" Tc=1.0 min CN=74 Runoff=0.10 cfs 261 cf Subcatchment 4S: Proposed Impervious Runoff Area=15,377 sf 100.00% Impervious Runoff Depth=6.07" Tc=1.0 min CN=98 Runoff=2.54 cfs 7,780 cf Pond 2P: Basin A Peak Elev=97.57' Storage=2,678 cf Inflow=2.31 cfs 7,050 cf Discarded=0.02 cfs 3,241 cf Primary=1.27 cfs 3,809 cf Outflow=1.30 cfs 7,050 cf Pond 5P: Porous Pavement B Peak Elev=97.56' Storage=3,162 cf Inflow=2.65 cfs 8,041 cf Discarded=0.07 cfs 6,043 cf Primary=0.08 cfs 1,997 cf Outflow=0.15 cfs 8,041 cf Total Runoff Area = 30,218 sf Runoff Volume = 15,091 cf Average Runoff Depth = 5.99" 3.00% Pervious = 907 sf 97.00% Impervious = 29,311 sf

Proposed Flows NOAA10 24-hr D 10-Year-Future Rainfall=6.31" Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 5/26/2026 HydroCAD® 10.20-8a Sampler s/n S05110 © 2025 HydroCAD Software Solutions LLC This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and educational use ONLY. For actual design or modeling applications you MUST use a full version of HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical support,training materials, and additional features which are essential for actual design work. Summary for Subcatchment 1S: Proposed Impervious Runoff = 2.31 cfs @ 12.06 hrs, Volume= 7,050 cf, Depth= 6.07" Routed to Pond 2P : Basin A Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA10 24-hr D 10-Year-Future Rainfall=6.31" Area (sf) CN Description 13,934 98 Roofs, HSG C 13,934 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 1S: Proposed Impervious Hydrograph Runoff 2.31 cfs NOAA10 24-hr D 10-Year-Future Rainfall=6.31" 2 Runoff Area=13,934 sf Runoff Volume=7,050 cf Runoff Depth=6.07" Flow (cfs)

Runoff Depth=6.07" Flow (cfs) Tc=1.0 min CN=98 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)

Proposed Flows NOAA10 24-hr D 10-Year-Future Rainfall=6.31" Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 5/26/2026 HydroCAD® 10.20-8a Sampler s/n S05110 © 2025 HydroCAD Software Solutions LLC This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and educational use ONLY. For actual design or modeling applications you MUST use a full version of HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical support,training materials, and additional features which are essential for actual design work. Hydrograph for Subcatchment 1S: Proposed Impervious Time Precip. Excess Runoff Time Precip. Excess Runoff (hours) (inches) (inches) (cfs) (hours) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 47.00 6.31 6.07 0.00 1.00 0.08 0.01 0.01 48.00 6.31 6.07 0.00 2.00 0.18 0.06 0.02 49.00 6.31 6.07 0.00 3.00 0.29 0.14 0.03 50.00 6.31 6.07 0.00 4.00 0.41 0.24 0.04 51.00 6.31 6.07 0.00 5.00 0.55 0.37 0.04 52.00 6.31 6.07 0.00 6.00 0.70 0.51 0.05 53.00 6.31 6.07 0.00 7.00 0.87 0.66 0.05 54.00 6.31 6.07 0.00 8.00 1.05 0.84 0.06 55.00 6.31 6.07 0.00 9.00 1.24 1.03 0.07 56.00 6.31 6.07 0.00 10.00 1.51 1.29 0.09 57.00 6.31 6.07 0.00 11.00 1.87 1.64 0.15 58.00 6.31 6.07 0.00 12.00 2.99 2.75 1.42 59.00 6.31 6.07 0.00 13.00 4.44 4.21 0.16 60.00 6.31 6.07 0.00 14.00 4.80 4.56 0.09 61.00 6.31 6.07 0.00 15.00 5.07 4.83 0.08 62.00 6.31 6.07 0.00 16.00 5.26 5.02 0.06 63.00 6.31 6.07 0.00 17.00 5.44 5.20 0.06 64.00 6.31 6.07 0.00 18.00 5.61 5.37 0.05 65.00 6.31 6.07 0.00 19.00 5.76 5.52 0.05 66.00 6.31 6.07 0.00 20.00 5.90 5.66 0.04 67.00

0 18.00 5.61 5.37 0.05 65.00 6.31 6.07 0.00 19.00 5.76 5.52 0.05 66.00 6.31 6.07 0.00 20.00 5.90 5.66 0.04 67.00 6.31 6.07 0.00 21.00 6.02 5.78 0.04 68.00 6.31 6.07 0.00 22.00 6.13 5.89 0.03 69.00 6.31 6.07 0.00 23.00 6.23 5.99 0.03 70.00 6.31 6.07 0.00 24.00 6.31 6.07 0.02 71.00 6.31 6.07 0.00 25.00 6.31 6.07 0.00 72.00 6.31 6.07 0.00 26.00 6.31 6.07 0.00 27.00 6.31 6.07 0.00 28.00 6.31 6.07 0.00 29.00 6.31 6.07 0.00 30.00 6.31 6.07 0.00 31.00 6.31 6.07 0.00 32.00 6.31 6.07 0.00 33.00 6.31 6.07 0.00 34.00 6.31 6.07 0.00 35.00 6.31 6.07 0.00 36.00 6.31 6.07 0.00 37.00 6.31 6.07 0.00 38.00 6.31 6.07 0.00 39.00 6.31 6.07 0.00 40.00 6.31 6.07 0.00 41.00 6.31 6.07 0.00 42.00 6.31 6.07 0.00 43.00 6.31 6.07 0.00 44.00 6.31 6.07 0.00 45.00 6.31 6.07 0.00 46.00 6.31 6.07 0.00