JMA02P003 262 270 Main Street Development Stormwater Management Report

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. 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 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 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 0.03 47 97.01 0.02 0.02 0.00 5.00 0.05 93 97.02 0.04 0.04 0.00 7.50 0.06 127 97.02 0.06 0.06 0.00 10.00 0.10 252 97.04 0.07 0.07 0.00 12.50 0.26 3,035 97.53 0.14 0.07 0.08 15.00 0.09 2,933 97.52 0.14 0.07 0.08 17.50 0.06 2,367 97.42 0.12 0.07 0.05 20.00 0.05 1,894 97.33 0.09 0.07 0.03 22.50 0.04 1,525 97.27 0.07 0.07 0.01 25.00 0.00 1,078 97.19 0.07 0.07 0.00 27.50 0.00 486 97.09 0.07 0.07 0.00 30.00 0.00 25 97.00 0.01 0.01 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 100-Year-Future Rainfall=11.52" 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=11.28" Tc=1.0 min CN=98 Runoff=4.22 cfs 13,096 cf Subcatchment 3S: Proposed Pervious Runoff Area=907 sf 0.00% Impervious Runoff Depth=8.17" Tc=1.0 min CN=74 Runoff=0.23 cfs 617 cf Subcatchment 4S: Proposed Impervious Runoff Area=15,377 sf 100.00% Impervious Runoff Depth=11.28" Tc=1.0 min CN=98 Runoff=4.66 cfs 14,453 cf Pond 2P: Basin A Peak Elev=97.81' Storage=2,970 cf Inflow=4.22 cfs 13,096 cf Discarded=0.02 cfs 3,400 cf Primary=3.91 cfs 9,697 cf Outflow=3.94 cfs 13,096 cf Pond 5P: Porous Pavement B Peak Elev=98.25' Storage=7,105 cf Inflow=4.89 cfs 15,070 cf Discarded=0.07 cfs 7,967 cf Primary=0.16 cfs 7,103 cf Outflow=0.23 cfs 15,070 cf Total Runoff Area = 30,218 sf Runoff Volume = 28,166 cf Average Runoff Depth = 11.19" 3.00% Pervious = 907 sf 97.00% Impervious = 29,311 sf

Proposed Flows NOAA10 24-hr D 100-Year-Future Rainfall=11.52" 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 = 4.22 cfs @ 12.06 hrs, Volume= 13,096 cf, Depth=11.28" 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 100-Year-Future Rainfall=11.52" 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 4.22 cfs NOAA10 24-hr D 4 100-Year-Future Rainfall=11.52" Runoff Area=13,934 sf Runoff Volume=13,096 cf 3 Runoff Depth=11.28"

3 Runoff Depth=11.28" Tc=1.0 min Flow (cfs) CN=98 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)

Proposed Flows NOAA10 24-hr D 100-Year-Future Rainfall=11.52" 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 11.52 11.28 0.00 1.00 0.15 0.04 0.03 48.00 11.52 11.28 0.00 2.00 0.33 0.17 0.05 49.00 11.52 11.28 0.00 3.00 0.53 0.34 0.06 50.00 11.52 11.28 0.00 4.00 0.76 0.56 0.07 51.00 11.52 11.28 0.00 5.00 1.01 0.80 0.08 52.00 11.52 11.28 0.00 6.00 1.28 1.07 0.09 53.00 11.52 11.28 0.00 7.00 1.59 1.37 0.10 54.00 11.52 11.28 0.00 8.00 1.92 1.69 0.11 55.00 11.52 11.28 0.00 9.00 2.27 2.04 0.12 56.00 11.52 11.28 0.00 10.00 2.76 2.53 0.17 57.00 11.52 11.28 0.00 11.00 3.41 3.18 0.28 58.00 11.52 11.28 0.00 12.00 5.45 5.21 2.60 59.00 11.52 11.28 0.00 13.00 8.11 7.87 0.29 60.00 11.52 11.28 0.00 14.00 8.76 8.52 0.17 61.00 11.52 11.28 0.00 15.00 9.25 9.01 0.14 62.00 11.52 11.28 0.00 16.00 9.60 9.36 0.11 63.00 11.52 11.28 0.00 17.00 9.93 9.69 0.10 64.00 11.52 11.28 0.00 18.00 10.24 9.99 0.09 65.00 11.52 11.28 0.00 19.00 10.51 10.27 0.09 66.00 11.52 11.28 0.00 20.00 10.76 10.52 0.08 67.00

00 18.00 10.24 9.99 0.09 65.00 11.52 11.28 0.00 19.00 10.51 10.27 0.09 66.00 11.52 11.28 0.00 20.00 10.76 10.52 0.08 67.00 11.52 11.28 0.00 21.00 10.99 10.75 0.07 68.00 11.52 11.28 0.00 22.00 11.19 10.95 0.06 69.00 11.52 11.28 0.00 23.00 11.37 11.13 0.05 70.00 11.52 11.28 0.00 24.00 11.52 11.28 0.04 71.00 11.52 11.28 0.00 25.00 11.52 11.28 0.00 72.00 11.52 11.28 0.00 26.00 11.52 11.28 0.00 27.00 11.52 11.28 0.00 28.00 11.52 11.28 0.00 29.00 11.52 11.28 0.00 30.00 11.52 11.28 0.00 31.00 11.52 11.28 0.00 32.00 11.52 11.28 0.00 33.00 11.52 11.28 0.00 34.00 11.52 11.28 0.00 35.00 11.52 11.28 0.00 36.00 11.52 11.28 0.00 37.00 11.52 11.28 0.00 38.00 11.52 11.28 0.00 39.00 11.52 11.28 0.00 40.00 11.52 11.28 0.00 41.00 11.52 11.28 0.00 42.00 11.52 11.28 0.00 43.00 11.52 11.28 0.00 44.00 11.52 11.28 0.00 45.00 11.52 11.28 0.00 46.00 11.52 11.28 0.00

Proposed Flows NOAA10 24-hr D 100-Year-Future Rainfall=11.52" 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 3S: Proposed Pervious Runoff = 0.23 cfs @ 12.06 hrs, Volume= 617 cf, Depth= 8.17" Routed to Pond 5P : Porous Pavement B 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 100-Year-Future Rainfall=11.52" Area (sf) CN Description 907 74 >75% Grass cover, Good, HSG C 907 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 3S: Proposed Pervious Hydrograph Runoff 0.23 cfs 0.24 NOAA10 24-hr D 0.22 100-Year-Future Rainfall=11.52" 0.2 Runoff Area=907 sf 0.18 Runoff Volume=617 cf 0.16 Runoff Depth=8.17"

Runoff Volume=617 cf 0.16 Runoff Depth=8.17" Tc=1.0 min Flow (cfs) 0.14 CN=74 0.12 0.1 0.08 0.06 0.04 0.02 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)