JMA02P003 262 270 Main Street Development Stormwater Management Report

Existing Flows NOAA10 24-hr D 10-Year-Current Rainfall=5.33" 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: Existing 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 5.33 5.09 0.00 1.00 0.07 0.00 0.01 48.00 5.33 5.09 0.00 2.00 0.15 0.04 0.03 49.00 5.33 5.09 0.00 3.00 0.24 0.10 0.05 50.00 5.33 5.09 0.00 4.00 0.35 0.19 0.06 51.00 5.33 5.09 0.00 5.00 0.47 0.29 0.08 52.00 5.33 5.09 0.00 6.00 0.59 0.40 0.09 53.00 5.33 5.09 0.00 7.00 0.73 0.54 0.10 54.00 5.33 5.09 0.00 8.00 0.89 0.68 0.10 55.00 5.33 5.09 0.00 9.00 1.05 0.84 0.12 56.00 5.33 5.09 0.00 10.00 1.28 1.06 0.16 57.00 5.33 5.09 0.00 11.00 1.58 1.36 0.27 58.00 5.33 5.09 0.00 12.00 2.52 2.29 2.62 59.00 5.33 5.09 0.00 13.00 3.75 3.52 0.29 60.00 5.33 5.09 0.00 14.00 4.05 3.82 0.17 61.00 5.33 5.09 0.00 15.00 4.28 4.04 0.14 62.00 5.33 5.09 0.00 16.00 4.44 4.21 0.11 63.00 5.33 5.09 0.00 17.00 4.60 4.36 0.10 64.00 5.33 5.09 0.00 18.00 4.74 4.50 0.09 65.00 5.33 5.09 0.00 19.00 4.86 4.63 0.08 66.00 5.33

.60 4.36 0.10 64.00 5.33 5.09 0.00 18.00 4.74 4.50 0.09 65.00 5.33 5.09 0.00 19.00 4.86 4.63 0.08 66.00 5.33 5.09 0.00 20.00 4.98 4.74 0.08 67.00 5.33 5.09 0.00 21.00 5.09 4.85 0.07 68.00 5.33 5.09 0.00 22.00 5.18 4.94 0.06 69.00 5.33 5.09 0.00 23.00 5.26 5.02 0.05 70.00 5.33 5.09 0.00 24.00 5.33 5.09 0.03 71.00 5.33 5.09 0.00 25.00 5.33 5.09 0.00 72.00 5.33 5.09 0.00 26.00 5.33 5.09 0.00 27.00 5.33 5.09 0.00 28.00 5.33 5.09 0.00 29.00 5.33 5.09 0.00 30.00 5.33 5.09 0.00 31.00 5.33 5.09 0.00 32.00 5.33 5.09 0.00 33.00 5.33 5.09 0.00 34.00 5.33 5.09 0.00 35.00 5.33 5.09 0.00 36.00 5.33 5.09 0.00 37.00 5.33 5.09 0.00 38.00 5.33 5.09 0.00 39.00 5.33 5.09 0.00 40.00 5.33 5.09 0.00 41.00 5.33 5.09 0.00 42.00 5.33 5.09 0.00 43.00 5.33 5.09 0.00 44.00 5.33 5.09 0.00 45.00 5.33 5.09 0.00 46.00 5.33 5.09 0.00

Existing Flows NOAA10 24-hr D 10-Year-Current Rainfall=5.33" 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 2S: Existing Pervious Runoff = 0.03 cfs @ 12.07 hrs, Volume= 66 cf, Depth= 2.63" Routed to Link 3L : Total Site Flows 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-Current Rainfall=5.33" Area (sf) CN Description 302 74 >75% Grass cover, Good, HSG C 302 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 2S: Existing Pervious Hydrograph 0.028 Runoff 0.03 cfs 0.026 NOAA10 24-hr D 0.024 10-Year-Current Rainfall=5.33" 0.022 Runoff Area=302 sf 0.02 Runoff Volume=66 cf 0.018 Runoff

Runoff Volume=66 cf 0.018 Runoff Depth=2.63" Flow (cfs) 0.016 Tc=1.0 min 0.014 CN=74 0.012 0.01 0.008 0.006 0.004 0.002 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)

Existing Flows NOAA10 24-hr D 10-Year-Current Rainfall=5.33" 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 2S: Existing Pervious 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 5.33 2.63 0.00 1.00 0.07 0.00 0.00 48.00 5.33 2.63 0.00 2.00 0.15 0.00 0.00 49.00 5.33 2.63 0.00 3.00 0.24 0.00 0.00 50.00 5.33 2.63 0.00 4.00 0.35 0.00 0.00 51.00 5.33 2.63 0.00 5.00 0.47 0.00 0.00 52.00 5.33 2.63 0.00 6.00 0.59 0.00 0.00 53.00 5.33 2.63 0.00 7.00 0.73 0.00 0.00 54.00 5.33 2.63 0.00 8.00 0.89 0.01 0.00 55.00 5.33 2.63 0.00 9.00 1.05 0.03 0.00 56.00 5.33 2.63 0.00 10.00 1.28 0.08 0.00 57.00 5.33 2.63 0.00 11.00 1.58 0.17 0.00 58.00 5.33 2.63 0.00 12.00 2.52 0.62 0.01 59.00 5.33 2.63 0.00 13.00 3.75 1.42 0.00 60.00 5.33 2.63 0.00 14.00 4.05 1.64 0.00 61.00 5.33 2.63 0.00 15.00 4.28 1.81 0.00 62.00 5.33 2.63 0.00 16.00 4.44 1.93 0.00 63.00 5.33 2.63 0.00 17.00 4.60 2.05 0.00 64.00 5.33 2.63 0.00 18.00 4.74 2.16 0.00 65.00 5.33 2.63 0.00 19.00 4.86 2.26 0.00 66.00 5.33 2.63 0.00 20.00

.00 64.00 5.33 2.63 0.00 18.00 4.74 2.16 0.00 65.00 5.33 2.63 0.00 19.00 4.86 2.26 0.00 66.00 5.33 2.63 0.00 20.00 4.98 2.35 0.00 67.00 5.33 2.63 0.00 21.00 5.09 2.43 0.00 68.00 5.33 2.63 0.00 22.00 5.18 2.51 0.00 69.00 5.33 2.63 0.00 23.00 5.26 2.57 0.00 70.00 5.33 2.63 0.00 24.00 5.33 2.63 0.00 71.00 5.33 2.63 0.00 25.00 5.33 2.63 0.00 72.00 5.33 2.63 0.00 26.00 5.33 2.63 0.00 27.00 5.33 2.63 0.00 28.00 5.33 2.63 0.00 29.00 5.33 2.63 0.00 30.00 5.33 2.63 0.00 31.00 5.33 2.63 0.00 32.00 5.33 2.63 0.00 33.00 5.33 2.63 0.00 34.00 5.33 2.63 0.00 35.00 5.33 2.63 0.00 36.00 5.33 2.63 0.00 37.00 5.33 2.63 0.00 38.00 5.33 2.63 0.00 39.00 5.33 2.63 0.00 40.00 5.33 2.63 0.00 41.00 5.33 2.63 0.00 42.00 5.33 2.63 0.00 43.00 5.33 2.63 0.00 44.00 5.33 2.63 0.00 45.00 5.33 2.63 0.00 46.00 5.33 2.63 0.00

Existing Flows NOAA10 24-hr D 10-Year-Current Rainfall=5.33" 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 Link 3L: Total Site Flows Inflow Area = 30,218 sf, 99.00% Impervious, Inflow Depth = 5.07" for 10-Year-Current event Inflow = 4.20 cfs @ 12.06 hrs, Volume= 12,762 cf Primary = 4.20 cfs @ 12.06 hrs, Volume= 12,762 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Link 3L: Total Site Flows Hydrograph Inflow 4.20 cfs Primary 4.20 cfs Inflow Area=30,218 sf 4 3 Flow (cfs) 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)

Existing Flows NOAA10 24-hr D 10-Year-Current Rainfall=5.33" 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 Link 3L: Total Site Flows Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 0.00 0.00 0.00 0.00 47.00 0.00 0.00 0.00 1.00 0.01 0.00 0.01 48.00 0.00 0.00 0.00 2.00 0.03 0.00 0.03 49.00 0.00 0.00 0.00 3.00 0.05 0.00 0.05 50.00 0.00 0.00 0.00 4.00 0.06 0.00 0.06 51.00 0.00 0.00 0.00 5.00 0.08 0.00 0.08 52.00 0.00 0.00 0.00 6.00 0.09 0.00 0.09 53.00 0.00 0.00 0.00 7.00 0.10 0.00 0.10 54.00 0.00 0.00 0.00 8.00 0.10 0.00 0.10 55.00 0.00 0.00 0.00 9.00 0.12 0.00 0.12 56.00 0.00 0.00 0.00 10.00 0.16 0.00 0.16 57.00 0.00 0.00 0.00 11.00 0.28 0.00 0.28 58.00 0.00 0.00 0.00 12.00 2.64 0.00 2.64 59.00 0.00 0.00 0.00 13.00 0.29 0.00 0.29 60.00 0.00 0.00 0.00 14.00 0.17 0.00 0.17 61.00 0.00 0.00 0.00 15.00 0.14 0.00 0.14 62.00 0.00 0.00 0.00 16.00 0.11 0.00 0.11 63.00 0.00 0.00 0.00 17.00

0.00 0.00 15.00 0.14 0.00 0.14 62.00 0.00 0.00 0.00 16.00 0.11 0.00 0.11 63.00 0.00 0.00 0.00 17.00 0.10 0.00 0.10 64.00 0.00 0.00 0.00 18.00 0.09 0.00 0.09 65.00 0.00 0.00 0.00 19.00 0.09 0.00 0.09 66.00 0.00 0.00 0.00 20.00 0.08 0.00 0.08 67.00 0.00 0.00 0.00 21.00 0.07 0.00 0.07 68.00 0.00 0.00 0.00 22.00 0.06 0.00 0.06 69.00 0.00 0.00 0.00 23.00 0.05 0.00 0.05 70.00 0.00 0.00 0.00 24.00 0.03 0.00 0.03 71.00 0.00 0.00 0.00 25.00 0.00 0.00 0.00 72.00 0.00 0.00 0.00 26.00 0.00 0.00 0.00 27.00 0.00 0.00 0.00 28.00 0.00 0.00 0.00 29.00 0.00 0.00 0.00 30.00 0.00 0.00 0.00 31.00 0.00 0.00 0.00 32.00 0.00 0.00 0.00 33.00 0.00 0.00 0.00 34.00 0.00 0.00 0.00 35.00 0.00 0.00 0.00 36.00 0.00 0.00 0.00 37.00 0.00 0.00 0.00 38.00 0.00 0.00 0.00 39.00 0.00 0.00 0.00 40.00 0.00 0.00 0.00 41.00 0.00 0.00 0.00 42.00 0.00 0.00 0.00 43.00 0.00 0.00 0.00 44.00 0.00 0.00 0.00 45.00 0.00 0.00 0.00 46.00 0.00 0.00 0.00

Existing Flows NOAA10 24-hr D 100-Year-Current Rainfall=9.18" 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: Existing Impervious Runoff Area=29,916 sf 100.00% Impervious Runoff Depth=8.94" Flow Length=166' Tc=0.9 min CN=98 Runoff=7.21 cfs 22,286 cf Subcatchment 2S: Existing Pervious Runoff Area=302 sf 0.00% Impervious Runoff Depth=5.99" Tc=1.0 min CN=74 Runoff=0.06 cfs 151 cf Link 3L: Total Site Flows Inflow=7.27 cfs 22,437 cf Primary=7.27 cfs 22,437 cf Total Runoff Area = 30,218 sf Runoff Volume = 22,437 cf Average Runoff Depth = 8.91" 1.00% Pervious = 302 sf 99.00% Impervious = 29,916 sf