JMA02P003 262 270 Main Street Development Stormwater Management Report

Proposed Flows 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. Area Listing (all nodes) Area CN Description (sq-ft) (subcatchment-numbers) 907 74 >75% Grass cover, Good, HSG C (3S) 15,377 98 Paved parking, HSG C (4S) 13,934 98 Roofs, HSG C (1S) 30,218 97 TOTAL AREA

Proposed Flows 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. Soil Listing (all nodes) Area Soil Subcatchment (sq-ft) Group Numbers 0 HSG A 0 HSG B 30,218 HSG C 1S, 3S, 4S 0 HSG D 0 Other 30,218 TOTAL AREA

Proposed Flows 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. Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatch (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) Cover Numbers 0 0 907 0 0 907 >75% Grass cover, Good 0 0 15,377 0 0 15,377 Paved parking 0 0 13,934 0 0 13,934 Roofs 0 0 30,218 0 0 30,218 TOTAL AREA

Proposed Flows NOAA10 24-hr D 2-Year-Current Rainfall=3.43" 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=3.20" Tc=1.0 min CN=98 Runoff=1.24 cfs 3,712 cf Subcatchment 3S: Proposed Pervious Runoff Area=907 sf 0.00% Impervious Runoff Depth=1.19" Tc=1.0 min CN=74 Runoff=0.03 cfs 90 cf Subcatchment 4S: Proposed Impervious Runoff Area=15,377 sf 100.00% Impervious Runoff Depth=3.20" Tc=1.0 min CN=98 Runoff=1.37 cfs 4,096 cf Pond 2P: Basin A Peak Elev=96.83' Storage=1,526 cf Inflow=1.24 cfs 3,712 cf Discarded=0.02 cfs 2,932 cf Primary=0.06 cfs 779 cf Outflow=0.08 cfs 3,712 cf Pond 5P: Porous Pavement B Peak Elev=97.26' Storage=1,489 cf Inflow=1.41 cfs 4,186 cf Discarded=0.07 cfs 4,115 cf Primary=0.01 cfs 71 cf Outflow=0.07 cfs 4,186 cf Total Runoff Area = 30,218 sf Runoff Volume = 7,898 cf Average Runoff Depth = 3.14" 3.00% Pervious = 907 sf 97.00% Impervious = 29,311 sf

Proposed Flows NOAA10 24-hr D 2-Year-Current Rainfall=3.43" 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 = 1.24 cfs @ 12.06 hrs, Volume= 3,712 cf, Depth= 3.20" 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 2-Year-Current Rainfall=3.43" 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 1.24 cfs NOAA10 24-hr D 2-Year-Current Rainfall=3.43" 1 Runoff Area=13,934 sf Runoff Volume=3,712 cf Runoff Depth=3.20" Flow (cfs)

Runoff Depth=3.20" Flow (cfs) Tc=1.0 min CN=98 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-Current Rainfall=3.43" 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 3.43 3.20 0.00 1.00 0.04 0.00 0.00 48.00 3.43 3.20 0.00 2.00 0.10 0.01 0.01 49.00 3.43 3.20 0.00 3.00 0.16 0.04 0.01 50.00 3.43 3.20 0.00 4.00 0.22 0.09 0.02 51.00 3.43 3.20 0.00 5.00 0.30 0.14 0.02 52.00 3.43 3.20 0.00 6.00 0.38 0.21 0.02 53.00 3.43 3.20 0.00 7.00 0.47 0.29 0.03 54.00 3.43 3.20 0.00 8.00 0.57 0.38 0.03 55.00 3.43 3.20 0.00 9.00 0.68 0.48 0.03 56.00 3.43 3.20 0.00 10.00 0.82 0.62 0.05 57.00 3.43 3.20 0.00 11.00 1.02 0.81 0.08 58.00 3.43 3.20 0.00 12.00 1.62 1.40 0.76 59.00 3.43 3.20 0.00 13.00 2.41 2.19 0.09 60.00 3.43 3.20 0.00 14.00 2.61 2.38 0.05 61.00 3.43 3.20 0.00 15.00 2.75 2.52 0.04 62.00 3.43 3.20 0.00 16.00 2.86 2.63 0.03 63.00 3.43 3.20 0.00 17.00 2.96 2.73 0.03 64.00 3.43 3.20 0.00 18.00 3.05 2.82 0.03 65.00 3.43 3.20 0.00 19.00 3.13 2.90 0.03 66.00 3.43 3.20 0.00 20.00 3.21 2.97 0.02 67.00

0 18.00 3.05 2.82 0.03 65.00 3.43 3.20 0.00 19.00 3.13 2.90 0.03 66.00 3.43 3.20 0.00 20.00 3.21 2.97 0.02 67.00 3.43 3.20 0.00 21.00 3.27 3.04 0.02 68.00 3.43 3.20 0.00 22.00 3.33 3.10 0.02 69.00 3.43 3.20 0.00 23.00 3.39 3.15 0.02 70.00 3.43 3.20 0.00 24.00 3.43 3.20 0.01 71.00 3.43 3.20 0.00 25.00 3.43 3.20 0.00 72.00 3.43 3.20 0.00 26.00 3.43 3.20 0.00 27.00 3.43 3.20 0.00 28.00 3.43 3.20 0.00 29.00 3.43 3.20 0.00 30.00 3.43 3.20 0.00 31.00 3.43 3.20 0.00 32.00 3.43 3.20 0.00 33.00 3.43 3.20 0.00 34.00 3.43 3.20 0.00 35.00 3.43 3.20 0.00 36.00 3.43 3.20 0.00 37.00 3.43 3.20 0.00 38.00 3.43 3.20 0.00 39.00 3.43 3.20 0.00 40.00 3.43 3.20 0.00 41.00 3.43 3.20 0.00 42.00 3.43 3.20 0.00 43.00 3.43 3.20 0.00 44.00 3.43 3.20 0.00 45.00 3.43 3.20 0.00 46.00 3.43 3.20 0.00

Proposed Flows NOAA10 24-hr D 2-Year-Current Rainfall=3.43" 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 = 0.03 cfs @ 12.07 hrs, Volume= 90 cf, Depth= 1.19" 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 2-Year-Current Rainfall=3.43" 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 0.038 Runoff 0.036 0.03 cfs 0.034 NOAA10 24-hr D 0.032 2-Year-Current Rainfall=3.43" 0.03 0.028 Runoff Area=907 sf 0.026 Runoff Volume=90 cf 0.024 Runoff Depth=1.19"

Runoff Volume=90 cf 0.024 Runoff Depth=1.19" 0.022 Flow (cfs) 0.02 Tc=1.0 min 0.018 CN=74 0.016 0.014 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)