JMA02P003 262 270 Main Street Development Stormwater Management Report

Proposed 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. Summary for Pond 5P: Porous Pavement B Inflow Area = 16,284 sf, 94.43% Impervious, Inflow Depth = 8.78" for 100-Year-Current event Inflow = 3.88 cfs @ 12.06 hrs, Volume= 11,908 cf Outflow = 0.20 cfs @ 13.48 hrs, Volume= 11,908 cf, Atten= 95%, Lag= 85.4 min Discarded = 0.07 cfs @ 4.95 hrs, Volume= 7,190 cf Primary = 0.13 cfs @ 13.48 hrs, Volume= 4,718 cf Routed to nonexistent node 6L Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 97.93' @ 13.48 hrs Surf.Area= 5,690 sf Storage= 5,275 cf Plug-Flow detention time= 313.2 min calculated for 11,900 cf (100% of inflow) Center-of-Mass det. time= 313.4 min ( 1,053.1 - 739.7 ) Volume Invert Avail.Storage Storage Description #1 97.00' 14,225 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 97.00 5,690 0 0 98.00 5,690 5,690 5,690 99.00 5,690 5,690 11,380 99.50 5,690 2,845 14,225 Device Routing Invert Outlet Devices #1 Primary 97.20' 2.5" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Discarded 97.00' 0.500 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.07 cfs @ 4.95 hrs HW=97.03' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.07 cfs) Primary OutFlow Max=0.13 cfs @ 13.48 hrs HW=97.93' (Free Discharge)

ce area Discarded OutFlow Max=0.07 cfs @ 4.95 hrs HW=97.03' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.07 cfs) Primary OutFlow Max=0.13 cfs @ 13.48 hrs HW=97.93' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.13 cfs @ 3.80 fps)

Proposed 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. Pond 5P: Porous Pavement B Hydrograph 3.88 cfs Inflow Outflow Inflow Area=16,284 sf Discarded Primary 4 Peak Elev=97.93' Storage=5,275 cf 3 Flow (cfs) 2 1 0.20 cfs 0.07 cfs 0.13 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 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. 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 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. 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 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. 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 0.05 83 97.01 0.04 0.04 0.00 5.00 0.07 143 97.03 0.07 0.07 0.00 7.50 0.09 293 97.05 0.07 0.07 0.00 10.00 0.15 744 97.13 0.07 0.07 0.00 12.50 0.38 5,016 97.88 0.19 0.07 0.12 15.00 0.13 5,044 97.89 0.19 0.07 0.13 17.50 0.09 4,291 97.75 0.18 0.07 0.11 20.00 0.07 3,516 97.62 0.16 0.07 0.09 22.50 0.05 2,752 97.48 0.14 0.07 0.07 25.00 0.00 1,932 97.34 0.10 0.07 0.03 27.50 0.00 1,233 97.22 0.07 0.07 0.00 30.00 0.00 640 97.11 0.07 0.07 0.00 32.50 0.00 73 97.01 0.03 0.03 0.00 35.00 0.00 1 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 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. 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=3.81" Tc=1.0 min CN=98 Runoff=1.47 cfs 4,418 cf Subcatchment 3S: Proposed Pervious Runoff Area=907 sf 0.00% Impervious Runoff Depth=1.63" Tc=1.0 min CN=74 Runoff=0.05 cfs 123 cf Subcatchment 4S: Proposed Impervious Runoff Area=15,377 sf 100.00% Impervious Runoff Depth=3.81" Tc=1.0 min CN=98 Runoff=1.62 cfs 4,876 cf Pond 2P: Basin A Peak Elev=97.01' Storage=1,835 cf Inflow=1.47 cfs 4,418 cf Discarded=0.02 cfs 3,042 cf Primary=0.09 cfs 1,376 cf Outflow=0.12 cfs 4,418 cf Pond 5P: Porous Pavement B Peak Elev=97.32' Storage=1,820 cf Inflow=1.67 cfs 4,999 cf Discarded=0.07 cfs 4,681 cf Primary=0.02 cfs 318 cf Outflow=0.09 cfs 4,999 cf Total Runoff Area = 30,218 sf Runoff Volume = 9,417 cf Average Runoff Depth = 3.74" 3.00% Pervious = 907 sf 97.00% Impervious = 29,311 sf

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. Summary for Subcatchment 1S: Proposed Impervious Runoff = 1.47 cfs @ 12.06 hrs, Volume= 4,418 cf, Depth= 3.81" 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-Future Rainfall=4.04" 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 1.47 cfs NOAA10 24-hr D 2-Year-Future Rainfall=4.04" Runoff Area=13,934 sf Runoff Volume=4,418 cf 1 Runoff Depth=3.81" Flow (cfs) Tc=1.0 min

Runoff Depth=3.81" 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)