251203_42 ERW_Stormwater Report

250903_42 ERW Waystone - Future Rainfall NOAA 24-hr D 2-Year Rainfall=4.09" Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment EDA-2 (PERV.): Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 1.00 0.05 0.00 2.00 0.10 0.00 3.00 0.15 0.00 4.00 0.21 0.00 5.00 0.28 0.00 6.00 0.35 0.00 7.00 0.43 0.00 8.00 0.53 0.00 9.00 0.65 0.00 10.00 0.81 0.00 11.00 1.06 0.03 12.00 1.96 0.33 13.00 3.03 0.93 14.00 3.28 1.09 15.00 3.44 1.20 16.00 3.56 1.28 17.00 3.66 1.35 18.00 3.74 1.41 19.00 3.81 1.46 20.00 3.88 1.51 21.00 3.94 1.55 22.00 3.99 1.59 23.00 4.04 1.63 24.00 4.09 1.66 25.00 4.09 1.66 26.00 4.09 1.66 27.00 4.09 1.66 28.00 4.09 1.66 29.00 4.09 1.66 30.00 4.09 1.66 31.00 4.09 1.66 32.00 4.09 1.66 33.00 4.09 1.66 34.00 4.09 1.66 35.00 4.09 1.66 36.00 4.09 1.66 37.00 4.09 1.66 38.00 4.09 1.66 39.00 4.09 1.66 40.00 4.09 1.66 41.00 4.09 1.66 42.00 4.09 1.66 43.00 4.09 1.66 44.00 4.09 1.66 45.00 4.09 1.66 46.00 4.09 1.66 47.00 4.09 1.66 48.00 4.09 1.66 49.00 4.09 1.66 50.00 4.09 1.66 51.00 4.09 1.66 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.34 0.11 0.06 0.04 0.03 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Time Precip. Excess (hours) (inches) (inches) 52.00 4.09 1.66 53.00 4.09 1.66 54.00 4.09 1.66 55.00 4.09 1.66 56.00 4.09 1.66 57.00 4.09 1.66 58.00 4.09 1.66 59.00 4.09 1.66 60.00 4.09 1.66 61.00 4.09 1.66 62.00 4.09 1.66 63.00 4.09 1.66 64.00 4.09 1.66 65.00 4.09 1.66 66.00 4.09 1.66 67.00 4.09 1.66 68.00 4.09 1.66 69.00 4.09 1.66 70.00 4.09 1.66 71.00 4.09 1.66 72.00 4.09 1.66 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Printed 11/25/2025 Page 10

NOAA 24-hr D 2-Year Rainfall=4.09" 250903_42 ERW Waystone - Future Rainfall Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 11/25/2025 Page 11 Summary for Reach DP1-EX: Inflow Area = Inflow = Outflow = 2.669 ac, 11.97% Impervious, Inflow Depth = 1.93" for 2-Year event 3.95 cfs @ 12.20 hrs, Volume= 0.428 af 3.95 cfs @ 12.20 hrs, Volume= 0.428 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Reach DP1-EX: Hydrograph Inflow Outflow 3.95 cfs 4 3.95 cfs Inflow Area=2.669 ac Flow (cfs) 3 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)

NOAA 24-hr D 2-Year Rainfall=4.09" 250903_42 ERW Waystone - Future Rainfall Printed 11/25/2025 Page 12 Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Reach DP1-EX: Time (hours) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00 23.00 24.00 25.00 26.00 27.00 28.00 29.00 30.00 31.00 32.00 33.00 34.00 35.00 36.00 37.00 38.00 39.00 40.00 41.00 42.00 43.00 44.00 45.00 46.00 47.00 48.00 49.00 50.00 51.00 Inflow Elevation (cfs) (feet) 0.00 0.00 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.08 0.22 2.02 0.79 0.39 0.27 0.22 0.19 0.15 0.14 0.13 0.12 0.11 0.10 0.09 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Outflow (cfs) 0.00 0.00 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.08 0.22 2.02 0.79 0.39 0.27 0.22 0.19 0.15 0.14 0.13 0.12 0.11 0.10 0.09 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Time (hours) 52.00 53.00 54.00 55.00 56.00 57.00 58.00 59.00 60.00 61.00 62.00 63.00 64.00 65.00 66.00 67.00 68.00 69.00 70.00 71.00 72.00 Inflow (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Elevation (feet) Outflow (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

NOAA 24-hr D 2-Year Rainfall=4.09" 250903_42 ERW Waystone - Future Rainfall Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 11/25/2025 Page 13 Summary for Reach DP2-EX: Inflow Area = Inflow = Outflow = 0.423 ac, 0.00% Impervious, Inflow Depth = 1.66" for 2-Year event 0.77 cfs @ 12.15 hrs, Volume= 0.059 af 0.77 cfs @ 12.15 hrs, Volume= 0.059 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Reach DP2-EX: Hydrograph 0.85 0.8 0.75 Inflow Outflow 0.77 cfs 0.77 cfs Inflow Area=0.423 ac 0.7 0.65 0.6 Flow (cfs) 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 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)

NOAA 24-hr D 2-Year Rainfall=4.09" 250903_42 ERW Waystone - Future Rainfall Printed 11/25/2025 Page 14 Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Reach DP2-EX: Time (hours) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00 23.00 24.00 25.00 26.00 27.00 28.00 29.00 30.00 31.00 32.00 33.00 34.00 35.00 36.00 37.00 38.00 39.00 40.00 41.00 42.00 43.00 44.00 45.00 46.00 47.00 48.00 49.00 50.00 51.00 Inflow Elevation (cfs) (feet) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.34 0.11 0.06 0.04 0.03 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Outflow (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.34 0.11 0.06 0.04 0.03 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Time (hours) 52.00 53.00 54.00 55.00 56.00 57.00 58.00 59.00 60.00 61.00 62.00 63.00 64.00 65.00 66.00 67.00 68.00 69.00 70.00 71.00 72.00 Inflow (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Elevation (feet) Outflow (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

250903_42 ERW Waystone - Future Rainfall NOAA 24-hr D 10-Year Rainfall=6.37" Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 11/25/2025 Page 15 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 EDA-1 (IMPERV): Runoff Area=13,913 sf 100.00% Impervious Runoff Depth=6.13" Flow Length=275' Tc=2.8 min CN=98 Runoff=2.12 cfs 0.163 af Subcatchment EDA-1 (PERV): Runoff Area=102,351 sf 0.00% Impervious Runoff Depth=3.50" Flow Length=501' Tc=13.1 min CN=74 Runoff=7.42 cfs 0.685 af Subcatchment EDA-2 (PERV.): Runoff Area=0.423 ac 0.00% Impervious Runoff Depth=3.50" Flow Length=121' Tc=7.2 min CN=74 Runoff=1.63 cfs 0.123 af Reach DP1-EX: Inflow=8.17 cfs 0.848 af Outflow=8.17 cfs 0.848 af Reach DP2-EX: Inflow=1.63 cfs 0.123 af Outflow=1.63 cfs 0.123 af Total Runoff Area = 3.092 ac Runoff Volume = 0.972 af Average Runoff Depth = 3.77" 89.67% Pervious = 2.773 ac 10.33% Impervious = 0.319 ac

250903_42 ERW Waystone - Future Rainfall NOAA 24-hr D 10-Year Rainfall=6.37" Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 11/25/2025 Page 16 Summary for Subcatchment EDA-1 (IMPERV): Runoff = 2.12 cfs @ 12.09 hrs, Volume= Routed to Reach DP1-EX : 0.163 af, Depth= 6.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 10-Year Rainfall=6.37" Area (sf) 8,137 5,776 13,913 13,913 CN 98 98 98 Description Paved parking, HSG C Roofs, HSG C Weighted Average 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.1 78 0.0150 1.21 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.44" 1.0 12 0.0800 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 0.7 185 0.0830 4.64 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 2.8 275 Total Subcatchment EDA-1 (IMPERV): Hydrograph Runoff 2.12 cfs NOAA 24-hr D 10-Year Rainfall=6.37" Runoff Area=13,913 sf Runoff Volume=0.163 af Runoff Depth=6.13" Flow Length=275' Tc=2.8 min CN=98 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)

250903_42 ERW Waystone - Future Rainfall NOAA 24-hr D 10-Year Rainfall=6.37" Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment EDA-1 (IMPERV): Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 1.00 0.07 0.00 2.00 0.15 0.04 3.00 0.24 0.10 4.00 0.33 0.17 5.00 0.44 0.26 6.00 0.54 0.36 7.00 0.67 0.48 8.00 0.83 0.62 9.00 1.01 0.80 10.00 1.26 1.05 11.00 1.66 1.43 12.00 3.05 2.82 13.00 4.71 4.48 14.00 5.11 4.87 15.00 5.36 5.12 16.00 5.54 5.31 17.00 5.70 5.46 18.00 5.83 5.59 19.00 5.93 5.70 20.00 6.04 5.80 21.00 6.13 5.89 22.00 6.22 5.98 23.00 6.30 6.06 24.00 6.37 6.13 25.00 6.37 6.13 26.00 6.37 6.13 27.00 6.37 6.13 28.00 6.37 6.13 29.00 6.37 6.13 30.00 6.37 6.13 31.00 6.37 6.13 32.00 6.37 6.13 33.00 6.37 6.13 34.00 6.37 6.13 35.00 6.37 6.13 36.00 6.37 6.13 37.00 6.37 6.13 38.00 6.37 6.13 39.00 6.37 6.13 40.00 6.37 6.13 41.00 6.37 6.13 42.00 6.37 6.13 43.00 6.37 6.13 44.00 6.37 6.13 45.00 6.37 6.13 46.00 6.37 6.13 47.00 6.37 6.13 48.00 6.37 6.13 49.00 6.37 6.13 50.00 6.37 6.13 51.00 6.37 6.13 Runoff (cfs) 0.00 0.01 0.02 0.02 0.03 0.03 0.03 0.04 0.05 0.06 0.09 0.17 1.28 0.19 0.10 0.07 0.06 0.05 0.04 0.03 0.03 0.03 0.03 0.02 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Time Precip. Excess (hours) (inches) (inches) 52.00 6.37 6.13 53.00 6.37 6.13 54.00 6.37 6.13 55.00 6.37 6.13 56.00 6.37 6.13 57.00 6.37 6.13 58.00 6.37 6.13 59.00 6.37 6.13 60.00 6.37 6.13 61.00 6.37 6.13 62.00 6.37 6.13 63.00 6.37 6.13 64.00 6.37 6.13 65.00 6.37 6.13 66.00 6.37 6.13 67.00 6.37 6.13 68.00 6.37 6.13 69.00 6.37 6.13 70.00 6.37 6.13 71.00 6.37 6.13 72.00 6.37 6.13 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Printed 11/25/2025 Page 17

NOAA 24-hr D 10-Year Rainfall=6.37" 250903_42 ERW Waystone - Future Rainfall Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 11/25/2025 Page 18 Summary for Subcatchment EDA-1 (PERV): Runoff = 7.42 cfs @ 12.21 hrs, Volume= Routed to Reach DP1-EX : 0.685 af, Depth= 3.50" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 10-Year Rainfall=6.37" Area (sf) 102,351 102,351 CN 74 Description >75% Grass cover, Good, HSG C 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 100 0.0140 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 2.2 401 0.0350 3.01 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 13.1 501 Total Subcatchment EDA-1 (PERV): Hydrograph Runoff 8 7.42 cfs NOAA 24-hr D 10-Year Rainfall=6.37" Runoff Area=102,351 sf Runoff Volume=0.685 af Runoff Depth=3.50" Flow Length=501' Tc=13.1 min CN=74 7 6 Flow (cfs) 5 4 3 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)

250903_42 ERW Waystone - Future Rainfall NOAA 24-hr D 10-Year Rainfall=6.37" Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment EDA-1 (PERV): Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 1.00 0.07 0.00 2.00 0.15 0.00 3.00 0.24 0.00 4.00 0.33 0.00 5.00 0.44 0.00 6.00 0.54 0.00 7.00 0.67 0.00 8.00 0.83 0.00 9.00 1.01 0.02 10.00 1.26 0.08 11.00 1.66 0.20 12.00 3.05 0.94 13.00 4.71 2.14 14.00 5.11 2.45 15.00 5.36 2.65 16.00 5.54 2.80 17.00 5.70 2.93 18.00 5.83 3.04 19.00 5.93 3.13 20.00 6.04 3.22 21.00 6.13 3.29 22.00 6.22 3.37 23.00 6.30 3.44 24.00 6.37 3.50 25.00 6.37 3.50 26.00 6.37 3.50 27.00 6.37 3.50 28.00 6.37 3.50 29.00 6.37 3.50 30.00 6.37 3.50 31.00 6.37 3.50 32.00 6.37 3.50 33.00 6.37 3.50 34.00 6.37 3.50 35.00 6.37 3.50 36.00 6.37 3.50 37.00 6.37 3.50 38.00 6.37 3.50 39.00 6.37 3.50 40.00 6.37 3.50 41.00 6.37 3.50 42.00 6.37 3.50 43.00 6.37 3.50 44.00 6.37 3.50 45.00 6.37 3.50 46.00 6.37 3.50 47.00 6.37 3.50 48.00 6.37 3.50 49.00 6.37 3.50 50.00 6.37 3.50 51.00 6.37 3.50 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.06 0.16 0.40 2.86 1.28 0.61 0.43 0.34 0.29 0.23 0.21 0.20 0.18 0.17 0.16 0.14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Time Precip. Excess (hours) (inches) (inches) 52.00 6.37 3.50 53.00 6.37 3.50 54.00 6.37 3.50 55.00 6.37 3.50 56.00 6.37 3.50 57.00 6.37 3.50 58.00 6.37 3.50 59.00 6.37 3.50 60.00 6.37 3.50 61.00 6.37 3.50 62.00 6.37 3.50 63.00 6.37 3.50 64.00 6.37 3.50 65.00 6.37 3.50 66.00 6.37 3.50 67.00 6.37 3.50 68.00 6.37 3.50 69.00 6.37 3.50 70.00 6.37 3.50 71.00 6.37 3.50 72.00 6.37 3.50 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Printed 11/25/2025 Page 19