251203_42 ERW_Stormwater Report

NOAA 24-hr D 25-Year Rainfall=6.44" 251202_42 ERW Waystone - Future Rainfall Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 12/3/2025 Page 51 Summary for Subcatchment PR 1B-P: Runoff = 7.74 cfs @ 12.15 hrs, Volume= Routed to Reach 10R : 0.602 af, Depth= 4.07" 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 25-Year Rainfall=6.44" Area (sf) 50,619 26,576 77,195 77,195 CN 74 89 79 Description >75% Grass cover, Good, HSG C Gravel roads, HSG C Weighted Average 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.2 100 0.0400 0.23 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 0.5 95 0.0361 3.06 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 7.7 195 Total Subcatchment PR 1B-P: Hydrograph Runoff 7.74 cfs 8 NOAA 24-hr D 25-Year Rainfall=6.44" Runoff Area=77,195 sf Runoff Volume=0.602 af Runoff Depth=4.07" Flow Length=195' Tc=7.7 min CN=79 7 Flow (cfs) 6 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)

251202_42 ERW Waystone - Future Rainfall NOAA 24-hr D 25-Year Rainfall=6.44" Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment PR 1B-P: 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 0.34 0.00 5.00 0.44 0.00 6.00 0.55 0.00 7.00 0.68 0.01 8.00 0.84 0.03 9.00 1.02 0.08 10.00 1.28 0.16 11.00 1.67 0.34 12.00 3.09 1.25 13.00 4.77 2.60 14.00 5.16 2.94 15.00 5.42 3.16 16.00 5.60 3.33 17.00 5.76 3.47 18.00 5.89 3.58 19.00 6.00 3.68 20.00 6.10 3.77 21.00 6.20 3.86 22.00 6.29 3.94 23.00 6.37 4.01 24.00 6.44 4.07 25.00 6.44 4.07 26.00 6.44 4.07 27.00 6.44 4.07 28.00 6.44 4.07 29.00 6.44 4.07 30.00 6.44 4.07 31.00 6.44 4.07 32.00 6.44 4.07 33.00 6.44 4.07 34.00 6.44 4.07 35.00 6.44 4.07 36.00 6.44 4.07 37.00 6.44 4.07 38.00 6.44 4.07 39.00 6.44 4.07 40.00 6.44 4.07 41.00 6.44 4.07 42.00 6.44 4.07 43.00 6.44 4.07 44.00 6.44 4.07 45.00 6.44 4.07 46.00 6.44 4.07 47.00 6.44 4.07 48.00 6.44 4.07 49.00 6.44 4.07 50.00 6.44 4.07 51.00 6.44 4.07 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.06 0.10 0.20 0.45 3.72 0.98 0.49 0.34 0.28 0.23 0.19 0.17 0.16 0.15 0.14 0.13 0.11 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 6.44 4.07 53.00 6.44 4.07 54.00 6.44 4.07 55.00 6.44 4.07 56.00 6.44 4.07 57.00 6.44 4.07 58.00 6.44 4.07 59.00 6.44 4.07 60.00 6.44 4.07 61.00 6.44 4.07 62.00 6.44 4.07 63.00 6.44 4.07 64.00 6.44 4.07 65.00 6.44 4.07 66.00 6.44 4.07 67.00 6.44 4.07 68.00 6.44 4.07 69.00 6.44 4.07 70.00 6.44 4.07 71.00 6.44 4.07 72.00 6.44 4.07 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 12/3/2025 Page 52

NOAA 24-hr D 25-Year Rainfall=6.44" 251202_42 ERW Waystone - Future Rainfall Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 12/3/2025 Page 53 Summary for Subcatchment PR 2-P: Runoff = 0.76 cfs @ 12.11 hrs, Volume= Routed to Reach DP2-PR : 0.053 af, Depth= 3.76" 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 25-Year Rainfall=6.44" Area (sf) 6,447 958 7,405 7,405 CN 74 89 76 Description >75% Grass cover, Good, HSG C Gravel roads, HSG C Weighted Average 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.6 84 0.0833 0.30 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" Subcatchment PR 2-P: Hydrograph Runoff 0.8 0.76 cfs NOAA 24-hr D 25-Year Rainfall=6.44" Runoff Area=7,405 sf Runoff Volume=0.053 af Runoff Depth=3.76" Flow Length=84' Slope=0.0833 '/' Tc=4.6 min CN=76 0.75 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)

251202_42 ERW Waystone - Future Rainfall NOAA 24-hr D 25-Year Rainfall=6.44" Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment PR 2-P: 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 0.34 0.00 5.00 0.44 0.00 6.00 0.55 0.00 7.00 0.68 0.00 8.00 0.84 0.01 9.00 1.02 0.04 10.00 1.28 0.11 11.00 1.67 0.26 12.00 3.09 1.07 13.00 4.77 2.34 14.00 5.16 2.67 15.00 5.42 2.88 16.00 5.60 3.04 17.00 5.76 3.18 18.00 5.89 3.29 19.00 6.00 3.38 20.00 6.10 3.47 21.00 6.20 3.55 22.00 6.29 3.63 23.00 6.37 3.70 24.00 6.44 3.76 25.00 6.44 3.76 26.00 6.44 3.76 27.00 6.44 3.76 28.00 6.44 3.76 29.00 6.44 3.76 30.00 6.44 3.76 31.00 6.44 3.76 32.00 6.44 3.76 33.00 6.44 3.76 34.00 6.44 3.76 35.00 6.44 3.76 36.00 6.44 3.76 37.00 6.44 3.76 38.00 6.44 3.76 39.00 6.44 3.76 40.00 6.44 3.76 41.00 6.44 3.76 42.00 6.44 3.76 43.00 6.44 3.76 44.00 6.44 3.76 45.00 6.44 3.76 46.00 6.44 3.76 47.00 6.44 3.76 48.00 6.44 3.76 49.00 6.44 3.76 50.00 6.44 3.76 51.00 6.44 3.76 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.02 0.04 0.42 0.09 0.04 0.03 0.03 0.02 0.02 0.02 0.01 0.01 0.01 0.01 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 6.44 3.76 53.00 6.44 3.76 54.00 6.44 3.76 55.00 6.44 3.76 56.00 6.44 3.76 57.00 6.44 3.76 58.00 6.44 3.76 59.00 6.44 3.76 60.00 6.44 3.76 61.00 6.44 3.76 62.00 6.44 3.76 63.00 6.44 3.76 64.00 6.44 3.76 65.00 6.44 3.76 66.00 6.44 3.76 67.00 6.44 3.76 68.00 6.44 3.76 69.00 6.44 3.76 70.00 6.44 3.76 71.00 6.44 3.76 72.00 6.44 3.76 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 12/3/2025 Page 54

NOAA 24-hr D 25-Year Rainfall=6.44" 251202_42 ERW Waystone - Future Rainfall Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 12/3/2025 Page 55 Summary for Reach 10R: Inflow Area = 2.619 ac, 32.35% Impervious, Inflow Depth = 4.76" for 25-Year event Inflow = 11.97 cfs @ 12.10 hrs, Volume= 1.040 af Outflow = 11.97 cfs @ 12.10 hrs, Volume= 1.040 af, Atten= 0%, Lag= 0.0 min Routed to Pond BASIN : Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Reach 10R: Hydrograph Inflow Outflow 11.97 cfs 13 11.97 cfs 12 Inflow Area=2.619 ac 11 10 Flow (cfs) 9 8 7 6 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)

NOAA 24-hr D 25-Year Rainfall=6.44" 251202_42 ERW Waystone - Future Rainfall Printed 12/3/2025 Page 56 Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Reach 10R: 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 0.02 0.04 0.06 0.07 0.08 0.09 0.14 0.20 0.26 0.45 0.91 7.39 1.49 0.76 0.52 0.42 0.35 0.29 0.26 0.24 0.23 0.21 0.19 0.17 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 0.02 0.04 0.06 0.07 0.08 0.09 0.14 0.20 0.26 0.45 0.91 7.39 1.49 0.76 0.52 0.42 0.35 0.29 0.26 0.24 0.23 0.21 0.19 0.17 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 25-Year Rainfall=6.44" 251202_42 ERW Waystone - Future Rainfall Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 12/3/2025 Page 57 Summary for Reach DP1-PR: Inflow Area = Inflow = Outflow = 2.922 ac, 29.00% Impervious, Inflow Depth = 2.86" for 25-Year event 5.46 cfs @ 12.18 hrs, Volume= 0.697 af 5.46 cfs @ 12.18 hrs, Volume= 0.697 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-PR: Hydrograph 6 Inflow Outflow 5.46 cfs 5.46 cfs Inflow Area=2.922 ac 5 Flow (cfs) 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)

NOAA 24-hr D 25-Year Rainfall=6.44" 251202_42 ERW Waystone - Future Rainfall Printed 12/3/2025 Page 58 Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Reach DP1-PR: 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 0.01 0.02 0.03 0.08 2.07 2.29 1.20 0.69 0.33 0.21 0.13 0.08 0.06 0.04 0.02 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 Outflow (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.02 0.03 0.08 2.07 2.29 1.20 0.69 0.33 0.21 0.13 0.08 0.06 0.04 0.02 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 (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 25-Year Rainfall=6.44" 251202_42 ERW Waystone - Future Rainfall Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 12/3/2025 Page 59 Summary for Reach DP2-PR: Inflow Area = Inflow = Outflow = 0.170 ac, 0.00% Impervious, Inflow Depth = 3.76" for 25-Year event 0.76 cfs @ 12.11 hrs, Volume= 0.053 af 0.76 cfs @ 12.11 hrs, Volume= 0.053 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-PR: Hydrograph Inflow Outflow 0.76 cfs 0.8 0.75 0.76 cfs Inflow Area=0.170 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 25-Year Rainfall=6.44" 251202_42 ERW Waystone - Future Rainfall Printed 12/3/2025 Page 60 Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Reach DP2-PR: 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 0.01 0.02 0.04 0.42 0.09 0.04 0.03 0.03 0.02 0.02 0.02 0.01 0.01 0.01 0.01 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 0.01 0.02 0.04 0.42 0.09 0.04 0.03 0.03 0.02 0.02 0.02 0.01 0.01 0.01 0.01 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