251203_42 ERW_Stormwater Report

251202_42 ERW Waystone - Future Rainfall Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Soil Listing (selected nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 0.000 3.092 0.000 0.000 3.092 HSG A HSG B HSG C HSG D Other PR 1A-P, PR 1B-I, PR 1B-P, PR 2-P TOTAL AREA Printed 12/3/2025 Page 3

251202_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 Printed 12/3/2025 Page 4 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 PR 1A-P: Runoff Area=13,167 sf 0.00% Impervious Runoff Depth=1.96" Flow Length=203' Tc=5.9 min CN=78 Runoff=0.68 cfs 0.049 af Subcatchment PR 1B-I: Runoff Area=36,906 sf 100.00% Impervious Runoff Depth=3.85" Flow Length=136' Tc=1.5 min CN=98 Runoff=3.62 cfs 0.272 af Subcatchment PR 1B-P: Runoff Area=77,195 sf 0.00% Impervious Runoff Depth=2.04" Flow Length=195' Tc=7.7 min CN=79 Runoff=3.92 cfs 0.301 af Subcatchment PR 2-P: Runoff Area=7,405 sf 0.00% Impervious Runoff Depth=1.81" Flow Length=84' Slope=0.0833 '/' Tc=4.6 min CN=76 Runoff=0.37 cfs 0.026 af Reach 10R: Inflow=6.68 cfs 0.573 af Outflow=6.68 cfs 0.573 af Reach DP1-PR: Inflow=1.75 cfs 0.278 af Outflow=1.75 cfs 0.278 af Reach DP2-PR: Inflow=0.37 cfs 0.026 af Outflow=0.37 cfs 0.026 af Pond BASIN: Peak Elev=16.73' Storage=0.189 af Inflow=6.68 cfs 0.573 af Discarded=0.31 cfs 0.345 af Primary=1.36 cfs 0.228 af Outflow=1.68 cfs 0.573 af Total Runoff Area = 3.092 ac Runoff Volume = 0.648 af Average Runoff Depth = 2.51" 72.60% Pervious = 2.244 ac 27.40% Impervious = 0.847 ac

NOAA 24-hr D 2-Year Rainfall=4.09" 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 5 Summary for Subcatchment PR 1A-P: Runoff = 0.68 cfs @ 12.13 hrs, Volume= Routed to Reach DP1-PR : 0.049 af, Depth= 1.96" 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 2-Year Rainfall=4.09" Area (sf) 9,975 3,192 13,167 13,167 CN 74 89 78 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) 5.6 100 0.0725 0.30 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 0.3 103 0.1090 5.32 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 5.9 203 Total Subcatchment PR 1A-P: Hydrograph 0.75 Runoff 0.68 cfs 0.7 NOAA 24-hr D 2-Year Rainfall=4.09" Runoff Area=13,167 sf Runoff Volume=0.049 af Runoff Depth=1.96" Flow Length=203' Tc=5.9 min CN=78 0.65 0.6 0.55 Flow (cfs) 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 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 PR 1A-P: 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 0.02 11.00 1.06 0.08 12.00 1.96 0.46 13.00 3.03 1.15 14.00 3.28 1.33 15.00 3.44 1.45 16.00 3.56 1.54 17.00 3.66 1.62 18.00 3.74 1.68 19.00 3.81 1.74 20.00 3.88 1.79 21.00 3.94 1.84 22.00 3.99 1.88 23.00 4.04 1.92 24.00 4.09 1.96 25.00 4.09 1.96 26.00 4.09 1.96 27.00 4.09 1.96 28.00 4.09 1.96 29.00 4.09 1.96 30.00 4.09 1.96 31.00 4.09 1.96 32.00 4.09 1.96 33.00 4.09 1.96 34.00 4.09 1.96 35.00 4.09 1.96 36.00 4.09 1.96 37.00 4.09 1.96 38.00 4.09 1.96 39.00 4.09 1.96 40.00 4.09 1.96 41.00 4.09 1.96 42.00 4.09 1.96 43.00 4.09 1.96 44.00 4.09 1.96 45.00 4.09 1.96 46.00 4.09 1.96 47.00 4.09 1.96 48.00 4.09 1.96 49.00 4.09 1.96 50.00 4.09 1.96 51.00 4.09 1.96 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.03 0.33 0.09 0.05 0.03 0.03 0.02 0.02 0.02 0.02 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 4.09 1.96 53.00 4.09 1.96 54.00 4.09 1.96 55.00 4.09 1.96 56.00 4.09 1.96 57.00 4.09 1.96 58.00 4.09 1.96 59.00 4.09 1.96 60.00 4.09 1.96 61.00 4.09 1.96 62.00 4.09 1.96 63.00 4.09 1.96 64.00 4.09 1.96 65.00 4.09 1.96 66.00 4.09 1.96 67.00 4.09 1.96 68.00 4.09 1.96 69.00 4.09 1.96 70.00 4.09 1.96 71.00 4.09 1.96 72.00 4.09 1.96 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 6

251202_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 Printed 12/3/2025 Page 7 Summary for Subcatchment PR 1B-I: Runoff = 3.62 cfs @ 12.07 hrs, Volume= Routed to Reach 10R : 0.272 af, Depth= 3.85" 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 2-Year Rainfall=4.09" Area (sf) 21,449 15,457 36,906 36,906 CN 98 98 98 Description Roofs, HSG C Paved parking, HSG C Weighted Average 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.2 100 0.0200 1.43 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.44" 0.3 36 0.0097 2.00 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.5 136 Total Subcatchment PR 1B-I: Hydrograph 4 Runoff 3.62 cfs NOAA 24-hr D 2-Year Rainfall=4.09" Runoff Area=36,906 sf Runoff Volume=0.272 af Runoff Depth=3.85" Flow Length=136' Tc=1.5 min CN=98 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)

251202_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 PR 1B-I: Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 1.00 0.05 0.00 2.00 0.10 0.01 3.00 0.15 0.04 4.00 0.21 0.08 5.00 0.28 0.13 6.00 0.35 0.19 7.00 0.43 0.26 8.00 0.53 0.35 9.00 0.65 0.46 10.00 0.81 0.61 11.00 1.06 0.85 12.00 1.96 1.73 13.00 3.03 2.79 14.00 3.28 3.05 15.00 3.44 3.21 16.00 3.56 3.33 17.00 3.66 3.43 18.00 3.74 3.51 19.00 3.81 3.58 20.00 3.88 3.64 21.00 3.94 3.70 22.00 3.99 3.76 23.00 4.04 3.81 24.00 4.09 3.85 25.00 4.09 3.85 26.00 4.09 3.85 27.00 4.09 3.85 28.00 4.09 3.85 29.00 4.09 3.85 30.00 4.09 3.85 31.00 4.09 3.85 32.00 4.09 3.85 33.00 4.09 3.85 34.00 4.09 3.85 35.00 4.09 3.85 36.00 4.09 3.85 37.00 4.09 3.85 38.00 4.09 3.85 39.00 4.09 3.85 40.00 4.09 3.85 41.00 4.09 3.85 42.00 4.09 3.85 43.00 4.09 3.85 44.00 4.09 3.85 45.00 4.09 3.85 46.00 4.09 3.85 47.00 4.09 3.85 48.00 4.09 3.85 49.00 4.09 3.85 50.00 4.09 3.85 51.00 4.09 3.85 Runoff (cfs) 0.00 0.00 0.02 0.03 0.04 0.05 0.05 0.07 0.08 0.10 0.16 0.29 2.32 0.32 0.17 0.11 0.09 0.08 0.06 0.06 0.05 0.05 0.05 0.04 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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 3.85 53.00 4.09 3.85 54.00 4.09 3.85 55.00 4.09 3.85 56.00 4.09 3.85 57.00 4.09 3.85 58.00 4.09 3.85 59.00 4.09 3.85 60.00 4.09 3.85 61.00 4.09 3.85 62.00 4.09 3.85 63.00 4.09 3.85 64.00 4.09 3.85 65.00 4.09 3.85 66.00 4.09 3.85 67.00 4.09 3.85 68.00 4.09 3.85 69.00 4.09 3.85 70.00 4.09 3.85 71.00 4.09 3.85 72.00 4.09 3.85 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 8

NOAA 24-hr D 2-Year Rainfall=4.09" 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 9 Summary for Subcatchment PR 1B-P: Runoff = 3.92 cfs @ 12.15 hrs, Volume= Routed to Reach 10R : 0.301 af, Depth= 2.04" 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 2-Year Rainfall=4.09" 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 3.92 cfs 4 NOAA 24-hr D 2-Year Rainfall=4.09" Runoff Area=77,195 sf Runoff Volume=0.301 af Runoff Depth=2.04" Flow Length=195' Tc=7.7 min CN=79 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)

251202_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 PR 1B-P: 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 0.03 11.00 1.06 0.09 12.00 1.96 0.50 13.00 3.03 1.21 14.00 3.28 1.40 15.00 3.44 1.52 16.00 3.56 1.61 17.00 3.66 1.69 18.00 3.74 1.76 19.00 3.81 1.81 20.00 3.88 1.86 21.00 3.94 1.91 22.00 3.99 1.96 23.00 4.04 2.00 24.00 4.09 2.04 25.00 4.09 2.04 26.00 4.09 2.04 27.00 4.09 2.04 28.00 4.09 2.04 29.00 4.09 2.04 30.00 4.09 2.04 31.00 4.09 2.04 32.00 4.09 2.04 33.00 4.09 2.04 34.00 4.09 2.04 35.00 4.09 2.04 36.00 4.09 2.04 37.00 4.09 2.04 38.00 4.09 2.04 39.00 4.09 2.04 40.00 4.09 2.04 41.00 4.09 2.04 42.00 4.09 2.04 43.00 4.09 2.04 44.00 4.09 2.04 45.00 4.09 2.04 46.00 4.09 2.04 47.00 4.09 2.04 48.00 4.09 2.04 49.00 4.09 2.04 50.00 4.09 2.04 51.00 4.09 2.04 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.06 0.17 1.77 0.54 0.27 0.19 0.15 0.13 0.11 0.10 0.09 0.08 0.08 0.07 0.07 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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 2.04 53.00 4.09 2.04 54.00 4.09 2.04 55.00 4.09 2.04 56.00 4.09 2.04 57.00 4.09 2.04 58.00 4.09 2.04 59.00 4.09 2.04 60.00 4.09 2.04 61.00 4.09 2.04 62.00 4.09 2.04 63.00 4.09 2.04 64.00 4.09 2.04 65.00 4.09 2.04 66.00 4.09 2.04 67.00 4.09 2.04 68.00 4.09 2.04 69.00 4.09 2.04 70.00 4.09 2.04 71.00 4.09 2.04 72.00 4.09 2.04 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 10

NOAA 24-hr D 2-Year Rainfall=4.09" 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 11 Summary for Subcatchment PR 2-P: Runoff = 0.37 cfs @ 12.11 hrs, Volume= Routed to Reach DP2-PR : 0.026 af, Depth= 1.81" 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 2-Year Rainfall=4.09" 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 0.4 Runoff 0.38 0.37 cfs NOAA 24-hr D 2-Year Rainfall=4.09" Runoff Area=7,405 sf Runoff Volume=0.026 af Runoff Depth=1.81" Flow Length=84' Slope=0.0833 '/' Tc=4.6 min CN=76 0.36 0.34 0.32 0.3 0.28 Flow (cfs) 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 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 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 PR 2-P: 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 0.01 11.00 1.06 0.05 12.00 1.96 0.39 13.00 3.03 1.03 14.00 3.28 1.21 15.00 3.44 1.32 16.00 3.56 1.41 17.00 3.66 1.48 18.00 3.74 1.54 19.00 3.81 1.59 20.00 3.88 1.64 21.00 3.94 1.69 22.00 3.99 1.73 23.00 4.04 1.77 24.00 4.09 1.81 25.00 4.09 1.81 26.00 4.09 1.81 27.00 4.09 1.81 28.00 4.09 1.81 29.00 4.09 1.81 30.00 4.09 1.81 31.00 4.09 1.81 32.00 4.09 1.81 33.00 4.09 1.81 34.00 4.09 1.81 35.00 4.09 1.81 36.00 4.09 1.81 37.00 4.09 1.81 38.00 4.09 1.81 39.00 4.09 1.81 40.00 4.09 1.81 41.00 4.09 1.81 42.00 4.09 1.81 43.00 4.09 1.81 44.00 4.09 1.81 45.00 4.09 1.81 46.00 4.09 1.81 47.00 4.09 1.81 48.00 4.09 1.81 49.00 4.09 1.81 50.00 4.09 1.81 51.00 4.09 1.81 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.19 0.05 0.02 0.02 0.01 0.01 0.01 0.01 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 4.09 1.81 53.00 4.09 1.81 54.00 4.09 1.81 55.00 4.09 1.81 56.00 4.09 1.81 57.00 4.09 1.81 58.00 4.09 1.81 59.00 4.09 1.81 60.00 4.09 1.81 61.00 4.09 1.81 62.00 4.09 1.81 63.00 4.09 1.81 64.00 4.09 1.81 65.00 4.09 1.81 66.00 4.09 1.81 67.00 4.09 1.81 68.00 4.09 1.81 69.00 4.09 1.81 70.00 4.09 1.81 71.00 4.09 1.81 72.00 4.09 1.81 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 12