251203_42 ERW_Stormwater Report

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 13 Summary for Reach 10R: Inflow Area = 2.619 ac, 32.35% Impervious, Inflow Depth = 2.62" for 2-Year event Inflow = 6.68 cfs @ 12.09 hrs, Volume= 0.573 af Outflow = 6.68 cfs @ 12.09 hrs, Volume= 0.573 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 6.68 cfs 7 6.68 cfs Inflow Area=2.619 ac 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)

NOAA 24-hr D 2-Year Rainfall=4.09" 251202_42 ERW Waystone - Future Rainfall Printed 12/3/2025 Page 14 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 0.00 0.02 0.03 0.04 0.05 0.05 0.07 0.08 0.12 0.21 0.45 4.08 0.86 0.44 0.30 0.25 0.21 0.17 0.15 0.14 0.13 0.12 0.11 0.10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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 0.02 0.03 0.04 0.05 0.05 0.07 0.08 0.12 0.21 0.45 4.08 0.86 0.44 0.30 0.25 0.21 0.17 0.15 0.14 0.13 0.12 0.11 0.10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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" 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 15 Summary for Reach DP1-PR: Inflow Area = Inflow = Outflow = 2.922 ac, 29.00% Impervious, Inflow Depth = 1.14" for 2-Year event 1.75 cfs @ 12.16 hrs, Volume= 0.278 af 1.75 cfs @ 12.16 hrs, Volume= 0.278 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 Inflow Outflow 1.75 cfs Flow (cfs) 1.75 cfs Inflow Area=2.922 ac 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" 251202_42 ERW Waystone - Future Rainfall Printed 12/3/2025 Page 16 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 0.00 0.00 0.01 0.03 0.60 1.29 0.69 0.25 0.11 0.05 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 Outflow (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 0.60 1.29 0.69 0.25 0.11 0.05 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 (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" 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 17 Summary for Reach DP2-PR: Inflow Area = Inflow = Outflow = 0.170 ac, 0.00% Impervious, Inflow Depth = 1.81" for 2-Year event 0.37 cfs @ 12.11 hrs, Volume= 0.026 af 0.37 cfs @ 12.11 hrs, Volume= 0.026 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: Flow (cfs) Hydrograph 0.4 0.38 0.36 0.34 0.32 0.3 0.28 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 Inflow Outflow 0.37 cfs 0.37 cfs Inflow Area=0.170 ac 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" 251202_42 ERW Waystone - Future Rainfall Printed 12/3/2025 Page 18 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 0.00 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 Outflow (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 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 (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

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 19 Summary for Pond BASIN: Inflow Area = 2.619 ac, 32.35% Impervious, Inflow Depth = 2.62" for 2-Year event Inflow = 6.68 cfs @ 12.09 hrs, Volume= 0.573 af Outflow = 1.68 cfs @ 12.47 hrs, Volume= 0.573 af, Atten= 75%, Lag= 22.5 min Discarded = 0.31 cfs @ 12.47 hrs, Volume= 0.345 af Primary = 1.36 cfs @ 12.47 hrs, Volume= 0.228 af Routed to Reach DP1-PR : Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 16.73' @ 12.47 hrs Surf.Area= 0.168 ac Storage= 0.189 af Plug-Flow detention time= 106.8 min calculated for 0.573 af (100% of inflow) Center-of-Mass det. time= 106.7 min ( 906.3 - 799.6 ) Volume #1A Invert 15.00' Avail.Storage 0.199 af #2A 15.75' 0.341 af 0.539 af Storage Description 51.42'W x 141.93'L x 5.00'H Field A 0.838 af Overall - 0.341 af Embedded = 0.497 af x 40.0% Voids ADS_StormTech MC-3500 d +Cap x 133 Inside #1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap 133 Chambers in 7 Rows Cap Storage= 14.9 cf x 2 x 7 rows = 208.6 cf Total Available Storage Storage Group A created with Chamber Wizard Device #1 Routing Primary Invert 15.89' #2 Primary 16.73' #3 Primary 18.75' #4 Discarded 15.00' Outlet Devices 14.0" W x 3.5" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads 20.0" W x 5.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads 1.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 13.00' Discarded OutFlow Max=0.31 cfs @ 12.47 hrs HW=16.73' (Free Discharge) 4=Exfiltration ( Controls 0.31 cfs) Primary OutFlow Max=1.36 cfs @ 12.47 hrs HW=16.73' (Free Discharge) 1=Orifice/Grate (Orifice Controls 1.36 cfs @ 4.00 fps) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

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 20 Pond BASIN: - Chamber Wizard Field A Chamber Model = ADS_StormTechMC-3500 d +Cap (ADS StormTech® MC-3500 d rev 03/14 with Cap volume) Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= 14.9 cf x 2 x 7 rows = 208.6 cf 77.0" Wide + 9.0" Spacing = 86.0" C-C Row Spacing 19 Chambers/Row x 7.17' Long +1.85' Cap Length x 2 = 139.93' Row Length +12.0" End Stone x 2 = 141.93' Base Length 7 Rows x 77.0" Wide + 9.0" Spacing x 6 + 12.0" Side Stone x 2 = 51.42' Base Width 9.0" Stone Base + 45.0" Chamber Height + 6.0" Stone Cover = 5.00' Field Height 133 Chambers x 110.0 cf + 14.9 cf Cap Volume x 2 x 7 Rows = 14,832.2 cf Chamber Storage 36,487.8 cf Field - 14,832.2 cf Chambers = 21,655.6 cf Stone x 40.0% Voids = 8,662.3 cf Stone Storage Chamber Storage + Stone Storage = 23,494.5 cf = 0.539 af Overall Storage Efficiency = 64.4% Overall System Size = 141.93' x 51.42' x 5.00' 133 Chambers 1,351.4 cy Field 802.1 cy Stone

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 21 Pond BASIN: Hydrograph 6.68 cfs Inflow Area=2.619 ac Peak Elev=16.73' Storage=0.189 af 7 6 Flow (cfs) 5 4 3 1.68 cfs 2 1.36 cfs 1 0.31 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) Inflow Outflow Discarded Primary

251202_42 ERW Waystone - Future Rainfall NOAA 24-hr D 2-Year Rainfall=4.09" Printed 12/3/2025 Page 22 Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Hydrograph for Pond BASIN: Time (hours) 0.00 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00 22.50 25.00 27.50 30.00 32.50 35.00 37.50 40.00 42.50 45.00 47.50 50.00 52.50 55.00 57.50 60.00 62.50 65.00 67.50 70.00 Inflow (cfs) 0.00 0.02 0.05 0.08 0.21 1.60 0.30 0.19 0.14 0.12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Storage Elevation (acre-feet) (feet) 0.000 15.00 0.000 15.01 0.001 15.01 0.001 15.02 0.004 15.06 0.189 16.73 0.092 16.04 0.073 15.91 0.056 15.79 0.037 15.54 0.010 15.14 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 0.000 15.00 Outflow (cfs) 0.00 0.02 0.04 0.07 0.17 1.67 0.48 0.26 0.24 0.21 0.18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Discarded (cfs) 0.00 0.02 0.04 0.07 0.17 0.31 0.26 0.25 0.24 0.21 0.18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Primary (cfs) 0.00 0.00 0.00 0.00 0.00 1.36 0.22 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