251203_42 ERW_Stormwater Report

NOAA 24-hr D 10-Year Rainfall=6.37" 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 32 Summary for Subcatchment PR 2-P: Runoff = 0.74 cfs @ 12.11 hrs, Volume= Routed to Reach DP2-PR : 0.052 af, Depth= 3.70" 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) 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 0.74 cfs 0.75 NOAA 24-hr D 10-Year Rainfall=6.37" Runoff Area=7,405 sf Runoff Volume=0.052 af Runoff Depth=3.70" Flow Length=84' Slope=0.0833 '/' Tc=4.6 min CN=76 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 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 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 0.33 0.00 5.00 0.44 0.00 6.00 0.54 0.00 7.00 0.67 0.00 8.00 0.83 0.01 9.00 1.01 0.04 10.00 1.26 0.11 11.00 1.66 0.25 12.00 3.05 1.05 13.00 4.71 2.30 14.00 5.11 2.62 15.00 5.36 2.83 16.00 5.54 2.99 17.00 5.70 3.12 18.00 5.83 3.23 19.00 5.93 3.32 20.00 6.04 3.41 21.00 6.13 3.49 22.00 6.22 3.57 23.00 6.30 3.64 24.00 6.37 3.70 25.00 6.37 3.70 26.00 6.37 3.70 27.00 6.37 3.70 28.00 6.37 3.70 29.00 6.37 3.70 30.00 6.37 3.70 31.00 6.37 3.70 32.00 6.37 3.70 33.00 6.37 3.70 34.00 6.37 3.70 35.00 6.37 3.70 36.00 6.37 3.70 37.00 6.37 3.70 38.00 6.37 3.70 39.00 6.37 3.70 40.00 6.37 3.70 41.00 6.37 3.70 42.00 6.37 3.70 43.00 6.37 3.70 44.00 6.37 3.70 45.00 6.37 3.70 46.00 6.37 3.70 47.00 6.37 3.70 48.00 6.37 3.70 49.00 6.37 3.70 50.00 6.37 3.70 51.00 6.37 3.70 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 0.41 0.08 0.04 0.03 0.02 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 6.37 3.70 53.00 6.37 3.70 54.00 6.37 3.70 55.00 6.37 3.70 56.00 6.37 3.70 57.00 6.37 3.70 58.00 6.37 3.70 59.00 6.37 3.70 60.00 6.37 3.70 61.00 6.37 3.70 62.00 6.37 3.70 63.00 6.37 3.70 64.00 6.37 3.70 65.00 6.37 3.70 66.00 6.37 3.70 67.00 6.37 3.70 68.00 6.37 3.70 69.00 6.37 3.70 70.00 6.37 3.70 71.00 6.37 3.70 72.00 6.37 3.70 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 33

NOAA 24-hr D 10-Year Rainfall=6.37" 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 34 Summary for Reach 10R: Inflow Area = 2.619 ac, 32.35% Impervious, Inflow Depth = 4.70" for 10-Year event Inflow = 11.81 cfs @ 12.10 hrs, Volume= 1.025 af Outflow = 11.81 cfs @ 12.10 hrs, Volume= 1.025 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 13 Inflow Outflow 11.81 cfs 11.81 cfs 12 Inflow Area=2.619 ac 11 10 9 Flow (cfs) 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 10-Year Rainfall=6.37" 251202_42 ERW Waystone - Future Rainfall Printed 12/3/2025 Page 35 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 0.13 0.19 0.26 0.44 0.90 7.29 1.47 0.75 0.51 0.42 0.35 0.28 0.26 0.24 0.22 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 0.13 0.19 0.26 0.44 0.90 7.29 1.47 0.75 0.51 0.42 0.35 0.28 0.26 0.24 0.22 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 10-Year Rainfall=6.37" 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 36 Summary for Reach DP1-PR: Inflow Area = Inflow = Outflow = 2.922 ac, 29.00% Impervious, Inflow Depth = 2.81" for 10-Year event 5.37 cfs @ 12.19 hrs, Volume= 0.683 af 5.37 cfs @ 12.19 hrs, Volume= 0.683 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 5.37 cfs 5.37 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 10-Year Rainfall=6.37" 251202_42 ERW Waystone - Future Rainfall Printed 12/3/2025 Page 37 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 0.01 0.03 0.07 2.04 2.25 1.19 0.68 0.32 0.21 0.13 0.08 0.05 0.03 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 0.01 0.03 0.07 2.04 2.25 1.19 0.68 0.32 0.21 0.13 0.08 0.05 0.03 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 10-Year Rainfall=6.37" 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 38 Summary for Reach DP2-PR: Inflow Area = Inflow = Outflow = 0.170 ac, 0.00% Impervious, Inflow Depth = 3.70" for 10-Year event 0.74 cfs @ 12.11 hrs, Volume= 0.052 af 0.74 cfs @ 12.11 hrs, Volume= 0.052 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 0.8 0.74 cfs 0.75 Inflow Outflow 0.74 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 10-Year Rainfall=6.37" 251202_42 ERW Waystone - Future Rainfall Printed 12/3/2025 Page 39 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 0.41 0.08 0.04 0.03 0.02 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 0.41 0.08 0.04 0.03 0.02 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

251202_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 12/3/2025 Page 40 Summary for Pond BASIN: Inflow Area = 2.619 ac, 32.35% Impervious, Inflow Depth = 4.70" for 10-Year event Inflow = 11.81 cfs @ 12.10 hrs, Volume= 1.025 af Outflow = 5.09 cfs @ 12.29 hrs, Volume= 1.025 af, Atten= 57%, Lag= 11.6 min Discarded = 0.39 cfs @ 12.29 hrs, Volume= 0.440 af Primary = 4.70 cfs @ 12.29 hrs, Volume= 0.585 af Routed to Reach DP1-PR : Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 17.58' @ 12.29 hrs Surf.Area= 0.168 ac Storage= 0.304 af Plug-Flow detention time= 91.9 min calculated for 1.025 af (100% of inflow) Center-of-Mass det. time= 92.0 min ( 880.9 - 789.0 ) 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=0.39 cfs @ 12.29 hrs HW=17.58' (Free Discharge) 4=Exfiltration ( Controls 0.39 cfs) Primary OutFlow Max=4.70 cfs @ 12.29 hrs HW=17.58' (Free Discharge) 1=Orifice/Grate (Orifice Controls 2.03 cfs @ 5.98 fps) 2=Orifice/Grate (Orifice Controls 2.66 cfs @ 3.83 fps) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

251202_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 12/3/2025 Page 41 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