complete drainage report rev 9

POA-3 NOAA 24-hr D 2-Year Rainfall=3.44" 2024-05-12 HydroCad - Proposed POA 3B Printed 10/25/2024 Page 14 Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Pond 29P: Basin 12 Stage-Area-Storage 0 50 100 150 200 250 Surface/Horizontal/Wetted Area (sq-ft) 300 350 400 450 500 550 600 650 700 750 599 Elevation (feet) 598 597 Custom Stage Data + Vertical Cone/Cylinder 596 0 200 400 600 Storage (cubic-feet) 800 1,000 800 850 900 Surface Storage

POA-3 2024-05-12 HydroCad - Proposed POA 3B NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Hydrograph for Pond 29P: Basin 12 Time (hours) 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 30.00 32.00 34.00 36.00 38.00 40.00 42.00 44.00 46.00 48.00 50.00 52.00 54.00 56.00 58.00 60.00 62.00 64.00 66.00 68.00 70.00 72.00 Inflow (cfs) 0.00 0.00 0.00 0.00 0.00 0.01 0.20 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 Storage (cubic-feet) 0 0 0 0 0 0 11 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Elevation (feet) 596.00 596.00 596.00 596.00 596.00 596.00 596.03 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 596.00 Discarded (cfs) 0.00 0.00 0.00 0.00 0.00 0.01 0.19 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 Printed 10/25/2024 Page 15

POA-3 NOAA 24-hr D 2-Year Rainfall=3.44" 2024-05-12 HydroCad - Proposed POA 3B Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Stage-Discharge for Pond 29P: Basin 12 Elevation (feet) 596.00 596.02 596.04 596.06 596.08 596.10 596.12 596.14 596.16 596.18 596.20 596.22 596.24 596.26 596.28 596.30 596.32 596.34 596.36 596.38 596.40 596.42 596.44 596.46 596.48 596.50 596.52 596.54 596.56 596.58 596.60 596.62 596.64 596.66 596.68 596.70 596.72 596.74 596.76 596.78 596.80 596.82 596.84 596.86 596.88 596.90 596.92 596.94 596.96 596.98 597.00 Discarded (cfs) 0.00 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 Elevation (feet) 597.02 597.04 597.06 597.08 597.10 597.12 597.14 597.16 597.18 597.20 597.22 597.24 597.26 597.28 597.30 597.32 597.34 597.36 597.38 597.40 597.42 597.44 597.46 597.48 597.50 597.52 597.54 597.56 597.58 597.60 597.62 597.64 597.66 597.68 597.70 597.72 597.74 597.76 597.78 597.80 597.82 597.84 597.86 597.88 597.90 597.92 597.94 597.96 597.98 598.00 598.02 Discarded (cfs) 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 Elevation (feet) 598.04 598.06 598.08 598.10 598.12 598.14 598.16 598.18 598.20 598.22 598.24 598.26 598.28 598.30 598.32 598.34 598.36 598.38 598.40 598.42 598.44 598.46 598.48 598.50 598.52 598.54 598.56 598.58 598.60 598.62 598.64 598.66 598.68 598.70 598.72 598.74 598.76 598.78 598.80 598.82 598.84 598.86 598.88 598.90 598.92 598.94 598.96 598.98 599.00 Discarded (cfs) 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21 Printed 10/25/2024 Page 16

POA-3 2024-05-12 HydroCad - Proposed POA 3B NOAA 24-hr D 2-Year Rainfall=3.44" Printed 10/25/2024 Page 17 Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 29P: Basin 12 Elevation (feet) 596.00 596.05 596.10 596.15 596.20 596.25 596.30 596.35 596.40 596.45 596.50 596.55 596.60 596.65 596.70 596.75 596.80 596.85 596.90 596.95 597.00 597.05 597.10 597.15 597.20 597.25 597.30 597.35 597.40 597.45 597.50 597.55 597.60 597.65 597.70 597.75 597.80 597.85 597.90 597.95 598.00 598.05 598.10 598.15 598.20 598.25 598.30 598.35 598.40 598.45 598.50 Surface (sq-ft) 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 900 Storage (cubic-feet) 0 19 38 58 77 96 115 135 154 173 192 212 231 250 269 289 308 327 346 366 385 404 423 443 462 481 500 520 539 558 577 596 616 635 654 673 693 712 731 750 770 789 808 827 847 866 885 904 924 943 962 Elevation (feet) 598.55 598.60 598.65 598.70 598.75 598.80 598.85 598.90 598.95 599.00 Surface (sq-ft) 900 900 900 900 900 900 900 900 900 900 Storage (cubic-feet) 981 1,001 1,020 1,039 1,058 1,077 1,097 1,116 1,135 1,154

POA-3 2024-05-12 HydroCad - Proposed POA 3B NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Printed 10/25/2024 Page 18 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=2,500 sf 100.00% Impervious Runoff Depth=4.98" Flow Length=110' Slope=0.1200 '/' Tc=4.0 min CN=98 Runoff=0.30 cfs 0.024 af Subcatchment 28S: Basin 12 - Imp Runoff Area=5,251 sf 0.00% Impervious Runoff Depth=2.54" Flow Length=110' Slope=0.1200 '/' Tc=4.0 min CN=74 Runoff=0.39 cfs 0.026 af Subcatchment 30S: Basin 12 - Perv Pond 29P: Basin 12 Peak Elev=596.73' Storage=280 cf Inflow=0.69 cfs 0.049 af Outflow=0.21 cfs 0.049 af Total Runoff Area = 0.178 ac Runoff Volume = 0.049 af Average Runoff Depth = 3.33" 67.75% Pervious = 0.121 ac 32.25% Impervious = 0.057 ac

POA-3 2024-05-12 HydroCad - Proposed POA 3B NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Printed 10/25/2024 Page 19 Summary for Subcatchment 28S: Basin 12 - Imp Runoff = 0.30 cfs @ 12.11 hrs, Volume= Routed to Pond 29P : Basin 12 0.024 af, Depth= 4.98" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) 2,500 2,500 CN 98 Description Paved parking, HSG C 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.8 50 0.1200 0.22 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" 0.2 60 0.1200 5.20 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 4.0 110 Total Sheet Flow (A-B) Subcatchment 28S: Basin 12 - Imp Subcatchment 28S: Basin 12 - Imp Hydrograph 0.34 Runoff 0.32 0.30 cfs NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=2,500 sf Runoff Volume=0.024 af Runoff Depth=4.98" Flow Length=110' Slope=0.1200 '/' Tc=4.0 min CN=98 0.3 0.28 0.26 0.24 Flow (cfs) 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)

POA-3 2024-05-12 HydroCad - Proposed POA 3B NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 28S: Basin 12 - Imp Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 1.00 0.06 0.00 2.00 0.13 0.02 3.00 0.20 0.07 4.00 0.27 0.12 5.00 0.36 0.19 6.00 0.45 0.27 7.00 0.55 0.36 8.00 0.68 0.48 9.00 0.83 0.63 10.00 1.03 0.82 11.00 1.36 1.14 12.00 2.50 2.27 13.00 3.86 3.63 14.00 4.19 3.95 15.00 4.39 4.16 16.00 4.54 4.31 17.00 4.67 4.43 18.00 4.77 4.54 19.00 4.86 4.63 20.00 4.95 4.71 21.00 5.02 4.79 22.00 5.09 4.86 23.00 5.16 4.92 24.00 5.22 4.98 25.00 5.22 4.98 26.00 5.22 4.98 27.00 5.22 4.98 28.00 5.22 4.98 29.00 5.22 4.98 30.00 5.22 4.98 31.00 5.22 4.98 32.00 5.22 4.98 33.00 5.22 4.98 34.00 5.22 4.98 35.00 5.22 4.98 36.00 5.22 4.98 37.00 5.22 4.98 38.00 5.22 4.98 39.00 5.22 4.98 40.00 5.22 4.98 41.00 5.22 4.98 42.00 5.22 4.98 43.00 5.22 4.98 44.00 5.22 4.98 45.00 5.22 4.98 46.00 5.22 4.98 47.00 5.22 4.98 48.00 5.22 4.98 49.00 5.22 4.98 50.00 5.22 4.98 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.02 0.18 0.03 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 0.00 0.00 0.00 0.00 0.00 Time Precip. Excess (hours) (inches) (inches) 51.00 5.22 4.98 52.00 5.22 4.98 53.00 5.22 4.98 54.00 5.22 4.98 55.00 5.22 4.98 56.00 5.22 4.98 57.00 5.22 4.98 58.00 5.22 4.98 59.00 5.22 4.98 60.00 5.22 4.98 61.00 5.22 4.98 62.00 5.22 4.98 63.00 5.22 4.98 64.00 5.22 4.98 65.00 5.22 4.98 66.00 5.22 4.98 67.00 5.22 4.98 68.00 5.22 4.98 69.00 5.22 4.98 70.00 5.22 4.98 71.00 5.22 4.98 72.00 5.22 4.98 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 0.00 Printed 10/25/2024 Page 20

POA-3 NOAA 24-hr D 10-Year Rainfall=5.22" 2024-05-12 HydroCad - Proposed POA 3B Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Printed 10/25/2024 Page 21 Summary for Subcatchment 30S: Basin 12 - Perv Runoff = 0.39 cfs @ 12.12 hrs, Volume= Routed to Pond 29P : Basin 12 0.026 af, Depth= 2.54" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) 5,251 5,251 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) 3.8 50 0.1200 0.22 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" 0.2 60 0.1200 5.20 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 4.0 110 Total Sheet Flow (A-B) Subcatchment 30S: Basin 12 - Perv Subcatchment 30S: Basin 12 - Perv Flow (cfs) Hydrograph Runoff 0.42 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 0.39 cfs NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=5,251 sf Runoff Volume=0.026 af Runoff Depth=2.54" Flow Length=110' Slope=0.1200 '/' Tc=4.0 min CN=74 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)

POA-3 2024-05-12 HydroCad - Proposed POA 3B NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 30S: Basin 12 - Perv Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 1.00 0.06 0.00 2.00 0.13 0.00 3.00 0.20 0.00 4.00 0.27 0.00 5.00 0.36 0.00 6.00 0.45 0.00 7.00 0.55 0.00 8.00 0.68 0.00 9.00 0.83 0.00 10.00 1.03 0.03 11.00 1.36 0.10 12.00 2.50 0.61 13.00 3.86 1.50 14.00 4.19 1.73 15.00 4.39 1.89 16.00 4.54 2.01 17.00 4.67 2.10 18.00 4.77 2.19 19.00 4.86 2.26 20.00 4.95 2.32 21.00 5.02 2.38 22.00 5.09 2.44 23.00 5.16 2.49 24.00 5.22 2.54 25.00 5.22 2.54 26.00 5.22 2.54 27.00 5.22 2.54 28.00 5.22 2.54 29.00 5.22 2.54 30.00 5.22 2.54 31.00 5.22 2.54 32.00 5.22 2.54 33.00 5.22 2.54 34.00 5.22 2.54 35.00 5.22 2.54 36.00 5.22 2.54 37.00 5.22 2.54 38.00 5.22 2.54 39.00 5.22 2.54 40.00 5.22 2.54 41.00 5.22 2.54 42.00 5.22 2.54 43.00 5.22 2.54 44.00 5.22 2.54 45.00 5.22 2.54 46.00 5.22 2.54 47.00 5.22 2.54 48.00 5.22 2.54 49.00 5.22 2.54 50.00 5.22 2.54 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 0.20 0.04 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 Time Precip. Excess (hours) (inches) (inches) 51.00 5.22 2.54 52.00 5.22 2.54 53.00 5.22 2.54 54.00 5.22 2.54 55.00 5.22 2.54 56.00 5.22 2.54 57.00 5.22 2.54 58.00 5.22 2.54 59.00 5.22 2.54 60.00 5.22 2.54 61.00 5.22 2.54 62.00 5.22 2.54 63.00 5.22 2.54 64.00 5.22 2.54 65.00 5.22 2.54 66.00 5.22 2.54 67.00 5.22 2.54 68.00 5.22 2.54 69.00 5.22 2.54 70.00 5.22 2.54 71.00 5.22 2.54 72.00 5.22 2.54 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 0.00 Printed 10/25/2024 Page 22

POA-3 NOAA 24-hr D 10-Year Rainfall=5.22" 2024-05-12 HydroCad - Proposed POA 3B Prepared by Anderson Consulting Services HydroCAD® 10.20-5c s/n 06666 © 2023 HydroCAD Software Solutions LLC Printed 10/25/2024 Page 23 Summary for Pond 29P: Basin 12 Inflow Area = Inflow = Outflow = Discarded = 0.178 ac, 32.25% Impervious, Inflow Depth = 3.33" for 10-Year event 0.69 cfs @ 12.11 hrs, Volume= 0.049 af 0.21 cfs @ 11.91 hrs, Volume= 0.049 af, Atten= 70%, Lag= 0.0 min 0.21 cfs @ 11.91 hrs, Volume= 0.049 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 596.73' @ 12.28 hrs Surf.Area= 900 sf Storage= 280 cf Plug-Flow detention time= 5.8 min calculated for 0.049 af (100% of inflow) Center-of-Mass det. time= 5.8 min ( 802.8 - 797.0 ) Volume #1 Invert 596.00' Avail.Storage 1,004 cf #2 596.00' 151 cf 1,154 cf Elevation (feet) 596.00 599.00 Device #1 Surf.Area (sq-ft) 900 900 Routing Discarded Invert 596.00' Storage Description Custom Stage Data (Prismatic) Listed below (Recalc) 2,700 cf Overall - 191 cf Embedded = 2,509 cf x 40.0% Voids 8.00'D x 3.00'H Vertical Cone/Cylinder Inside #1 191 cf Overall - 6.0" Wall Thickness = 151 cf Total Available Storage Inc.Store (cubic-feet) 0 2,700 Cum.Store (cubic-feet) 0 2,700 Outlet Devices 10.000 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.21 cfs @ 11.91 hrs HW=596.03' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.21 cfs) Pond 29P: Basin 12 Exfiltration