Drainage Report

Basin 2-4 without exfiltration Proposed Basin 2-4 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 18 Stage-Area-Storage for Pond 43P: pond 2-4 Elevation Surface Storage Elevation Surface Storage (feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet) 542.00 11,090 0 544.55 11,090 28,279 542.05 11,090 554 544.60 11,090 28,834 542.10 11,090 1,109 544.65 11,090 29,388 542.15 11,090 1,663 544.70 11,090 29,943 542.20 11,090 2,218 544.75 11,090 30,498 542.25 11,090 2,773 544.80 11,090 31,052 542.30 11,090 3,327 544.85 11,090 31,607 542.35 11,090 3,882 544.90 11,090 32,161 542.40 11,090 4,436 544.95 11,090 32,716 542.45 11,090 4,991 545.00 11,090 33,270 542.50 11,090 5,545 545.05 11,090 33,824 542.55 11,090 6,099 545.10 11,090 34,379 542.60 11,090 6,654 545.15 11,090 34,933 542.65 11,090 7,208 545.20 11,090 35,488 542.70 11,090 7,763 545.25 11,090 36,043 542.75 11,090 8,318 545.30 11,090 36,597 542.80 11,090 8,872 545.35 11,090 37,152 542.85 11,090 9,427 545.40 11,090 37,706 542.90 11,090 9,981 545.45 11,090 38,261 542.95 11,090 10,536 545.50 11,090 38,815 543.00 11,090 11,090 545.55 11,090 39,369 543.05 11,090 11,644 545.60 11,090 39,924 543.10 11,090

38,815 543.00 11,090 11,090 545.55 11,090 39,369 543.05 11,090 11,644 545.60 11,090 39,924 543.10 11,090 12,199 545.65 11,090 40,478 543.15 11,090 12,753 545.70 11,090 41,033 543.20 11,090 13,308 545.75 11,090 41,588 543.25 11,090 13,863 545.80 11,090 42,142 543.30 11,090 14,417 545.85 11,090 42,697 543.35 11,090 14,972 545.90 11,090 43,251 543.40 11,090 15,526 545.95 11,090 43,806 543.45 11,090 16,081 546.00 11,090 44,360 543.50 11,090 16,635 543.55 11,090 17,189 543.60 11,090 17,744 543.65 11,090 18,298 543.70 11,090 18,853 543.75 11,090 19,408 543.80 11,090 19,962 543.85 11,090 20,517 543.90 11,090 21,071 543.95 11,090 21,626 544.00 11,090 22,180 544.05 11,090 22,734 544.10 11,090 23,289 544.15 11,090 23,843 544.20 11,090 24,398 544.25 11,090 24,953 544.30 11,090 25,507 544.35 11,090 26,062 544.40 11,090 26,616 544.45 11,090 27,171 544.50 11,090 27,725

Basin 2-4 without exfiltration Proposed Basin 2-4 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 19 Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 38S: Basin 2-4 Runoff Area=96,037 sf Runoff Depth=3.46" Flow Length=1,912' Tc=10.1 min CN=78/98 Runoff=7.12 cfs 0.636 af Subcatchment 45S: Basin 2-4 pe-development Runoff Area=96,036 sf Runoff Depth=2.20" Flow Length=390' Tc=18.0 min CN=70/0 Runoff=3.80 cfs 0.404 af Pond 43P: pond 2-4 Peak Elev=543.52' Storage=16,883 cf Inflow=7.12 cfs 0.636 af Outflow=0.62 cfs 0.403 af Total Runoff Area = 4.409 ac Runoff Volume = 1.040 af Average Runoff Depth = 2.83"

Basin 2-4 without exfiltration Proposed Basin 2-4 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 38S: Basin 2-4 [47] Hint: Peak is 262% of capacity of segment #3 Runoff = 7.12 cfs @ 12.17 hrs, Volume= 0.636 af, Depth= 3.46" Routed to Pond 43P : pond 2-4 Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) CN Description 26,461 98 Roofs, HSG C 11,090 98 Water Surface, 0% imp, HSG C 58,486 74 >75% Grass cover, Good, HSG C 96,037 83 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.4 100 0.0800 0.31 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 0.9 120 0.0200 2.12 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.7 1,692 0.0390 7.60 2.72 Pipe Channel, pipe to basin 15.0" Round w/ 10.0" inside fill Area= 0.4 sf Perim= 2.7' r= 0.13' n= 0.010 10.1 1,912 Total

Basin 2-4 without exfiltration Proposed Basin 2-4 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 21 Subcatchment 38S: Basin 2-4 Hydrograph Runoff 7.12 cfs 7 NOAA 24-hr D 6 10-Year Rainfall=5.22" Runoff Area=96,037 sf 5 Runoff Volume=0.636 af Flow (cfs) 4 Runoff Depth=3.46" Flow Length=1,912' 3 Tc=10.1 min 2 CN=78/98 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)

Basin 2-4 without exfiltration Proposed Basin 2-4 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 22 Hydrograph for Subcatchment 38S: Basin 2-4 Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 2.50 0.16 0.00 0.04 0.02 5.00 0.36 0.00 0.19 0.04 7.50 0.61 0.00 0.42 0.07 10.00 1.03 0.07 0.82 0.23 12.50 3.57 1.54 3.33 2.04 15.00 4.39 2.19 4.16 0.34 17.50 4.73 2.47 4.49 0.21 20.00 4.95 2.65 4.71 0.16 22.50 5.13 2.81 4.89 0.13 25.00 5.22 2.88 4.98 0.00 27.50 5.22 2.88 4.98 0.00 30.00 5.22 2.88 4.98 0.00 32.50 5.22 2.88 4.98 0.00 35.00 5.22 2.88 4.98 0.00 37.50 5.22 2.88 4.98 0.00 40.00 5.22 2.88 4.98 0.00 42.50 5.22 2.88 4.98 0.00 45.00 5.22 2.88 4.98 0.00 47.50 5.22 2.88 4.98 0.00 50.00 5.22 2.88 4.98 0.00 52.50 5.22 2.88 4.98 0.00 55.00 5.22 2.88 4.98 0.00 57.50 5.22 2.88 4.98 0.00 60.00 5.22 2.88 4.98 0.00 62.50 5.22 2.88 4.98 0.00 65.00 5.22 2.88 4.98 0.00 67.50 5.22 2.88 4.98 0.00 70.00 5.22 2.88 4.98 0.00

Basin 2-4 without exfiltration Proposed Basin 2-4 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment 45S: Basin 2-4 pe-development Runoff = 3.80 cfs @ 12.27 hrs, Volume= 0.404 af, Depth= 2.20" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) CN Description 96,036 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.4 100 0.0500 0.12 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.44" 3.6 290 0.0720 1.34 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 18.0 390 Total Subcatchment 45S: Basin 2-4 pe-development Hydrograph Runoff 4 3.80 cfs NOAA 24-hr D 10-Year Rainfall=5.22" 3 Runoff Area=96,036 sf Runoff Volume=0.404 af Flow (cfs) Runoff Depth=2.20" 2

fs) Runoff Depth=2.20" 2 Flow Length=390' Tc=18.0 min CN=70/0 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)

Basin 2-4 without exfiltration Proposed Basin 2-4 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 24 Hydrograph for Subcatchment 45S: Basin 2-4 pe-development Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 2.50 0.16 0.00 0.00 0.00 5.00 0.36 0.00 0.00 0.00 7.50 0.61 0.00 0.00 0.00 10.00 1.03 0.01 0.00 0.03 12.50 3.57 1.05 0.00 2.22 15.00 4.39 1.60 0.00 0.29 17.50 4.73 1.83 0.00 0.18 20.00 4.95 2.00 0.00 0.13 22.50 5.13 2.13 0.00 0.11 25.00 5.22 2.20 0.00 0.00 27.50 5.22 2.20 0.00 0.00 30.00 5.22 2.20 0.00 0.00 32.50 5.22 2.20 0.00 0.00 35.00 5.22 2.20 0.00 0.00 37.50 5.22 2.20 0.00 0.00 40.00 5.22 2.20 0.00 0.00 42.50 5.22 2.20 0.00 0.00 45.00 5.22 2.20 0.00 0.00 47.50 5.22 2.20 0.00 0.00 50.00 5.22 2.20 0.00 0.00 52.50 5.22 2.20 0.00 0.00 55.00 5.22 2.20 0.00 0.00 57.50 5.22 2.20 0.00 0.00 60.00 5.22 2.20 0.00 0.00 62.50 5.22 2.20 0.00 0.00 65.00 5.22 2.20 0.00 0.00 67.50 5.22 2.20 0.00 0.00 70.00 5.22 2.20 0.00 0.00

Basin 2-4 without exfiltration Proposed Basin 2-4 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 25 Summary for Pond 43P: pond 2-4 Inflow Area = 2.205 ac, Inflow Depth = 3.46" for 10-Year event Inflow = 7.12 cfs @ 12.17 hrs, Volume= 0.636 af Outflow = 0.62 cfs @ 13.56 hrs, Volume= 0.403 af, Atten= 91%, Lag= 83.3 min Primary = 0.62 cfs @ 13.56 hrs, Volume= 0.403 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 543.52' @ 13.56 hrs Surf.Area= 11,090 sf Storage= 16,883 cf Plug-Flow detention time= 442.1 min calculated for 0.402 af (63% of inflow) Center-of-Mass det. time= 327.7 min ( 1,132.3 - 804.5 ) Volume Invert Avail.Storage Storage Description #1 542.00' 44,360 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 542.00 11,090 0 0 546.00 11,090 44,360 44,360 Device Routing Invert Outlet Devices #1 Primary 542.90' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 543.40' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.62 cfs @ 13.56 hrs HW=543.52' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.58 cfs @ 2.94 fps) 2=Orifice/Grate (Orifice Controls 0.04 cfs @ 1.19 fps)