Drainage Report

Basin 2-1 Proposed Basin 2-1 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 18 Pond 41P: Pond 2-1 Hydrograph Inflow 1.62 cfs Primary Inflow Area=0.599 ac Peak Elev=547.31' Storage=2,643 cf Flow (cfs) 1 0.44 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)

Basin 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" 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 33S: All basin's 2 undetained Runoff Area=34,308 sf Runoff Depth=5.52" Flow Length=36' Slope=0.1600 '/' Tc=10.0 min CN=74/0 Runoff=4.26 cfs 0.362 af Subcatchment 34S: Pre-dev basin 2 All Runoff Area=465,453 sf Runoff Depth=5.04" Flow Length=1,360' Tc=31.9 min CN=70/0 Runoff=32.35 cfs 4.485 af Subcatchment 40S: Basin 2-1 Runoff Area=26,074 sf Runoff Depth=5.81" Flow Length=190' Tc=10.0 min CN=76/98 Runoff=3.38 cfs 0.290 af Pond 41P: Pond 2-1 Peak Elev=547.85' Storage=3,730 cf Inflow=3.38 cfs 0.290 af Outflow=2.50 cfs 0.246 af Total Runoff Area = 12.072 ac Runoff Volume = 5.137 af Average Runoff Depth = 5.11"

Basin 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" 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 33S: All basin's 2 undetained Runoff = 4.26 cfs @ 12.17 hrs, Volume= 0.362 af, Depth= 5.52" 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 100-Year Rainfall=8.66" Area (sf) CN Description 34,308 74 >75% Grass cover, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.0 36 0.1600 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.44" 4.0 36 Total, Increased to minimum Tc = 10.0 min Subcatchment 33S: All basin's 2 undetained Hydrograph Runoff 4.26 cfs 4 NOAA 24-hr D 100-Year Rainfall=8.66" Runoff Area=34,308 sf 3 Runoff Volume=0.362 af Flow (cfs) Runoff Depth=5.52" 2 Flow Length=36'

Runoff Depth=5.52" 2 Flow Length=36' Slope=0.1600 '/' Tc=10.0 min 1 CN=74/0 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 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 21 Summary for Subcatchment 34S: Pre-dev basin 2 All Runoff = 32.35 cfs @ 12.45 hrs, Volume= 4.485 af, Depth= 5.04" 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 100-Year Rainfall=8.66" Area (sf) CN Description 465,453 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" 17.6 1,260 0.0570 1.19 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 31.9 1,360 Total Subcatchment 34S: Pre-dev basin 2 All Hydrograph 36 Runoff 34 32.35 cfs 32 NOAA 24-hr D 30 28 100-Year Rainfall=8.66" 26 Runoff Area=465,453 sf 24 22 Runoff Volume=4.485 af Flow (cfs) 20 18 Runoff Depth=5.04"

Runoff Volume=4.485 af Flow (cfs) 20 18 Runoff Depth=5.04" 16 Flow Length=1,360' 14 12 Tc=31.9 min 10 CN=70/0 8 6 4 2 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 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment 40S: Basin 2-1 Runoff = 3.38 cfs @ 12.17 hrs, Volume= 0.290 af, Depth= 5.81" Routed to Pond 41P : Pond 2-1 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 100-Year Rainfall=8.66" Area (sf) CN Description 23,447 74 >75% Grass cover, Good, HSG C 607 98 Roofs, HSG C 2,020 98 Water Surface, 0% imp, HSG C 26,074 76 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.1 100 0.0600 0.27 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 0.5 90 0.0340 2.77 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 6.6 190 Total, Increased to minimum Tc = 10.0 min Subcatchment 40S: Basin 2-1 Hydrograph Runoff 3.38 cfs NOAA 24-hr D 3 100-Year Rainfall=8.66" Runoff Area=26,074 sf

100-Year Rainfall=8.66" Runoff Area=26,074 sf Runoff Volume=0.290 af Flow (cfs) 2 Runoff Depth=5.81" Flow Length=190' Tc=10.0 min 1 CN=76/98 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 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" 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 Pond 41P: Pond 2-1 Inflow Area = 0.599 ac, Inflow Depth = 5.81" for 100-Year event Inflow = 3.38 cfs @ 12.17 hrs, Volume= 0.290 af Outflow = 2.50 cfs @ 12.26 hrs, Volume= 0.246 af, Atten= 26%, Lag= 5.5 min Primary = 2.50 cfs @ 12.26 hrs, Volume= 0.246 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 547.85' @ 12.26 hrs Surf.Area= 2,020 sf Storage= 3,730 cf Plug-Flow detention time= 142.0 min calculated for 0.246 af (85% of inflow) Center-of-Mass det. time= 72.1 min ( 889.9 - 817.8 ) Volume Invert Avail.Storage Storage Description #1 546.00' 4,040 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 546.00 2,020 0 0 548.00 2,020 4,040 4,040 Device Routing Invert Outlet Devices #1 Primary 546.95' 8.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 547.20' 10.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=2.48 cfs @ 12.26 hrs HW=547.84' (Free Discharge) 1=Orifice/Grate (Orifice Controls 1.25 cfs @ 3.59 fps) 2=Orifice/Grate (Orifice Controls 1.22 cfs @ 2.72 fps)

Basin 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 24 Pond 41P: Pond 2-1 Hydrograph Inflow 3.38 cfs Primary Inflow Area=0.599 ac 3 Peak Elev=547.85' 2.50 cfs Storage=3,730 cf Flow (cfs) 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)