Supporting Documentation · Jul 30, 2024
Revised Stormwater Management Report
69ec9df8b1f4567abd2a92749a074a179a57821dd07f0cd16dd61242156a3c29Indexed text
POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 79 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Link 34L: DA 2 Undetained Inflow Area = 177,655 sf, 29.56% Impervious, Inflow Depth = 1.92" for 2-Year event Inflow = 7.56 cfs @ 12.16 hrs, Volume= 28,487 cf Primary = 7.56 cfs @ 12.16 hrs, Volume= 28,487 cf, Atten= 0%, Lag= 0.0 min Routed to Link 28L : POA 2 Primary outflow = Inflow, Time Span= 0.00-80.00 hrs, dt= 0.04 hrs Link 34L: DA 2 Undetained Hydrograph 8 7.56 cfs 7.56 cfs Inflow Primary Inflow Area=177,655 sf 7 Flow (cfs) 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 74 76 78 80 Time (hours)
POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 80 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Hydrograph for Link 34L: DA 2 Undetained Time (hours) 0.00 0.80 1.60 2.40 3.20 4.00 4.80 5.60 6.40 7.20 8.00 8.80 9.60 10.40 11.20 12.00 12.80 13.60 14.40 15.20 16.00 16.80 17.60 18.40 19.20 20.00 20.80 21.60 22.40 23.20 24.00 24.80 25.60 26.40 27.20 28.00 28.80 29.60 30.40 31.20 32.00 32.80 33.60 34.40 35.20 36.00 36.80 37.60 38.40 39.20 40.00 Inflow (cfs) 0.00 0.00 0.01 0.02 0.03 0.04 0.05 0.05 0.06 0.08 0.10 0.11 0.15 0.25 0.56 3.34 1.28 0.64 0.47 0.34 0.30 0.26 0.23 0.19 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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 0.01 0.02 0.03 0.04 0.05 0.05 0.06 0.08 0.10 0.11 0.15 0.25 0.56 3.34 1.28 0.64 0.47 0.34 0.30 0.26 0.23 0.19 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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) 40.80 41.60 42.40 43.20 44.00 44.80 45.60 46.40 47.20 48.00 48.80 49.60 50.40 51.20 52.00 52.80 53.60 54.40 55.20 56.00 56.80 57.60 58.40 59.20 60.00 60.80 61.60 62.40 63.20 64.00 64.80 65.60 66.40 67.20 68.00 68.80 69.60 70.40 71.20 72.00 72.80 73.60 74.40 75.20 76.00 76.80 77.60 78.40 79.20 80.00 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 81 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 19S: Basin 3 - Imp Runoff = 3.40 cfs @ 12.15 hrs, Volume= Routed to Pond 21P : Basin 3 13,465 cf, Depth= 4.98" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-80.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) 6,970 18,295 7,163 32,428 32,428 Tc (min) 8.3 Length (feet) 75 CN 98 98 98 98 Description Roofs, HSG D Roofs, HSG C Paved parking, HSG C Weighted Average 100.00% Impervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.0400 0.15 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" Subcatchment 19S: Basin 3 - Imp Hydrograph Runoff 3.40 cfs Flow (cfs) 3 2 1 0 NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=32,428 sf Runoff Volume=13,465 cf Runoff Depth=4.98" Flow Length=75' Slope=0.0400 '/' Tc=8.3 min CN=98 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 74 76 78 80 Time (hours)
POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 82 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 19S: Basin 3 - Imp Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.80 0.05 0.00 1.60 0.10 0.01 2.40 0.15 0.04 3.20 0.21 0.08 4.00 0.27 0.12 4.80 0.34 0.18 5.60 0.41 0.24 6.40 0.48 0.30 7.20 0.57 0.39 8.00 0.68 0.48 8.80 0.80 0.59 9.60 0.94 0.74 10.40 1.14 0.93 11.20 1.46 1.24 12.00 2.50 2.27 12.80 3.76 3.53 13.60 4.08 3.84 14.40 4.28 4.04 15.20 4.42 4.19 16.00 4.54 4.31 16.80 4.65 4.41 17.60 4.74 4.50 18.40 4.81 4.57 19.20 4.88 4.64 20.00 4.95 4.71 20.80 5.01 4.77 21.60 5.07 4.83 22.40 5.12 4.88 23.20 5.17 4.94 24.00 5.22 4.98 24.80 5.22 4.98 25.60 5.22 4.98 26.40 5.22 4.98 27.20 5.22 4.98 28.00 5.22 4.98 28.80 5.22 4.98 29.60 5.22 4.98 30.40 5.22 4.98 31.20 5.22 4.98 32.00 5.22 4.98 32.80 5.22 4.98 33.60 5.22 4.98 34.40 5.22 4.98 35.20 5.22 4.98 36.00 5.22 4.98 36.80 5.22 4.98 37.60 5.22 4.98 38.40 5.22 4.98 39.20 5.22 4.98 40.00 5.22 4.98 Runoff (cfs) 0.00 0.00 0.02 0.03 0.04 0.05 0.05 0.06 0.07 0.08 0.10 0.11 0.15 0.20 0.37 1.73 0.48 0.23 0.17 0.12 0.11 0.09 0.08 0.07 0.06 0.06 0.06 0.05 0.05 0.05 0.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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)
17 0.12 0.11 0.09 0.08 0.07 0.06 0.06 0.06 0.05 0.05 0.05 0.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 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) 40.80 5.22 4.98 41.60 5.22 4.98 42.40 5.22 4.98 43.20 5.22 4.98 44.00 5.22 4.98 44.80 5.22 4.98 45.60 5.22 4.98 46.40 5.22 4.98 47.20 5.22 4.98 48.00 5.22 4.98 48.80 5.22 4.98 49.60 5.22 4.98 50.40 5.22 4.98 51.20 5.22 4.98 52.00 5.22 4.98 52.80 5.22 4.98 53.60 5.22 4.98 54.40 5.22 4.98 55.20 5.22 4.98 56.00 5.22 4.98 56.80 5.22 4.98 57.60 5.22 4.98 58.40 5.22 4.98 59.20 5.22 4.98 60.00 5.22 4.98 60.80 5.22 4.98 61.60 5.22 4.98 62.40 5.22 4.98 63.20 5.22 4.98 64.00 5.22 4.98 64.80 5.22 4.98 65.60 5.22 4.98 66.40 5.22 4.98 67.20 5.22 4.98 68.00 5.22 4.98 68.80 5.22 4.98 69.60 5.22 4.98 70.40 5.22 4.98 71.20 5.22 4.98 72.00 5.22 4.98 72.80 5.22 4.98 73.60 5.22 4.98 74.40 5.22 4.98 75.20 5.22 4.98 76.00 5.22 4.98 76.80 5.22 4.98 77.60 5.22 4.98 78.40 5.22 4.98 79.20 5.22 4.98 80.00 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 83 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 20S: Basin 3 - Perv Runoff = 1.20 cfs @ 12.16 hrs, Volume= Routed to Pond 21P : Basin 3 4,074 cf, Depth= 2.54" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-80.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) 19,242 19,242 Tc (min) 8.3 Length (feet) 75 CN 74 Description >75% Grass cover, Good, HSG C 100.00% Pervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.0400 0.15 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" Subcatchment 20S: Basin 3 - Perv Hydrograph Runoff 1.20 cfs Flow (cfs) 1 0 NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=19,242 sf Runoff Volume=4,074 cf Runoff Depth=2.54" Flow Length=75' Slope=0.0400 '/' Tc=8.3 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 74 76 78 80 Time (hours)
POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 84 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 20S: Basin 3 - Perv Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.80 0.05 0.00 1.60 0.10 0.00 2.40 0.15 0.00 3.20 0.21 0.00 4.00 0.27 0.00 4.80 0.34 0.00 5.60 0.41 0.00 6.40 0.48 0.00 7.20 0.57 0.00 8.00 0.68 0.00 8.80 0.80 0.00 9.60 0.94 0.02 10.40 1.14 0.05 11.20 1.46 0.13 12.00 2.50 0.61 12.80 3.76 1.42 13.60 4.08 1.65 14.40 4.28 1.80 15.20 4.42 1.91 16.00 4.54 2.01 16.80 4.65 2.09 17.60 4.74 2.16 18.40 4.81 2.21 19.20 4.88 2.27 20.00 4.95 2.32 20.80 5.01 2.37 21.60 5.07 2.42 22.40 5.12 2.46 23.20 5.17 2.50 24.00 5.22 2.54 24.80 5.22 2.54 25.60 5.22 2.54 26.40 5.22 2.54 27.20 5.22 2.54 28.00 5.22 2.54 28.80 5.22 2.54 29.60 5.22 2.54 30.40 5.22 2.54 31.20 5.22 2.54 32.00 5.22 2.54 32.80 5.22 2.54 33.60 5.22 2.54 34.40 5.22 2.54 35.20 5.22 2.54 36.00 5.22 2.54 36.80 5.22 2.54 37.60 5.22 2.54 38.40 5.22 2.54 39.20 5.22 2.54 40.00 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 0.01 0.02 0.07 0.52 0.20 0.10 0.08 0.05 0.05 0.04 0.04 0.03 0.03 0.03 0.03 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 Time Precip. Excess (hours) (inches)
08 0.05 0.05 0.04 0.04 0.03 0.03 0.03 0.03 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 Time Precip. Excess (hours) (inches) (inches) 40.80 5.22 2.54 41.60 5.22 2.54 42.40 5.22 2.54 43.20 5.22 2.54 44.00 5.22 2.54 44.80 5.22 2.54 45.60 5.22 2.54 46.40 5.22 2.54 47.20 5.22 2.54 48.00 5.22 2.54 48.80 5.22 2.54 49.60 5.22 2.54 50.40 5.22 2.54 51.20 5.22 2.54 52.00 5.22 2.54 52.80 5.22 2.54 53.60 5.22 2.54 54.40 5.22 2.54 55.20 5.22 2.54 56.00 5.22 2.54 56.80 5.22 2.54 57.60 5.22 2.54 58.40 5.22 2.54 59.20 5.22 2.54 60.00 5.22 2.54 60.80 5.22 2.54 61.60 5.22 2.54 62.40 5.22 2.54 63.20 5.22 2.54 64.00 5.22 2.54 64.80 5.22 2.54 65.60 5.22 2.54 66.40 5.22 2.54 67.20 5.22 2.54 68.00 5.22 2.54 68.80 5.22 2.54 69.60 5.22 2.54 70.40 5.22 2.54 71.20 5.22 2.54 72.00 5.22 2.54 72.80 5.22 2.54 73.60 5.22 2.54 74.40 5.22 2.54 75.20 5.22 2.54 76.00 5.22 2.54 76.80 5.22 2.54 77.60 5.22 2.54 78.40 5.22 2.54 79.20 5.22 2.54 80.00 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 85 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 21S: Basin 4 - Imp Runoff = 5.76 cfs @ 12.12 hrs, Volume= Routed to Pond 22P : Basin 4 20,787 cf, Depth= 4.98" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-80.00 hrs, dt= 0.04 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) 6,970 43,091 50,061 50,061 Tc (min) 0.9 Length (feet) 70 4.6 5.5 685 755 CN 98 98 98 Description Roofs, HSG D Paved parking, HSG C Weighted Average 100.00% Impervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.0200 1.33 Sheet Flow, Sheet Flow (A-B) Smooth surfaces n= 0.011 P2= 3.47" 2.50 Direct Entry, Pipe Flow (B-C) Total Subcatchment 21S: Basin 4 - Imp Hydrograph Runoff 6 5 Flow (cfs) 4 3 2 5.76 cfs NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=50,061 sf Runoff Volume=20,787 cf Runoff Depth=4.98" Flow Length=755' Slope=0.0200 '/' Tc=5.5 min CN=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 74 76 78 80 Time (hours)
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