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HydroCAD Report (50 & 100) Revised 3-19-21 (1)1S A1 2S A2 3S A3 4S A4 5S B2 6S POND 7S PRE REAR 8S A5 9S A6 10S A7 11S A8 12S A9 13S A10 14S A11 15S A12 16S A13 17S A14 18S A15 19S B1 20S PRE FRONT 1CCB CB1 1D CB DMH1 1P POST REAR 2CCB CB2 2D CB DMH2 2P POST FRONT 3C CB CB3 3D CB DMH3 4CCB CB4 9P RG9 12P RG12 13P RG13 14P RG14 15P RG1516P INF-10+11 17P INF-6+8 18P INF-5+7 Routing Diagram for 2018-082 Colvest Northampton As-Built Modifications Prepared by J.R. Russo & Associates, LLC, Printed 3/19/2021 HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 51HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Time span=1.00-20.00 hrs, dt=0.01 hrs, 1901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=8,350 sf 98.42% Impervious Runoff Depth>6.28"Subcatchment 1S: A1 Tc=5.0 min CN=97 Runoff=1.35 cfs 0.100 af Runoff Area=4,496 sf 92.70% Impervious Runoff Depth>6.04"Subcatchment 2S: A2 Tc=5.0 min CN=95 Runoff=0.72 cfs 0.052 af Runoff Area=6,870 sf 97.82% Impervious Runoff Depth>6.28"Subcatchment 3S: A3 Tc=5.0 min CN=97 Runoff=1.11 cfs 0.083 af Runoff Area=8,648 sf 82.34% Impervious Runoff Depth>5.58"Subcatchment 4S: A4 Tc=5.0 min CN=91 Runoff=1.33 cfs 0.092 af Runoff Area=25,964 sf 100.00% Impervious Runoff Depth>6.39"Subcatchment 5S: B2 Tc=5.0 min CN=98 Runoff=4.20 cfs 0.318 af Runoff Area=7,072 sf 0.00% Impervious Runoff Depth>2.45"Subcatchment 6S: POND Tc=0.0 min CN=61 Runoff=0.60 cfs 0.033 af Runoff Area=57,882 sf 0.00% Impervious Runoff Depth>5.58"Subcatchment 7S: PRE REAR Tc=5.0 min CN=91 Runoff=8.89 cfs 0.618 af Runoff Area=5,095 sf 91.89% Impervious Runoff Depth>6.04"Subcatchment 8S: A5 Tc=5.0 min CN=95 Runoff=0.81 cfs 0.059 af Runoff Area=6,947 sf 89.75% Impervious Runoff Depth>5.93"Subcatchment 9S: A6 Tc=5.0 min CN=94 Runoff=1.10 cfs 0.079 af Runoff Area=4,230 sf 90.85% Impervious Runoff Depth>6.04"Subcatchment 10S: A7 Tc=5.0 min CN=95 Runoff=0.67 cfs 0.049 af Runoff Area=5,823 sf 87.02% Impervious Runoff Depth>5.81"Subcatchment 11S: A8 Tc=5.0 min CN=93 Runoff=0.91 cfs 0.065 af Runoff Area=11,231 sf 77.08% Impervious Runoff Depth>5.47"Subcatchment 12S: A9 Tc=5.0 min CN=90 Runoff=1.70 cfs 0.117 af Runoff Area=9,635 sf 93.98% Impervious Runoff Depth>6.16"Subcatchment 13S: A10 Tc=5.0 min CN=96 Runoff=1.55 cfs 0.114 af Runoff Area=6,395 sf 85.41% Impervious Runoff Depth>5.81"Subcatchment 14S: A11 Tc=5.0 min CN=93 Runoff=1.00 cfs 0.071 af Runoff Area=9,957 sf 48.28% Impervious Runoff Depth>4.25"Subcatchment 15S: A12 Tc=5.0 min CN=79 Runoff=1.25 cfs 0.081 af Runoff Area=3,453 sf 73.59% Impervious Runoff Depth>5.24"Subcatchment 16S: A13 Tc=5.0 min CN=88 Runoff=0.51 cfs 0.035 af Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 52HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Runoff Area=2,168 sf 59.73% Impervious Runoff Depth>4.68"Subcatchment 17S: A14 Tc=5.0 min CN=83 Runoff=0.29 cfs 0.019 af Runoff Area=2,826 sf 51.91% Impervious Runoff Depth>4.36"Subcatchment 18S: A15 Tc=5.0 min CN=80 Runoff=0.36 cfs 0.024 af Runoff Area=6,971 sf 100.00% Impervious Runoff Depth>6.39"Subcatchment 19S: B1 Tc=5.0 min CN=98 Runoff=1.13 cfs 0.085 af Runoff Area=71,761 sf 44.08% Impervious Runoff Depth>5.35"Subcatchment 20S: PRE FRONT Tc=5.0 min CN=89 Runoff=10.75 cfs 0.735 af Peak Elev=145.49' Inflow=1.35 cfs 0.100 afPond 1C: CB1 12.0" Round Culvert n=0.012 L=124.0' S=0.0050 '/' Outflow=1.35 cfs 0.100 af Peak Elev=145.50' Inflow=6.27 cfs 0.470 afPond 1D: DMH1 18.0" Round Culvert n=0.012 L=58.0' S=0.0050 '/' Outflow=6.27 cfs 0.470 af Peak Elev=146.89' Storage=10,820 cf Inflow=9.10 cfs 0.678 afPond 1P: POST REAR Discarded=0.13 cfs 0.122 af Primary=7.95 cfs 0.346 af Outflow=8.09 cfs 0.468 af Peak Elev=145.43' Inflow=0.72 cfs 0.052 afPond 2C: CB2 12.0" Round Culvert n=0.012 L=8.0' S=0.0437 '/' Outflow=0.72 cfs 0.052 af Peak Elev=145.35' Inflow=7.38 cfs 0.552 afPond 2D: DMH2 18.0" Round Culvert n=0.012 L=50.0' S=0.0050 '/' Outflow=7.38 cfs 0.552 af Peak Elev=148.07' Storage=8,192 cf Inflow=9.31 cfs 0.663 afPond 2P: POST FRONT Outflow=8.21 cfs 0.625 af Peak Elev=145.40' Inflow=1.11 cfs 0.083 afPond 3C: CB3 12.0" Round Culvert n=0.012 L=13.0' S=0.0115 '/' Outflow=1.11 cfs 0.083 af Peak Elev=145.38' Inflow=8.70 cfs 0.645 afPond 3D: DMH3 18.0" Round Culvert n=0.012 L=54.0' S=0.0056 '/' Outflow=8.70 cfs 0.645 af Peak Elev=145.46' Inflow=1.33 cfs 0.092 afPond 4C: CB4 12.0" Round Culvert n=0.012 L=8.0' S=0.0188 '/' Outflow=1.33 cfs 0.092 af Peak Elev=148.07' Storage=550 cf Inflow=1.70 cfs 0.117 afPond 9P: RG9 Discarded=0.03 cfs 0.004 af Primary=1.11 cfs 0.113 af Outflow=1.14 cfs 0.117 af Peak Elev=147.94' Storage=375 cf Inflow=1.25 cfs 0.081 afPond 12P: RG12 Discarded=0.04 cfs 0.003 af Primary=0.56 cfs 0.077 af Outflow=0.60 cfs 0.081 af Peak Elev=147.59' Storage=23 cf Inflow=0.51 cfs 0.035 afPond 13P: RG13 Discarded=0.00 cfs 0.001 af Primary=0.50 cfs 0.033 af Outflow=0.50 cfs 0.035 af Peak Elev=146.60' Storage=20 cf Inflow=0.29 cfs 0.019 afPond 14P: RG14 Discarded=0.00 cfs 0.002 af Primary=0.28 cfs 0.018 af Outflow=0.28 cfs 0.019 af Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 53HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Peak Elev=146.80' Storage=28 cf Inflow=0.36 cfs 0.024 afPond 15P: RG15 Discarded=0.00 cfs 0.002 af Primary=0.33 cfs 0.022 af Outflow=0.34 cfs 0.024 af Peak Elev=147.36' Storage=495 cf Inflow=2.55 cfs 0.185 afPond 16P: INF-10+11 Discarded=0.04 cfs 0.041 af Primary=2.51 cfs 0.133 af Outflow=2.55 cfs 0.173 af Peak Elev=147.14' Storage=335 cf Inflow=2.01 cfs 0.143 afPond 17P: INF-6+8 Discarded=0.02 cfs 0.026 af Primary=1.99 cfs 0.112 af Outflow=2.01 cfs 0.137 af Peak Elev=147.02' Storage=358 cf Inflow=1.49 cfs 0.108 afPond 18P: INF-5+7 Discarded=0.03 cfs 0.031 af Primary=1.46 cfs 0.069 af Outflow=1.49 cfs 0.100 af Total Runoff Area = 6.101 ac Runoff Volume = 2.828 af Average Runoff Depth = 5.56" 45.85% Pervious = 2.798 ac 54.15% Impervious = 3.304 ac Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 54HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: A1 Runoff = 1.35 cfs @ 12.07 hrs, Volume= 0.100 af, Depth> 6.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 8,218 98 Paved parking, HSG B 132 61 >75% Grass cover, Good, HSG B 8,350 97 Weighted Average 132 1.58% Pervious Area 8,218 98.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: A2 Runoff = 0.72 cfs @ 12.07 hrs, Volume= 0.052 af, Depth> 6.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 4,168 98 Paved parking, HSG B 328 61 >75% Grass cover, Good, HSG B 4,496 95 Weighted Average 328 7.30% Pervious Area 4,168 92.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 3S: A3 Runoff = 1.11 cfs @ 12.07 hrs, Volume= 0.083 af, Depth> 6.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 6,720 98 Paved parking, HSG B 150 61 >75% Grass cover, Good, HSG B 6,870 97 Weighted Average 150 2.18% Pervious Area 6,720 97.82% Impervious Area Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 55HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 4S: A4 Runoff = 1.33 cfs @ 12.07 hrs, Volume= 0.092 af, Depth> 5.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 7,121 98 Paved parking, HSG B 1,527 61 >75% Grass cover, Good, HSG B 8,648 91 Weighted Average 1,527 17.66% Pervious Area 7,121 82.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: B2 Runoff = 4.20 cfs @ 12.07 hrs, Volume= 0.318 af, Depth> 6.39" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 25,964 98 Roofs, HSG B 0 61 >75% Grass cover, Good, HSG B 25,964 98 Weighted Average 25,964 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6S: POND Runoff = 0.60 cfs @ 12.00 hrs, Volume= 0.033 af, Depth> 2.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 56HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Area (sf) CN Description 7,072 61 >75% Grass cover, Good, HSG B 7,072 100.00% Pervious Area Summary for Subcatchment 7S: PRE REAR Runoff = 8.89 cfs @ 12.07 hrs, Volume= 0.618 af, Depth> 5.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 9,064 67 Brush, Poor, HSG B 48,818 96 Gravel surface, HSG B 57,882 91 Weighted Average 57,882 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 8S: A5 Runoff = 0.81 cfs @ 12.07 hrs, Volume= 0.059 af, Depth> 6.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 4,682 98 Paved parking, HSG B 413 61 >75% Grass cover, Good, HSG B 5,095 95 Weighted Average 413 8.11% Pervious Area 4,682 91.89% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: A6 Runoff = 1.10 cfs @ 12.07 hrs, Volume= 0.079 af, Depth> 5.93" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 57HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Area (sf) CN Description 6,235 98 Paved parking, HSG B 712 61 >75% Grass cover, Good, HSG B 6,947 94 Weighted Average 712 10.25% Pervious Area 6,235 89.75% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 10S: A7 Runoff = 0.67 cfs @ 12.07 hrs, Volume= 0.049 af, Depth> 6.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 3,843 98 Paved parking, HSG B 387 61 >75% Grass cover, Good, HSG B 4,230 95 Weighted Average 387 9.15% Pervious Area 3,843 90.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 11S: A8 Runoff = 0.91 cfs @ 12.07 hrs, Volume= 0.065 af, Depth> 5.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 5,067 98 Paved parking, HSG B 756 61 >75% Grass cover, Good, HSG B 5,823 93 Weighted Average 756 12.98% Pervious Area 5,067 87.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 58HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: A9 Runoff = 1.70 cfs @ 12.07 hrs, Volume= 0.117 af, Depth> 5.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 8,657 98 Paved parking, HSG B 2,574 61 >75% Grass cover, Good, HSG B 11,231 90 Weighted Average 2,574 22.92% Pervious Area 8,657 77.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 13S: A10 Runoff = 1.55 cfs @ 12.07 hrs, Volume= 0.114 af, Depth> 6.16" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 9,055 98 Paved parking, HSG B 580 61 >75% Grass cover, Good, HSG B 9,635 96 Weighted Average 580 6.02% Pervious Area 9,055 93.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 14S: A11 Runoff = 1.00 cfs @ 12.07 hrs, Volume= 0.071 af, Depth> 5.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 5,462 98 Paved parking, HSG B 933 61 >75% Grass cover, Good, HSG B 6,395 93 Weighted Average 933 14.59% Pervious Area 5,462 85.41% Impervious Area Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 59HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 15S: A12 Runoff = 1.25 cfs @ 12.07 hrs, Volume= 0.081 af, Depth> 4.25" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 4,807 98 Paved parking, HSG B 5,150 61 >75% Grass cover, Good, HSG B 9,957 79 Weighted Average 5,150 51.72% Pervious Area 4,807 48.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 16S: A13 Runoff = 0.51 cfs @ 12.07 hrs, Volume= 0.035 af, Depth> 5.24" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 2,541 98 Paved parking, HSG B 912 61 >75% Grass cover, Good, HSG B 3,453 88 Weighted Average 912 26.41% Pervious Area 2,541 73.59% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 17S: A14 Runoff = 0.29 cfs @ 12.07 hrs, Volume= 0.019 af, Depth> 4.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 60HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Area (sf) CN Description 1,295 98 Paved parking, HSG B 873 61 >75% Grass cover, Good, HSG B 2,168 83 Weighted Average 873 40.27% Pervious Area 1,295 59.73% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 18S: A15 Runoff = 0.36 cfs @ 12.07 hrs, Volume= 0.024 af, Depth> 4.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 1,467 98 Paved parking, HSG B 1,359 61 >75% Grass cover, Good, HSG B 2,826 80 Weighted Average 1,359 48.09% Pervious Area 1,467 51.91% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 19S: B1 Runoff = 1.13 cfs @ 12.07 hrs, Volume= 0.085 af, Depth> 6.39" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 6,971 98 Roofs, HSG B 0 61 >75% Grass cover, Good, HSG B 6,971 98 Weighted Average 6,971 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 61HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 20S: PRE FRONT Runoff = 10.75 cfs @ 12.07 hrs, Volume= 0.735 af, Depth> 5.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94" Area (sf) CN Description 24,527 96 Gravel surface, HSG B 15,601 61 >75% Grass cover, Good, HSG B 31,633 98 Paved parking, HSG B 71,761 89 Weighted Average 40,128 55.92% Pervious Area 31,633 44.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 1C: CB1 Inflow Area = 0.192 ac, 98.42% Impervious, Inflow Depth > 6.28" for 50-Year event Inflow = 1.35 cfs @ 12.07 hrs, Volume= 0.100 af Outflow = 1.35 cfs @ 12.07 hrs, Volume= 0.100 af, Atten= 0%, Lag= 0.0 min Primary = 1.35 cfs @ 12.07 hrs, Volume= 0.100 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.49' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 144.80'12.0" Round Culvert L= 124.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.80' / 144.18' S= 0.0050 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.35 cfs @ 12.07 hrs HW=145.49' (Free Discharge) 1=Culvert (Barrel Controls 1.35 cfs @ 3.29 fps) Summary for Pond 1D: DMH1 Inflow Area = 0.891 ac, 98.81% Impervious, Inflow Depth > 6.33" for 50-Year event Inflow = 6.27 cfs @ 12.07 hrs, Volume= 0.470 af Outflow = 6.27 cfs @ 12.07 hrs, Volume= 0.470 af, Atten= 0%, Lag= 0.0 min Primary = 6.27 cfs @ 12.07 hrs, Volume= 0.470 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.50' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 144.00'18.0" Round 18" CPEP Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 62HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC L= 58.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.00' / 143.71' S= 0.0050 '/' Cc= 0.900 n= 0.012, Flow Area= 1.77 sf Primary OutFlow Max=6.27 cfs @ 12.07 hrs HW=145.50' (Free Discharge) 1=18" CPEP (Barrel Controls 6.27 cfs @ 4.41 fps) Summary for Pond 1P: POST REAR Inflow Area = 1.410 ac, 85.00% Impervious, Inflow Depth > 5.77" for 50-Year event Inflow = 9.10 cfs @ 12.07 hrs, Volume= 0.678 af Outflow = 8.09 cfs @ 12.11 hrs, Volume= 0.468 af, Atten= 11%, Lag= 2.4 min Discarded = 0.13 cfs @ 12.11 hrs, Volume= 0.122 af Primary = 7.95 cfs @ 12.11 hrs, Volume= 0.346 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 146.89' @ 12.11 hrs Surf.Area= 4,482 sf Storage= 10,820 cf Plug-Flow detention time= 131.1 min calculated for 0.468 af (69% of inflow) Center-of-Mass det. time= 57.2 min ( 784.0 - 726.8 ) Volume Invert Avail.Storage Storage Description #1 143.00' 11,310 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 143.00 1,320 0 0 144.00 1,986 1,653 1,653 145.00 2,752 2,369 4,022 146.00 3,619 3,186 7,208 147.00 4,586 4,103 11,310 Device Routing Invert Outlet Devices #1 Discarded 143.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 135.00' #2 Primary 146.50'12.0' long x 16.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Discarded OutFlow Max=0.13 cfs @ 12.11 hrs HW=146.89' (Free Discharge) 1=Exfiltration ( Controls 0.13 cfs) Primary OutFlow Max=7.94 cfs @ 12.11 hrs HW=146.89' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 7.94 cfs @ 1.69 fps) Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 63HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Pond 2C: CB2 Inflow Area = 0.103 ac, 92.70% Impervious, Inflow Depth > 6.04" for 50-Year event Inflow = 0.72 cfs @ 12.07 hrs, Volume= 0.052 af Outflow = 0.72 cfs @ 12.07 hrs, Volume= 0.052 af, Atten= 0%, Lag= 0.0 min Primary = 0.72 cfs @ 12.07 hrs, Volume= 0.052 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.43' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 145.00'12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 145.00' / 144.65' S= 0.0437 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.72 cfs @ 12.07 hrs HW=145.43' (Free Discharge) 1=Culvert (Inlet Controls 0.72 cfs @ 2.23 fps) Summary for Pond 2D: DMH2 Inflow Area = 1.049 ac, 98.66% Impervious, Inflow Depth > 6.32" for 50-Year event Inflow = 7.38 cfs @ 12.07 hrs, Volume= 0.552 af Outflow = 7.38 cfs @ 12.07 hrs, Volume= 0.552 af, Atten= 0%, Lag= 0.0 min Primary = 7.38 cfs @ 12.07 hrs, Volume= 0.552 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.35' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 143.63'18.0" Round 18" CPEP L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 143.63' / 143.38' S= 0.0050 '/' Cc= 0.900 n= 0.012, Flow Area= 1.77 sf Primary OutFlow Max=7.38 cfs @ 12.07 hrs HW=145.35' (Free Discharge) 1=18" CPEP (Barrel Controls 7.38 cfs @ 4.56 fps) Summary for Pond 2P: POST FRONT Inflow Area = 1.716 ac, 80.40% Impervious, Inflow Depth > 4.64" for 50-Year event Inflow = 9.31 cfs @ 12.07 hrs, Volume= 0.663 af Outflow = 8.21 cfs @ 12.13 hrs, Volume= 0.625 af, Atten= 12%, Lag= 3.4 min Primary = 8.21 cfs @ 12.13 hrs, Volume= 0.625 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Starting Elev= 144.27' Surf.Area= 2,195 sf Storage= 940 cf Peak Elev= 148.07' @ 12.13 hrs Surf.Area= 508 sf Storage= 8,192 cf (7,252 cf above start) Flood Elev= 148.20' Surf.Area= 508 sf Storage= 8,258 cf (7,318 cf above start) Plug-Flow detention time= 69.0 min calculated for 0.603 af (91% of inflow) Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 64HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Center-of-Mass det. time= 37.2 min ( 787.7 - 750.5 ) Volume Invert Avail.Storage Storage Description #1 143.90' 509 cf 4.00'D x 4.50'H DMH x 9 #2 143.86' 226 cf 30.0" Round 30" Flat CPEP (10-11) L= 46.0' S= 0.0070 '/' #3 143.74' 324 cf 30.0" Round 30" Flat CPEP (11-12) L= 66.0' S= 0.0003 '/' #4 143.78' 275 cf 30.0" Round 30" Flat CPEP (12-Out) L= 56.0' S= 0.0016 '/' #5 143.88' 1,924 cf 30.0" Round 30" Flat CPEP (9-Out) x 4 L= 98.0' S= 0.0030 '/' #6 143.39' 1,031 cf 30.0" Round 30" Flat CPEP (6-9) x 3 L= 70.0' S= 0.0007 '/' #7 143.59' 260 cf 30.0" Round 30" Flat CPEP (8-9) L= 53.0' S= 0.0008 '/' #8 143.38' 476 cf 30.0" Round 30" Flat CPEP (7-8) L= 97.0' S= 0.0008 '/' #9 143.39' 285 cf 30.0" Round 30" Flat CPEP (5-6) L= 58.0' S= 0.0007 '/' #10 143.50' 422 cf 30.0" Round 30" Flat CPEP (4-5) L= 86.0' S= 0.0003 '/' #11 148.00' 333 cf Custom Stage Data (Prismatic) Listed below (Recalc) #12 144.27' 2,376 cf 30.0" Round Prop. 30" Flat CPEP L= 484.0' #13 144.27' 113 cf 4.00'D x 4.50'H Prop. DMH x 2 8,554 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 148.00 370 0 0 148.90 370 333 333 Device Routing Invert Outlet Devices #1 Device 3 144.27'10.0" Vert. 10" Orifice C= 0.600 #2 Device 3 146.85'36.0" W x 4.0" H Vert. 4"x36" Weir/Orifice C= 0.600 #3 Primary 144.65'12.0" Round 12" Culvert L= 16.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.65' / 143.50' S= 0.0719 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Primary 148.00'37.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=8.17 cfs @ 12.13 hrs HW=148.07' (Free Discharge) 3=12" Culvert (Inlet Controls 6.46 cfs @ 8.23 fps) 1=10" Orifice (Passes < 4.83 cfs potential flow) 2=4"x36" Weir/Orifice (Passes < 4.94 cfs potential flow) 4=Broad-Crested Rectangular Weir (Weir Controls 1.70 cfs @ 0.66 fps) Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 65HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Pond 3C: CB3 Inflow Area = 0.158 ac, 97.82% Impervious, Inflow Depth > 6.28" for 50-Year event Inflow = 1.11 cfs @ 12.07 hrs, Volume= 0.083 af Outflow = 1.11 cfs @ 12.07 hrs, Volume= 0.083 af, Atten= 0%, Lag= 0.0 min Primary = 1.11 cfs @ 12.07 hrs, Volume= 0.083 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.40' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 144.80'12.0" Round Culvert L= 13.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.80' / 144.65' S= 0.0115 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.11 cfs @ 12.07 hrs HW=145.40' (Free Discharge) 1=Culvert (Barrel Controls 1.11 cfs @ 3.21 fps) Summary for Pond 3D: DMH3 Inflow Area = 1.247 ac, 96.07% Impervious, Inflow Depth > 6.20" for 50-Year event Inflow = 8.70 cfs @ 12.07 hrs, Volume= 0.645 af Outflow = 8.70 cfs @ 12.07 hrs, Volume= 0.645 af, Atten= 0%, Lag= 0.0 min Primary = 8.70 cfs @ 12.07 hrs, Volume= 0.645 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.38' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 143.30'18.0" Round Culvert L= 54.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 143.30' / 143.00' S= 0.0056 '/' Cc= 0.900 n= 0.012, Flow Area= 1.77 sf Primary OutFlow Max=8.70 cfs @ 12.07 hrs HW=145.38' (Free Discharge) 1=Culvert (Barrel Controls 8.70 cfs @ 4.92 fps) Summary for Pond 4C: CB4 Inflow Area = 0.199 ac, 82.34% Impervious, Inflow Depth > 5.58" for 50-Year event Inflow = 1.33 cfs @ 12.07 hrs, Volume= 0.092 af Outflow = 1.33 cfs @ 12.07 hrs, Volume= 0.092 af, Atten= 0%, Lag= 0.0 min Primary = 1.33 cfs @ 12.07 hrs, Volume= 0.092 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.46' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 144.80'12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 66HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Inlet / Outlet Invert= 144.80' / 144.65' S= 0.0188 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.33 cfs @ 12.07 hrs HW=145.46' (Free Discharge) 1=Culvert (Barrel Controls 1.33 cfs @ 3.44 fps) Summary for Pond 9P: RG9 Inflow Area = 0.258 ac, 77.08% Impervious, Inflow Depth > 5.47" for 50-Year event Inflow = 1.70 cfs @ 12.07 hrs, Volume= 0.117 af Outflow = 1.14 cfs @ 12.15 hrs, Volume= 0.117 af, Atten= 33%, Lag= 4.8 min Discarded = 0.03 cfs @ 12.15 hrs, Volume= 0.004 af Primary = 1.11 cfs @ 12.15 hrs, Volume= 0.113 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 148.07' @ 12.15 hrs Surf.Area= 1,072 sf Storage= 550 cf Flood Elev= 148.40' Surf.Area= 1,804 sf Storage= 1,004 cf Plug-Flow detention time= 4.1 min calculated for 0.117 af (100% of inflow) Center-of-Mass det. time= 3.9 min ( 753.9 - 750.0 ) Volume Invert Avail.Storage Storage Description #1 147.40' 963 cf Rain Garden (Prismatic) Listed below (Recalc) #2A 145.60' 25 cf 3.21'W x 21.33'L x 1.21'H Field A 83 cf Overall - 21 cf Embedded = 62 cf x 40.0% Voids #3A 145.60' 16 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 1,004 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.40 632 0 0 148.00 853 445 445 148.40 1,736 518 963 Device Routing Invert Outlet Devices #1 Device 3 148.00'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 145.60'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 144.50'12.0" Round Culvert L= 34.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.50' / 143.94' S= 0.0165 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 145.60'4.0" Vert. Underdrain C= 0.600 Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 67HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.03 cfs @ 12.15 hrs HW=148.07' (Free Discharge) 2=Exfiltration ( Controls 0.03 cfs) Primary OutFlow Max=1.10 cfs @ 12.15 hrs HW=148.07' (Free Discharge) 3=Culvert (Passes 1.10 cfs of 6.62 cfs potential flow) 1=CB Inlet (Weir Controls 0.47 cfs @ 0.85 fps) 4=Underdrain (Orifice Controls 0.64 cfs @ 7.30 fps) Summary for Pond 12P: RG12 Inflow Area = 0.229 ac, 48.28% Impervious, Inflow Depth > 4.25" for 50-Year event Inflow = 1.25 cfs @ 12.07 hrs, Volume= 0.081 af Outflow = 0.60 cfs @ 12.22 hrs, Volume= 0.081 af, Atten= 52%, Lag= 8.8 min Discarded = 0.04 cfs @ 12.22 hrs, Volume= 0.003 af Primary = 0.56 cfs @ 12.22 hrs, Volume= 0.077 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 147.94' @ 12.22 hrs Surf.Area= 1,603 sf Storage= 375 cf Flood Elev= 148.40' Surf.Area= 3,301 sf Storage= 1,481 cf Plug-Flow detention time= 3.6 min calculated for 0.081 af (100% of inflow) Center-of-Mass det. time= 3.3 min ( 780.2 - 776.9 ) Volume Invert Avail.Storage Storage Description #1 147.50' 1,440 cf Rain Garden (Prismatic) Listed below (Recalc) #2A 146.00' 25 cf 3.21'W x 21.33'L x 1.21'H Field A 83 cf Overall - 21 cf Embedded = 62 cf x 40.0% Voids #3A 146.00' 16 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 1,481 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.50 0 0 0 148.00 1,764 441 441 148.40 3,233 999 1,440 Device Routing Invert Outlet Devices #1 Device 3 148.00'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 146.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 144.50'12.0" Round Culvert L= 19.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.50' / 144.09' S= 0.0216 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 146.00'4.0" Vert. Underdrain C= 0.600 Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 68HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.04 cfs @ 12.22 hrs HW=147.94' (Free Discharge) 2=Exfiltration ( Controls 0.04 cfs) Primary OutFlow Max=0.56 cfs @ 12.22 hrs HW=147.94' (Free Discharge) 3=Culvert (Passes 0.56 cfs of 6.48 cfs potential flow) 1=CB Inlet ( Controls 0.00 cfs) 4=Underdrain (Orifice Controls 0.56 cfs @ 6.40 fps) Summary for Pond 13P: RG13 Inflow Area = 0.079 ac, 73.59% Impervious, Inflow Depth > 5.24" for 50-Year event Inflow = 0.51 cfs @ 12.07 hrs, Volume= 0.035 af Outflow = 0.50 cfs @ 12.08 hrs, Volume= 0.035 af, Atten= 1%, Lag= 0.6 min Discarded = 0.00 cfs @ 12.08 hrs, Volume= 0.001 af Primary = 0.50 cfs @ 12.08 hrs, Volume= 0.033 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 147.59' @ 12.08 hrs Surf.Area= 60 sf Storage= 23 cf Flood Elev= 148.70' Surf.Area= 1,047 sf Storage= 282 cf Plug-Flow detention time= 0.8 min calculated for 0.035 af (100% of inflow) Center-of-Mass det. time= 0.6 min ( 756.5 - 755.9 ) Volume Invert Avail.Storage Storage Description #1 147.50' 261 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 146.00' 13 cf 3.21'W x 11.33'L x 1.21'H Field A 44 cf Overall - 10 cf Embedded = 33 cf x 40.0% Voids #3A 146.00' 8 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf Row Length Adjustment= -10.00' x 0.81 sf x 1 rows 282 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.50 0 0 0 148.00 127 32 32 148.40 249 75 107 148.50 269 26 133 148.70 1,011 128 261 Device Routing Invert Outlet Devices #1 Device 3 148.30'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 146.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 145.10'12.0" Round Culvert L= 10.0' CPP, square edge headwall, Ke= 0.500 Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 69HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Inlet / Outlet Invert= 145.10' / 144.84' S= 0.0260 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 146.00'4.0" Vert. Underdrain C= 0.600 Discarded OutFlow Max=0.00 cfs @ 12.08 hrs HW=147.59' (Free Discharge) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.50 cfs @ 12.08 hrs HW=147.59' (Free Discharge) 3=Culvert (Passes 0.50 cfs of 5.34 cfs potential flow) 1=CB Inlet ( Controls 0.00 cfs) 4=Underdrain (Orifice Controls 0.50 cfs @ 5.75 fps) Summary for Pond 14P: RG14 Inflow Area = 0.050 ac, 59.73% Impervious, Inflow Depth > 4.68" for 50-Year event Inflow = 0.29 cfs @ 12.07 hrs, Volume= 0.019 af Outflow = 0.28 cfs @ 12.10 hrs, Volume= 0.019 af, Atten= 6%, Lag= 1.6 min Discarded = 0.00 cfs @ 12.10 hrs, Volume= 0.002 af Primary = 0.28 cfs @ 12.10 hrs, Volume= 0.018 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 146.60' @ 12.10 hrs Surf.Area= 68 sf Storage= 20 cf Flood Elev= 148.70' Surf.Area= 1,131 sf Storage= 357 cf Plug-Flow detention time= 1.6 min calculated for 0.019 af (100% of inflow) Center-of-Mass det. time= 1.2 min ( 769.6 - 768.3 ) Volume Invert Avail.Storage Storage Description #1 148.00' 316 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 146.00' 25 cf 3.21'W x 21.33'L x 1.21'H Field A 83 cf Overall - 21 cf Embedded = 62 cf x 40.0% Voids #3A 146.00' 16 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 357 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 148.00 0 0 0 148.30 331 50 50 148.40 450 39 89 148.70 1,063 227 316 Device Routing Invert Outlet Devices #1 Device 3 148.40'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 146.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 145.26'12.0" Round Culvert Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 70HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC L= 10.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 145.10' / 145.26' S= -0.0160 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 146.00'4.0" Vert. Underdrain C= 0.600 Discarded OutFlow Max=0.00 cfs @ 12.10 hrs HW=146.60' (Free Discharge) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.28 cfs @ 12.10 hrs HW=146.60' (Free Discharge) 3=Culvert (Passes 0.28 cfs of 3.35 cfs potential flow) 1=CB Inlet ( Controls 0.00 cfs) 4=Underdrain (Orifice Controls 0.28 cfs @ 3.17 fps) Summary for Pond 15P: RG15 Inflow Area = 0.065 ac, 51.91% Impervious, Inflow Depth > 4.36" for 50-Year event Inflow = 0.36 cfs @ 12.07 hrs, Volume= 0.024 af Outflow = 0.34 cfs @ 12.10 hrs, Volume= 0.024 af, Atten= 7%, Lag= 1.8 min Discarded = 0.00 cfs @ 12.10 hrs, Volume= 0.002 af Primary = 0.33 cfs @ 12.10 hrs, Volume= 0.022 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 146.80' @ 12.10 hrs Surf.Area= 68 sf Storage= 28 cf Flood Elev= 148.70' Surf.Area= 880 sf Storage= 337 cf Plug-Flow detention time= 1.6 min calculated for 0.024 af (100% of inflow) Center-of-Mass det. time= 1.2 min ( 776.0 - 774.8 ) Volume Invert Avail.Storage Storage Description #1 147.80' 296 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 146.00' 25 cf 3.21'W x 21.33'L x 1.21'H Field A 83 cf Overall - 21 cf Embedded = 62 cf x 40.0% Voids #3A 146.00' 16 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 337 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.80 0 0 0 148.00 173 17 17 148.30 300 71 88 148.40 354 33 121 148.70 812 175 296 Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 71HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Device 3 148.40'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 146.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 145.20'12.0" Round Culvert L= 10.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 145.20' / 144.84' S= 0.0360 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 146.00'4.0" Vert. Underdrain C= 0.600 Discarded OutFlow Max=0.00 cfs @ 12.10 hrs HW=146.80' (Free Discharge) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.33 cfs @ 12.10 hrs HW=146.80' (Free Discharge) 3=Culvert (Passes 0.33 cfs of 3.96 cfs potential flow) 1=CB Inlet ( Controls 0.00 cfs) 4=Underdrain (Orifice Controls 0.33 cfs @ 3.83 fps) Summary for Pond 16P: INF-10+11 Inflow Area = 0.368 ac, 90.56% Impervious, Inflow Depth > 6.02" for 50-Year event Inflow = 2.55 cfs @ 12.07 hrs, Volume= 0.185 af Outflow = 2.55 cfs @ 12.07 hrs, Volume= 0.173 af, Atten= 0%, Lag= 0.0 min Discarded = 0.04 cfs @ 12.07 hrs, Volume= 0.041 af Primary = 2.51 cfs @ 12.07 hrs, Volume= 0.133 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 147.36' @ 12.07 hrs Surf.Area= 909 sf Storage= 495 cf Flood Elev= 149.00' Surf.Area= 11,205 sf Storage= 3,082 cf Plug-Flow detention time= 38.2 min calculated for 0.173 af (94% of inflow) Center-of-Mass det. time= 14.6 min ( 746.2 - 731.7 ) Volume Invert Avail.Storage Storage Description #1 146.00' 271 cf Stone Bedding (Prismatic) Listed below (Recalc) 897 cf Overall - 219 cf Embedded = 678 cf x 40.0% Voids #2 146.08' 219 cf 10.0" Round Pipe Storage Inside #1 L= 402.0' #3 147.00' 2,592 cf Custom Stage Data (Prismatic) Listed below (Recalc) x 2 3,082 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 146.00 897 0 0 147.00 897 897 897 Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 72HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 6 0 0 148.00 6 6 6 148.50 5,154 1,290 1,296 Device Routing Invert Outlet Devices #1 Device 2 147.10'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #2 Primary 144.70'12.0" Round Culvert L= 32.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.70' / 144.44' S= 0.0081 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 4 147.10'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #4 Primary 144.80'12.0" Round Culvert L= 32.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.80' / 144.18' S= 0.0194 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #5 Discarded 146.00'1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' Discarded OutFlow Max=0.04 cfs @ 12.07 hrs HW=147.36' (Free Discharge) 5=Exfiltration ( Controls 0.04 cfs) Primary OutFlow Max=2.51 cfs @ 12.07 hrs HW=147.36' (Free Discharge) 2=Culvert (Passes 1.25 cfs of 5.55 cfs potential flow) 1=Sharp-Crested Rectangular Weir (Weir Controls 1.25 cfs @ 1.66 fps) 4=Culvert (Passes 1.25 cfs of 5.42 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Weir Controls 1.25 cfs @ 1.66 fps) Summary for Pond 17P: INF-6+8 Inflow Area = 0.293 ac, 88.50% Impervious, Inflow Depth > 5.87" for 50-Year event Inflow = 2.01 cfs @ 12.07 hrs, Volume= 0.143 af Outflow = 2.01 cfs @ 12.07 hrs, Volume= 0.137 af, Atten= 0%, Lag= 0.0 min Discarded = 0.02 cfs @ 12.07 hrs, Volume= 0.026 af Primary = 1.99 cfs @ 12.07 hrs, Volume= 0.112 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 147.14' @ 12.07 hrs Surf.Area= 628 sf Storage= 335 cf Flood Elev= 148.90' Surf.Area= 14,038 sf Storage= 3,704 cf Plug-Flow detention time= 30.7 min calculated for 0.137 af (95% of inflow) Center-of-Mass det. time= 12.8 min ( 750.4 - 737.6 ) Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 73HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 146.00' 188 cf Stone Bedding (Prismatic) Listed below (Recalc) 616 cf Overall - 146 cf Embedded = 470 cf x 40.0% Voids #2 146.08' 146 cf 10.0" Round Pipe Storage Inside #1 L= 267.0' #3 147.00' 3,371 cf Custom Stage Data (Prismatic) Listed below (Recalc) x 2 3,704 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 146.00 616 0 0 147.00 616 616 616 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 6 0 0 148.00 6 6 6 148.50 6,711 1,679 1,685 Device Routing Invert Outlet Devices #1 Device 2 147.10'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #2 Primary 144.80'12.0" Round Culvert L= 31.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.80' / 144.32' S= 0.0155 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 4 146.80'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #4 Primary 144.50'12.0" Round Culvert L= 31.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.50' / 144.15' S= 0.0113 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #5 Discarded 146.00'1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' Discarded OutFlow Max=0.02 cfs @ 12.07 hrs HW=147.14' (Free Discharge) 5=Exfiltration ( Controls 0.02 cfs) Primary OutFlow Max=1.98 cfs @ 12.07 hrs HW=147.14' (Free Discharge) 2=Culvert (Passes 0.08 cfs of 5.13 cfs potential flow) 1=Sharp-Crested Rectangular Weir (Weir Controls 0.08 cfs @ 0.66 fps) 4=Culvert (Passes 1.90 cfs of 5.53 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Weir Controls 1.90 cfs @ 1.91 fps) Summary for Pond 18P: INF-5+7 Inflow Area = 0.214 ac, 91.42% Impervious, Inflow Depth > 6.04" for 50-Year event Inflow = 1.49 cfs @ 12.07 hrs, Volume= 0.108 af Outflow = 1.49 cfs @ 12.07 hrs, Volume= 0.100 af, Atten= 0%, Lag= 0.0 min Discarded = 0.03 cfs @ 12.07 hrs, Volume= 0.031 af Primary = 1.46 cfs @ 12.07 hrs, Volume= 0.069 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.94"2018-082 Colvest Northampton As-Built Modifications Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 74HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Peak Elev= 147.02' @ 12.07 hrs Surf.Area= 664 sf Storage= 358 cf Flood Elev= 148.90' Surf.Area= 5,822 sf Storage= 1,665 cf Plug-Flow detention time= 43.9 min calculated for 0.100 af (93% of inflow) Center-of-Mass det. time= 17.4 min ( 748.8 - 731.4 ) Volume Invert Avail.Storage Storage Description #1 145.60' 199 cf Stone Bedding (Prismatic) Listed below (Recalc) 652 cf Overall - 154 cf Embedded = 498 cf x 40.0% Voids #2 145.68' 154 cf 10.0" Round Pipe Storage Inside #1 L= 282.0' #3 146.60' 1,312 cf Custom Stage Data (Prismatic) Listed below (Recalc) x 2 1,665 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 145.60 652 0 0 146.60 652 652 652 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 146.60 6 0 0 148.00 6 8 8 148.50 2,585 648 656 Device Routing Invert Outlet Devices #1 Device 2 146.80'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #2 Primary 144.60'12.0" Round Culvert L= 29.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.60' / 144.32' S= 0.0097 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 4 146.90'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #4 Primary 144.70'12.0" Round Culvert L= 29.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.70' / 144.15' S= 0.0190 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #5 Discarded 145.60'1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' Discarded OutFlow Max=0.03 cfs @ 12.07 hrs HW=147.02' (Free Discharge) 5=Exfiltration ( Controls 0.03 cfs) Primary OutFlow Max=1.45 cfs @ 12.07 hrs HW=147.02' (Free Discharge) 2=Culvert (Passes 1.03 cfs of 5.25 cfs potential flow) 1=Sharp-Crested Rectangular Weir (Weir Controls 1.03 cfs @ 1.55 fps) 4=Culvert (Passes 0.43 cfs of 5.11 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Weir Controls 0.43 cfs @ 1.15 fps) Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 75HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Time span=1.00-20.00 hrs, dt=0.01 hrs, 1901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=8,350 sf 98.42% Impervious Runoff Depth>7.12"Subcatchment 1S: A1 Tc=5.0 min CN=97 Runoff=1.52 cfs 0.114 af Runoff Area=4,496 sf 92.70% Impervious Runoff Depth>6.88"Subcatchment 2S: A2 Tc=5.0 min CN=95 Runoff=0.81 cfs 0.059 af Runoff Area=6,870 sf 97.82% Impervious Runoff Depth>7.12"Subcatchment 3S: A3 Tc=5.0 min CN=97 Runoff=1.25 cfs 0.094 af Runoff Area=8,648 sf 82.34% Impervious Runoff Depth>6.41"Subcatchment 4S: A4 Tc=5.0 min CN=91 Runoff=1.51 cfs 0.106 af Runoff Area=25,964 sf 100.00% Impervious Runoff Depth>7.23"Subcatchment 5S: B2 Tc=5.0 min CN=98 Runoff=4.74 cfs 0.359 af Runoff Area=7,072 sf 0.00% Impervious Runoff Depth>3.06"Subcatchment 6S: POND Tc=0.0 min CN=61 Runoff=0.76 cfs 0.041 af Runoff Area=57,882 sf 0.00% Impervious Runoff Depth>6.41"Subcatchment 7S: PRE REAR Tc=5.0 min CN=91 Runoff=10.12 cfs 0.710 af Runoff Area=5,095 sf 91.89% Impervious Runoff Depth>6.88"Subcatchment 8S: A5 Tc=5.0 min CN=95 Runoff=0.92 cfs 0.067 af Runoff Area=6,947 sf 89.75% Impervious Runoff Depth>6.76"Subcatchment 9S: A6 Tc=5.0 min CN=94 Runoff=1.24 cfs 0.090 af Runoff Area=4,230 sf 90.85% Impervious Runoff Depth>6.88"Subcatchment 10S: A7 Tc=5.0 min CN=95 Runoff=0.76 cfs 0.056 af Runoff Area=5,823 sf 87.02% Impervious Runoff Depth>6.64"Subcatchment 11S: A8 Tc=5.0 min CN=93 Runoff=1.04 cfs 0.074 af Runoff Area=11,231 sf 77.08% Impervious Runoff Depth>6.29"Subcatchment 12S: A9 Tc=5.0 min CN=90 Runoff=1.94 cfs 0.135 af Runoff Area=9,635 sf 93.98% Impervious Runoff Depth>7.00"Subcatchment 13S: A10 Tc=5.0 min CN=96 Runoff=1.75 cfs 0.129 af Runoff Area=6,395 sf 85.41% Impervious Runoff Depth>6.64"Subcatchment 14S: A11 Tc=5.0 min CN=93 Runoff=1.14 cfs 0.081 af Runoff Area=9,957 sf 48.28% Impervious Runoff Depth>5.02"Subcatchment 15S: A12 Tc=5.0 min CN=79 Runoff=1.47 cfs 0.096 af Runoff Area=3,453 sf 73.59% Impervious Runoff Depth>6.06"Subcatchment 16S: A13 Tc=5.0 min CN=88 Runoff=0.58 cfs 0.040 af Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 76HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Runoff Area=2,168 sf 59.73% Impervious Runoff Depth>5.48"Subcatchment 17S: A14 Tc=5.0 min CN=83 Runoff=0.34 cfs 0.023 af Runoff Area=2,826 sf 51.91% Impervious Runoff Depth>5.14"Subcatchment 18S: A15 Tc=5.0 min CN=80 Runoff=0.42 cfs 0.028 af Runoff Area=6,971 sf 100.00% Impervious Runoff Depth>7.23"Subcatchment 19S: B1 Tc=5.0 min CN=98 Runoff=1.27 cfs 0.096 af Runoff Area=71,761 sf 44.08% Impervious Runoff Depth>6.17"Subcatchment 20S: PRE FRONT Tc=5.0 min CN=89 Runoff=12.29 cfs 0.848 af Peak Elev=145.54' Inflow=1.52 cfs 0.114 afPond 1C: CB1 12.0" Round Culvert n=0.012 L=124.0' S=0.0050 '/' Outflow=1.52 cfs 0.114 af Peak Elev=145.65' Inflow=7.07 cfs 0.532 afPond 1D: DMH1 18.0" Round Culvert n=0.012 L=58.0' S=0.0050 '/' Outflow=7.07 cfs 0.532 af Peak Elev=146.93' Storage=11,013 cf Inflow=10.33 cfs 0.773 afPond 1P: POST REAR Discarded=0.13 cfs 0.126 af Primary=9.29 cfs 0.437 af Outflow=9.43 cfs 0.563 af Peak Elev=145.46' Inflow=0.81 cfs 0.059 afPond 2C: CB2 12.0" Round Culvert n=0.012 L=8.0' S=0.0437 '/' Outflow=0.81 cfs 0.059 af Peak Elev=145.66' Inflow=8.32 cfs 0.626 afPond 2D: DMH2 18.0" Round Culvert n=0.012 L=50.0' S=0.0050 '/' Outflow=8.32 cfs 0.626 af Peak Elev=148.13' Storage=8,224 cf Inflow=10.67 cfs 0.775 afPond 2P: POST FRONT Outflow=11.25 cfs 0.736 af Peak Elev=145.45' Inflow=1.25 cfs 0.094 afPond 3C: CB3 12.0" Round Culvert n=0.012 L=13.0' S=0.0115 '/' Outflow=1.25 cfs 0.094 af Peak Elev=145.63' Inflow=9.83 cfs 0.732 afPond 3D: DMH3 18.0" Round Culvert n=0.012 L=54.0' S=0.0056 '/' Outflow=9.83 cfs 0.732 af Peak Elev=145.51' Inflow=1.51 cfs 0.106 afPond 4C: CB4 12.0" Round Culvert n=0.012 L=8.0' S=0.0188 '/' Outflow=1.51 cfs 0.106 af Peak Elev=148.11' Storage=589 cf Inflow=1.94 cfs 0.135 afPond 9P: RG9 Discarded=0.03 cfs 0.004 af Primary=1.54 cfs 0.131 af Outflow=1.58 cfs 0.135 af Peak Elev=148.02' Storage=514 cf Inflow=1.47 cfs 0.096 afPond 12P: RG12 Discarded=0.05 cfs 0.004 af Primary=0.64 cfs 0.091 af Outflow=0.69 cfs 0.096 af Peak Elev=147.79' Storage=32 cf Inflow=0.58 cfs 0.040 afPond 13P: RG13 Discarded=0.00 cfs 0.001 af Primary=0.54 cfs 0.039 af Outflow=0.54 cfs 0.040 af Peak Elev=146.74' Storage=26 cf Inflow=0.34 cfs 0.023 afPond 14P: RG14 Discarded=0.00 cfs 0.002 af Primary=0.32 cfs 0.021 af Outflow=0.32 cfs 0.023 af Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 77HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Peak Elev=147.02' Storage=36 cf Inflow=0.42 cfs 0.028 afPond 15P: RG15 Discarded=0.00 cfs 0.002 af Primary=0.39 cfs 0.026 af Outflow=0.39 cfs 0.028 af Peak Elev=147.38' Storage=495 cf Inflow=2.88 cfs 0.210 afPond 16P: INF-10+11 Discarded=0.04 cfs 0.042 af Primary=2.85 cfs 0.157 af Outflow=2.88 cfs 0.199 af Peak Elev=147.16' Storage=336 cf Inflow=2.28 cfs 0.164 afPond 17P: INF-6+8 Discarded=0.02 cfs 0.026 af Primary=2.26 cfs 0.131 af Outflow=2.28 cfs 0.157 af Peak Elev=147.04' Storage=358 cf Inflow=1.68 cfs 0.123 afPond 18P: INF-5+7 Discarded=0.03 cfs 0.032 af Primary=1.65 cfs 0.083 af Outflow=1.68 cfs 0.115 af Total Runoff Area = 6.101 ac Runoff Volume = 3.245 af Average Runoff Depth = 6.38" 45.85% Pervious = 2.798 ac 54.15% Impervious = 3.304 ac Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 78HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: A1 Runoff = 1.52 cfs @ 12.07 hrs, Volume= 0.114 af, Depth> 7.12" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 8,218 98 Paved parking, HSG B 132 61 >75% Grass cover, Good, HSG B 8,350 97 Weighted Average 132 1.58% Pervious Area 8,218 98.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: A2 Runoff = 0.81 cfs @ 12.07 hrs, Volume= 0.059 af, Depth> 6.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 4,168 98 Paved parking, HSG B 328 61 >75% Grass cover, Good, HSG B 4,496 95 Weighted Average 328 7.30% Pervious Area 4,168 92.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 3S: A3 Runoff = 1.25 cfs @ 12.07 hrs, Volume= 0.094 af, Depth> 7.12" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 6,720 98 Paved parking, HSG B 150 61 >75% Grass cover, Good, HSG B 6,870 97 Weighted Average 150 2.18% Pervious Area 6,720 97.82% Impervious Area Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 79HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 4S: A4 Runoff = 1.51 cfs @ 12.07 hrs, Volume= 0.106 af, Depth> 6.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 7,121 98 Paved parking, HSG B 1,527 61 >75% Grass cover, Good, HSG B 8,648 91 Weighted Average 1,527 17.66% Pervious Area 7,121 82.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: B2 Runoff = 4.74 cfs @ 12.07 hrs, Volume= 0.359 af, Depth> 7.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 25,964 98 Roofs, HSG B 0 61 >75% Grass cover, Good, HSG B 25,964 98 Weighted Average 25,964 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6S: POND Runoff = 0.76 cfs @ 12.00 hrs, Volume= 0.041 af, Depth> 3.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 80HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Area (sf) CN Description 7,072 61 >75% Grass cover, Good, HSG B 7,072 100.00% Pervious Area Summary for Subcatchment 7S: PRE REAR Runoff = 10.12 cfs @ 12.07 hrs, Volume= 0.710 af, Depth> 6.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 9,064 67 Brush, Poor, HSG B 48,818 96 Gravel surface, HSG B 57,882 91 Weighted Average 57,882 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 8S: A5 Runoff = 0.92 cfs @ 12.07 hrs, Volume= 0.067 af, Depth> 6.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 4,682 98 Paved parking, HSG B 413 61 >75% Grass cover, Good, HSG B 5,095 95 Weighted Average 413 8.11% Pervious Area 4,682 91.89% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: A6 Runoff = 1.24 cfs @ 12.07 hrs, Volume= 0.090 af, Depth> 6.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 81HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Area (sf) CN Description 6,235 98 Paved parking, HSG B 712 61 >75% Grass cover, Good, HSG B 6,947 94 Weighted Average 712 10.25% Pervious Area 6,235 89.75% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 10S: A7 Runoff = 0.76 cfs @ 12.07 hrs, Volume= 0.056 af, Depth> 6.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 3,843 98 Paved parking, HSG B 387 61 >75% Grass cover, Good, HSG B 4,230 95 Weighted Average 387 9.15% Pervious Area 3,843 90.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 11S: A8 Runoff = 1.04 cfs @ 12.07 hrs, Volume= 0.074 af, Depth> 6.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 5,067 98 Paved parking, HSG B 756 61 >75% Grass cover, Good, HSG B 5,823 93 Weighted Average 756 12.98% Pervious Area 5,067 87.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 82HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: A9 Runoff = 1.94 cfs @ 12.07 hrs, Volume= 0.135 af, Depth> 6.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 8,657 98 Paved parking, HSG B 2,574 61 >75% Grass cover, Good, HSG B 11,231 90 Weighted Average 2,574 22.92% Pervious Area 8,657 77.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 13S: A10 Runoff = 1.75 cfs @ 12.07 hrs, Volume= 0.129 af, Depth> 7.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 9,055 98 Paved parking, HSG B 580 61 >75% Grass cover, Good, HSG B 9,635 96 Weighted Average 580 6.02% Pervious Area 9,055 93.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 14S: A11 Runoff = 1.14 cfs @ 12.07 hrs, Volume= 0.081 af, Depth> 6.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 5,462 98 Paved parking, HSG B 933 61 >75% Grass cover, Good, HSG B 6,395 93 Weighted Average 933 14.59% Pervious Area 5,462 85.41% Impervious Area Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 83HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 15S: A12 Runoff = 1.47 cfs @ 12.07 hrs, Volume= 0.096 af, Depth> 5.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 4,807 98 Paved parking, HSG B 5,150 61 >75% Grass cover, Good, HSG B 9,957 79 Weighted Average 5,150 51.72% Pervious Area 4,807 48.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 16S: A13 Runoff = 0.58 cfs @ 12.07 hrs, Volume= 0.040 af, Depth> 6.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 2,541 98 Paved parking, HSG B 912 61 >75% Grass cover, Good, HSG B 3,453 88 Weighted Average 912 26.41% Pervious Area 2,541 73.59% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 17S: A14 Runoff = 0.34 cfs @ 12.07 hrs, Volume= 0.023 af, Depth> 5.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 84HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Area (sf) CN Description 1,295 98 Paved parking, HSG B 873 61 >75% Grass cover, Good, HSG B 2,168 83 Weighted Average 873 40.27% Pervious Area 1,295 59.73% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 18S: A15 Runoff = 0.42 cfs @ 12.07 hrs, Volume= 0.028 af, Depth> 5.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 1,467 98 Paved parking, HSG B 1,359 61 >75% Grass cover, Good, HSG B 2,826 80 Weighted Average 1,359 48.09% Pervious Area 1,467 51.91% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 19S: B1 Runoff = 1.27 cfs @ 12.07 hrs, Volume= 0.096 af, Depth> 7.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 6,971 98 Roofs, HSG B 0 61 >75% Grass cover, Good, HSG B 6,971 98 Weighted Average 6,971 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 85HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 20S: PRE FRONT Runoff = 12.29 cfs @ 12.07 hrs, Volume= 0.848 af, Depth> 6.17" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82" Area (sf) CN Description 24,527 96 Gravel surface, HSG B 15,601 61 >75% Grass cover, Good, HSG B 31,633 98 Paved parking, HSG B 71,761 89 Weighted Average 40,128 55.92% Pervious Area 31,633 44.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 1C: CB1 Inflow Area = 0.192 ac, 98.42% Impervious, Inflow Depth > 7.12" for 100-Year event Inflow = 1.52 cfs @ 12.07 hrs, Volume= 0.114 af Outflow = 1.52 cfs @ 12.07 hrs, Volume= 0.114 af, Atten= 0%, Lag= 0.0 min Primary = 1.52 cfs @ 12.07 hrs, Volume= 0.114 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.54' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 144.80'12.0" Round Culvert L= 124.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.80' / 144.18' S= 0.0050 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.52 cfs @ 12.07 hrs HW=145.54' (Free Discharge) 1=Culvert (Barrel Controls 1.52 cfs @ 3.38 fps) Summary for Pond 1D: DMH1 Inflow Area = 0.891 ac, 98.81% Impervious, Inflow Depth > 7.17" for 100-Year event Inflow = 7.07 cfs @ 12.07 hrs, Volume= 0.532 af Outflow = 7.07 cfs @ 12.07 hrs, Volume= 0.532 af, Atten= 0%, Lag= 0.0 min Primary = 7.07 cfs @ 12.07 hrs, Volume= 0.532 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.65' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 144.00'18.0" Round 18" CPEP Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 86HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC L= 58.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.00' / 143.71' S= 0.0050 '/' Cc= 0.900 n= 0.012, Flow Area= 1.77 sf Primary OutFlow Max=7.07 cfs @ 12.07 hrs HW=145.65' (Free Discharge) 1=18" CPEP (Barrel Controls 7.07 cfs @ 4.54 fps) Summary for Pond 1P: POST REAR Inflow Area = 1.410 ac, 85.00% Impervious, Inflow Depth > 6.58" for 100-Year event Inflow = 10.33 cfs @ 12.07 hrs, Volume= 0.773 af Outflow = 9.43 cfs @ 12.10 hrs, Volume= 0.563 af, Atten= 9%, Lag= 2.0 min Discarded = 0.13 cfs @ 12.10 hrs, Volume= 0.126 af Primary = 9.29 cfs @ 12.10 hrs, Volume= 0.437 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 146.93' @ 12.10 hrs Surf.Area= 4,523 sf Storage= 11,013 cf Plug-Flow detention time= 124.5 min calculated for 0.562 af (73% of inflow) Center-of-Mass det. time= 55.7 min ( 780.8 - 725.1 ) Volume Invert Avail.Storage Storage Description #1 143.00' 11,310 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 143.00 1,320 0 0 144.00 1,986 1,653 1,653 145.00 2,752 2,369 4,022 146.00 3,619 3,186 7,208 147.00 4,586 4,103 11,310 Device Routing Invert Outlet Devices #1 Discarded 143.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 135.00' #2 Primary 146.50'12.0' long x 16.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Discarded OutFlow Max=0.13 cfs @ 12.10 hrs HW=146.93' (Free Discharge) 1=Exfiltration ( Controls 0.13 cfs) Primary OutFlow Max=9.28 cfs @ 12.10 hrs HW=146.93' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 9.28 cfs @ 1.78 fps) Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 87HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Pond 2C: CB2 Inflow Area = 0.103 ac, 92.70% Impervious, Inflow Depth > 6.88" for 100-Year event Inflow = 0.81 cfs @ 12.07 hrs, Volume= 0.059 af Outflow = 0.81 cfs @ 12.07 hrs, Volume= 0.059 af, Atten= 0%, Lag= 0.0 min Primary = 0.81 cfs @ 12.07 hrs, Volume= 0.059 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.46' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 145.00'12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 145.00' / 144.65' S= 0.0437 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=0.81 cfs @ 12.07 hrs HW=145.46' (Free Discharge) 1=Culvert (Inlet Controls 0.81 cfs @ 2.31 fps) Summary for Pond 2D: DMH2 Inflow Area = 1.049 ac, 98.66% Impervious, Inflow Depth > 7.16" for 100-Year event Inflow = 8.32 cfs @ 12.07 hrs, Volume= 0.626 af Outflow = 8.32 cfs @ 12.07 hrs, Volume= 0.626 af, Atten= 0%, Lag= 0.0 min Primary = 8.32 cfs @ 12.07 hrs, Volume= 0.626 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.66' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 143.63'18.0" Round 18" CPEP L= 50.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 143.63' / 143.38' S= 0.0050 '/' Cc= 0.900 n= 0.012, Flow Area= 1.77 sf Primary OutFlow Max=8.32 cfs @ 12.07 hrs HW=145.66' (Free Discharge) 1=18" CPEP (Barrel Controls 8.32 cfs @ 4.71 fps) Summary for Pond 2P: POST FRONT Inflow Area = 1.716 ac, 80.40% Impervious, Inflow Depth > 5.42" for 100-Year event Inflow = 10.67 cfs @ 12.09 hrs, Volume= 0.775 af Outflow = 11.25 cfs @ 12.09 hrs, Volume= 0.736 af, Atten= 0%, Lag= 0.1 min Primary = 11.25 cfs @ 12.09 hrs, Volume= 0.736 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Starting Elev= 144.27' Surf.Area= 2,195 sf Storage= 940 cf Peak Elev= 148.13' @ 12.09 hrs Surf.Area= 508 sf Storage= 8,224 cf (7,284 cf above start) Flood Elev= 148.20' Surf.Area= 508 sf Storage= 8,258 cf (7,318 cf above start) Plug-Flow detention time= 64.4 min calculated for 0.714 af (92% of inflow) Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 88HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Center-of-Mass det. time= 34.8 min ( 783.8 - 749.0 ) Volume Invert Avail.Storage Storage Description #1 143.90' 509 cf 4.00'D x 4.50'H DMH x 9 #2 143.86' 226 cf 30.0" Round 30" Flat CPEP (10-11) L= 46.0' S= 0.0070 '/' #3 143.74' 324 cf 30.0" Round 30" Flat CPEP (11-12) L= 66.0' S= 0.0003 '/' #4 143.78' 275 cf 30.0" Round 30" Flat CPEP (12-Out) L= 56.0' S= 0.0016 '/' #5 143.88' 1,924 cf 30.0" Round 30" Flat CPEP (9-Out) x 4 L= 98.0' S= 0.0030 '/' #6 143.39' 1,031 cf 30.0" Round 30" Flat CPEP (6-9) x 3 L= 70.0' S= 0.0007 '/' #7 143.59' 260 cf 30.0" Round 30" Flat CPEP (8-9) L= 53.0' S= 0.0008 '/' #8 143.38' 476 cf 30.0" Round 30" Flat CPEP (7-8) L= 97.0' S= 0.0008 '/' #9 143.39' 285 cf 30.0" Round 30" Flat CPEP (5-6) L= 58.0' S= 0.0007 '/' #10 143.50' 422 cf 30.0" Round 30" Flat CPEP (4-5) L= 86.0' S= 0.0003 '/' #11 148.00' 333 cf Custom Stage Data (Prismatic) Listed below (Recalc) #12 144.27' 2,376 cf 30.0" Round Prop. 30" Flat CPEP L= 484.0' #13 144.27' 113 cf 4.00'D x 4.50'H Prop. DMH x 2 8,554 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 148.00 370 0 0 148.90 370 333 333 Device Routing Invert Outlet Devices #1 Device 3 144.27'10.0" Vert. 10" Orifice C= 0.600 #2 Device 3 146.85'36.0" W x 4.0" H Vert. 4"x36" Weir/Orifice C= 0.600 #3 Primary 144.65'12.0" Round 12" Culvert L= 16.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.65' / 143.50' S= 0.0719 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Primary 148.00'37.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=10.88 cfs @ 12.09 hrs HW=148.13' (Free Discharge) 3=12" Culvert (Inlet Controls 6.53 cfs @ 8.31 fps) 1=10" Orifice (Passes < 4.87 cfs potential flow) 2=4"x36" Weir/Orifice (Passes < 5.08 cfs potential flow) 4=Broad-Crested Rectangular Weir (Weir Controls 4.35 cfs @ 0.90 fps) Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 89HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Summary for Pond 3C: CB3 Inflow Area = 0.158 ac, 97.82% Impervious, Inflow Depth > 7.12" for 100-Year event Inflow = 1.25 cfs @ 12.07 hrs, Volume= 0.094 af Outflow = 1.25 cfs @ 12.07 hrs, Volume= 0.094 af, Atten= 0%, Lag= 0.0 min Primary = 1.25 cfs @ 12.07 hrs, Volume= 0.094 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.45' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 144.80'12.0" Round Culvert L= 13.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.80' / 144.65' S= 0.0115 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.25 cfs @ 12.07 hrs HW=145.45' (Free Discharge) 1=Culvert (Barrel Controls 1.25 cfs @ 3.29 fps) Summary for Pond 3D: DMH3 Inflow Area = 1.247 ac, 96.07% Impervious, Inflow Depth > 7.04" for 100-Year event Inflow = 9.83 cfs @ 12.07 hrs, Volume= 0.732 af Outflow = 9.83 cfs @ 12.07 hrs, Volume= 0.732 af, Atten= 0%, Lag= 0.0 min Primary = 9.83 cfs @ 12.07 hrs, Volume= 0.732 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.63' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 143.30'18.0" Round Culvert L= 54.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 143.30' / 143.00' S= 0.0056 '/' Cc= 0.900 n= 0.012, Flow Area= 1.77 sf Primary OutFlow Max=9.83 cfs @ 12.07 hrs HW=145.63' (Free Discharge) 1=Culvert (Barrel Controls 9.83 cfs @ 5.56 fps) Summary for Pond 4C: CB4 Inflow Area = 0.199 ac, 82.34% Impervious, Inflow Depth > 6.41" for 100-Year event Inflow = 1.51 cfs @ 12.07 hrs, Volume= 0.106 af Outflow = 1.51 cfs @ 12.07 hrs, Volume= 0.106 af, Atten= 0%, Lag= 0.0 min Primary = 1.51 cfs @ 12.07 hrs, Volume= 0.106 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 145.51' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 144.80'12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 90HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Inlet / Outlet Invert= 144.80' / 144.65' S= 0.0188 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Primary OutFlow Max=1.51 cfs @ 12.07 hrs HW=145.51' (Free Discharge) 1=Culvert (Barrel Controls 1.51 cfs @ 3.53 fps) Summary for Pond 9P: RG9 Inflow Area = 0.258 ac, 77.08% Impervious, Inflow Depth > 6.29" for 100-Year event Inflow = 1.94 cfs @ 12.07 hrs, Volume= 0.135 af Outflow = 1.58 cfs @ 12.12 hrs, Volume= 0.135 af, Atten= 19%, Lag= 3.2 min Discarded = 0.03 cfs @ 12.12 hrs, Volume= 0.004 af Primary = 1.54 cfs @ 12.12 hrs, Volume= 0.131 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 148.11' @ 12.12 hrs Surf.Area= 1,154 sf Storage= 589 cf Flood Elev= 148.40' Surf.Area= 1,804 sf Storage= 1,004 cf Plug-Flow detention time= 4.0 min calculated for 0.135 af (100% of inflow) Center-of-Mass det. time= 3.8 min ( 750.6 - 746.7 ) Volume Invert Avail.Storage Storage Description #1 147.40' 963 cf Rain Garden (Prismatic) Listed below (Recalc) #2A 145.60' 25 cf 3.21'W x 21.33'L x 1.21'H Field A 83 cf Overall - 21 cf Embedded = 62 cf x 40.0% Voids #3A 145.60' 16 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 1,004 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.40 632 0 0 148.00 853 445 445 148.40 1,736 518 963 Device Routing Invert Outlet Devices #1 Device 3 148.00'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 145.60'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 144.50'12.0" Round Culvert L= 34.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.50' / 143.94' S= 0.0165 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 145.60'4.0" Vert. Underdrain C= 0.600 Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 91HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.03 cfs @ 12.12 hrs HW=148.10' (Free Discharge) 2=Exfiltration ( Controls 0.03 cfs) Primary OutFlow Max=1.53 cfs @ 12.12 hrs HW=148.10' (Free Discharge) 3=Culvert (Passes 1.53 cfs of 6.66 cfs potential flow) 1=CB Inlet (Weir Controls 0.89 cfs @ 1.06 fps) 4=Underdrain (Orifice Controls 0.64 cfs @ 7.36 fps) Summary for Pond 12P: RG12 Inflow Area = 0.229 ac, 48.28% Impervious, Inflow Depth > 5.02" for 100-Year event Inflow = 1.47 cfs @ 12.07 hrs, Volume= 0.096 af Outflow = 0.69 cfs @ 12.23 hrs, Volume= 0.096 af, Atten= 53%, Lag= 9.2 min Discarded = 0.05 cfs @ 12.23 hrs, Volume= 0.004 af Primary = 0.64 cfs @ 12.23 hrs, Volume= 0.091 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 148.02' @ 12.23 hrs Surf.Area= 1,898 sf Storage= 514 cf Flood Elev= 148.40' Surf.Area= 3,301 sf Storage= 1,481 cf Plug-Flow detention time= 4.5 min calculated for 0.096 af (100% of inflow) Center-of-Mass det. time= 4.3 min ( 777.2 - 772.9 ) Volume Invert Avail.Storage Storage Description #1 147.50' 1,440 cf Rain Garden (Prismatic) Listed below (Recalc) #2A 146.00' 25 cf 3.21'W x 21.33'L x 1.21'H Field A 83 cf Overall - 21 cf Embedded = 62 cf x 40.0% Voids #3A 146.00' 16 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 1,481 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.50 0 0 0 148.00 1,764 441 441 148.40 3,233 999 1,440 Device Routing Invert Outlet Devices #1 Device 3 148.00'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 146.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 144.50'12.0" Round Culvert L= 19.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.50' / 144.09' S= 0.0216 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 146.00'4.0" Vert. Underdrain C= 0.600 Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 92HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.05 cfs @ 12.23 hrs HW=148.02' (Free Discharge) 2=Exfiltration ( Controls 0.05 cfs) Primary OutFlow Max=0.63 cfs @ 12.23 hrs HW=148.02' (Free Discharge) 3=Culvert (Passes 0.63 cfs of 6.57 cfs potential flow) 1=CB Inlet (Weir Controls 0.06 cfs @ 0.44 fps) 4=Underdrain (Orifice Controls 0.57 cfs @ 6.55 fps) Summary for Pond 13P: RG13 Inflow Area = 0.079 ac, 73.59% Impervious, Inflow Depth > 6.06" for 100-Year event Inflow = 0.58 cfs @ 12.07 hrs, Volume= 0.040 af Outflow = 0.54 cfs @ 12.10 hrs, Volume= 0.040 af, Atten= 8%, Lag= 1.9 min Discarded = 0.00 cfs @ 12.10 hrs, Volume= 0.001 af Primary = 0.54 cfs @ 12.10 hrs, Volume= 0.039 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 147.79' @ 12.10 hrs Surf.Area= 110 sf Storage= 32 cf Flood Elev= 148.70' Surf.Area= 1,047 sf Storage= 282 cf Plug-Flow detention time= 0.8 min calculated for 0.040 af (100% of inflow) Center-of-Mass det. time= 0.6 min ( 753.1 - 752.4 ) Volume Invert Avail.Storage Storage Description #1 147.50' 261 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 146.00' 13 cf 3.21'W x 11.33'L x 1.21'H Field A 44 cf Overall - 10 cf Embedded = 33 cf x 40.0% Voids #3A 146.00' 8 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf Row Length Adjustment= -10.00' x 0.81 sf x 1 rows 282 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.50 0 0 0 148.00 127 32 32 148.40 249 75 107 148.50 269 26 133 148.70 1,011 128 261 Device Routing Invert Outlet Devices #1 Device 3 148.30'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 146.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 145.10'12.0" Round Culvert L= 10.0' CPP, square edge headwall, Ke= 0.500 Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 93HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Inlet / Outlet Invert= 145.10' / 144.84' S= 0.0260 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 146.00'4.0" Vert. Underdrain C= 0.600 Discarded OutFlow Max=0.00 cfs @ 12.10 hrs HW=147.79' (Free Discharge) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.54 cfs @ 12.10 hrs HW=147.79' (Free Discharge) 3=Culvert (Passes 0.54 cfs of 5.59 cfs potential flow) 1=CB Inlet ( Controls 0.00 cfs) 4=Underdrain (Orifice Controls 0.54 cfs @ 6.13 fps) Summary for Pond 14P: RG14 Inflow Area = 0.050 ac, 59.73% Impervious, Inflow Depth > 5.48" for 100-Year event Inflow = 0.34 cfs @ 12.07 hrs, Volume= 0.023 af Outflow = 0.32 cfs @ 12.10 hrs, Volume= 0.023 af, Atten= 7%, Lag= 1.8 min Discarded = 0.00 cfs @ 12.10 hrs, Volume= 0.002 af Primary = 0.32 cfs @ 12.10 hrs, Volume= 0.021 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 146.74' @ 12.10 hrs Surf.Area= 68 sf Storage= 26 cf Flood Elev= 148.70' Surf.Area= 1,131 sf Storage= 357 cf Plug-Flow detention time= 1.6 min calculated for 0.023 af (100% of inflow) Center-of-Mass det. time= 1.2 min ( 765.8 - 764.6 ) Volume Invert Avail.Storage Storage Description #1 148.00' 316 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 146.00' 25 cf 3.21'W x 21.33'L x 1.21'H Field A 83 cf Overall - 21 cf Embedded = 62 cf x 40.0% Voids #3A 146.00' 16 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 357 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 148.00 0 0 0 148.30 331 50 50 148.40 450 39 89 148.70 1,063 227 316 Device Routing Invert Outlet Devices #1 Device 3 148.40'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 146.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 145.26'12.0" Round Culvert Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 94HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC L= 10.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 145.10' / 145.26' S= -0.0160 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 146.00'4.0" Vert. Underdrain C= 0.600 Discarded OutFlow Max=0.00 cfs @ 12.10 hrs HW=146.74' (Free Discharge) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.32 cfs @ 12.10 hrs HW=146.74' (Free Discharge) 3=Culvert (Passes 0.32 cfs of 3.73 cfs potential flow) 1=CB Inlet ( Controls 0.00 cfs) 4=Underdrain (Orifice Controls 0.32 cfs @ 3.63 fps) Summary for Pond 15P: RG15 Inflow Area = 0.065 ac, 51.91% Impervious, Inflow Depth > 5.14" for 100-Year event Inflow = 0.42 cfs @ 12.07 hrs, Volume= 0.028 af Outflow = 0.39 cfs @ 12.11 hrs, Volume= 0.028 af, Atten= 8%, Lag= 1.9 min Discarded = 0.00 cfs @ 12.11 hrs, Volume= 0.002 af Primary = 0.39 cfs @ 12.11 hrs, Volume= 0.026 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 147.02' @ 12.11 hrs Surf.Area= 68 sf Storage= 36 cf Flood Elev= 148.70' Surf.Area= 880 sf Storage= 337 cf Plug-Flow detention time= 1.5 min calculated for 0.028 af (100% of inflow) Center-of-Mass det. time= 1.2 min ( 772.1 - 770.9 ) Volume Invert Avail.Storage Storage Description #1 147.80' 296 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 146.00' 25 cf 3.21'W x 21.33'L x 1.21'H Field A 83 cf Overall - 21 cf Embedded = 62 cf x 40.0% Voids #3A 146.00' 16 cf ADS N-12 12" Inside #2 Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cf Outside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf 337 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.80 0 0 0 148.00 173 17 17 148.30 300 71 88 148.40 354 33 121 148.70 812 175 296 Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 95HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Device 3 148.40'24.0" x 24.0" Horiz. CB Inlet C= 0.600 Limited to weir flow at low heads #2 Discarded 146.00'1.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' #3 Primary 145.20'12.0" Round Culvert L= 10.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 145.20' / 144.84' S= 0.0360 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #4 Device 3 146.00'4.0" Vert. Underdrain C= 0.600 Discarded OutFlow Max=0.00 cfs @ 12.11 hrs HW=147.01' (Free Discharge) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.39 cfs @ 12.11 hrs HW=147.01' (Free Discharge) 3=Culvert (Passes 0.39 cfs of 4.34 cfs potential flow) 1=CB Inlet ( Controls 0.00 cfs) 4=Underdrain (Orifice Controls 0.39 cfs @ 4.43 fps) Summary for Pond 16P: INF-10+11 Inflow Area = 0.368 ac, 90.56% Impervious, Inflow Depth > 6.86" for 100-Year event Inflow = 2.88 cfs @ 12.07 hrs, Volume= 0.210 af Outflow = 2.88 cfs @ 12.07 hrs, Volume= 0.199 af, Atten= 0%, Lag= 0.0 min Discarded = 0.04 cfs @ 12.07 hrs, Volume= 0.042 af Primary = 2.85 cfs @ 12.07 hrs, Volume= 0.157 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 147.38' @ 12.07 hrs Surf.Area= 909 sf Storage= 495 cf Flood Elev= 149.00' Surf.Area= 11,205 sf Storage= 3,082 cf Plug-Flow detention time= 35.6 min calculated for 0.199 af (95% of inflow) Center-of-Mass det. time= 14.3 min ( 743.5 - 729.2 ) Volume Invert Avail.Storage Storage Description #1 146.00' 271 cf Stone Bedding (Prismatic) Listed below (Recalc) 897 cf Overall - 219 cf Embedded = 678 cf x 40.0% Voids #2 146.08' 219 cf 10.0" Round Pipe Storage Inside #1 L= 402.0' #3 147.00' 2,592 cf Custom Stage Data (Prismatic) Listed below (Recalc) x 2 3,082 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 146.00 897 0 0 147.00 897 897 897 Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 96HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 6 0 0 148.00 6 6 6 148.50 5,154 1,290 1,296 Device Routing Invert Outlet Devices #1 Device 2 147.10'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #2 Primary 144.70'12.0" Round Culvert L= 32.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.70' / 144.44' S= 0.0081 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 4 147.10'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #4 Primary 144.80'12.0" Round Culvert L= 32.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.80' / 144.18' S= 0.0194 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #5 Discarded 146.00'1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' Discarded OutFlow Max=0.04 cfs @ 12.07 hrs HW=147.38' (Free Discharge) 5=Exfiltration ( Controls 0.04 cfs) Primary OutFlow Max=2.85 cfs @ 12.07 hrs HW=147.38' (Free Discharge) 2=Culvert (Passes 1.42 cfs of 5.58 cfs potential flow) 1=Sharp-Crested Rectangular Weir (Weir Controls 1.42 cfs @ 1.73 fps) 4=Culvert (Passes 1.42 cfs of 5.45 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Weir Controls 1.42 cfs @ 1.73 fps) Summary for Pond 17P: INF-6+8 Inflow Area = 0.293 ac, 88.50% Impervious, Inflow Depth > 6.71" for 100-Year event Inflow = 2.28 cfs @ 12.07 hrs, Volume= 0.164 af Outflow = 2.28 cfs @ 12.07 hrs, Volume= 0.157 af, Atten= 0%, Lag= 0.0 min Discarded = 0.02 cfs @ 12.07 hrs, Volume= 0.026 af Primary = 2.26 cfs @ 12.07 hrs, Volume= 0.131 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Peak Elev= 147.16' @ 12.07 hrs Surf.Area= 628 sf Storage= 336 cf Flood Elev= 148.90' Surf.Area= 14,038 sf Storage= 3,704 cf Plug-Flow detention time= 28.6 min calculated for 0.157 af (96% of inflow) Center-of-Mass det. time= 12.4 min ( 747.2 - 734.8 ) Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 97HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 146.00' 188 cf Stone Bedding (Prismatic) Listed below (Recalc) 616 cf Overall - 146 cf Embedded = 470 cf x 40.0% Voids #2 146.08' 146 cf 10.0" Round Pipe Storage Inside #1 L= 267.0' #3 147.00' 3,371 cf Custom Stage Data (Prismatic) Listed below (Recalc) x 2 3,704 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 146.00 616 0 0 147.00 616 616 616 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 6 0 0 148.00 6 6 6 148.50 6,711 1,679 1,685 Device Routing Invert Outlet Devices #1 Device 2 147.10'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #2 Primary 144.80'12.0" Round Culvert L= 31.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.80' / 144.32' S= 0.0155 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 4 146.80'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #4 Primary 144.50'12.0" Round Culvert L= 31.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.50' / 144.15' S= 0.0113 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #5 Discarded 146.00'1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' Discarded OutFlow Max=0.02 cfs @ 12.07 hrs HW=147.16' (Free Discharge) 5=Exfiltration ( Controls 0.02 cfs) Primary OutFlow Max=2.25 cfs @ 12.07 hrs HW=147.16' (Free Discharge) 2=Culvert (Passes 0.16 cfs of 5.16 cfs potential flow) 1=Sharp-Crested Rectangular Weir (Weir Controls 0.16 cfs @ 0.82 fps) 4=Culvert (Passes 2.10 cfs of 5.56 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Weir Controls 2.10 cfs @ 1.97 fps) Summary for Pond 18P: INF-5+7 Inflow Area = 0.214 ac, 91.42% Impervious, Inflow Depth > 6.88" for 100-Year event Inflow = 1.68 cfs @ 12.07 hrs, Volume= 0.123 af Outflow = 1.68 cfs @ 12.07 hrs, Volume= 0.115 af, Atten= 0%, Lag= 0.0 min Discarded = 0.03 cfs @ 12.07 hrs, Volume= 0.032 af Primary = 1.65 cfs @ 12.07 hrs, Volume= 0.083 af Routing by Stor-Ind method, Time Span= 1.00-20.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.82"2018-082 Colvest Northampton As-Built Modification Printed 3/19/2021Prepared by J.R. Russo & Associates, LLC Page 98HydroCAD® 10.00-25 s/n 05524 © 2019 HydroCAD Software Solutions LLC Peak Elev= 147.04' @ 12.07 hrs Surf.Area= 664 sf Storage= 358 cf Flood Elev= 148.90' Surf.Area= 5,822 sf Storage= 1,665 cf Plug-Flow detention time= 40.7 min calculated for 0.115 af (94% of inflow) Center-of-Mass det. time= 15.8 min ( 744.7 - 728.9 ) Volume Invert Avail.Storage Storage Description #1 145.60' 199 cf Stone Bedding (Prismatic) Listed below (Recalc) 652 cf Overall - 154 cf Embedded = 498 cf x 40.0% Voids #2 145.68' 154 cf 10.0" Round Pipe Storage Inside #1 L= 282.0' #3 146.60' 1,312 cf Custom Stage Data (Prismatic) Listed below (Recalc) x 2 1,665 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 145.60 652 0 0 146.60 652 652 652 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 146.60 6 0 0 148.00 6 8 8 148.50 2,585 648 656 Device Routing Invert Outlet Devices #1 Device 2 146.80'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #2 Primary 144.60'12.0" Round Culvert L= 29.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.60' / 144.32' S= 0.0097 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #3 Device 4 146.90'3.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) #4 Primary 144.70'12.0" Round Culvert L= 29.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 144.70' / 144.15' S= 0.0190 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf #5 Discarded 145.60'1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 144.00' Discarded OutFlow Max=0.03 cfs @ 12.07 hrs HW=147.04' (Free Discharge) 5=Exfiltration ( Controls 0.03 cfs) Primary OutFlow Max=1.65 cfs @ 12.07 hrs HW=147.04' (Free Discharge) 2=Culvert (Passes 1.14 cfs of 5.27 cfs potential flow) 1=Sharp-Crested Rectangular Weir (Weir Controls 1.14 cfs @ 1.60 fps) 4=Culvert (Passes 0.51 cfs of 5.13 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Weir Controls 0.51 cfs @ 1.22 fps)