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HomeMy WebLinkAbout07/24/2019 - Revised Drainage Report & Stormwater Management Plan (Part 2) - 481 Sutton Street North Andover Senior Center Proposed Conditions-PIPE Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 ©2018 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.538 61 >75% Grass cover, Good, HSG B (PR1 A, PR1 B) 0.191 98 Building, HSG B (PR1 A) 0.423 98 Parking, Walkways, HSG B (PR1 A) 0.362 98 Paved parking, HSG B (PR1 B) 1.514 85 TOTAL AREA 35 North Andover Senior Center Proposed Conditions-PIPE Type /I/24-hr 0.50 Inch Rainfall=0.50" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 @ 2018 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment PR1 A: Detained Runoff = 0.02 cfs @ 12.16 hrs, Volume= 0.004 af, Depth= 0.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Type III 24-hr 0.50 Inch Rainfall=0.50" Area (sf) CN Description 8,304 98 Building, HSG B 7,888 61 >75% Grass cover, Good, HSG B 18,446 98 Parking, Walkways, HSG B 34,638 90 Weighted Average 7,888 22.77% Pervious Area 26,750 77.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f t/f t) (f Us e c) (cfs) 6.0 Direct Entry, Subcatchment PR1 A: Detained Hydrograph 0.026 0.102 cfs - —Runoff 0.024 [ Type, 1124 hr , 0.022-' 0.50 Inch Rain1fc111'=0.50", I I Run, Off Ar0a; 30 ' 0.018' RunoffVo -404 0.014- l6me0.016- RUnoff Deothl=0.06" 0.012- -6 MIn 0.01-1 i r r i i i 1� CNI -60 0.008- r 1 T I I F f 0.006 i F 0.004-' 0.002 0 . .............. ........ 0 1 2 3 4 5 6 7 8 9 16 11 12 13 14 15 16 17 18 1920 21 2223 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 36 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 0.50 Inch Rainfall=0.50" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/n08761 @2018 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment PR1 B: Un-Detained Runoff = 0.00 cfs @ 24.07 hrs, Volume= 0.000 af, Depth= 0.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Type III 24-hr 0.50 Inch Rainfall=0.50" Area (sf) CN Description 15,776 98 Paved parking, HSG B 15,556 61 >75% Grass cover, Good, HSG B 31,332 80 Weighted Average 15,556 49.65% Pervious Area 15,776 50.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f t/ft) (ft/sec) (Cf S) 6.0 Direct Entry, Subcatchment PR1 B: Un-Detained Hydrograph Type 1,11 24-hr 0150 InCK ROWOI1-6'50" Runoff Area"31,332, Sf 'Roff VoIbm' 'e.--0.000 of U un ' 117 1111 ' 111111 Runoff DePth=0.00 U. I'c=' 6.0 M'ih CN'-_qO 0 .......................... 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 37 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 0.50 Inch Rainfall=0.50" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/n08761 @2018 HydroCAD Software Solutions LLC Page 5 Summary for Reach DP-1: DP-1 Inflow Area = 1.514 ac, 64.46% Impervious, Inflow Depth = 0.00" for 0.50 Inch event Inflow = 0.00 cfs @ 24.07 hrs, Volume= 0.000 of Outflow = 0.00 cfs @ 24.07 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Reach DP-1: DP-1 Hydrograph ii If F_—_1n_fio­w7_i LLaU_1f1ojW In, f10W 'Area--1 .514 �ac 0_ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 38 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 0.50 Inch Rainfall=0.50" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 ©2018 HydroCAD Software Solutions LLC Page 6 Summary for Pond 1 P: Detention Basin Inflow Area= 0.795 ac, 77.23% Impervious, Inflow Depth = 0.06" for 0.50 Inch event Inflow = 0.02 cfs @ 12.16 hrs, Volume= 0.004 of Outflow = 0.02 cfs @ 12.37 hrs, Volume= 0.004 af, Atten= 17%, Lag= 12.3 min Discarded = 0.02 cfs @ 12.37 hrs, Volume= 0.004 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Peak Elev= 161.01' @ 12.37 hrs Surf.Area= 3,360 sf Storage= 9 cf Plug-Flow detention time= 7.0 min calculated for 0.004 of (100% of inflow) Center-of-Mass det. time= 7.0 min ( 936.9 - 929.9 ) Volume Invert Avail.Storage Storage Description #1 161.00' 2,399 cf Custom Stage Data(Prismatic) Listed below (Recalc) 8,400 cf Overall - 2,403 cf Embedded = 5,997 cf x 40.0% Voids #2 161.50' 2,403 cf 18.0" Round Pipe Storage x 17 Inside#1 L= 80.0' 4,802 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 161.00 3,360 0 0 162.00 3,360 3,360 3,360 163.00 3,360 3,360 6,720 163.50 3,360 1,680 8,400 Device Routing Invert Outlet Devices #1 Primary 161.65' 12.0" Round Culvert L= 106.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 161.65'/ 157.90' S= 0.0354 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf #2 Discarded 161.00' 1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 159.00' Discarded OutFlow Max=0.08 cfs @ 12.37 hrs HW=161.01' (Free Discharge) L2=Exfiltration ( Controls 0.08 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=161.00' (Free Discharge) t-1=Culvert ( Controls 0.00 cfs) 39 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 0.50 Inch Rainfall=0.50" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 @ 2018 HydroCAD Software Solutions LLG Page 7 Pond 1 P: Detention Basin Hydrograph 0.026.' 0.02 cis Inflow Outflow 0.024 Discarded n q Primary 0 179-5, ,i Ad it I f I 'W Arlea- 0.022 0.02 cfs 0.02 e PeakE -1 Ola - V, 0.018-- - St&696-9 d - 0.016- 0.014- 0 0.012 0.01 t, V 0.006- 0,004 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2021 22 23 24 25 26 27 28 29 30 31 3233 34 35 36 Time (hours) 40 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 2-year Rainfall=3.20" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/nO8761 @2018 HydroCAD Software Solutions LLQ Page 8 Summary for Subcatchment PR1 A: Detained Runoff = 1.96 cfs @ 12.09 hrs, Volume= 0.144 af, Depth= 2.17" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Type III 24-hr 2-year Rainfall=3.20" Area (sf) CN Description 8,304 98 Building, HSG B 7,888 61 >75% Grass cover, Good, HSG B 18,446 98 Parking, Walkways, HSG B 34,638 90 Weighted Average 7,888 22.77% Pervious Area 26,750 77.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR1A: Detained Hydrograph 2- L. 1.9 cis T pe 111 24-hr y6,ar 86f 2- nfall-3.20"� Runoff l Area=�34,I638 Sf Runoff iVlloMurte=l,0;144 at Runoff Depth-2.17" 0 LL IIIIIIIIII Tc=j6,.O t;,nlnl, PN--' 9P 0 77 T 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 41 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 2-year Rainfall=3.20" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/nO8761 @2018 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment PR1 B: Un-Detained Runoff = 1.15 cfs @ 12.10 hrs, Volume= 0.084 af, Depth= 1.40" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Type III 24-hr 2-year Rainfall=3.20" Area (sf) CN Description 15,776 98 Paved parking, HSG B 15,556 61 >75% Grass cover, Good, HSG B 31,332 80 Weighted Average 15,556 49.65% Pervious Area 15,776 50.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f t/f t) (ft/sec) (cf S) 6.0 Direct Entry, Subcatchment PR1 B: Un-Detained Hydrograph 1.15 cis ..Runoff Type '111 24-fir ' j-par RaiInfal .2, Runoff�Area--31 ;332 sf Runoff VolOnie=0;004 at RUhl offDelpth_-1 .40"� ILL hrillh 6N ' 86 0- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 42 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 2-year Rainfall=3.20" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 @ 2018 HydroCAD Software Solutions LLC Page 10 Summary for Reach DP-1: DP-1 Inflow Area= 1.514 ac, 64.46% Impervious, Inflow Depth = 1.01" for 2-year event Inflow = 1.31 cfs @ 12.12 hrs, Volume= 0.128 of Outflow = 1.31 cfs @ 12.12 hrs, Volume= 0.128 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Reach DP-1: DP-1 Hydrograph ®Inflow L11.31 cis :Outflow ItIfloyV Aeep=l 05�1411qt LL J� 0-- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 43 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 2-year Rainfall=3.20" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 ©2018 HydroCAD Software Solutions LLC Page 11 Summary for Pond 1 P: Detention Basin Inflow Area= 0.795 ac, 77.23% Impervious, Inflow Depth = 2.17" for 2-year event Inflow = 1.96 cfs @ 12.09 hrs, Volume= 0.144 of Outflow = 0.70 cfs @ 12.37 hrs, Volume= 0.144 af, Atten= 64%, Lag= 16.9 min Discarded = 0.12 cfs @ 12.37 hrs, Volume= 0.100 of Primary = 0.57 cfs @ 12.37 hrs, Volume= 0.044 of Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Peak Elev= 162.08' @ 12.37 hrs Surf.Area= 3,360 sf Storage= 1,971 cf Plug-Flow detention time= 76.9 min calculated for 0.144 of (100% of inflow) Center-of-Mass det. time= 76.8 min ( 883.7 - 806.9 ) Volume Invert Avail.Storage Storage Description #1 161.00' 2,399 cf Custom Stage Data(Prismatic) Listed below (Recalc) 8,400 cf Overall - 2,403 cf Embedded = 5,997 cf x 40.0%Voids #2 161.50' 2,403 cf 18.0" Round Pipe Storage x 17 Inside#1 L= 80.0' 4,802 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 161.00 3,360 0 0 162.00 3,360 3,360 3,360 163.00 3,360 3,360 6,720 163.50 3,360 1,680 8,400 Device Routing Invert Outlet Devices #1 Primary 161.65' 12.0" Round Culvert L= 106.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 161.65'/ 157.90' S= 0.0354 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf #2 Discarded 161.00' 1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 159.00' Discarded OutFlow Max=0.12 cfs @ 12.37 hrs HW=162.08' (Free Discharge) L2=Exfiltration ( Controls 0.12 cfs) Primary OutFlow Max=0.57 cfs @ 12.37 hrs HW=162.08' (Free Discharge) L1=Culvert (Inlet Controls 0.57 cfs @ 1.76 fps) 44 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 2-year Rainfall=3.20" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/n08761 @2018 HydroCAD Software Solutions LLC Page 12 Pond 1 P: Detention Basin Hydrograph Inflow 2- 1.9 cfs Outflow Discarded Inflow Primary Arliao-' 0-795 Alt �Ple'ak' EhPVF'_1 62.OW Slorage=1 e971 Of _1 I t ii- J I 0.70 cfs 1 0.57 cfs 0.1 S 0_r ............ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 45 North Andover Senior Center Proposed Conditions-PIPE Type III 24-hr 10-yearRainfal/=4.80" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@ 10.00-24 s/n 08761 @ 2018 HydroCAD Software Solutions LLC Page 13 Summary for Subcatchment PR1 A: Detained Runoff = 3.25 cfs 9 12.09 hrs, Volume= 0.244 af, Depth= 3.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Type III 24-hr 1 0-year Rainfall=4.80" Area (sf) CN Description 8,304 98 Building, HSG B 7,888 61 >75% Grass cover, Good, HSG B 18,446 98 Parking, Walkways, HSG B 34,638 90 Weighted Average 7,888 22.77% Pervious Area 26,750 77.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment Pill A: Detained Hydrograph 3.25 cfs -Runoff 3- -Type ill 24-hr 10.year Rafnfall=4-80"I Runoff I Area-34,638 Sf Runoff Vokjnie=O 2444 af , 2- R11.11hoff Diepth-3.68" Tc--6,.O min' PN-9 0 ... ............................. ....... ............... 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 46 North Andover Senior Center Proposed Conditions-PIPE Type III 24-hr 10-yearRainfall=4.80" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 @ 2018 HydroGAD Software Solutions LLC Page 14 Summary for Subcatchment PR1 B: Un-Detained Runoff = 2.25 cfs @ 12.09 hrs, Volume= 0.163 af, Depth= 2.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Type III 24-hr 1 0-year Rainfall=4.80" Area (sf) CN Description 15,776 98 Paved parking, HSG B 15,556 61 >75% Grass cover, Good, HSG B 31,332 80 Weighted Average 15,556 49.65% Pervious Area 15,776 50.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f t/f 0 (ft/sec) (cf S) 6.0 Direct Entry, Subcatchment PR1 B: Un-Detained Hydrograph 2.2 cfs RUnOff Type 11 24-hr 2- 1, O-Oair FlOintall-4-00'! Runoff Are� 31 ;332 Sf I I I I . 7 1 , , i i Rbnoff VojUnie=O;16, 3 at Riphoff Diepthi-_2.72" TC 161-O min M , 711111 PN-80 0.-1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 47 North Andover Senior Center Proposed Conditions-PIPE Type/1/24-hr 10-year Rainfall=4.80" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD® 10.00-24 s/n 08761 ©2018 HydroCAD Software Solutions LLC Page 15 Summary for Reach DP-1: DP-1 Inflow Area= 1.514 ac, 64.46% Impervious, Inflow Depth = 2.21" for 10-year event Inflow = 3.44 cfs @ 12.12 hrs, Volume= 0.278 of Outflow = 3.44 cfs @ 12.12 hrs, Volume= 0.278 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Reach DP-1: DP-1 Hydrograph ®Inflow -"Outf10W Ioflow Area'1 Z14!aq .Vi _1 I1 1 1 I _I _ 1 -1 I 1 _. I. 1 ...L. I1 1 -1_- I a LL o rrr° rrr�^ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 48 North Andover Senior Center Proposed Conditions-PIPE Type/1/24-hr 10-year Rainfall=4.80" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 02018 HydroCAD Software Solutions LLC Page 16 Summary for Pond 1 P: Detention Basin Inflow Area = 0.795 ac, 77.23% Impervious, Inflow Depth = 3.68" for 10-year event Inflow = 3.25 cfs @ 12.09 hrs, Volume= 0.244 of Outflow = 1.73 cfs @ 12.23 hrs, Volume= 0.244 af, Atten= 47%, Lag= 8.3 min Discarded = 0.14 cfs @ 12.23 hrs, Volume= 0.129 of Primary = 1.59 cfs @ 12.23 hrs, Volume= 0.115 of Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Peak Elev= 162.44' @ 12.23 hrs Surf.Area= 3,360 sf Storage= 2,887 cf Plug-Flow detention time= 66.5 min calculated for 0.244 of (100% of inflow) Center-of-Mass det. time= 66.4 min ( 858.5 - 792.1 ) Volume Invert Avail.Storage Storage Description #1 161.00' 2,399 cf Custom Stage Data(Prismatic) Listed below (Recalc) 8,400 cf Overall - 2,403 cf Embedded = 5,997 cf x 40.0% Voids #2 161.50' 2,403 cf 18.0" Round Pipe Storage x 17 Inside#1 L= 80.0' 4,802 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 161.00 3,360 0 0 162.00 3,360 3,360 3,360 163.00 3,360 3,360 6,720 163.50 3,360 1,680 8,400 Device Routing Invert Outlet Devices #1 Primary 161.65' 12.0" Round Culvert L= 106.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 161.65'/ 157.90' S= 0.0354 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf #2 Discarded 161.00' 1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 159.00' Discarded OutFlow Max=0.14 cfs @ 12.23 hrs HW=162.44' (Free Discharge) t-2=Exfiltration ( Controls 0.14 cfs) Primary OutFlow Max=1.58 cfs @ 12.23 hrs HW=162.44' (Free Discharge) t-1=Culvert (Inlet Controls 1.58 cfs @ 2.39 fps) 49 North Andover Senior Center Proposed Conditions-PIPE Type III 24-hr 10-yearRainfall=4.80" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 @ 2018 HydroCAD Software Solutions LLC Page 17 Pond 1P: Detention Basin Hydrograph Inflow 3.2 efs Outflow Discarded 3-- r I Primary hf 10W Arqa_-, 079 PeaKZIP'062.44 Storage# X7 0, f 12 2- - 1.73 cls 1.59 cfs f 0 IL 2 5 1, J, c 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2021 2223 2425 26 27 2829 30 31 32 33 34 35 36 Time (hours) 50 North Andover Senior Center Proposed Conditions-PIPE Type 1/1 24-hr 25-Year Raintall=6.00" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADSIO.00-24 s/n08761 @2018 HydroCAD Software Solutions LLC Pacie 18 Summary for Subcatchment Pill A: Detained Runoff = 4.21 cfs @ 12.09 hrs, Volume= 0.321 af, Depth= 4.85" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (sf) CN Description 8,304 98 Building, HSG B 7,888 61 >75% Grass cover, Good, HSG B 18,446 98 Parking, Walkways, HSG B 34,638 90 Weighted Average 7,888 22.77% Pervious Area 26,750 77.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f t/f t) (ft/sec) (cf S) 6.0 Direct Entry, Subcatchment Pill A: Detained Hydrograph 4.21 cfs 4- Tpa.ill 24-hr- 25-Y6ar Rain fall-6.00" 3- - Runoff'Area-_34,638 Sf T 11111 R6noff Volyini, 6=0;321 at 5 fthoff Depth,4.85" U. 2- T' - c=6�.0 min IN-99 T I I r 0. I F 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 51 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 25-Year Raintall=6.00" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 @ 2018 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment PR1 B: Un-Detained Runoff = 3.11 cfs @ 12.09 hrs, Volume= 0.227 af, Depth= 3.78" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Type III 24-hr 25-Year Rainfall=6.00" Area (sf) CN Description 15,776 98 Paved parking, HSG B 15,556 61 >75% Grass cover, Good, HSG B 31,332 80 Weighted Average 15,556 49.65% Pervious Area 15,776 50.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f t/f t) (ft/s e c) (cf S) 6.0 Direct Entry, Subcatchment PR1 B: Un-Detained Hydrograph 3.11 Cis 3- _T_ -Y III 24-hr, pe ,� I I I I 25-Year Rain fall-6.00" R U noff Area-31 �332 sf, 7 2- Runoff Volyr�, 6=0�22-7 of 1 � lll ` � 11 � 171 , 1 17177 Rphoff Depth-' 3.78 c= " T �6.0 mInI CN-80 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 52 North Andover Senior Center Proposed Conditions-PIPE Type ///24-hr 25-Year Rainfall=6.00" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD010.00-24 s/n08761 @2018 HydroCAD Software Solutions LLC Page 20 Summary for Reach DP-1: DP-1 Inflow Area= 1.514 ac, 64.46% Impervious, Inflow Depth = 3.18" for 25-Year event Inflow = 4.98 cfs @ 12.11 hrs, Volume= 0.402 of Outflow = 4.98 cfs @ 12.11 hrs, Volume= 0.402 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Reach DP-1: DP-1 Hydrograph 4.98 cfs F Inflow 5-- -1 -7- -1--1- -f 4 +1 IW 1Z�14�at 1nf1pW' Aeea=_ 4-- 16 3- 2- 0 "*....... ... 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 26 21 22 23'2­4­2'5 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 53 North Andover Senior Center Proposed Conditions-PIPE Type 111 24-hr 25-Year Rainfall=6.00" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 ©2018 HydroCAD Software Solutions LLC Page 21 Summary for Pond 1 P: Detention Basin Inflow Area = 0.795 ac, 77.23% Impervious, Inflow Depth = 4.85" for 25-Year event Inflow = 4.21 cfs @ 12.09 hrs, Volume= 0.321 of Outflow = 2.37 cfs @ 12.22 hrs, Volume= 0.321 af, Atten= 44%, Lag= 7.7 min Discarded = 0.15 cfs @ 12.22 hrs, Volume= 0.146 of Primary = 2.22 cfs @ 12.22 hrs, Volume= 0.175 of Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Peak Elev= 162.70' @ 12.22 hrs Surf.Area= 3,360 sf Storage= 3,529 cf Plug-Flow detention time= 63.0 min calculated for 0.321 of (100% of inflow) Center-of-Mass det. time= 63.0 min ( 847.7 - 784.7 ) Volume Invert Avail.Storage Storage Description #1 161.00' 2,399 cf Custom Stage Data (Prismatic) Listed below (Recalc) 8,400 cf Overall - 2,403 cf Embedded = 5,997 cf x 40.0%Voids #2 161.50' 2,403 cf 18.0" Round Pipe Storage x 17 Inside#1 L= 80.0' 4,802 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 161.00 3,360 0 0 162.00 3,360 3,360 3,360 163.00 3,360 3,360 6,720 163.50 3,360 1,680 8,400 Device Routing Invert Outlet Devices #1 Primary 161.65' 12.0" Round Culvert L= 106.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 161.65'/ 157.90' S= 0.03547' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf #2 Discarded 161.00' 1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 159.00' Discarded OutFlow Max=0.15 cfs @ 12.22 hrs HW=162.70' (Free Discharge) t-2=Exfiltration ( Controls 0.15 cfs) Primary Outflow Max=2.21 cfs @ 12.22 hrs HW=162.70' (Free Discharge) t-1=Culvert (Inlet Controls 2.21 cfs @ 2.81 fps) 54 North Andover Senior Center Proposed Conditions-PIPE Type 1//24-hr 25-Year Rainfall=6.00" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/n08761 @2018 HydroCAD Software Solutions LLC Pacie 22 Pond 1 P: Detention Basin Hydrograph Inflow Outflow Discarded Primary 79-�-Oc' 4, 1 nf I ow j.4roo", O Peak Elov ..162-70'� St0rc!,ge=,%52,9, of 51 nf 2.2 2 cfs ti 2- 1 T I 11 0. 5 ct 0.. L"M� -IqT-- .1.1-1.11.1-1.............. 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 2223 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 55 North Andover Senior Center Proposed Conditions-PIPE Type III 24-h/ / R]int38=8.SD" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 Summary for Subcaƒchment PR1A: Detained Runoff 8.27ofs@ 12.89 hrs. Vo|umo= 0490nf, Dopth= 7.40" Runoff by8CSTR'28 method, UH=GCG, Weighted-CN' TimmGp8n= 0.00-36.00 h[a' dt= 0.O5 hra Typo III 24-hr 100'ym8rR8infa||=8.60" A fDescription ° 8,304 gO Building, HS{5B 7,888 61 >75% Grass cover, Good, HSG B 34'638 90 Weighted Average 7,888 22.77% Pervious Area 26'750 77.23% Impervious Area To Length Slope Velocity Capacity Description 6.0 Direct Entry, SWbcatchmeMt PR1 A: Detained Hydrogmsph 1, 00 ear Rainfall-0.6, 0' � � 0 c- min Time (hours) 56 North Andover Senior Center Proposed Conditions-PIPE Type III 24-hr 100-yearRainfal/=8.60" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/nO8761 @2018 HydroCAD Software Solutions LLC Pacie 24 Summary for Subcatchment PR1 B: Un-Detained Runoff = 5.00 cfs @ 12.09 hrs, Volume= 0.371 af, Depth= 6.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Type III 24-hr 1 00-year Rainfall=8.60" Area (sf) ION Description 15,776 98 Paved parking, HSG B 15,556 61 >75% Grass cover, Good, HSG B 31,332 80 Weighted Average 15,556 49.65% Pervious Area 15,776 50.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f t/f t) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR1 B: Un-Detained Hydrograph 5.00 cfsRunoff 5­ Type 111 24-6r r H- I - 0.-y l r- 6 4- 100eaOnta 0" R u n,off Area-31 i332 Sf Run,6ff;VojLjrvle=,'0,�37, 1 M 3- I RUhOff Depth-_' 6.19 .2 M-n 2­ CN--' 80 1. - 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 1819 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 57 North Andover Senior Center Proposed Conditions-PIPE Type III 24-hr 100-yearRainfall=8.60" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/n08761 @2018 HydroCAD Software Solutions LLC Page 25 Summary for Reach DP-1: DP-1 Inflow Area= 1.514 ac, 64.46% Impervious, Inflow Depth = 5.43" for 1 00-year event Inflow = 7.82 cfs @ 12.11 hrs, Volume= 0.685 of Outflow = 7.82 cfs @ 12.11 hrs, Volume= 0.685 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Reach DP-1: DP-1 Hydrograph 7.82 cfs I ®Inflow 8- Outflowl 10f10W Are,a_-J .5,14�at 7 6- 5 2 4,' - 3.. ... . .. . ........ 2- - 'rL.................... 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 58 North Andover Senior Center Proposed Conditions-PIPE Type III 24-hr 100-year Rainfall=8.60" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADB 10.00-24 s/n 08761 ©2018 HydroCAD Software Solutions LLC Page 26 Summary for Pond 1 P: Detention Basin Inflow Area = 0.795 ac, 77.23% Impervious, Inflow Depth = 7.40" for 100-year event Inflow = 6.27 cfs @ 12.09 hrs, Volume= 0.490 of Outflow = 3.60 cfs @ 12.21 hrs, Volume= 0.490 af, Atten=43%, Lag= 7.4 min Discarded = 0.18 cfs @ 12.21 hrs, Volume= 0.176 of Primary = 3.43 cfs @ 12.21 hrs, Volume= 0.314 of Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.05 hrs Peak Elev= 163.47' @ 12.21 hrs Surf.Area= 3,360 sf Storage= 4,756 cf Plug-Flow detention time= 58.0 min calculated for 0.490 of (100% of inflow) Center-of-Mass det. time= 57.9 min ( 831.7 - 773.8 ) Volume Invert Avail.Storage Storage Description #1 161.00' 2,399 cf Custom Stage Data(Prismatic) Listed below(Recalc) 8,400 cf Overall - 2,403 cf Embedded = 5,997 cf x 40.0%Voids #2 161.50' 2,403 cf 18.0" Round Pipe Storage x 17 Inside#1 L= 80.0' 4,802 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 161.00 3,360 0 0 162.00 3,360 3,360 3,360 163.00 3,360 3,360 6,720 163.50 3,360 1,680 8,400 Device Routing Invert Outlet Devices #1 Primary 161.65' 12.0" Round Culvert L= 106.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 161.65'/ 157,90' S= 0.03547' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf #2 Discarded 161.00' 1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 159.00' Discarded OutFlow Max=0.18 cfs @ 12.21 hrs HW=163.45' (Free Discharge) L2=Exfiltration ( Controls 0.18 cfs) Primary OutFlow Max=3.41 cfs @ 12.21 hrs HW=163.45' (Free Discharge) 1-1=Culvert (Inlet Controls 3.41 cfs @ 4.34 fps) 59 North Andover Senior Center Proposed Conditions-PIPE Type III 24-hr 100-yearRainfall=8.60" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADS 10.00-24 s/n 08761 2018 HydroCAD Software Solutions LLC Page 27 Pond 1 P: Detention Basin Hydrograph 7- 6.2 cis Inflow Outflow Discarded ..-Primary _'W Ar �1�0■7,95 14 11 � 1 I n 16 , 1 1 5 Pe'WEIOV-' 10-47_ Stprqge=4J56 Of 4- '1 J I L I L. 1 1, j I 1 2 60 afc I I I 3,43 cis 3- 2 1 T t 0 8 cf 0 ...... ......................0 1 2 3 4 5 6 7 "1"6...I' 1 l....2 1...3­14....1'5 1*'6'...17....1'8*'1'9­2F0 2'r1 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Time (hours) 60 ,Adult Center North Andover, Drainage Report Appendix B — TSS Calculations The proposed design exceeds the Department of Environmental Protection requirements for Best Management Practices and water quality. The roof runoff is collected and discharged through a rain garden and then into the subsurface underground system and carries no parking lot suspended solids. The areas of the parking lot are broken up and collected into proposed water quality units to be determined which by themselves would remove 80% of the TSS. Tabulation for this is included in this section. DeVellis Zrein Inc. May 24,2019 Revised July 24,2019 61 F.' - - • •• 2 Drainage Report Water Volume Calculations • Infiltration Volume Calculations DeVellis Zrein Inc. May 24,2019 Revised July 24,2019 62 Date: 7/1412019 Location: North Andover,MA 8m A� Fu&*KA w3.BS83 om Project: North Andover Senior Center Storm Intensity: 25 Year dMitaMn- Project No:385 Prepared By: IAZ DeVellis Zrein Inc. Checked By: LOCATION DRAINAGE AREA FLOW TIME RUNOFF FLOW IN PIPE (Acres) (min) (cfs) PIPE FULL FLOW DESIGNFLOW RIM INVERT Description From 70 Area , Runoff Incramentl Sum To Ovdand Time In Intensity Design Diam length Slope Manning Capacity Velocity Depth Velocity Upper, ;Upper;: Lower Ac Coeff.,C" CA CA ': Time Section (In/Hr) Flow (In.) '.(Ft.) (FttFt.) Coeff, (Cis) (Fps) (Ft) (Fps.) DA1 Roof/RG DMH1 0.32 0.77 0.25 5.0 0.1 6.0 T. 8 25 0.0100 0.010 U 4.5 0.52 5.1 165.00 164.75 DMH1 DMH2 O.25 5.1 0.3 6.0 8 98 0.0097 0.010 "B" 4.4 0.52 5.0 167.90 164.75 163.80 DA2 CB1 DMH2 O.11 0.87 0.10 5.0 0.0 6.0 &Z' 10 10 0.0150 0.010 1$ 6.4 0.24 4.9 166.20 163.95 163.80 DMH2 DMH3 0.35 5.4 0.3 5.9 10 94 0.0106 0.010 Z9 ' 5A 0.54 5.9 166,30 163.70 162.70 DA3 Rain Garden DMH4 0.10 0.67 0.07 5.0 0.1 6.0 &41 6 22 0.0220 0.010 M 5.5 0.21 5.0 164.50 162.00 161.52 DA4 CB6 DMH4 0.09 0.90 0.08 5.0 0.2 6.0 10 45 0.0075 0.010 25 4.5 0.26 3.6 164.40 161.85 161.51 DAB C87 DMH6 0.23 0.65 0.15 5.0 0.1 6.0 1-4 10 22 0.0070 0.010 i 2A 4.4 0.35 4.0 164.30 161.65 161.50 DAB C133 DMH8 0.12 0.30 0.04 5.0 0.0 6.0 ; 8 12 0.0330 0.010 2,9 8.1 0.15 5.4 159.50 157.30 156.90 DA9 CB4 DMH8 0.13 0.90 0.12 5.0 0.0 6.0 ej 10 6 0.0330 0.010 til s 9.5 0.22 6.9 159.50 157.10 156.90 DMH8 DMH9 0.16 5.5 0.1 5.9 3A ` 10 36 0.0110 0.010 >t, 5.5 0.31 4.8 159.50 156.90 156.50 DAB C82 DMH9 0.13 0.90 0.12 5.0 0.1 6.0 O;T 10 60 0.0500 0.010 11.6 0.21 8.0 162.80 159,50 156.50 DA7 CB5 DMH9 0,16 0.80 0.13 5.0 0.0 6.0 Ma`. 10 10 0.0300 0.010 A.s 9.0 0.24 6.9 159.90 156.80 156.50 DMH9 DMH7 0.41 5.6 0.0 5.8 14: 12 15 0.0100 0.010 .;.i 5.9 0.51 5.9 160.10 156,40 156.25 DMH6 DMH7 4jg� 12 102 0.0350 0.010 It7 11.0 0.54 11.3 164.70 161.65 158.08 DMH7 EX 7.3 12 30 0,0250 0.010 7,3 9.3 0.82 160,70 156.20 155.45 Notes: Site Planning CMI Engineering Landscape Architecture Computations Po Box 307 508.393.8583 A Project Adult Center Project# 2G1 S-385 508.393.8583 phone � � devellismin.com Location North Andover Sheet 1 of 1 Calculated by JJD Date 7/24/2019 DeVellis Zrein Inc. Checked by TOG Date 7/24/2019 Title Recharge Calculations Methodology MA Department of Environmental Protection (DEP) Stormwater Management (Volume One) Design Criteria: Based on the Site Hydrologic Soil Group: Hydrologic Soil Group Volume to Recharge (x Total Imp. Area) A 0.60 inches of runoff B 0.35 inches of runoff C 0.25 inches of runoff D 0.10 inches of runoff Recharge Area Required: Total Incease in Impervious areas = 0.482 acres (21,000 square feet) Required recharge Volume =21,000 x 0.35/12 = 613 cubic feet Recharge Using the simple dynamoce method, the runoff volume infiltrated into the ground through the Provided: infiltration system is 0.028 of = 1213 cubic feet. Note that the rain gardens also provide infiltration into the ground, however this volume has not been factored in to the volume provided above. 64 DeVellis Zrein Inc. lie • Land Planning /Civil Engineering PO Box 307 Project North Andover Senior Center Project# 385 Foxboro MA 02035 Location North Andover Sheet 1 of 1 Calculated by IAZ Date 7/14/19 Checked by Date Title Water Quality& Recharge Volumes Methodology: DEP Stormwater Management Standards Design Criteria 1: Based on the NRCS Hydrologic Soil Group "B" (for Recharge Volume) Depth Factor= 0.35 inches Design Criteria 2: Depth Factor=0.50 inches (for Water Quality Volume) Water Quality Volume: Impervious Area =0.984 acres(42,860 SF) Required Water Quality Volume = 42860 x 0.50/12 Required Water Quality Volume = 1,786 C.F. (This volume is used for 72 hours drawdown` Recharge Volume: Impervious Area = 0.984 acres(42,860 SF) Required Recharge Volume = 42860 x 0.35/12 Required Recharge Volume = 1250 C.F. _ RV Draw Down: Timedrawdown (K)(Bottoni.Area) Rv= Storage Volume K= Rawls Rate for Hydraulic Conductivity Bottom Area = Bottom Area of Recharge Basin 1786 cubic feet Time = (1.02hr)(172in)(3360 sf) Time = 6.25 hours < 72 hours 65 �PR1 A Detained 1 P asi Detention B��\ DP-1 DP-1 Routing Diagram for Proposed Conditions-W-RECH Prepared by DeVellis Zrein Inc., Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 @ 2018 HydroCAD Software Solutions LLC 66 North Andover Senior Center Proposed Conditions-W-RECH Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 ©2018 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.191 98 Building, HSG B (PR1A) 0.423 98 Parking, Walkways, HSG B (PR1 A) 0.614 98 TOTAL AREA 67 North Andover Senior Center Proposed Conditions-W-RECH Type ///24-hr RECH Rainfall=1.20" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/n08761 @2018 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment PR1 A: Detained Runoff = 0.66 cfs @ 12.09 hrs, Volume= 0.028 af, Depth> 0.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 11.00-13.00 hrs, dt= 0.05 hrs Type III 24-hr RECH Rainfall=1.20" Area (sf) CN Description 8,304 98 Building, HSG B 18,446 98 Parking, Walkways, HSG B 26,750 98 Weighted Average 26,750 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f t/f t) (f t/s e c) (cf S) 6.0 Direct Entry, Subcatchment PR1A: Detained Hydrograph 0.66 0.7.. is �Runoff 0.65 Type, III 24-hr....- 0,' 0.55 RECH Rainfall=1 .20'1! Runoff Area 26,750 sf 0.45' Runoff Volume=0.028 of 0.4': 0.35: Runoff Depth>0.55", 0 U. 0,3- Tc=6.0 min 0.25- C N=' -9-8- 0.2. 0.05': - 11 12 13 Time (hours) 68 North Andover Senior Center Proposed Conditions-W-RECH Type ///24-hr RECH Rainfall=1.20" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/nO8761 @2018 HVdroCAD Software Solutions LLC Page 4 Summary for Reach DP-1: DP-1 Inflow Area= 0.614 ac,100.00% Impervious, Inflow Depth = 0.00" for RECH event Inflow = 0.00 cfs @ 11.00 hrs, Volume= 0.000 of Outflow = 0.00 cfs @ 11.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 11.00-13.00 hrs, dt= 0.05 hrs Reach DP-1: DP-1 Hydrograph F--—Inflow—i Outflow Inflow Area=0.614 ac 0 U. 0.00 cfs 0 11 12 13 Time (hours) 69 North Andover Senior Center Proposed Conditions-W-RECH Type ///24-hr RECH Rainfall=1.20" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCADO 10.00-24 s/n 08761 ©2018 HydroCAD Software Solutions LLC Page 5 Summary for Pond 1 P: Detention Basin Inflow Area = 0.614 ac,100.00% Impervious, Inflow Depth > 0.55" for RECH event Inflow = 0.66 cfs @ 12.09 hrs, Volume= 0.028 of Outflow = 0.10 cfs @ 12.58 hrs, Volume= 0.013 af, Atten= 85%, Lag= 29.8 min Discarded = 0.10 cfs @ 12.58 hrs, Volume= 0.013 of Primary = 0.00 cfs @ 11.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 11.00-13.00 hrs, dt= 0.05 hrs Peak Elev= 161.52' @ 12.58 hrs Surf.Area= 3,360 sf Storage= 697 cf Plug-Flow detention time= 23.4 min calculated for 0.013 of (45% of inflow) Center-of-Mass det. time= 5.6 min ( 730.5 - 725.0 ) Volume Invert Avail.Storage Storage Description #1 161.00' 2,399 cf Custom Stage Data(Prismatic) Listed below (Recalc) 8,400 cf Overall - 2,463 cf Embedded = 5,997 cf x 40.0% Voids #2 161.50' 2,403 cf 18.0" Round Pipe Storage x 17 Inside #1 L= 80.0' 4,802 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 161.00 3,360 0 0 162.00 3,360 3,360 3,360 163.00 3,360 3,360 6,720 163.50 3,360 1,680 8,400 Device Routing Invert Outlet Devices #1 Primary 161.65' 12.0" Round Culvert L= 106.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 161.65'/ 157.90' S= 0.0354 7' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean, Flow Area= 0.79 sf #2 Discarded 161.00' 1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 159.00' Discarded OutFlow Max=0.10 cfs @ 12.58 hrs HW=161.52' (Free Discharge) t-2=Exfiltration ( Controls 0.10 cfs) Primary OutFlow Max=0.00 cfs @ 11.00 hrs HW=161.00' (Free Discharge) t-1=Culvert ( Controls 0.00 cfs) 70 North Andover Senior Center Proposed Conditions-W-RECH Type 24-hr RECH Rainfall=1.20" Prepared by DeVellis Zrein Inc. Printed 7/20/2019 HydroCAD@10.00-24 s/n08761 @2018 HydroCAD Software Solutions LLC Page 6 Pond 1 P: Detention Basin Hydrograph 0.7- 0.66 cfs Inflow 0.65-' Outflow L—Discardjed Primary Inflow Area=0.614 ac 0.55 Peak Elev--1 61,52 0.5-- 0A.: Storage=697 Cf- - t 0.4- 0 U. 0.3- .. . . ................ 0.25 0.2 0.15- 0.10 cfs 0.1- 0.00 cfs 11 12 13 Time (hours) 71 Drainage Report Appendix C — Test Pit Data DeVellis Zrein, Inc. May 24,2019 Revised July 24,2019 72 TEST PIT (DZI-1 ) TEST PIT (DZI-2) TEST PIT (DZI-3) SOIL SOIL SOIL SOIL SOIL SOIL HORIZON TEXTURE HORIZON TEXTURE HORIZON TEXTURE O" O" O" 8„ Ap SANDY LOAM 12„ Ap SANDY LOAM 10" Ap SANDY LOAM 22" Bv, SANDY LOAM 20" B,., SANDY LOAM 22" B,y SANDY LOAM 42" ESHGW 43" ESHGW 35" ESHGW 2C SANDY LOAM 2C SANDY LOAM 2C SANDY LOAM GRAVELLY GRAVELLY GRAVELLY 96/f 88„I I���I I GRAVELLY I II 99"�I I I I�I II SURFACE ELEVATION=162.5 SURFACE ELEVATION=163.5 SURFACE ELEVATION=162.2 TEST PIT TEST PIT (DZI-5) TEST PIT (DZI-6) SOIL SOIL SOIL SOIL SOIL SOIL HORIZON TEXTURE HORIZON TEXTURE HORIZON TEXTURE 0" O" Of' 7„ Ap SANDY LOAM 10„ Ap SANDY LOAM 12„ Ap SANDY LOAM 19" BW SANDY LOAM 20" BW SANDY LOAM 181, B,v SANDY LOAM 38" ESHGW 36" ESHGW 38" ESHGW 2C SANDY LOAM 2C SANDY LOAM 2C SANDY LOAM GRAVELLY GRAVELLY GRAVELLY 96" _� �— 98" _117 96" _111- I SURFACE ELEVATION=163.7 SURFACE ELEVATION=158.5 SURFACE ELEVATION=162.9 TEST PIT AND PERCOLATION TEST WERE PERFORMED ON APRIL 11, 2019 THE TESTING WAS PERFORMED BY JAMES J DEVELLIS, P.E. / REGISTERED SOIL EVALUATOR se 571 OF DEVELLIS ZREIN INC. OF FOXBOROUGH, MA 73 forw "'r-090110, • •• Drainage Report Appendix D — Site Plans REDUCED AND FULL SIZE PLANS PROVIDED WITHIN THE APPLICATION SUBMISSION PROVIDED BY THE PROJECT ARCHITECT THESE REDUCED COPIES ARE PROVIDED WTIHIN THIS REPORT FOR CONVENIENT REFERENCE PURPOSES DeVellis Zrein, Inc. May 24,2019 Revised July 24,2019 74