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25A-182 Drainage report 12.7.2011REVISED DRAINAGE CALCULATIONS NEW STORAGE BUILDINGS #9 & #10 SPACES FOR RENT 94 INDUSTRIAL DRIVE NORTHAMPTON, MA Prepared for: 94 Industrial Drive, LLC c/o Robert T. Foote, Jr. P.O. Box 177 - 94 Industrial Drive Northampton, MA 01060 Prepared by: 241 College Hi &Mlark Street Post O ox 1 Southampton, MM� 01073 (413) 527 -3600 p No: 6569-100209 Se- September 29, , 2011 11 Revised: October 28, 2011 November 18, 2011 December 7, 2011 HERITAGE SURVEYS, INC. Professional Surveyors and Engineers 241 College Hwy & Clark St, P O Box 1 Southampton, Massachusetts 01073-0001 Bruce A. Coombs, President Professional Surveyor, MA, CT & VT E -mail: bruce@heritagesurveys.com September 29, 2011 Revised October 28, 2011 Revised November 18, 2011 Revised December 7, 2011 HSI Job # 6569- 100209 Telephone (413) 527 -3600 Facsimile (413) 527 -8280 Website: heritagesurveys.com Summary of Existing Conditions & Post Construction Drainage Calculations The drainage report was prepared using the computer program HydroCAD version 9.10 by Applied Microcomputer Systems. The report is broken into four sections. The four sections of the drainage report are the post construction information for the 2, 10, 25 and 100 year storm events. The existing conditions have not been revised from the November 18, 2011 revisions and are not included within this report. The December 7, 2011 revisions to the drainage calculations include changing the CN value of the proposed basin areas to be 98. A 3 inch outlet pipe has been added to the proposed basins on the westerly (3PB) and side easterly (4PB) of proposed building 10. The proposed stonnwater management system has been designed to have no increase in peak discharge for the 2, 10, 25 and 100 year stormevents. Enclosed are hydrograph tables for the 10 year storm event showing the basin on the westerly side of proposed building 10 (3PB) will have zero storage within the basin at hour 35 and the basin on the easterly side of proposed building 10 (4PB) will have zero storage within the basin at hour 57.5. A TSS removal calculation worksheet is enclosed showing the TSS removal for the bio- retention area and basin for the small paved parking area. 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G \ c \z : \ % J( a < _ - \ �` ] ( ! « POST CONSTRUCTION 2 YEAR STORM EVENT 3.00 INCH RAINFALL 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 1PS: PROPOSED BUILDING 9 - DRAINAGE TO BASIN Runoff = 0.27 cfs @ 12.09 hrs, Volume= 0.020 af, Depth= 1.90" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Area (sf) CN Description 2,000 98 Roofs, HSG C " 1,347 98 Basin 2,047 74 >75% Grass cover, Good, HSG C 5,394 89 Weighted Average 2,047 37.95% Pervious Area 3,347 62.05% Impervious Area Tc Length Slope Velocity Capacity Description in) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2PS: PROPOSED PAVEMENT ALONG FRONT OF BUILDING 9 Runoff = 0.09 cfs @ 12.09 hrs, Volume= 0.008 af, Depth= 2.77" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Area (sf) CN Descri 1,419 98 Paved parking, HSG C 1,419 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Pond 1 PB: BASIN FOR BUILDING 9 Inflow Area = 0.124 ac, 62.05% Impervious, Inflow Depth = 1.90" for 2 YEAR STORMEVENT event Inflow = 0.27 cfs @ 12.09 hrs, Volume= 0.020 of Outflow = 0.01 cfs @ 15.86 hrs, Volume= 0.006 af, Atten= 96 %, Lag= 226.1 min Primary = 0.01 cfs @ 15.86 hrs, Volume= 0.006 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 135.86' @ 15.86 hrs Surf.Area= 1,183 sf Storage= 664 cf Plug -Flow detention time= 527.9 min calculated for 0.006 of (30% of inflow) Center -of -Mass det. time= 394.1 min ( 1,207.7 - 813.7 ) 6569 SPACES FOR RENT rev 5 Type /1124 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Prepared by HERITAGE SURVEYS, INC. HydroCAD® 9.10 s/n 00860 @ 2010 HydroCAD Software Solutions LLC Page 2 Volume Invert Avail.Storage Storage Description #1 135.00' 847 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 135.00 432 0 0 432 136.00 1,347 847 847 1,353 Device Routing Invert Outlet Devices #1 Primary 135.80' 6.0" Vert. Orifice /Grate C= 0.600 Primary OutFlow Max =0.01 cfs @ 15.86 hrs HW= 135.86' (Free Discharge) L1= Orifice /Grate (Orifice Controls 0.01 cfs @ 0.80 fps) 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 0 2010 HydroCAD Software Solutions LLC Page 3 Summary for Reach 1 R: WETLAND AREA NEAR WF4 Inflow Area = 0.156 ac, 69.95% Impervious, Inflow Depth > 1.02" for 2 YEAR STORMEVENT event Inflow = 0.09 cfs @ 12.09 hrs, Volume= 0.013 of Outflow = 0.09 cfs @ 12.09 hrs, Volume= 0.013 af, Atten= 0 %, Lag= 0.0 min Routing by Stor- Ind +Trans method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 6569 SPACES FOR RENT rev 5 Type 11124 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Prepared by HERITAGE SURVEYS, INC. Software Summary for Subcatchment 3PS: DRAINAGE TO EASTERLY SIDE PROPOSED BUILDING 10 Runoff = 0.41 cfs @ 12.09 hrs, Volume= 0.030 af, Depth= 1.90" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Area (sf) CN Description 3,737 98 Roofs, HSG C 1,472 98 Basin 2,971 74 >75% Grass cover, Good, HSG C 8,180 89 Weighted Average 2,971 36.32% Pervious Area 5,209 63.68% Impervious Area Tc Length .1 Capacity Description Direct Entry, Summary for Subcatchment 6PS: PAVEMENT DRAINAGE TO EXISTING BASIN AREA Runoff = 0.08 cfs @ 12.09 hrs, Volume= 0.006 af, Depth= 2.77" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Area (sf) CN Description _ 1,199 98 Paved parking, HSG C 1,199 100.00% Impervious Area Tc Length Slope Velocity Capacity Description in) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Pond 2PB: BASIN EASTERLY SIDE BUILDING 10 Inflow Area = 0.188 ac, 63.68% Impervious, Inflow Depth = 1.90" for 2 YEAR STORMEVENT event Inflow = 0.41 cfs @ 12.09 hrs, Volume= 0.030 of Outflow = 0.13 cfs @ 12.42 hrs, Volume= 0.030 af, Atten= 68 %, Lag= 19.6 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Secondary = 0.13 cfs @ 12.42 hrs, Volume= 0.030 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 137.64' @ 12.42 hrs Surf.Area= 1,037 sf Storage= 404 cf Plug -Flow detention time= 71.7 min calculated for 0.030 of (100% of inflow) Center -of -Mass det. time= 71.5 min ( 885.2 - 813.7 ) 6569 SPACES FOR RENT rev 5 Type/// 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Prepared by HERITAGE SURVEYS, INC. Volume Invert Avail.Storage Storage Description #1 137.20' 1,494 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 137.20 817 0 0 817 138.00 1,240 817 817 1,250 138.50 1,472 677 1,494 1,491 Device Routing Invert Outlet Devices #1 Primary 138.40' 5.0' long x 3.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 232 2.81 2.92 2.97 3.07 3.32 #2 Secondary 137.20' 3.0" Round Culvert L= 18.0' Ke= 0.500 Inlet / Outlet Invert= 137.20'/ 137.00' S= 0.0111 T Cc= 0.900 n= 0.010 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 137.20' (Free Discharge) t1= Broad - Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max =0.13 cfs @ 12.42 hrs HW= 137.64' (Free Discharge) L2= Culvert (Barrel Controls 0.13 cfs @ 2.62 fps) 6569 SPACES FOR RENT rev 5 Type/// 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 @ 2010 HydroCAD Software Solutions LLC Page 6 Summary for Reach 2R: DRAINAGE TO EASTERLY EXISTING BASIN Inflow Area = 0.215 ac, 68.32% Impervious, Inflow Depth = 2.01" for 2 YEAR STORMEVENT event Inflow = 0.18 cfs @ 12.12 hrs, Volume= 0.036 of Outflow = 0.18 cfs'@ 12.12 hrs, Volume= 0.036 af, Atten= 0 %, Lag= 0.0 min Routing by Stor- Ind +Trans method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 6569 SPACES FOR RENT rev 5 Type/// 24 -hr 2 YEAR STORMEVENT Rainfall = 3.00" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 5PS: DRAINAGE AREA TO EASTERLY WETLAND Runoff = 0.08 cfs @ 12.09 hrs, Volume= 0.006 at, Depth= 2.77" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Area (sf) CN Description 1.199 98 Paved Darkina. HSG C 1,199 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 2 YEAR STORMEVENT Rainfal1= 3.00" Prepared by HERITAGE SURVEYS, INC. Summary for Subcatchment 4S: DRAINAGE TO WESTERLY SIDE PROPOSED BUILDING 10 Runoff = 0.57 cfs @ 12.09 hrs, Volume= 0.043 af, Depth= 2.25" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 YEAR STORMEVENT Rainfall= 3.00" Area (sf) CN Description 3,738 98 Roofs, HSG C 1,848 98 Paved parking, HSG C 2,202 98 Basin 2,154 74 >75% Grass cover, Good, HSG C 9,942 93 Weighted Average 2,154 0.19 cfs @ 21.67% Pervious Area 7,788 0.043 of 78.33% Impervious Area To Length Slope Velocity Capacity Description .I Direct Entry, Summary for Pond 3PB: BIORETENTION AREA WESTERLY SIDE BUILDING 10 Inflow Area = 0.228 ac, 78.33% Impervious, Inflow Depth = 2.25" for 2 YEAR STORMEVENT event Inflow = 0.57 cfs @ 12.09 hrs, Volume= 0.043 of Outflow = 0.19 cfs @ 12.38 hrs, Volume= 0.043 af, Atten= 66 %, Lag= 17.3 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Secondary = 0.19 cfs @ 12.38 hrs, Volume= 0.043 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 137.30' @ 12.38 hrs Surf.Area= 859 sf Storage= 469 of Plug -Flow detention time= 36.5 min calculated for 0.043 of (100% of inflow) Center -of -Mass det. time= 36.9 min ( 831.8 - 794.9 ) Volume Invert Avail.Storage Storage Description #1 136.50' 2,321 of Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 136.50 432 0 0 432 137.00 579 252 252 584 138.00 1,708 1,094 1,346 1,719 138.50 2,202 975 2,321 2,219 Device Routing Invert Outlet Devices #1 Primary 138.40' 10.0' long x 3.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 #2 Secondary 136.50' 3.0" Round Culvert L= 15.0' Ke= 0.500 6569 SPACES FOR RENT rev 5 Type 11124 -hr 2 YEAR STORMEVENT Rainfall = 3.00" Prepared by HERITAGE SURVEYS, INC. Inlet/ Outlet Invert= 136.50'/ 136.25' S=0.0167'/' Cc= 0.900 n= 0.010 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 136.50' (Free Discharge) L1 = Broad- Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max =0.19 cfs @ 12.38 hrs HW= 137.30' (Free Discharge) t2= Culvert (Inlet Controls 0.19 cfs @ 3.97 fps) POST CONSTRUCTION 10 YEAR STORM EVENT 4.50 INCH RAINFALL 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 10 YEAR STORMEVENT Rainfall = 4.50" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 1 PS: PROPOSED BUILDING 9 - DRAINAGE TO BASIN Runoff = 0.46 cfs @ 12.09 hrs, Volume= 0.034 af, Depth= 3.30" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Area (sf) CN Description 2,000 98 Roofs, HSG C 1,347 98 Basin 2,047 74 >75% Grass cover, Good, HSG C 5,394 89 Weighted Average 2,047 37.95% Pervious Area 3,347 62.05% Impervious Area Tc Length Slope Velocity Capacity Description 6.0 Direct Entry, Summary for Subcatchment 2PS: PROPOSED PAVEMENT ALONG FRONT OF BUILDING 9 Runoff = 0.14 cfs @ 12.09 hrs, Volume= 0.012 af, Depth= 4.26" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Area (sf) CN Description 1,419 98 Paved parking. HSG C 1,419 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Pond 1 PB: BASIN FOR BUILDING 9 Inflow Area = 0.124 ac, 62.05% Impervious, Inflow Depth = 3.30" for 10 YEAR STORMEVENT event Inflow = 0.46 cfs @ 12.09 hrs, Volume= 0.034 of Outflow = 0.09 cfs @ 12.53 hrs, Volume= 0.020 af, Atten= 80 %, Lag= 26.5 min Primary = 0.09 cfs @ 12.53 hrs, Volume= 0.020 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 135.98' @ 12.53 hrs Surf.Area= 1,321 sf Storage= 817 cf Plug -Flow detention time= 272.2 min calculated for 0.020 of (59% of inflow) Center -of -Mass det. time= 170.4 min ( 968.5 - 798.1 ) 6569 SPACES FOR RENT rev 5 Type 11124 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 O 2010 HydroGAD Software Solutions LLC Page 2 Volume Invert Avail.Storage Storage Description #1 135.00' 847 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 135.00 432 0 0 432 136.00 1,347 847 847 1,353 Invert Outlet Devices #1 Primary 135.80' 6.0" Vert. Orifice /Grate C= 0.600 Primary OutFlow Max =0.09 cfs @ 12.53 hrs HW= 135.98' (Free Discharge) t1= 0rifice /Grate (Orifice Controls 0.09 cfs @ 1.43 fps) 6569 SPACES FOR RENT rev 5 Type 11124 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Prepared by HERITAGE SURVEYS, INC. HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 3 Summary for Reach 1 R: WETLAND AREA NEAR WF4 Inflow Area = 0.156 ac, 69.95% Impervious, Inflow Depth = 2.44" for 10 YEAR STORMEVENT event Inflow = 0.14 cfs @ 12.09 hrs, Volume= 0.032 of Outflow = 0.14 cfs @ 12.09 hrs, Volume= 0.032 af, Atten= 0 %, Lag= 0.0 min Routing by Stor- Ind +Trans method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 10 YEAR STORMEVENT Rainfall = 4.50" Prepared by HERITAGE SURVEYS, INC. Summary for Subcatchment 3PS: DRAINAGE TO EASTERLY SIDE PROPOSED BUILDING 10 Runoff = 0.69 cfs @ 12.09 hrs, Volume= 0.052 af, Depth= 3.30" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Area (sf) CN Description 3,737 98 Roofs, HSG C 1,472 98 Basin 2.971 74 >75% Grass cover. Good. HSG C 8,180 89 Weighted Average 2,971 36.32% Pervious Area 5,209 63.68% Impervious Area Tc Length M Description Direct Entry, Summary for Subcatchment 6PS: PAVEMENT DRAINAGE TO EXISTING BASIN AREA Runoff = 0.12 cfs @ 12.09 hrs, Volume= 0.010 af, Depth= 4.26" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Area (sf) CN Description 1.199 98 Paved oarkino. HSG C 1,199 100.00% Impervious Area Tc Length Slope Velocity Capacity Description 6.0 Direct Entry, Summary for Pond 2PB: BASIN EASTERLY SIDE BUILDING 10 Inflow Area = 0.188 ac, 63.68% Impervious, Inflow Depth = 3.30" for 10 YEAR STORMEVENT event Inflow = 0.69 cfs @ 12.09 hrs, Volume= 0.052 of Outflow = 0.17 cfs @ 12.47 hrs, Volume= 0.052 af, Atten= 75 %, Lag= 23.1 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Secondary = 0.17 cfs @ 12.47 hrs, Volume= 0.052 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 137.94' @ 12.47 hrs Surf.Area= 1,205 sf Storage= 744 cf Plug -Flow detention time= 68.5 min calculated for 0.052 of (100% of inflow) Center -of -Mass det. time= 68.2 min ( 866.3 - 798.1 ) 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 10 YEAR STORMEVENT Rainfall = 4.50" Prepared by HERITAGE SURVEYS, INC. HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 5 Volume Invert Avail.Storage Storage Description #1 137.20' 1,494 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 137.20 817 0 0 817 138.00 1,240 817 817 1,250 138.50 1,472 677 1,494 1,491 Device Routing Invert Outlet Devices #1 Primary 138.40' 5.0' long x 3.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 #2 Secondary 137.20' 3.0" Round Culvert L= 18.0' Ke= 0.500 Inlet / Outlet Invert= 137.20'/ 137.00' S= 0.0111 T Cc= 0.900 n= 0.010 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 137.20' (Free Discharge) t1= 113road - Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max =0.17 cfs @ 12.47 hrs HW= 137.94' (Free Discharge) t2= Culvert (Barrel Controls 0.17 cfs @ 3.50 fps) 6569 SPACES FOR RENT rev 5 Type 11124 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Prepared by HERITAGE SURVEYS, INC. Summary for Reach 2R: DRAINAGE TO EASTERLY EXISTING BASIN Inflow Area = 0.215 ac, 68.32% Impervious, Inflow Depth = 3.42" for 10 YEAR STORMEVENT event Inflow = 0.26 cfs @ 12.11 hrs, Volume= 0.061 of Outflow = 0.26 cfs @ 12.11 hrs, Volume= 0.061 af, Atten= 0 %, Lag= 0.0 min Routing by Stor- Ind +Trans method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 6569 SPACES FOR RENT rev 5 Type 11124 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Prepared by HERITAGE SURVEYS, INC. HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 5PS: DRAINAGE AREA TO EASTERLY WETLAND Runoff = 0.12 cfs @ 12.09 hrs, Volume= 0.010 af, Depth= 4.26" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Area (sf) CN Description 1,199 98 Paved parking, HSG C 1,199 100.00% Impervious Area Tc Length Slope Velocity Capacity Description M Direct Entry, 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 4S: DRAINAGE TO WESTERLY SIDE PROPOSED BUILDING 10 Runoff = 0.92 cfs @ 12.09 hrs, Volume= 0.071 af, Depth= 3.71" Runoff by SCS TR -20 method, LIH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 YEAR STORMEVENT Rainfall= 4.50" Area (sf) CN Description 3,738 98 Roofs, HSG C 1,848 98 Paved parking, HSG C 2,202 98 Basin 2,154 74 >75% Grass cover, Good, HSG C 9,942 93 Weighted Average 2,154 0.24 cfs @ 21.67% Pervious Area 7,788 0.071 of 78.33% Impervious Area Tc Length Slope Velocity Capacity Description .e Direct Entry, Summary for Pond 3PB: BIORETENTION AREA WESTERLY SIDE BUILDING 10 Inflow Area = 0.228 ac, 78.33% Impervious, Inflow Depth = 3.71" for 10 YEAR STORMEVENT event Inflow = 0.92 cfs @ 12.09 hrs, Volume= 0.071 of Outflow = 0.24 cfs @ 12.46 hrs, Volume= 0.071 af, Atten= 74 %, Lag= 22.1 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Secondary = 0.24 cfs @ 12.46 hrs, Volume= 0.071 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 137.68' @ 12.46 hrs Surf.Area= 1,282 sf Storage= 870 cf Plug -Flow detention time= 41.7 min calculated for 0.071 of (100% of inflow) Center -of -Mass det, time= 40.9 min ( 822.4 - 781.5 ) Volume Invert Avail.Storage Storage Description #1 136.50' 2,321 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 136.50 432 0 0 432 137.00 579 252 252 584 138.00 1,708 1,094 1,346 1,719 138.50 2,202 975 2,321 2,219 Device Routing Invert Outlet Devices #1 Primary 138.40' 10.0' long x 3.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 #2 Secondary 136.50' 3.0" Round Culvert L= 15.0' Ke= 0.500 6569 SPACES FOR RENT rev 5 Type 11124 -hr 10 YEAR STORMEVENT Rainfall = 4.50" Prepared by HERITAGE SURVEYS, INC. HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 9 Inlet/ Outlet Invert= 136.50'/ 136.25' S=0.0167? Cc= 0.900 n= 0.010 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 136.50' (Free Discharge) t1= 13road - Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max =0.24 cfs @ 12.46 hrs HW= 137.68' (Free Discharge) t2= Culvert (Barrel Controls 0.24 cfs @ 4.82 fps) POST CONSTRUCTION 25 YEAR STORM EVENT 5.40 INCH RAINFALL 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Prepared by HERITAGE SURVEYS, INC. HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 1 PS: PROPOSED BUILDING 9 - DRAINAGE TO BASIN Runoff = 0.57 cfs @ 12.09 hrs, Volume= 0.043 af, Depth= 4.16" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Area (sf) CN Description 2,000 98 Roofs, HSG C 1,347 98 Basin >75% Grass cover. Good. HSG C 5,394 89 Weighted Average 2,047 37.95% Pervious Area 3,347 62.05% Impervious Area To Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) .e Direct Entry, Summary for Subcatchment 2PS: PROPOSED PAVEMENT ALONG FRONT OF BUILDING Runoff = 0.17 cfs @ 12.09 hrs, Volume= 0.014 af, Depth= 5.16" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Area (sf) CN 1,419 98 Paved parking, HSG C 1,419 100.00% Impervious Area To Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Pond 1PB: BASIN FOR BUILDING 9 Inflow Area = 0.124 ac, 62.05% Impervious, Inflow Depth = 4.16" for 25 YEAR STORMEVENT event Inflow = 0.57 cfs @ 12.09 hrs, Volume= 0.043 of Outflow = 0.48 cfs @ 12.22 hrs, Volume= 0.031 af, Atten= 16 %, Lag= 7.8 min Primary = 0.48 cfs @ 12.22 hrs, Volume= 0.031 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 136.30' @ 12.22 hrs Surf.Area= 1,347 sf Storage= 847 of Plug -Flow detention time= 206.8 min calculated for 0.031 of (73% of inflow) Center -of -Mass det. time= 120.7 min ( 912.5 - 791.7 ) 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 25 YEAR STORMEVENT Rainfall= 5.40" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 2 Volume Invert Avail.Storage Storage Description #1 135.00' 847 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 135.00 432 0 0 432 136.00 1,347 847 847 1,353 Device Routing Invert Outlet Devices #1 Primary 135.80' 6.0" Vert. Orifice /Grate C= 0.600 Primary OutFlow Max =0.43 cfs @ 12.22 hrs HW= 136.26' (Free Discharge) t1= Orifice /Grate (Orifice Controls 0.43 cfs @ 2.30 fps) 6569 SPACES FOR RENT rev 5 Type 11124 -hr 25 YEAR STORMEVENT Rainfa11= 5.40" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 @2010 HydroCAD Software Solutions LLC Page 3 Summary for Reach 1 R: WETLAND AREA NEAR WF4 Inflow Area = 0.156 ac, 69.95% Impervious, Inflow Depth = 3.47" for 25 YEAR STORMEVENT event Inflow = 0.57 cfs @ 12.22 hrs, Volume= 0.045 of Outflow = 0.57 cfs @ 12.22 hrs, Volume= 0.045 af, Atten= 0 %, Lag= 0.0 min Routing by Stor- Ind +Trans method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 6569 SPACES FOR RENT rev 5 Type 11124 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 3PS: DRAINAGE TO EASTERLY SIDE PROPOSED BUILDING 10 Runoff = 0.86 cfs @ 12.09 hrs, Volume= 0.065 af, Depth= 4.16" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Area (sf) CN Description 3,737 98 Roofs, HSG C 1,472 98 Basin 2.971 74 >75% Grass cover. Good. HSG C 8,180 89 Weighted Average 2,971 36.32% Pervious Area 5,209 63.68% Impervious Area Tc Length M Description Direct Entry, Summary for Subcatchment 6PS: PAVEMENT DRAINAGE TO EXISTING BASIN AREA Runoff = 0.14 cfs @ 12.09 hrs, Volume= 0.012 af, Depth= 5.16" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Area (sf) CN Description 1.199 98 Paved oarkina. HSG C 1,199 100.00% Impervious Area Tc Length Slope Velocity Capacity Description 6.0 Direct Entry, Summary for Pond 2PB: BASIN EASTERLY SIDE BUILDING 10 Inflow Area = 0.188 ac, 63.68% Impervious, Inflow Depth = 4.16" for 25 YEAR STORMEVENT event Inflow = 0.86 cfs @ 12.09 hrs, Volume= 0.065 of Outflow = 0.19 cfs @ 12.50 hrs, Volume= 0.065 af, Atten= 78 %, Lag= 24.6 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Secondary = 0.19 cfs @ 12.50 hrs, Volume= 0.065 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 138.12' @ 12.50 hrs Surt.Area= 1,293 sf Storage= 965 cf Plug -Flow detention time= 70.0 min calculated for 0.065 of (100% of inflow) Center -of -Mass det. time= 69.8 min ( 861.5 - 791.7 ) 6569 SPACES FOR RENT rev 5 Type 11124 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 O 2010 HydroCAD Software Solutions LLC Page 5 Volume Invert Avail.Storage Storage Description #1 137.20' 1,494 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surt.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 137.20 817 0 0 817 138.00 1,240 817 817 1,250 138.50 1,472 677 1,494 1,491 Device Routing Invert Outlet Devices #1 Primary 138.40' 5.0' long x 3.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 #2 Secondary 137.20' 3.0" Round Culvert L= 18.0' Ke= 0.500 Inlet / Outlet Invert= 137.20'/ 137.00' S= 0.0111 T Cc= 0.900 n= 0.010 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 137.20' (Free Discharge) tt= Broad- Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max =0.19 cfs @ 12.50 hrs HW= 138.12' (Free Discharge) t-2= Culvert (Barrel Controls 0.19 cfs @ 3.93 fps) 6569 SPACES FOR RENT rev 5 Type 11124 -hr 25 YEAR STORMEVENT Rainfall= 5.40" Prepared by HERITAGE SURVEYS, INC. HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Pape 6 Summary for Reach 2R: DRAINAGE TO EASTERLY EXISTING BASIN Inflow Area = 0.215 ac, 68.32% Impervious, Inflow Depth = 4.28" for 25 YEAR STORMEVENT event Inflow = 0.30 cfs @ 12.10 hrs, Volume= 0.077 of Outflow = 0.30 cfs @ 12.10 hrs, Volume= 0.077 af, Atten= 0 %, Lag= 0.0 min Routing by Stor- Ind +Trans method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 6569 SPACES FOR RENT rev 5 Type 11124 -hr 25 YEAR STORMEVENT Rainfall= 5.40" Prepared by HERITAGE SURVEYS, INC. Summary for Subcatchment 5PS: DRAINAGE AREA TO EASTERLY WETLAND Runoff = 0.14 cfs @ 12.09 hrs, Volume= 0.012 af, Depth= 5.16" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Area (sf) CN Description 1,199 98 Paved parking, HSG C 1,199 100.00% Impervious Area Tc Length .e Description Direct Entry, 6569 SPACES FOR RENT rev 5 Type /// 24 -hr 25 YEAR STORMEVENT Rainfall= 5.40" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Pape 8 Summary for Subcatchment 4S: DRAINAGE TO WESTERLY SIDE PROPOSED BUILDING 10 Runoff = 1.12 cfs @ 12.09 hrs, Volume= 0.087 af, Depth= 4.59" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Area (sf) CN 3,738 98 Roofs, HSG C 1,848 98 Paved parking, HSG C 2,202 98 Basin 2.154 74 >75% Grass cover, Good. HSG C 9,942 93 Weighted Average 2,154 21.67% Pervious Area 7,788 78.33% Impervious Area Tc Length min) (feet) 6.0 Description Direct Entry, Summary for Pond 3PB: BIORETENTION AREA WESTERLY SIDE BUILDING 10 Inflow Area = 0.228 ac, 78.33% Impervious, Inflow Depth = 4.59" for 25 YEAR STORMEVENT event Inflow = 1.12 cfs @ 12.09 hrs, Volume= 0.087 of Outflow = 0.25 cfs @ 12.49 hrs, Volume= 0.087 af, Atten= 77 %, Lag= 24.0 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Secondary = 0.25 cfs @ 12.49 hrs, Volume= 0.087 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 137.87' @ 12.49 hrs Surf.Area= 1,527 sf Storage= 1,135 cf Plug -Flow detention time= 44.6 min calculated for 0.087 of (100% of inflow) Center -of -Mass det. time= 44.9 min ( 820.9 - 776.0 ) Volume Invert Avail.Storage Storage Description #1 136.50' 2,321 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 136.50 432 0 0 432 137.00 579 252 252 584 138.00 1,708 1,094 1,346 1,719 138.50 2,202 975 2,321 2,219 Device Routing Invert Outlet Devices #1 Primary 138.40' 10.0' long x 3.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 #2 Secondary 136.50' 3.0" Round Culvert L= 15.0' Ke= 0.500 6569 SPACES FOR RENT rev 5 Type //l 24 -hr 25 YEAR STORMEVENT Rainfall = 5.40" Prepared by HERITAGE SURVEYS, INC. Inlet/ Outlet Invert= 136.50'/ 136.25' S=0.0167'/' Cc= 0.900 n= 0.010 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 136.50' (Free Discharge) L1= 13road - Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max =0.25 cfs @ 12.49 hrs HW= 137.87' (Free Discharge) t2= Culvert (Barrel Controls 0.25 cfs @ 5.19 fps) POST CONSTRUCTION 100 YEAR STORM EVENT 6.50 INCH RAINFALL 6569 SPACES FOR RENT rev 5 Type 11124 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 1PS: PROPOSED BUILDING 9 - DRAINAGE TO BASIN Runoff = 0.71 cfs @ 12.09 hrs, Volume= 0.054 af, Depth= 5.22" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Area (sf) CN Description 2,000 98 Roofs, HSG C 1,347 98 Basin 2,047 74 >75% Grass cover, Good, HSG C 5,394 89 Weighted Average 2,047 37.95% Pervious Area 3,347 62.05% Impervious Area Tc Length Slope Velocity Capacity Description 6.0 Direct Entry, Summary for Subcatchment 2PS: PROPOSED PAVEMENT ALONG FRONT OF BUILDING 9 Runoff = 0.20 cfs @ 12.09 hrs, Volume= 0.017 af, Depth= 6.26" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Area (sf) CN Description 1,419 98 Paved parking, HSG C 1,419 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 6.0 Direct Entry, Summary for Pond 1PB: BASIN FOR BUILDING 9 Inflow Area = 0.124 ac, 62.05% Impervious, Inflow Depth = 5.22" for 100 YEAR STORMEVENT event Inflow = 0.71 cfs @ 12.09 hrs, Volume= 0.054 of Outflow = 0.39 cfs @ 12.11 hrs, Volume= 0.032 af, Atten= 45 %, Lag= 1.2 min Primary = 0.39 cfs @ 12.11 hrs, Volume= 0.032 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 136.22' @ 12.11 hrs Surf.Area= 1,347 sf Storage= 847 cf Plug -Flow detention time= 254.0 min calculated for 0.032 of (60% of inflow) Center -of -Mass det. time= 150.4 min ( 935.9 - 785.6 ) 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Prepared by HERITAGE SURVEYS, INC. Volume Invert Avail.Storage Storage Description #1 135.00' 847 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 135.00 432 0 0 432 136.00 1,347 847 847 1,353 Device Routing Invert Outlet Devices #1 Primary 135.80' 6.0" Vert. Orifice /Grate C= 0.600 Primary OutFlow Max =0.36 cfs @ 12.11 hrs HW= 136.20' (Free Discharge) t1= Orifice /Grate (Orifice Controls 0.36 cfs @ 2.15 fps) 6569 SPACES FOR RENT rev 5 Type 11124 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Prepared by HERITAGE SURVEYS, INC. HvdroCADO 9.10 s/n 00860 © 2010 HvdroCAD Software Solutions LLC Pana :I Summary for Reach 1 R: WETLAND AREA NEAR WF4 Inflow Area = 0.156 ac, 69.95% Impervious, Inflow Depth = 3.77" for 100 YEAR STORMEVENT event Inflow = 0.59 cfs @ 12.11 hrs, Volume= 0.049 of Outflow = 0.59 cfs @ 12.11 hrs, Volume= 0.049 af, Atten= 0 %, Lag= 0.0 min Routing by Stor- Ind +Trans method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 100 YEAR STORMEVENT Rainfal1= 6.50" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 3PS: DRAINAGE TO EASTERLY SIDE PROPOSED BUILDING 10 Runoff = 1.07 cfs @ 12.09 hrs, Volume= 0.082 af, Depth= 5.22" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Area (sf) CN Description 3,737 98 Roofs, HSG C 1,472 98 Basin 2.971 74 >75% Grass cover. Good. HSG C 8,180 89 Weighted Average 2,971 36.32% Pervious Area 5,209 63.68% Impervious Area Tc Length min) (feet) 6.0 Description Direct Entry, Summary for Subcatchment 6PS: PAVEMENT DRAINAGE TO EXISTING BASIN AREA Runoff = 0.17 cfs @ 12.09 hrs, Volume= 0.014 af, Depth= 6.26" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Area (sf) CN Description 1.199 98 Paved parking. HSG C 1,199 100.00% Impervious Area Tc Length Slope Velocity Capacity Description 6.0 Direct Entry, Summary for Pond 2PB: BASIN EASTERLY SIDE BUILDING 10 Inflow Area = 0.188 ac, 63.68% Impervious, Inflow Depth = 5.22" for 100 YEAR STORMEVENT event Inflow = 1.07 cfs @ 12.09 hrs, Volume= 0.082 of Outflow = 0.21 cfs @ 12.52 hrs, Volume= 0.082 af, Atten= 80 %, Lag= 25.9 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Secondary = 0.21 cfs @ 12.52 hrs, Volume= 0.082 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 138.33' @ 12.52 hrs Surf.Area= 1,390 sf Storage= 1,248 cf Plug -Flow detention time= 72.1 min calculated for 0.082 of (100% of inflow) Center -of -Mass det. time= 73.1 min ( 858.7 - 785.6 ) 6569 SPACES FOR RENT rev 5 Type 11124 -hr 100 YEAR STORMEVENT Rainfall = 6.50" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 5 Volume Invert Avail.Storage Storage Description #1 137.20' 1,494 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 137.20 817 0 0 817 138.00 1,240 817 817 1,250 138.50 1,472 677 1,494 1,491 Device Routing Invert Outlet Devices #1 Primary 138.40' 5.0' long x 3.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 #2 Secondary 137.20' 3.0" Round Culvert L= 18.0' Ke= 0.500 Inlet / Outlet Invert= 137.20'/ 137.00' S= 0.0111 T Cc= 0.900 n= 0.010 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 137.20' (Free Discharge) t1= Broad - Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max =0.21 cfs @ 12.52 hrs HW= 138.33' (Free Discharge) L2= Culvert (Barrel Controls 0.21 cfs @ 4.38 fps) 6569 SPACES FOR RENT rev 5 Type 11124 -hr 100 YEAR STORMEVENT Rainfall = 6.50" Prepared by HERITAGE SURVEYS, INC. HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 6 Summary for Reach 2R: DRAINAGE TO EASTERLY EXISTING BASIN Inflow Area = 0.215 ac, 68.32% Impervious, Inflow Depth = 5.35' for 100 YEAR STORMEVENT event Inflow = 0.35 cfs @ 12.10 hrs, Volume= 0.096 of Outflow = 0.35 cfs @ 12.10 hrs, Volume= 0.096 af, Atten= 0 %, Lag= 0.0 min Routing by Stor- Ind +Trans method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 6569 SPACES FOR RENT rev 5 Type Ill 24 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Prepared by HERITAGE SURVEYS, INC. HydroCAD® 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 5PS: DRAINAGE AREA TO EASTERLY WETLAND Runoff = 0.17 cfs @ 12.09 hrs, Volume= 0.014 af, Depth= 6.26" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Area (sf) CN Description 1,199 98 Paved parking, HSG C 1,199 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (It/sec) (cfs) 6.0 Direct Entry, 6569 SPACES FOR RENT rev 5 Type 11124 -hr 100 YEAR STORMEVENT Rainfall = 6.50" Prepared by HERITAGE SURVEYS, INC. Summary for Subcatchment 4S: DRAINAGE TO WESTERLY SIDE PROPOSED BUILDING 10 Runoff = 1.37 cfs @ 12.09 hrs, Volume= 0.108 af, Depth= 5.68" Runoff by SCS TR -20 method, UH =SCS, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 YEAR STORMEVENT Rainfall= 6.50" Area (sf) CN Description 3,738 98 Roofs, HSG C 1,848 98 Paved parking, HSG C 2,202 98 Basin 2,154 74 >75% Grass cover, Good, HSG C 9,942 93 Weighted Average 2,154 0.27 cfs @ 21.67% Pervious Area 7,788 0.108 of 78.33% Impervious Area Tc Length .M Description Direct Entry, Summary for Pond 3PB: BIORETENTION AREA WESTERLY SIDE BUILDING 10 Inflow Area = 0.228 ac, 78.33% Impervious, Inflow Depth = 5.68" for 100 YEAR STORMEVENT event Inflow = 1.37 cfs @ 12.09 hrs, Volume= 0.108 of Outflow = 0.27 cfs @ 12.52 hrs, Volume= 0.108 af, Atten= 80 %, Lag= 25.8 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Secondary = 0.27 cfs @ 12.52 hrs, Volume= 0.108 of Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 138.08' @ 12.52 hrs Surf.Area= 1,778 sf Storage= 1,477 cf Plug -Flow detention time= 50.4 min calculated for 0.108 of (100% of inflow) Center -of -Mass det. time= 50.7 min ( 821.4 - 770.8 ) Volume Invert Avail.Storage Storage Description #1 136.50' 2,321 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (cubic -feet) (cubic -feet) (sq -ft) 136.50 432 0 0 432 137.00 579 252 252 584 138.00 1,708 1,094 1,346 1,719 138.50 2,202 975 2,321 2,219 dice Routing Invert Outlet Devices #1 Primary 138.40' 10.0' long x 3.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 #2 Secondary 136.50' 3.0" Round Culvert L= 15.0' Ke= 0.500 6569 SPACES FOR RENT rev 5 Type 11124 -hr 100 YEAR STORMEVENT Rainfal1= 6.50" Prepared by HERITAGE SURVEYS, INC. HydroCADO 9.10 s/n 00860 © 2010 HydroCAD Software Solutions LLC Page 9 Inlet / Outlet Invert= 136.50'/ 136.25' S= 0.0167 '/' Cc= 0.900 n= 0.010 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 136.50' (Free Discharge) L1= Broad - Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max =0.27 cfs @ 12.52 hrs HW= 138.07' (Free Discharge) L2= Culvert (Barrel Controls 0.27 cfs @ 5.57 fps) BASIN DRAWDOWN 10 YEAR STORM EVENT 6569 SPACES FOR RENT rev 5 Type 111 24 -hr 10 YEAR STORMEVENT Rainfall = 4.50" Prepared by HERITAGE SURVEYS, INC. Hydrograph for Pond 3PB; BIORETENTION AREA WESTERLY SIDE BUILDING 10 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic -feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 136.50 0.00 0.00 0.00 2.50 0.00 0 136.50 0.00 0.00 0.00 5.00 0.00 8 136.52 0.00 0.00 0.00 7.50 0.01 29 136.57 0.01 0.00 0.01 10.00 0.04 59 136.63 0.03 0.00 0.03 12.50 0.20 867 137.68 0.24 0.00 0.24 15.00 0.04 77 136.67 0.05 0.00 0.05 17.50 0.02 46 136.60 0.02 0.00 0.02 20.00 0.01 37 136.58 0.01 0.00 0.01 22.50 0.01 32 136.57 0.01 0.00 0.01 25.00 0.00 14 136.53 0.00 0.00 0.00 27.50 0.00 5 136.51 0.00 0.00 0.00 30.00 0.00 2 136.50 0.00 0.00 0.00 32.50 0.00 1 136.50 0.00 0.00 0.00 35.00 0.00 0 136.50 0.00 0.00 0.00 37.50 0.00 0 136.50 0.00 0.00 0.00 40.00 0.00 0 136.50 0.00 0.00 0.00 42.50 0.00 0 136.50 0.00 0.00 0.00 45.00 0.00 0 136.50 0.00 0.00 0.00 47.50 0.00 0 136.50 0.00 0.00 0.00 50.00 0.00 0 136.50 0.00 0.00 0.00 52.50 0.00 0 136.50 0.00 0.00 0.00 55.00 0.00 0 136.50 0.00 0.00 0.00 57.50 0.00 0 136.50 0.00 0.00 0.00 60.00 0.00 0 136.50 0.00 0.00 0.00 62.50 0.00 0 136.50 0.00 0.00 0.00 65.00 0.00 0 136.50 0.00 0.00 0.00 67.50 0.00 0 136.50 0.00 0.00 0.00 70.00 0.00 0 136.50 0.00 0.00 0.00 6569 SPACES FOR RENT rev 5 Type 11124 -hr 10 YEAR STORMEVENT Rainfall = 4.50" Prepared by HERITAGE SURVEYS, INC. Hydrograph for Pond 2PB: BASIN EASTERLY SIDE BUILDING 10 Time Inflow Storage Elevation Outflow Primary Secondary (hours) (cfs) (cubic -feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 137.20 0.00 0.00 0.00 2.50 0.00 0 137.20 0.00 0.00 0.00 5.00 0.00 0 137.20 0.00 0.00 0.00 7.50 0.01 17 137.22 0.00 0.00 0.00 10.00 0.02 71 137.29 0.01 0.00 0.01 12.50 0.16 743 137.94 0.17 0.00 0.17 15.00 0.03 148 137.37 0.05 0.00 0.05 17.50 0.02 81 137.30 0.02 0.00 0.02 20.00 0.01 63 137.28 0.01 0.00 0.01 22.50 0.01 55 137.27 0.01 0.00 0.01 25.00 0.00 33 137.24 0.00 0.00 0.00 27.50 0.00 17 137.22 0.00 0.00 0.00 30.00 0.00 11 137.21 0.00 0.00 0.00 32.50 0.00 8 137.21 0.00 0.00 0.00 35.00 0.00 6 137.21 0.00 0.00 0.00 37.50 0.00 5 137.21 0.00 0.00 0.00 40.00 0.00 4 137.20 0.00 0.00 0.00 42.50 0.00 3 137.20 0.00 0.00 0.00 45.00 0.00 2 137.20 0.00 0.00 0.00 47.50 0.00 1 137.20 0.00 0.00 0.00 50.00 0.00 1 137.20 0.00 0.00 0.00 52.50 0.00 1 137.20 0.00 0.00 0.00 55.00 0.00 1 137.20 0.00 0.00 0.00 57.50 0.00 0 137.20 0.00 0.00 0.00 60.00 0.00 0 137.20 0.00 0.00 0.00 62.50 0.00 0 137.20 0.00 0.00 0.00 65.00 0.00 0 137.20 0.00 0.00 0.00 67.50 0.00 0 137.20 0.00 0.00 0.00 70.00 0.00 0 137.20 0.00 0.00 0.00 0 O N v d 0 0 a 0 (D CL E 0 T f0 U E 0 C f0 a) � C � O C o E 0- o a U Cl o a) L � O Q N 0 c c o o (D � � m c c m O U) o 0 � CL U 2 N U 0 � C E (D U) E ° 0 Ln O _ L) U 7. d U a m =) 2 U m m 0 r U) c U) < Z N M a) l6 a C V a) m 0 w- LLB C C Q LL m C (D 0 Of J n U c �- Lu 0 0) Q O N� LL 0 z, Q 0 'C J VJ cu O U � U) O O O O O OA u O N HH" c U 0 0 w F E a � a a O m O O O HHHo m O O O O O OA u O 0 W c HH" c o 0 0 w F E a ar LL a Of O O O O O HHHo O O O O 0 0 0 0 0 o r E HHHH, o0 00 °o, rn o° 0 HLIH 6 0 0 0 01 t O o w i N � o � h W 3 m C � Q` OD o 0 O Q L � c c L w ad+ � O 0 a m Q LL ;aayslioM uopelnaleo JeAOWGM SSl O OA t OA u O 0 W c 0 Z W w F E a ar LL a 0 m m d a E G N m O d o d N ina0 °- E 0 o d L� r m o O C L 01 E O o � i N � o � U W 3 m II O E co N L� r r r O o N o � A N c m C � U CO cu O Q L � a L cu Q O a 0 U d d c c c w `o m 0 N G a w o 0 0 2 soy on 2 E m E U. o o N � (L Iwo N N N � o � � 5 a E = 7 Z E Operatioiq Maintenance of Stormwatl System For Buildings 9 & 10 Name of Project: Spaces For Rent — Building 9 & 10 Project Location: 94 Industrial Drive, Northampton Northampton Assessor's Map, Parcel: Map 25A, Parcels 182 & 187 Book: 9665 Page: 249 Owner of the Stormwater System: 94 Industrial Drive, LL_ C and the successors as their interest may appear as owner of record of the property. Responsible Party for Operation & Maintenance of Stormwater System 94 Industrial Drive, LLC and the successors as their interest may appear as owner of record of the property. Financial Responsibility for Operation & Maintenance of Stormwater System: 94 Industrial Drive, LLC and the successors as their interest may appear as owner of record of the property. Maintenance Schedule DrainaEe System The owner shall contact a licensed contractor qualified to perform the necessary maintenance to the stormwater system. The contractor shall perform the necessary maintenance to remove sediment, and debris from the stormwater system. The sediment and debris shall be properly disposed of. The owner shall inspect the stormwater management components as described below and after major stormevents (a maj or stornevent is defined as a storm that is equal to or greater than the 2 year, 24 hour stormevent - generally 2.9 to 3.6 inches of rain in a 24 -hour period). Pavement Maintenance Paved areas shall be maintained at least two times per year, Spring and Fall. If needed an additional cleaning shall be performed after fall leaf debris has ceased: Routinely pick up and remove litter from the paved areas and perimeter landscape areas. All materials from maintenance of paved areas shall be disposed in accordance with applicable local, state, and federal guidelines and regulations. Grass Stormwater Basins The grass stornwater basins shall be inspected once annually for cracking and erosion of side slopes and embankments, accumulation of sediment, condition of vegetative cover, and overall performance according to the design. The following routine maintenance shall be completed: • All areas in the grass stormwater basins, devoid of vegetation or found to be eroding shall be immediately repaired. Repairs shall include replacement of eroded soils, re- establishment and protection of vegetative cover, and immediate stabilization with erosion control measures to control erosion until stabilization occurs. • Sediment shall be removed from the basin areas when it reaches a thickness of 4 inches and/or as necessary for the proper functioning of the system. • All material removed from basins shall be disposed in accordance with applicable local, state, and federal guidelines and regulations. • Regular maintenance includes mowing, fertilizing, liming, watering, pruning, and weed and pest control. • The 3" pipes within the basins to the west and east of building 10 shall be maintained and cleaned to allow flow out of the basin at all times. Page 2 of 2 Spaces For Rent —Building 9 & 10 Bio- Retention Area Inspect bio- retention area regularly for sediment build -up, structural damage and standing water. Inspect soil and repair eroded areas and remove litter /debris monthly. Remove invasive species as needed to prevent these species from spreading into the bio - retention area. Upon failure, excavate bio-retention area, scarify bottom and side soils, and then add soil and replant. Avoid use of salts, fertilizers and pesticides. Never store snow in bio - retention area. BIO- RETENTION AREA MAINTENANCE SCHEDULE ACTIVITY TIME OF YEAR FREQUENCY Inspect and remove trash Year round Monthly Remove dead vegetation Fall or Spring Annually Re lace dead vegetation Spring Annually Prune Spring or Fall Annually Rip Rap Areas The rip rap areas shall be inspected at least two times per year, Spring and Fall remove sediment and debris as needed. Replace stone in required to maintain original design. Dlicit Dischar¢e There shall be no illicit discharge to the stormwater management systems, on the entire site, including wastewater discharges and discharges of stormwater contaminated by contact with process wastes, raw materials, toxic pollutants, hazardous substances, oil or grease. Record Keepine and Annual Reports Records shall be maintained by owner and his successors as their interest may appear as owner of record of the property at their offices as described above and shall document all routine and emergency maintenance work performed by licensed contractors to the stormwater management system and shall bear the signature of the individual supervising the work. Stoi vater Management System Inspection & Maintenance Log Stormwater Management System Inspector Name: Building #9 & #10 94 Industrial Drive Northampton, MA )ate: Contractor Name: Weather: Inspection ❑ ind/or Maintenance ❑ Specified Major Storm Event Inspection/Maintenance ❑ Inspection/Maintenance ❑ ❑ Vegetation Restoration ❑ Sediment Removal ❑ Cleaning Rip Rap ❑ Cleaning Basin ❑ Cleaning Bio- Retention Area INSPECTION & MAINTENANCE NOTES