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HomeMy WebLinkAboutStormwater Report - 350 HOLT ROAD 3/2/2007 t ._r� ANNING DEPART MEN i a EV� 707 Nay: ; 1,100VER PLANNING DEPARTMR-- INAGE REPORT t-,RUSDER PAPER CO., INC. L A ASSESSORS AP 78, PARCEL NORTH ANDOVER, MASSACHUSETTS Prepared for: Holt Road Realty, LLC. c/o Crusader Paper Co., Inc. 350 Holt Road North Andover, MA 01845 Prepared on: March?�W,0 CIVIL " pp i . New England Engineering Services, Inc. �° 4 1600 Osgood Street iAL •� Building 20, Suite 2-64 North Andover, MA 01845 Phone: (978) 686-1768 Fax: (978) 327-6138 Table of Contents Introduction......................................................................................................................... 1 USGSLocus Map ............................................................................................................... 2 NRCSSoil Map .................................................................................................................. 3 Drainage System Description............................................................................................. 4 Pre-Development Analysis ................................................................................................. 5 Post-Development Analysis.............................................................................................. 36 Summary........................................................................................................................... 67 Appendix A-Soil Map Unit Descriptions ......................................................................... 68 Appendix B-Soil Hydrologic Group................................................................................. 73 Appendix C-Runoff Curve Numbers................................................................................ 76 Appendix D-Rainfall Data Maps ...................................................................................... 81 i Introduction The proposed project consists of the addition of 18,000 square feet of warehouse space to an existing 100,000 square foot industrial building. The project site is currently home to Crusader Paper Inc. located at 350 Holt Road, North Andover, MA; Assessors Map 78, Parcel 1. This lot lies within an Industrial 2 district. The Lawrence Municipal Airport and Boston and Maine Railroad are in close proximity to the project site. The proposed work will include activities such as: adding fill for the proposed addition, adding fill for an access drive, installing an access drive, removing a portion of an existing access drive,removing fill for a detention pond, and re-routing an 18" storm drain pipe. No changes to the existing storm water drainage system are proposed with the exception of re-shaping and lowering the bottom of the existing detention pond. The existing drainage system and new detention pond will adequately service the site. Existing utilities (potable water, electric, telephone, and natural gas) are not expected to be altered. This site is serviced by an on-site subsurface sewage disposal system. The existing lot is approximately 437,613 square feet. The existing building is comprised of a steel frame and masonry slab, and has a 100,000 square foot footprint with a 3,200 square foot mezzanine level. The proposed addition will add 18,000 square feet to the floor area. The area of the proposed work is a combination of grassed areas, overgrown shrubs, saplings, and pavement. There are no bordering vegetated wetlands within 100 feet of the proposed work. A small portion of the property lies within the 200-foot river front offset of the Merrimack River. The project site is not located within an estimated habitat for rare wildlife or certified vernal pools. This property lies outside the 500-year flood plain. Drainage calculations show existing and proposed runoff for the two-year, ten-year, fifty- year, and one-hundred-year storm events using the SCS TR-20 Runoff Method. A Type III-24 hour storm type was used. Soil classification on the site is a combination of Windsor series (Hydrologic Soil Group "A"), Canton series (Hydrologic Soil Group "B"), and Woodbridge series (Hydrologic Soil Group "C"). 1 USGS Locus Map N N ` IV t fx� gICIPAL'MR 3t r1 r j°� 1 f ti r s r \ tl -v ` ) r 2�1A i r T�ai� h Q ♦ 6 f ^` St8 � li S 01 { � ��•: \ O''dA C f4j"�=,t.._.i�j' t �f ;'� t `,�,�-`so' � 3 �' �� �� r�,�,�W$�t�odi- `�'• `� t �`� ���s 1 � �,' 9RlDUE �` a' �\ �_r✓ ,j-S, I I 9p, t C' ' �t� �" ,��.�1 _ -,wry � •. �`» ��t�t'x` � �L'I�' �� 'sirT. -•r t � C: `` ` �4 �` I �J�'{ (�j;'-: r `1� fl Y6rn!'I't wl "rJ I itt t ->_ f�ittt,*II TI! r i, tl"(tta 5 a 1`„ t ktu.te�i.t_mlgA I�„1�1,lift t�_t•,g(J.H.1!v I;n:.:i.��.nvd 2 NRCS Soil Map i ,LL 4V € I T E -2, ILA, ff a r1 0 e I f - .1 �- F r d 3 4 r E l Zia- 3, w � ` RZ aA, y - .',. ex OR Of� �� PAassachusettsk � Map Unit Symbol INZap Unit Name 1 Water 255A Windsor loamy sand, 0 to 3 percent slopes 255B Windsor loamy sand,3 to S percent slopes 310B Woodbridge fine sandy loam, 3 to S percent slopes 421 C Canton fine sandy loam, 8 to 15 percent slopes, very stony 3 Drainage System Description The existing drainage area encompasses the entire lot. Existing catch basins collect storm water from the grassed steep slopes,roof top, and pavement. All drainage is detained in the existing detention pond on the north side of the lot. The outlet of the pond is a drainage system which leads to the Merrimack River. Alterations of the existing system will include the excavation for the new detention pond and re-routing of an existing 18" RCP. The proposed detention pond shall be excavated to lower its bottom by a depth of one foot. The area of the pond shall be expanded to the specifications on the accompanying plan. A single section of drainage pipe will be relocated to accommodate the proposed building addition. The proposed flared end section invert elevation shall be set to the specifications on the accompanying plan. 4 Pre-Development Analysis 5 S-A Subcat A Detention Pond Summation Pond Subc t �Reach Pon Link Drainage Diagram for 1272 Pre Development Prepared by New England Engineering Services, Inc. 2/23/2007 �--17- HydroCAD®8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 6 1272_Pre Development Prepared by New England Engineering Services, Inc. Page 7 IydroCAD®8 00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 2/23/2007 Area Listing (all nodes) Area (acres) CN Description (subcats) 1.139 68 <50% Grass cover, Poor, HSG A (S-A) 2.365 79 <50% Grass cover, Poor, HSG B (S-A) 1.274 86 <50% Grass cover, Poor, HSG C (S-A) 0.362 98 Paved parking, HSG A (S-A) 1.338 98 Paved parking, HSG B (S-A) 0.427 98 Paved parking, HSG C (S-A) 0.715 98 Pond, HSG A (S-A) 0.285 98 Roof, HSG A (S-A) 1.356 98 Roof, HSG B (S-A) 0.654 98 Roof, HSG C (S-A) 9.916 7 1272 Pre Development Type 11124-hr 2 Year Rainfall=3.20" °repared by New England Engineering Services, Inc. Page 8 droCAD®8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment S-A: Subcat A Runoff Area=431,952 sf Runoff Depth=2.00" Flow Length=1,121' Tc=10.2 min CN=88 Runoff=20.12 cfs 1.650 of Pond DP: Detention Pond Peak Elev=35.93' Storage=11,003 cf Inflow=20.12 cfs 1.650 of Outflow=8.47 cfs 1.650 of Pond SP: Summation Pond Peak Elev=0.01' Storage=0.000 of Inflow=8.47 cfs 1.650 of Outflow=8.47 cfs 1.650 of Total Runoff Area= 9.916 ac Runoff Volume = 1.650 of Average Runoff Depth =2.00" 48.19% Pervious Area = 4.778 ac 51.81% Impervious Area= 5.138 ac 8 1272 Pre Development Type 11124-hr 2 Year Rainfall=3.20" °repared by New England Engineering Services, Inc. Page 9 droCADO 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Subcatchment S-A: Subcat A Runoff = 20.12 cfs @ 12.14 hrs, Volume= 1.650 af, Depth= 2.00" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2 Year Rainfall=3.20" Area sf CN Description 55,512 86 <50% Grass cover, Poor, HSG C 18,601 98 Paved parking, HSG C 28,510 98 Roof, HSG C 103,001 79 <50% Grass cover, Poor, HSG B 58,280 98 Paved parking, HSG B 59,064 98 Roof, HSG B 49,632 68 <50% Grass cover, Poor, HSG A 15,760 98 Paved parking, HSG A 12,426 98 Roof, HSG A 31,166 98 Pond, HSG A 431,952 88 Weighted Average 208,145 Pervious Area 223,807 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 50 0.1041 0.20 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.20" 0.7 221 0.1041 5.19 Shallow Concentrated Flow, Flow over grass Unpaved Kv= 16.1 fps 0.3 55 0.0025 2.68 2.11 Circular Channel (pipe), Flow thru drainage pipe Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.011 Concrete pipe, straight & clean 0.9 198 0.0036 3.73 4.58 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 0.9 77 0.0005 1.39 1.71 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 1.7 316 0.0019 3.06 5.41 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 1.5 204 0.0010 2.22 3.93 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 47 r= 0.38' n= 0.011 Concrete pipe straight & clean 10.2 1,121 Total 9 1272 Pre Development Type 11124-hr 2 Year Rainfall=3.20" "repared by New England Engineering Services, Inc. Page 10 ZdroCADO 8.00 s/n 002248 © 2006 HydroCAD Software Solutions LLC _ 2/23/2007 Subcatchment S-,4: Subcat A Hydrograph 22 ❑Runoff 20 Zo,2�5 Runoff®20.12 efs 18 Type III 24-hr 2 Year 17' 16 Rainfall®3.20" 14 Runoff Area=431,952 sf w 13 12 Runoff Volume=1 .650 of 0 ' 0 11 Runoff Depth-2.00" 8 Flow Length=1,121' Tc-10.2 rain 6 AA�� ® 5_ CN=N® 4 3 2.. 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 0 2 8 29 30 Time (hours) 10 1272 Pre Development Type 11124-hr 2 Year Rainfall=3.20" "repared by New England Engineering Services, Inc. Page 11 droCAD®8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Pond DP: Detention Pond Inflow Area = 9.916 ac, Inflow Depth = 2.00" for 2 Year event Inflow = 20.12 cfs @ 12.14 hrs, Volume= 1.650 of Outflow = 8.47 cfs @ 12.43 hrs, Volume= 1.650 af, Atten= 58%, Lag= 17.4 min Primary = 8.47 cfs @ 12.43 hrs, Volume= 1.650 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 35.93' @ 12.43 hrs Surf.Area= 29,609 sf Storage= 11,003 cf Plug-Flow detention time= 7.3 min calculated for 1.650 of (100% of inflow) Center-of-Mass det. time= 7.3 min ( 826.2 - 819.0 ) Volume Invert Avail Storage Storage Description #1 35.50' 65,443 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 35.50 19,916 0 0 36.00 31,166 12,771 12,771 37.00 36,228 33,697 46,468 37.50 39,672 18,975 65,443 Device Routing Invert Outlet Devices #1 Primary 34.19' 18.0" x 52.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 33.35' S= 0.0162 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean #2 Primary 37.37' 50.0' long x 15.0' 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 Primary OutFlow Max=8.47 cfs @ 12.43 hrs HW=35.93' (Free Discharge) t1=Culvert (Inlet Controls 8.47 cfs @ 4.79 fps) 2=113road-Crested Rectangular Weir ( Controls 0.00 cfs) 11 1272 Pre Development Type /// 24-hr 2 Year Rainfall=3.20" r3repared by New England Engineering Services, Inc. Page droCADO 8.00 s/n 002248 © 2006 H droCAD Software Solutions LLC 2/23/20007 7 Pond DP: Detention Pond hlydrograph !>=E Inflow 22 ?zo�2 cfl ❑Primary 21 ' Inflow Area=9.916 ac 20 Inflow®20.12 cfs 19 18 i�.�'' 17 Primary=8.47 cf 14 Peak Elev=35.93' ;4 - f rage®11 ,003 cf 0 11 I ` 9 8 7' 6 t 5j 4 3 ' 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 Time (hours) 12 1272 Pre Development Type /// 24-hr 2 Year Rainfall=3.20" °repared by New England Engineering Services, Inc. Page 13 droCAD® 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Pond SP: Summation Pond Inflow Area = 9.916 ac, Inflow Depth = 2.00" for 2 Year event Inflow = 8.47 cfs @ 12.43 hrs, Volume= 1.650 of Outflow = 8.47 cfs @ 12.43 hrs, Volume= 1.650 af, Atten= 0%, Lag= 0.0 min Primary = 8.47 cfs @ 12.43 hrs, Volume= 1.650 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.01' @ 12.43 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.0 min ( 826.2 - 826.2 ) Volume Invert Avail.Stora e Storage Description #1 0.00' 0.005 of Custom Stage Data(Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 0.00 0.000 0.000 0.000 10.00 0.001 0.005 0.005 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' 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=2.78 cfs @ 12.43 hrs HW=0.01' (Free Discharge) "�--1=Broad-Crested Rectangular Weir (Weir Controls 2.78 cfs @ 0.26 fps) 13 1272 Pre Development Type 111 24-hr 2 Year Rainfall=3.20" °repared by New England Engineering Services, Inc. Page 14 ydroCADO 8.00 s/n 002248 © 2006 HydroCAD Software Solutions LLC 2/23/2007 Pond SP: Summation Pond Hydrograph Ll Inflow [e.a7 cr s l Primary 847crs , Inflow r ®9.916 ac 8 Inflow=0.47 cfs 7 rimary-0.47 cfs 6 Peak Elev=0.01 ' 5 orae®0.000 of w 4 1 3 1� 2t 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 Time (hours) 14 1272 Pre Development Type /// 24-hr 10 Year Rainfall=4.60" r'repared by New England Engineering Services, Inc. Page 15 droCAD®8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment S-A: Subcat A Runoff Area=431,952 sf Runoff Depth=3.29" Flow Length=1,121' Tc=10.2 min CN=88 Runoff=32.68 cfs 2.719 of Pond DP: Detention Pond Peak EIev=36.40' Storage=26,081 cf Inflow=32.68 cfs 2.719 of Outflow=10.26 cfs 2.719 of Pond SP: Summation Pond Peak EIev=0.01' Storage=0.000 of Inflow=10.26 cfs 2.719 of Outflow=10.26 cfs 2.719 of Total Runoff Area= 9.916 ac Runoff Volume = 2.719 of Average Runoff Depth = 3.29" 48.19% Pervious Area =4.778 ac 51.81% Impervious Area = 5.138 ac 15 1272 Pre Development Type III 24-hr 10 Year Rainfall=4.60" Irepared by New England Engineering Services, Inc. Page 16 ydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC _ 2/23/2007 Subcatchment S-A: Subcat A Runoff = 32.68 cfs @ 12.14 hrs, Volume= 2.719 af, Depth= 3.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Rainfall=4.60" Area (sf) CN Description 55,512 86 <50% Grass cover, Poor, HSG C 18,601 98 Paved parking, HSG C 28,510 98 Roof, HSG C 103,001 79 <50% Grass cover, Poor, HSG B 58,280 98 Paved parking, HSG B 59,064 98 Roof, HSG B 49,632 68 <50% Grass cover, Poor, HSG A 15,760 98 Paved parking, HSG A 12,426 98 Roof, HSG A 31,166 98 Pond, HSG A 431,952 88 Weighted Average 208,145 Pervious Area 223,807 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) - - 4.2 50 0.1041 0.20 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.20" 0.7 221 0.1041 5.19 Shallow Concentrated Flow, Flow over grass Unpaved Kv= 16.1 fps 0.3 55 0.0025 2.68 2.11 Circular Channel (pipe), Flow thru drainage pipe Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.011 Concrete pipe, straight & clean 0.9 198 0.0036 3.73 4.58 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 0.9 77 0.0005 1.39 1.71 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 1.7 316 0.0019 3.06 5.41 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 1.5 204 0.0010 2.22 3.93 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe straight & clean 10.2 1,121 Total 16 1272 Pre Development Type /// 24-hr 10 Year Rainfall=4.60" epared by New England Engineering Services, Inc. Page 17 droCADO 8.00 s/n 002248 © 2006 H droCAD Software Solutions LLC 2/23/2007 Subcatchment S-A: Subcat A Hydrograph ❑Runoff 36 34 32.68 crs 32 Runoff=32.63 cfs 30 Type III 24-hr 10 Year 28 Rainfall®4.60°' 26 24 Runoff Area=431,952 sf 20 Runoff Volume=2.719 of 3 18 Runoff Depth=3.29" a 16 14 Flow Length®1,121° 12, Tc=10.2 min 10 8 CN=33 6.. 4 2 0 0 ,1. 2 . 3. 4 5 6 7 8 9 10 11 12 13 14 1 1617 18 19 20 21 22 23 24 25 26 27 28 29 30 Time ( x) 17 1272 Pre Development Type /// 24-hr 10 Year Rainfall=4.60" prepared by New England Engineering Services, Inc. Page 18 droCADO 8.00 s/n 002248 © 2006 H droCAD Software Solutions LLC 2/23/2007 Pond DP: Detention Pond Inflow Area = 9.916 ac, Inflow Depth = 3.29" for 10 Year event Inflow = 32.68 cfs @ 12.14 hrs, Volume= 2.719 of Outflow = 10.26 cfs @ 12.51 hrs, Volume= 2.719 af, Atten= 69%, Lag= 22.3 min Primary = 10.26 cfs @ 12.51 hrs, Volume= 2.719 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 36.40' @ 12.51 hrs Surf.Area= 33,166 sf Storage= 26,081 cf Plug-Flow detention time= 15.4 min calculated for 2.719 of (100% of inflow) Center-of-Mass det. time= 15.4 min ( 820.2 - 804.8 ) Volume Invert Avail.Stora e Storage Description #1 35.50' 65,443 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 35.50 19,916 0 0 36.00 31,166 12,771 12,771 37.00 36,228 33,697 46,468 37.50 39,672 18,975 65,443 Device Routing Invert Outlet Devices #1 Primary 34.19' 18.0" x 52.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 33.35' S= 0.0162 T Cc= 0.900 n= 0.011 Concrete pipe, straight & clean #2 Primary 37.37' 50.0' long x 15.0' 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 Primary OutFlow Max=10.26 cfs @ 12.51 hrs HW=36.39' (Free Discharge) 1--2=Broad-Crested 1=Culvert (Inlet Controls 10.26 cfs @ 5.81 fps) Rectangular Weir ( Controls 0.00 cfs) 18 1272 Pre Development Type /// 24-hr 10 Year Rainfall=4.60" prepared by New England Engineering Services, Inc. Page 19 droCADO 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Pond DP: Detention Pond Hydrograph Inflow 36 sz 66 I ❑Primary d5 34 Inflow rea=9. 16 ac 30 Inflow=32.66 cfs 2 26 6 ;I I rirnary=1 . CfS _ �f� 22 k lev= 6. 0' 20 tra ,0 1 cf 3 18 16, ., 14- 12 - 10.26 ds 10 8 4 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 Time (hours) 19 1272 Pre Development Type /// 24-hr 10 Year Rainfall=4.60" --'repared by New England Engineering Services, Inc. Page 20 droCADO 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Pond SP: Summation Pond Inflow Area = 9.916 ac, Inflow Depth = 3.29" for 10 Year event Inflow = 10.26 cfs @ 12.51 hrs, Volume= 2.719 of Outflow = 10.26 cfs @ 12.51 hrs, Volume= 2.719 af, Atten= 0%, Lag= 0.0 min Primary = 10.26 cfs @ 12.51 hrs, Volume= 2.719 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.01' @ 12.51 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.0 min ( 820.2 - 820.2 ) Volume Invert Avail.Stora e Storage Descri tion #1 0.00' 0.005 of Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 0.00 0.000 0.000 0.000 10.00 0.001 0.005 0.005 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' 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=3.71 cfs @ 12.51 hrs HW=0.01' (Free Discharge) `�--1=Broad-Crested Rectangular Weir (Weir Controls 3.71 cfs @ 0.28 fps) 20 1272 Pre Development Type III 24-hr 10 Year Rainfall=4,60" �epared by New England Engineering Services, Inc. Page 21 2/23/2007 droCADO 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC Pond SP: Summation Pond Wydrograph `,.I Inflow ❑Primary 1, 0 26d5 X,y Inflow Area=9.916 ac Inflow=10.26 cS Primary=10.26 cfS 8 != 7 ea lev®0.01' N tra =0.000 6 af i' 3 o r' LL 5 / } 4 2 0 ...,:,, 0 1 2 3 4 5 6 7 8 9 loll 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) 21 1272 Pre Development Type 11124-hr 25 Year Rainfall=5.40" ' Inc. Page 22 repared by New England Engineering Services, n droCADO 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment S-A: Subcat A Runoff Area=431,952 sf Runoff Depth=4.05" Flow Length=1,121' Tc=10.2 min CN=88 Runoff=39.88 cfs 3.347 of Pond DP: Detention Pond Peak Elev=36.68' Storage=35,608 cf Inflow=39.88 cfs 3.347 of Outflow=11.22 cfs 3.347 of Pond SP: Summation Pond Peak Elev=0.01' Storage=0.000 of Inflow=11.22 cfs 3.347 of Outflow=11.22 cfs 3.347 of Total Runoff Area = 9.916 ac Runoff Volume = 3.347 of Average Runoff Depth = 4.05" 48.19% Pervious Area =4.778 ac 51.81% Impervious Area = 5.138 ac 22 1272 Pre Development Type /// 24-hr 25 Year Rainfall=5.40" °repared by New England Engineering Services, Inc. Page 23 IydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC _ 2/23/2007 Subcatchment S-A: Subcat A Runoff = 39.88 cfs @ 12.14 hrs, Volume= 3.347 af, Depth= 4.05" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 25 Year Rainfall=5.40" Area (sf) CN Description 55,512 86 <50% Grass cover, Poor, HSG C 18,601 98 Paved parking, HSG C 28,510 98 Roof, HSG C 103,001 79 <50% Grass cover, Poor, HSG B 58,280 98 Paved parking, HSG B 59,064 98 Roof, HSG B 49,632 68 <50% Grass cover, Poor, HSG A 15,760 98 Paved parking, HSG A 12,426 98 Roof, HSG A 31,166 98 Pond, HSG A 431,952 88 Weighted Average 208,145 Pervious Area 223,807 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 50 0.1041 0.20 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.20" 0.7 221 0.1041 5.19 Shallow Concentrated Flow, Flow over grass Unpaved Kv= 16.1 fps 0.3 55 0.0025 2.68 2.11 Circular Channel (pipe), Flow thru drainage pipe Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.011 Concrete pipe, straight & clean 0.9 198 0.0036 3.73 4.58 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 0.9 77 0.0005 1.39 1.71 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 1.7 316 0.0019 3.06 5.41 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 1.5 204 0.0010 2.22 3.93 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 10.2 1,121 Total 23 1272_Pre Development Type Ill 24-hr 25 Year Rainfall=5.40" °repared by New England Engineering Services, Inc. Page 24 jydroCAD®8 00 s/n 002248 ©2006 HydroCAD Software Solutions LLC _2/23/2007 Subcatchment S-A: Subcat A Hydrograph 44, ❑Runoff 42 39 sa cfs 40 Runoff-39.33 cfs 38 36 Type III 24-hr 25 Year 32 ainfall®5.40" 28 Runoff Area®431 ,952 sf 24 Runoff Volume®3.347 of 3 22.20 Runoff Depth=4.05" LL ,6 Flow Length=1 ,121 14 Tc°10.2 min 12` CN 8 6: 4.' 2 . 0 0. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1516 17 18 19 20 21 22 23 24 25 26 27 28..2 9 30 Time (hours) 24 1272 Pre Development Type Ill 24-hr 25 Year Rainfall=5.40" "3repared by New England Engineering Services, Inc. Page 25 AydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 2/23/2007 Pond DP: Detention Pond Inflow Area = 9.916 ac, Inflow Depth = 4.05" for 25 Year event Inflow = 39.88 cfs @ 12.14 hrs, Volume= 3.347 of Outflow = 11.22 cfs @ 12.54 hrs, Volume= 3.347 af, Atten= 72%, Lag= 23.9 min Primary = 11.22 cfs @ 12.54 hrs, Volume= 3.347 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 36.68' @ 12.54 hrs Surf.Area= 34,597 sf Storage= 35,608 cf Plug-Flow detention time= 20.2 min calculated for 3.347 of(100% of inflow) Center-of-Mass det. time= 20.2 min ( 819.2 - 799.0 ) Volume Invert Avail Storage Storage Description #1 35.50' 65,443 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 35.50 19,916 0 0 36.00 31,166 12,771 12,771 37.00 36,228 33,697 46,468 37.50 39,672 18,975 65,443 'Device Routing Invert Outlet Devices #1 Primary 34.19' 18.0" x 52.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 33.35' S= 0.0162 T Cc= 0.900 n= 0.011 Concrete pipe, straight & clean #2 Primary 37.37' 50.0' long x 15.0' 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 Primary OutFlow Max=11.22 cfs @ 12.54 hrs HW=36.68' (Free Discharge) �__2=113 1=Cul vert (Inlet Controls 11.22 cfs @ 6.35 fps) road-Crested Rectangular Weir ( Controls 0.00 cfs) 25 1272 Pre Development Type 11124-hr 25 Year Rainfall=5.40" -'repared by New England Engineering Services, Inc. Page 26 i droCAD®8.00 s/n 002248 © 2006 H droCAD Software Solutions LLC 2/23/2007 Pond DP: Detention Pond Hydrograph Inflow 44 1 3988cf5 ❑Primary 42 �y': Inflow Area=9.916 c 40 38 36 Inflow= 9. 0 cfs 7'�` 32 ,, rimary=11 cfs 30 js 28 Peak Elev=36.68' m 26 '; 24 A Storage=35,608 c 0 22 / LL 20` is 18 ✓ 16' 14 11.22 cfs 12` 10 8 2 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 Time (hours) 26 1272 Pre Development Type /// 24-hr 25 Year Rainfall=5.40" prepared by New England Engineering Services, Inc. Page 27 lydroCAD®8 00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 2/23/2007 Pond SP: Summation Pond Inflow Area = 9.916 ac, Inflow Depth = 4.05" for 25 Year event Inflow = 11.22 cfs @ 12.54 hrs, Volume= 3.347 of Outflow = 11.22 cfs @ 12.54 hrs, Volume= 3.347 af, Atten= 0%, Lag= 0.0 min Primary = 11.22 cfs @ 12.54 hrs, Volume= 3.347 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.01' @ 12.54 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.0 min ( 819.2 - 819.2 ) Volume Invert Avail Storage Storage Description #1 0.00' 0.005 of Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 0.00 0.000 0.000 0.000 10.00 0.001 0.005 0.005 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' 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=4.24 cfs @ 12.54 hrs HW=0.01' (Free Discharge) 't-1=Broad-Crested Rectangular Weir (Weir Controls 4.24 cfs @ 0.30 fps) 27 1272 Pre Development Type 111 24-hr 25 Year Rainfall=5.40" prepared by New England Engineering Services, Inc. Page 28 droCAD®8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Pond SP: Summation Pond Hydrograph '� Inflow ❑Primary 12 11,22 5 ;;; Inflow Are a=9.916 c 1, f ,o Inflow=11 .22 cs 9 rimary=1 1 .22 cf f 8 Peak Elev=0.01' y 7 r x torae®0.000 of 0 6 LL 5 4 3 !fir 2 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 Time (hours) 28 1272 Pre Development Type 11124-hr 100 Year Rainfall=6.40" -'repared by New England Engineering Services, Inc. Page 29 droCAD® 8.00 s/n 002248 © 2006 H droCAD Software Solutions LLC 2/23/2007 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment S-A: Subcat A Runoff Area=431,952 sf Runoff Depth=5.01" Flow Length=1,121' Tc=10.2 min CN=88 Runoff=48.84 cfs 4.142 of Pond DP: Detention Pond Peak EIev=37.04' Storage=47,978 cf Inflow=48.84 cfs 4.142 of Outflow=12.33 cfs 4.142 of Pond SP: Summation Pond Peak EIev=0.02' Storage=0.000 of Inflow=12.33 cfs 4.142 of Outflow=12.33 cfs 4.142 of Total Runoff Area = 9.916 ac Runoff Volume = 4.142 of Average Runoff Depth = 5.01" 48.19% Pervious Area = 4.778 ac 51.81% Impervious Area = 5.138 ac 29 1272 Pre Development Type /// 24-hr 100 Year Rainfall=6.40" ,epared by New England Engineering Services, Inc. Page 30 droCADO 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Subcatchment S®fie: Subcat A Runoff = 48.84 cfs @ 12.14 hrs, Volume= 4.142 af, Depth= 5.01" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Rainfall=6.40" Area sf CN Description 55,512 86 <50% Grass cover, Poor, HSG C 18,601 98 Paved parking, HSG C 28,510 98 Roof, HSG C 103,001 79 <50% Grass cover, Poor, HSG B 58,280 98 Paved parking, HSG B 59,064 98 Roof, HSG B 49,632 68 <50% Grass cover, Poor, HSG A 15,760 98 Paved parking, HSG A 12,426 98 Roof, HSG A 31,166 98 Pond, HSG A 431,952 88 Weighted Average 208,145 Pervious Area 223,807 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 50 0.1041 0.20 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.20" 0.7 221 0.1041 5.19 Shallow Concentrated Flow, Flow over grass Unpaved Kv= 16.1 fps 0.3 55 0.0025 2.68 2.11 Circular Channel (pipe), Flow thru drainage pipe Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.011 Concrete pipe, straight & clean 0.9 198 0.0036 3.73 4.58 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 0.9 77 0.0005 1.39 1.71 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 1.7 316 0.0019 3.06 5.41 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 1.5 204 0.0010 2.22 3.93 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 10.2 1,121 Total 30 1272 Pre Development Type 11124-hr 100 Year Rainfall=6.40" -epared by New England Engineering Services, Inc. Page 31 droCADO 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Subcatchment S-A: Subcat A Hydrograph ❑Runoff 48.84 cfs 50 Runoff=43.34 cfs 45 Type III 24-hr 100 Year 40 Rainfall®6.40" 35 Runoff Area®431,952 sf 30 Runoff Volume®4.142 of 25 Runoff Depth®5.01®' LL 20 Flow Length®1,121' Tc-10.2 min 15 CIV®33 10 5 221 22 O 0, 1. 2 ,.3. 4 5 6 7 8 9 10 11 12 13 14 15 166 170 2 22 23 24 25 26 27 28 29 30 Time (hours) 31 1272 Pre Development Type /// 24-hr 100 Year Rainfall=6.40" �repared by New England Engineering Services, Inc. Page 32 2/23/2007 droCADO 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC Pond DP: Detention Pond Inflow Area = 9.916 ac, Inflow Depth = 5.01" for 100 Year event Inflow = 48.84 cfs @ 12.14 hrs, Volume= 4.142 of Outflow = 12.33 cfs @ 12.56 hrs, Volume= 4.142 af, Atten= 75%, Lag= 25.4 min Primary = 12.33 cfs @ 12.56 hrs, Volume= 4.142 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 37.04' @ 12.56 hrs Surf.Area= 36,502 sf Storage= 47,978 cf Plug-Flow detention time= 25.9 min calculated for 4.140 of (100% of inflow) Center-of-Mass det. time= 25.9 min ( 819.1 - 793.2 ) Volume Invert Avail.Stora e Storage Description #1 35.50' 65,443 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet 35.50 19,916 0 0 36.00 31,166 12,771 12,771 37.00 36,228 33,697 46,468 37.50 39,672 18,975 65,443 Device Routing Invert Outlet Devices #1 Primary 34.19' 18.0" x 52.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 33.35' S= 0.0162 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean #2 Primary 37.37' 50.0' long x 15.0' 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 Primary OutFlow Max=12.33 cfs @ 12.56 hrs HW=37.04' (Free Discharge) tJ=Culvert (Inlet Controls 12.33 cfs @ 6.98 fps) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 32 1272 Pre Development Type 11124-hr 100 Year Rainfall=6.40" epared by New England Engineering Services, Inc. Page 33 droCADO 8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Pond DP: Detention Pond Hydrograph Inflow 48 34 crs ❑Primary -'''- 50 Inflow r =9.916 c �: . 45 Inflow®43.34 cf 40 Primary=12.33 cfS 35 ,j Peak Elev=37.04' 30 Storage=47,978 c 0 25 r LL f/ 20 15 12.33ds " 10 5 T �✓ 'ilf r fir,% 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 Time (hours) 33 1272 Pre Development Type 11124-hr 100 Year Rainfall=6.40" Prepared by New England Engineering Services, Inc. Page 34 Solutions LLC 2/23/2007 droCADO 8.00 s/n 002248 © 2006 H droCAD Software Pond SP: Summation Pond Inflow Area = 9.916 ac, Inflow Depth = 5.01 for 100 Year event Inflow = 12.33 cfs @ 12.56 hrs, Volume= 4.142 of Outflow = 12.33 cfs @ 12.56 hrs, Volume= 4.142 af, Atten= 0%, Lag= 0.0 min Primary = 12.33 cfs @ 12.56 hrs, Volume= 4.142 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.02' @ 12.56 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= 0.0 min calculated for 4.140 of (100% of inflow) Center-of-Mass det. time= 0.0 min ( 819.1 - 819.1 ) Volume Invert Avail.Storacie Storage Description #1 0.00' 0.005 of Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 0.00 0.000 0.000 0.000 10.00 0.001 0.005 0.005 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' 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=4.88 cfs @ 12.56 hrs HW=0.02' (Free Discharge) 1 Broad-Crested Rectangular Weir (Weir Controls 4.88 cfs @ 0.31 fps) 34 1272 Pre Development Type 11124-hr 100 Year Rainfall=6.40" 'repared by New England Engineering Services, Inc. Page 35 droCAD®8.00 s/n 002248 ©2006 H droCAD Software Solutions LLC 2/23/2007 Pond SP: Summation Pond Hydrograph ! ;_1lnflow z.sscrs ❑Primary L——"A 13 12,33c(s ,lam Inflow Area=9.916 ac 12 1 Inflow=12.33 cfS 11 � 10 f = Primary=12.33 cfs 9 "- Peak Elev=0.02' 8. r tore a®0.000 af 0 LL 6 5 � 4, fa, 3 .. / 2 p 0. .1.< 2. .3..4 5. .6 7 .8: 9 10 11 12 13 14 1(5 � 16s17 18 19 20 21 .22 25 23.; ._, . . ., .._ 24 26 27 28 29 30 35 Post-Development Analysis 36 Subcat A Detention Pond Summation Pond Subcat Reach on [Link Drainage Diagram for 1272_Post Development Prepared by New England Engineering Services, Inc. 3/1/2007 HydroCAD®8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 37 1272_Post Development Prepared by New England Engineering Services, Inc. Page 38 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Area Listing (all nodes) Area (acres) CN Description (subcats) 0.705 68 <50% Grass cover, Poor, HSG A (S-A) 2.365 79 <50% Grass cover, Poor, HSG B (S-A) 1.274 86 <50% Grass cover, Poor, HSG C (S-A) 0.367 98 Paved parking, HSG A (S-A) 1.338 98 Paved parking, HSG B (S-A) 0.427 98 Paved parking, HSG C (S-A) 0.732 98 Pond, HSG A (S-A) 0.698 98 Roof, HSG A (S-A) 1.356 98 Roof, HSG B (S-A) 0.654 98 Roof, HSG C (S-A) 9.916 38 1272 Post Development Type ///24-hr 2 Year Rainfall=3.20" Prepared by New England Engineering Services, Inc. Page 39 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment S-A: Subcat A Runoff Area=431,952 sf Runoff Depth=2.17" Flow Length=1,092' Tc=9.5 min CN=90 Runoff=22.18 cfs 1.792 of Pond DP: Detention Pond Peak EIev=35.50' Storage=26,614 cf Inflow=22.18 cfs 1.792 of Outflow=6.39 cfs 1.792 of Pond SP: Summation Pond Peak EIev=0.01' Storage=0.000 of Inflow=6.39 cfs 1.792 of Outflow=6.39 cfs 1.792 of Total Runoff Area= 9.916 ac Runoff Volume = 1.792 of Average Runoff Depth =2.17" 43.81% Pervious Area =4.344 ac 56.19% Impervious Area = 5.572 ac 39 1272 Post Development Type 11124-hr 2 Year Rainfall=3.20" Prepared by New England Engineering Services, Inc. Page 40 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Subcatchment S-A: Subcat A Runoff = 22.18 cfs @ 12.13 hrs, Volume= 1.792 af, Depth= 2.17" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2 Year Rainfall=3.20" Area (sf) CN Description 55,512 86 <50% Grass cover, Poor, HSG C 18,601 98 Paved parking, HSG C 28,510 98 Roof, HSG C 103,001 79 <50% Grass cover, Poor, HSG B 58,280 98 Paved parking, HSG B 59,064 98 Roof, HSG B 30,705 68 <50% Grass cover, Poor, HSG A 15,983 98 Paved parking, HSG A 30,426 98 Roof, HSG A 31,870 98 Pond, HSG A 431,952 90 Weighted Average 189,218 Pervious Area 242,734 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 50 0.1041 0.20 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.20" 0.7 221 0.1041 5.19 Shallow Concentrated Flow, Flow over grass Unpaved Kv= 16.1 fps 0.3 55 0.0025 2.68 2.11 Circular Channel (pipe), Flow thru drainage pipe Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.011 Concrete pipe, straight & clean 0.9 198 0.0036 3.73 4.58 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 0.9 77 0.0005 1.39 1.71 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 1.7 316 0.0019 3.06 5.41 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 0.8 175 0.0026 3.58 6.33 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 9.5 1,092 Total 40 1272 Post Development Type 11124-hr 2 Year Rainfall=3.20" Prepared by New England Engineering Services, Inc. Page 41 HydroCAD®8 00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Subcatchment S-A: Subcat A Hydrograph Runoff 24 23 22.18 cts 22 Runoff=22.18 cfa 20 Type III 24-hr 2 Year 19 18 Rainfall=3.20 17:. 16 Area=431,952 sf 15 14 Runoff Volume=1.792 of 13: - 12 Runoff Depth=2.17 a 11: 10, 9- Flow Length=1 ,092' 8 Tc=9.5 min 6, 5- CN=90 4`. 3; 2_ " 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 Time (hours) 41 1272 Post Development Type /1124-hr 2 Year Rainfall=3.20" Prepared by New England Engineering Services, Inc. Page 42 HydroCAD®8 00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond DP: Detention Pond Inflow Area = 9.916 ac, Inflow Depth = 2.17" for 2 Year event Inflow = 22.18 cfs @ 12.13 hrs, Volume= 1.792 of Outflow = 6.39 cfs @ 12.52 hrs, Volume= 1.792 af, Atten= 71%, Lag= 23.4 min Primary = 6.39 cfs @ 12.52 hrs, Volume= 1.792 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 35.50' @ 12.52 hrs Surf.Area= 27,296 sf Storage= 26,614 cf Plug-Flow detention time= 60.8 min calculated for 1.792 of(100% of inflow) Center-of-Mass det. time= 60.8 min ( 871.0 - 810.1 ) Volume Invert Avail.Storage Storage Description #1 34.50' 70,302 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 34.50 25,330 0 0 35.00 26,306 12,909 12,909 36.00 28,278 27,292 40,201 37.00 31,924 30,101 70,302 Device Routing Invert Outlet Devices #1 Primary 34.19' 18.0" x 52.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 33.35' S= 0.0162 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean #2 Primary 37.37' 50.0' long x 15.0' 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 Primary OutFlow Max=6.39 cfs @ 12.52 hrs HW=35.50' (Free Discharge) t1=Culvert (Inlet Controls 6.39 cfs @ 3.90 fps) 2=13road-C rested Rectangular Weir ( Controls 0.00 cfs) 42 1272 Post Development Type 111 24-hr 2 Year Rainfall=3.20" Prepared by New England Engineering Services, Inc. Page 43 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond DP: Detention Pond Hydrograph 0 Inflow Primary 24,' 22.18 d( 23 - Inflow r ®9.916 ac 22- 21 20 Inflow-22.18 cfs- 19 18 rimary-6.39 cf 17 15 Peak lev®35.50' F 14; 13: Storage-26,614 cf 3, 12' LL 11 10' 9' 7 6.39 ds _ 6 5 4.; . 3 2 1' 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 Time (hours) 43 1272 Post Development Type 111 24-hr 2 Year Rainfall=3.20" Prepared by New England Engineering Services, Inc. Page 44 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond SP: Summation Pond Inflow Area = 9.916 ac, Inflow Depth = 2.17" for 2 Year event Inflow = 6.39 cfs @ 12.52 hrs, Volume= 1.792 of Outflow = 6.39 cfs @ 12.52 hrs, Volume= 1.792 af, Atten= 0%, Lag= 0.0 min Primary = 6.39 cfs @ 12.52 hrs, Volume= 1.792 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.01' @ 12.52 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= 0.0 min calculated for 1.791 of(100% of inflow) Center-of-Mass det. time= 0.0 min ( 871.0 - 871.0 ) Volume Invert Avail.Storage Storage Description #1 0.00' 0.005 of Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 0.00 0.000 0.000 0.000 10.00 0.001 0.005 0.005 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' 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=1.82 cfs @ 12.52 hrs HW=0.01' (Free Discharge) 't--1=Broad-Crested Rectangular Weir (Weir Controls 1.82 cfs @ 0.22 fps) 44 1272 Post Development Type ///24-hr 2 Year Rainfall=3.20" Prepared by New England Engineering Services, Inc. Page 45 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond SP: Summation Pond Hydrograph [D Inflow 7- 6.39ds 0 Primary 6.39cfs Inflow r = .916 ac 6 Infl w=6.3 'cfs 5- Primary=6.39 cfa Peak lev®0.01 U 4.. for ge=0.000 of 3 0 LL 3- 2 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 Time (hours) 45 1272 Post Development Type 111 24-hr 10 Year Rainfall=4.60" Prepared by New England Engineering Services, Inc. Page 46 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment S-A: Subcat A Runoff Area=431,952 sf Runoff Depth=3.49" Flow Length=1,092' Tc=9.5 min CN=90 Runoff=35.05 cfs 2.885 of Pond DP: Detention Pond Peak Elev=36.14' Storage=44,362 cf Inflow=35.05 cfs 2.885 of Outflow=9.31 cfs 2.885 of Pond SP: Summation Pond Peak Elev=0.01' Storage=0.000 of Inflow=9.31 cfs 2.885 of Outflow=9.31 cfs 2.885 of Total Runoff Area = 9.916 ac Runoff Volume =2.885 of Average Runoff Depth =3.49" 43.81% Pervious Area = 4.344 ac 56.19% Impervious Area = 5.572 ac 46 1272 Post Development Type 111 24-hr 10 Year Rainfall=4.60" Prepared by New England Engineering Services, Inc. Page 47 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/200.7 Subcatchment S-A: Subcat A Runoff = 35.05 cfs @ 12.13 hrs, Volume= 2.885 af, Depth= 3.49" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Rainfall=4.60" Area (sf) CN Description 55,512 86 <50% Grass cover, Poor, HSG C 18,601 98 Paved parking, HSG C 28,510 98 Roof, HSG C 103,001 79 <50% Grass cover, Poor, HSG B 58,280 98 Paved parking, HSG B 59,064 98 Roof, HSG B 30,705 68 <50% Grass cover, Poor, HSG A 15,983 98 Paved parking, HSG A 30,426 98 Roof, HSG A 31,870 98 Pond, HSG A 431,952 90 Weighted Average 189,218 Pervious Area 242,734 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 50 0.1041 0.20 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.20" 0.7 221 0.1041 5.19 Shallow Concentrated Flow, Flow over grass Unpaved Kv= 16.1 fps 0.3 55 0.0025 2.68 2.11 Circular Channel (pipe), Flow thru drainage pipe Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.011 Concrete pipe, straight & clean 0.9 198 0.0036 3.73 4.58 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 0.9 77 0.0005 1.39 1.71 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 1.7 316 0.0019 3.06 5.41 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 0.8 175 0.0026 3.58 6.33 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 9.5 1,092 Total 47 1272 Post Development Type 111 24-hr 10 Year Rainfall=4.60" Prepared by New England Engineering Services, Inc. Page 48 HydroCAD®8 00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Subcatchment S-A: Subcat A Hydrograph 38= _ ❑Runoff 36 35 05 cfs 34 Runoff®35.05 cfs 321 Type III '24-hr 10 Year 30 28 Rainfall®4.60" 26 24; Runoff Area=431,952 sf 22 Runoff Volume=2.885 of U 20" LL 18 Runoff Depth=3.49" 14 Flow Length=1,092' 12 Tc=9.5 min 10- 8 CN=90 6 4-: O— .>.t. . . ,. .. .g... i a 4....{ '.a<...j.. . ., . .... ....�. ..,.... .... .., .,...,F. , ...... ,n a..... ... . ..E.. 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 Time (hours) 48 1272 Post Development Type /// 24-hr 10 Year Rainfall=4.60" Prepared by New England Engineering Services, Inc. Page 49 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond DP: Detention Pond Inflow Area = 9.916 ac, Inflow Depth = 3.49" for 10 Year event Inflow = 35.05 cfs @ 12.13 hrs, Volume= 2.885 of Outflow = 9.31 cfs @ 12.53 hrs, Volume= 2.885 af, Atten= 73%, Lag= 24.2 min Primary = 9.31 cfs @ 12.53 hrs, Volume= 2.885 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 36.14' @ 12.53 hrs Surf.Area= 28,782 sf Storage= 44,362 cf Plug-Flow detention time= 66.2 min calculated for 2.885 of (100% of inflow) Center-of-Mass det. time= 66.1 min ( 863.0 - 796.8 ) Volume Invert Avail Storage Storage Description #1 34.50' 70,302 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 34.50 25,330 0 0 35.00 26,306 12,909 12,909 36.00 28,278 27,292 40,201 37.00 31,924 30,101 70,302 Device Routing Invert Outlet Devices #1 Primary 34.19' 18.0" x 52.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 33.35' S= 0.0162 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean #2 Primary 37.37' 50.0' long x 15.0' 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 Primary OutFlow Max=9.31 cfs @ 12.53 hrs HW=36.14' (Free Discharge) t1=Culvert (Inlet Controls 9.31 cfs @ 5.27 fps) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 49 1272 Post Development Type 111 24-hr 10 Year Rainfall=4.60" Prepared by New England Engineering Services, Inc. Page 50 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond DP: Detention Pond Hydrograph p Inflow .. .3505 cfs ❑Primary 38. 36: Inflow'Area=9.916 ac 34 32 Infl w=35.0 cfs 28 rimary=9.31 cfs 24 Peak lev=36.1 4` 20 t®rage=44, 2 c o 18 LL 16: 14-- - 12. -. _ _. . _ 9.31 cfs 10 8 6' _- 4 ' 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 Time (hours) 50 1272 Post Development Type 111.24-hr 10 Year Rainfall=4.60" Prepared by New England Engineering Services, Inc. Page 51 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond SP: Summation Pond Inflow Area = 9.916 ac, Inflow Depth = 3.49" for 10 Year event Inflow = 9.31 cfs @ 12.53 hrs, Volume= 2.885 of Outflow = 9.31 cfs @ 12.53 hrs, Volume= 2.885 af, Atten= 0%, Lag= 0.0 min Primary = 9.31 cfs @ 12.53 hrs, Volume= 2.885 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.01' @ 12.53 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= 0.0 min calculated for 2.884 of (100% of inflow) Center-of-Mass det. time= 0.0 min ( 863.0 - 863.0 ) Volume Invert Avail Storage Storage Description #1 0.00' 0.005 of Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 0.00 0.000 0.000 0.000 10.00 0.001 0.005 0.005 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' 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=3.20 cfs @ 12.53 hrs HW=0.01' (Free Discharge) 't--1=Broad-Crested Rectangular Weir (Weir Controls 3.20 cfs @ 0.27 fps) 51 1272 Post Development Type /// 24-hr 10 Year Rainfall=4.60" Prepared by New England Engineering Services, Inc. Page 52 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond SP: Summation Pond Hydrograph - F11 inflow 9.31 cfs ❑Primary 10 9.31 cfs Inflow Area=9.916 ac 9 Inflow=0.31 cfs 8_ rimary®9.31 cfs 7. Peak Iev-0.01' w 6 5 t®rage=0.000 of LL 0 � 4 3- 2.: o—�..�.�< ..3a ....X..v �.a. E>. .3, �, ..� ...�.....y .E,...a ...t.... .....j., 7 -..e �<.,. ,. ..,- .e a..t.. ...aE... ,. ..�.......... 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 Time (hours) 52 1272 Post Development Type ///24-hr 25 Year Rainfall=5.40" Prepared by New England Engineering Services, Inc. Page 53 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment S-A: Subcat A Runoff Area=431,952 sf Runoff Depth=4.26" Flow Length=1,092' Tc=9.5 min CN=90 Runoff=42.37 cfs 3.523 of Pond DP: Detention Pond Peak EIev=36.50' Storage=55,133 cf Inflow=42.37 cfs 3.523 of Outflow=10.61 cfs 3.523 of Pond SP: Summation Pond Peak EIev=0.01' Storage=0.000 of Inflow=10.61 cfs 3.523 of Outflow=10.61 cfs 3.523 of Total Runoff Area = 9.916 ac Runoff Volume =3.523 of Average Runoff Depth =4.26" 43.81% Pervious Area = 4.344 ac 56.19% Impervious Area = 5.572 ac 53 1272 Post Development Type 111 24-hr 25 Year Rainfall=5.40" Prepared by New England Engineering Services, Inc. Page 54 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Subcatchment S-A: Subcat A Runoff = 42.37 cfs @ 12.13 hrs, Volume= 3.523 af, Depth= 4.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 25 Year Rainfall=5.40" Area (sf) CN Description 55,512 86 <50% Grass cover, Poor, HSG C 18,601 98 Paved parking, HSG C 28,510 98 Roof, HSG C 103,001 79 <50% Grass cover, Poor, HSG B 58,280 98 Paved parking, HSG B 59,064 98 Roof, HSG B 30,705 68 <50% Grass cover, Poor, HSG A 15,983 98 Paved parking, HSG A 30,426 98 Roof, HSG A 31,870 98 Pond, HSG A 431,952 90 Weighted Average 189,218 Pervious Area 242,734 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 50 0.1041 0.20 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.20" 0.7 221 0.1041 5.19 Shallow Concentrated Flow, Flow over grass Unpaved Kv= 16.1 fps 0.3 55 0.0025 2.68 2.11 Circular Channel (pipe), Flow thru drainage pipe Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.011 Concrete pipe, straight & clean 0.9 198 0.0036 3.73 4.58 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 0.9 77 0.0005 1.39 1.71 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 1.7 316 0.0019 3.06 5.41 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 0.8 175 0.0026 3.58 6.33 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 47 r= 0.38' n= 0.011 Concrete pipe straight & clean 9.5 1,092 Total 54 1272 Post Development Type 111 24-hr 25 Year Rainfall=5.40" Prepared by New England Engineering Services, Inc. Page 55 HydroCAD®8 00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Subcatchment S-A: Subcat A Hydrograph ❑Runoff 46= 44.- 42.37 GIs 42: _ Runoff=42.37 cfs 40 38- Type III 24-hr 25 Year 36'; 34 - Rainfall=5.40" 321 30 Runoff Area®431 ,952 sf 28. 26- Runoff Volume®3.523 of 3 24 o 22 Runoff Depth=4.26" 20 18 Flow Length®1,092' 16. 14 1i c®9.5 min 12: _ 10 . CN=90 8- 6. _ 4 2- 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 Time (hours) 55 1272 Post Development Type /// 24-hr 25 Year Rainfall=5.40" Prepared by New England Engineering Services, Inc. Page 56 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond DP: Detention Pond Inflow Area = 9.916 ac, Inflow Depth = 4.26" for 25 Year event Inflow = 42.37 cfs @ 12.13 hrs, Volume= 3.523 of Outflow = 10.61 cfs @ 12.55 hrs, Volume= 3.523 af, Atten= 75%, Lag= 25.0 min Primary = 10.61 cfs @ 12.55 hrs, Volume= 3.523 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 36.50' @ 12.55 hrs Surf.Area= 30,087 sf Storage= 55,133 cf Plug-Flow detention time= 69.7 min calculated for 3.523 of (100% of inflow) Center-of-Mass det. time= 69.7 min ( 861.1 - 791.4 ) Volume Invert Avail Storage Storage Description #1 34.50' 70,302 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 34.50 25,330 0 0 35.00 26,306 12,909 12,909 36.00 28,278 27,292 40,201 37.00 31,924 30,101 70,302 Device Routing Invert Outlet Devices #1 Primary 34.19' 18.0" x 52.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 33.35' S= 0.0162T Cc= 0.900 n= 0.011 Concrete pipe, straight & clean #2 Primary 37.37' 50.0' long x 15.0' 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 Primary OutFlow Max=10.61 cfs @ 12.55 hrs HW=36.50' (Free Discharge) T__2=Broad-Crested 1=Culvert (Inlet Controls 10.61 cfs @ 6.01 fps) Rectangular Weir ( Controls 0.00 cfs) 56 1272_Post Development Type /// 24-hr 25 Year Rainfall=5.40" Prepared by New England Engineering Services, Inc. Page 57 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond DP: Detention Pond Hydrograph O Inflow 46. az.37crs ❑Primary 44, _ Inflow rea=98916. ac 42' 40 38 I n l Ow=4 .37 of 34 rimary=10.61 cfs 32 30 eak leV®36.50` 26 24 t0rage=551133 c 3 _o 22 a 20 16" 14 12: ds 10 ' 8- 6 4 2- 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 Time (hours) 57 1272 Post Development Type 111 24-hr 25 Year Rainfall=5.40" Prepared by New England Engineering Services, Inc. Page 58 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond SP: Summation Pond Inflow Area = 9.916 ac, Inflow Depth = 4.26" for 25 Year event Inflow = 10.61 cfs @ 12.55 hrs, Volume= 3.523 of Outflow = 10.61 cfs @ 12.55 hrs, Volume= 3.523 af, Atten= 0%, Lag= 0.0 min Primary = 10.61 cfs @ 12.55 hrs, Volume= 3.523 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.01' @ 12.55 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= 0.0 min calculated for 3.522 of(100% of inflow) Center-of-Mass det. time= 0.0 min ( 861.1 -861.1 ) Volume Invert Avail.Storage Storage Description #1 0.00' 0.005 of Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 0.00 0.000 0.000 0.000 10.00 0.001 0.005 0.005 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' 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=3.90 cfs @ 12.55 hrs HW=0.01' (Free Discharge) 't--1=Broad-Crested Rectangular Weir (Weir Controls 3.90 cfs @ 0.29 fps) 58 1272 Post Development Type 11124-hr 25 Year Rainfall=5.40" Prepared by New England Engineering Services, Inc. Page 59 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond SP: Summation Pond Hydrograph F11 Inflow - To.61 crs ❑Primary 11 _ _ _ 10s1 crs Inflow Area-9.916 a 10.: Inflow-10.61 cfs 9 8 rimary=10.61 cf 7 Peak Iev=0.01' 3 6 t®rage-0.000 of 0 LL 5_: 4 . 3- 2 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 29­'3O Time (hours) 59 1272 Post Development Type 11124-hr 100 Year Rainfall=6.40" Prepared by New England Engineering Services, Inc. Page 60 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment S-A: Subcat A Runoff Area=431,952 sf Runoff Depth=5.24" Flow Length=1,092' Tc=9.5 min CN=90 Runoff=51.47 cfs 4.327 of Pond DP: Detention Pond Peak Elev=36.95' Storage=68,905 cf Inflow=51.47 cfs 4.327 of Outflow=12.07 cfs 4.327 of Pond SP: Summation Pond Peak Elev=0.02' Storage=0.000 of Inflow=12.07 cfs 4.327 of Outflow=12.07 cfs 4.327 of Total Runoff Area = 9.916 ac Runoff Volume =4.327 of Average Runoff Depth = 5.24" 43.81% Pervious Area =4.344 ac 56.19% Impervious Area = 5.572 ac 60 1272 Post Development Type 111 24-hr 100 Year Rainfall=6.40" Prepared by New England Engineering Services, Inc. Page 61 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Subcatchment S-A: Subcat A Runoff = 51.47 cfs @ 12.13 hrs, Volume= 4.327 af, Depth= 5.24" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Rainfall=6.40" Area (sf) CN Description 55,512 86 <50% Grass cover, Poor, HSG C 18,601 98 Paved parking, HSG C 28,510 98 Roof, HSG C 103,001 79 <50% Grass cover, Poor, HSG B 58,280 98 Paved parking, HSG B 59,064 98 Roof, HSG B 30,705 68 <50% Grass cover, Poor, HSG A 15,983 98 Paved parking, HSG A 30,426 98 Roof, HSG A 31,870 98 Pond, HSG A 431,952 90 Weighted Average 189,218 Pervious Area 242,734 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 50 0.1041 0.20 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.20" 0.7 221 0.1041 5.19 Shallow Concentrated Flow, Flow over grass Unpaved Kv= 16.1 fps 0.3 55 0.0025 2.68 2.11 Circular Channel (pipe), Flow thru drainage pipe Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.011 Concrete pipe, straight & clean 0.9 198 0.0036 3.73 4.58 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight& clean 0.9 77 0.0005 1.39 1.71 Circular Channel (pipe), Flow thru drainage pipe Diam= 15.0" Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.011 Concrete pipe, straight & clean 1.7 316 0.0019 3.06 5.41 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 0.8 175 0.0026 3.58 6.33 Circular Channel (pipe), Flow thru drainage pipe Diam= 18.0" Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 9.5 1,092 Total 61 1272 Post Development Type /// 24-hr 100 Year Rainfall=6.40" Prepared by New England Engineering Services, Inc. Page 62 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Subcatchment S-A: Subcat A Hydrograph _ _ _ _ _ _ ❑Runoff 55 51.47 cfs 50- Runoff®51 .47 cfs 45 Type III 24-hr 100 Year 40-- 0 ainfall=6.40'° 35 Runoff Area=431,952 sf w Runoff Volume=4.327 of 30: 3 0 Runoff epth=5.24" M 25 zo Flow Length=1;092 Tc=9.5 min 15- - - - CN=90 10-' 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 Time (hours) 62 1272 Post Development Type /// 24-hr 100 Year Rainfall=6.40" Prepared by New England Engineering Services, Inc. Page 63 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond DP: Detention Pond Inflow Area = 9.916 ac, Inflow Depth = 5.24" for 100 Year event Inflow = 51.47 cfs @ 12.13 hrs, Volume= 4.327 of Outflow = 12.07 cfs @ 12.56 hrs, Volume= 4.327 af, Atten= 77%, Lag= 25.8 min Primary = 12.07 cfs @ 12.56 hrs, Volume= 4.327 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 36.95' @ 12.56 hrs Surf.Area= 31,755 sf Storage= 68,905 cf Plug-Flow detention time= 74.1 min calculated for 4.327 of(100% of inflow) Center-of-Mass det. time= 74.1 min ( 860.0 - 785.9 ) Volume Invert Avail.Storage Storage Description #1 34.50' 70,302 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 34.50 25,330 0 0 35.00 26,306 12,909 12,909 36.00 28,278 27,292 40,201 37.00 31,924 30,101 70,302 Device Routing Invert Outlet Devices #1 Primary 34.19' 18.0" x 52.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 33.35' S= 0.0162T Cc= 0.900 n= 0.011 Concrete pipe, straight & clean #2 Primary 37.37' 50.0' long x 15.0' 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 Primary OutFlow Max=12.07 cfs @ 12.56 hrs HW=36.95' (Free Discharge) �__2=13road-Crested 1=Culvert (Inlet Controls 12.07 cfs @ 6.83 fps) Rectangular Weir ( Controls 0.00 cfs) 63 1272 Post Development Type 111 24-hr 100 Year Rainfall=6.40" Prepared by New England Engineering Services, Inc. Page 64 HydroCAD®8 00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond DP: Detention Pond Hydrograph 0 Inflow sta7 cfs ❑Primary 55: - Inflow Area=9.916 ac 50_ Inflow=51 .47 cf 45 40 - rimary=12.07 cfs 35 . Peak lev®36.95' w 30 Storage-68,905 cf 3 0 LL 25 20 15- 12.07 ds 10 5°; 0 0 1 1 .:,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 Time (hours) 64 1272 Post Development Type 11124-hr 100 Year Rainfall=6.40" Prepared by New England Engineering Services, Inc. Page 65 HydroCADO 8.00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond SP: Summation Pond Inflow Area = 9.916 ac, Inflow Depth = 5.24" for 100 Year event Inflow = 12.07 cfs @ 12.56 hrs, Volume= 4.327 of Outflow = 12.07 cfs @ 12.56 hrs, Volume= 4.327 af, Atten= 0%, Lag= 0.0 min Primary = 12.07 cfs @ 12.56 hrs, Volume= 4.327 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.02' @ 12.56 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= 0.0 min calculated for 4.325 of(100% of inflow) Center-of-Mass det. time= 0.0 min ( 860.0 - 860.0 ) Volume Invert Avail.Storage Storage Description #1 0.00' 0.005 of Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (acres) (acre-feet) (acre-feet) 0.00 0.000 0.000 0.000 10.00 0.001 0.005 0.005 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' 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=4.73 cfs @ 12.56 hrs HW=0.02' (Free Discharge) L1=Broad-Crested Rectangular Weir (Weir Controls 4.73 cfs @ 0.31 fps) 65 1272 Post Development Type /// 24-hr 100 Year Rainfall=6.40" Prepared by New England Engineering Services, Inc. Page 66 HydroCAD®8 00 s/n 002248 ©2006 HydroCAD Software Solutions LLC 3/1/2007 Pond SP: Summation Pond Hydrograph - o Inflow 13- �z o�cts ❑Primary 12 12 Inflow rea=9°916 ac 11 Inflow®12.07 cf 10: . rimary=1 .07 cf 9 - Peak lev=0.02' 8.. w torage-0.000 of 3 0 6. FL 5- 4- 3- 2- 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 Time (hours) 66 Summary The post-development drainage watershed Area A shows a net decrease in runoff flow. This can be found in Table A. Table A. Rate of runoff. Pre-Development Post-Development Change in Flow(cfs) Flow(cfs) Flow(cfs) Storm Event Area A Area A 2-Year 8.47 6.39 (2.08) 10-Year 10.26 9.31 (0.95) 25-Year 11.22 10.61 (0.61) 100-Year 12.33 12.07 (0.26) Results from the pre-development analysis indicated that the existing detention pond had a potential to overflow onto the pavement of the cul-de-sac during a 100-year storm event. The design of the proposed detention pond addressed this issue and should hold the volume of runoff during l 00-year storm event. In each storm event analyzed, the rate of runoff was decreased compared to the pre- development conditions. The drainage system is designed accommodate surface drainage caused by rain, snow, and ice in an adequate manner. Therefore, there will be no significant impact as a result of discharges from the project site. 67 Appendix A® oil Map Unit Descriptions 68 ESSEX COUNTY, MASSACHUSETTS, NORTHERN PART 19 .gT.�, ( i'•. ':. t It7 g # a- fit' r' >dp .tee .. 'sY�`zt z' �, .k� F �. sb � l� a4�Y ��, tf§� � f4.�x�, �•��?.� , ��-�-. i ' ,fir 'i? i.,,, 2. # s �fjq/s `f� ,r �• ..,i l !21 f "; 1— i 7 7 ffd N: � a,mot_ i 5¢ al'. / ,,`S S :'t ,i j _j { F' n." {� ,: i is rft sj 4 , 4 x 5 t�l t a �zt t G f3 A -T1 'z r Af: Ig f :: C ;F fit. 7 f }Vti r` � pf��.�. � '.' f a7 ".f! j+ F''Y. i' _ �c i f $:gs7 -a ,. tC r; .>:dy2 ,,AS r s r +} t , i 'tt by «3 a z *c s s yy s _ i 5': }, •h y y nisi -_' +E ".:: f '�j^•S ? z 7 S rfa3 j f ate. ",#f �_a �,�E:, `�++(�i�aiS�T'€�'1 yi..� +• � f I i F7 1� ;� ' ' ���'��i q''�` � .1�� �f3-� ?�' + ,_. itSn I � Li rj* o i F .r I 2E "t: } '�'S -�" �. / �• i-. Al i, i +�<slr � �sd � �= -xX','-� •".rr ,� zt^t'�-�aS � � �7— t �1 N tAs,r ^y. RV ZRsrs Figul-e 10.—An area of very stony Canton soils used for residential development. slopes of hills throughout the survey area. The areas A few areas of this soil are farmed and are mainly range from 10 to 100 acres. Slopes are smooth, rolling, used for pasture. Many areas are wooded, and many are and 50 to 600 feet long. The surface is covered by in urban and residential development. stones 1 to 3 feet in diameter that are 30 to 100 feet The stones on the surface make this soil poorly suited apart. to cultivated crops. The use of proper stocking rates, Typically, the surface layer is very friable, dark brown deferred grazing, and pasture rotation help maintain de- fine sandy loam about 6 inches thick. The subsoil is very sirable pasture plant species. friable find sandy loam 27 inches thick. It is brown in the The soil is suitable for woodland wildlife habitat but is upper 10 inches, yellowish brown in the next 11 inches, poorly suited to timber production. Slope, the stony s ur- b�r pre..u., on. �ope, e �u and light olive brown in the lower 6 inches. The substra- face, the instability of the sides of shallow excavations, tum is loose, light brownish gray gravelly loamy sand to and the rapid permeability of the substratum limit this soil a depth of 60 inches or more. for most other nonfarm uses. Included with this soil in mapping are small areas of Scituate soils and Medisaprists, shallow, and soils with a This unit is in capability subclass Vls. surface layer and subsoil of silt loam. Included soils make up about 15 percent of this map unit. CbD®Canton very stony fine sandy loam, 15 to 25 The permeability of this soil is moderately rapid in the percent slopes. This deep, moderately steep, well subsoil and rapid in the substratum. Available water ca- drained soil is in irregularly shaped areas on the lower pacity is moderate, and reaction ranges from extremely ac t strongly acid. The rooting zone extends into the slopes of hills throughout the survey area. The areas sub-,,atum. range from 10 to 60 acres. Slopes are 50 to 400 feet 69 SOIL SURVEY 18 Included with this soil in mapping are small areas of major management concern. Where this soil is farmed, Scituate soils and Medisaprists, shallow, and soils with a minimum tillage and the use of cover crops and grasses surface layer of silt loam. Included soils make up about and legumes in the cropping system help to reduce runoff and control erosion. Mixing crop residue and 15 percent of this map unit. The permeability of this soil is moderately rapid in the manure into the surface layer improves tilth and in subsoil and rapid in the substratum. Available water ca- creases organic matter content. The use of proper stock- pacity is moderate, and reaction ranges from extremely ing rates, deferred grazing, and maintain desirable pasture plant species. The rotation help es.i acid to strongly acid. The rooting zone extends into the The soil is suitable for woodland wildlife habitat but is substratum. poorly suited to timber production. Slope is the main Most areas of this soil have been farmed. Some previ= limitation for most other nonfarm uses. The sides of ously cleared areas have reverted to or been planted to shallow excavations in this soil are unstable, and rapid trees. Some of the acreage still is farmed, and many permeability in the substratum limits use for sanitary areas are in urban and residential development. landfills. This soil is suited to cultivated crops, hay, and pasture. This unit is in capability subclass IVe. Good tilth is easily maintained in cultivated areas. The erosion hazard is moderately severe. If this soil is CbB -Canton very stony fine sandy loan, 3 to 8 farmed, minimum tillage and the use of cover crops and percent slopes. This deep, gently sloping, well drained grasses and legumes in the cropping system help to soil is in irregularly shaped areas on the lower slopes of reduce runoff and control erosion. Mixing crop residue hills throughout the survey area. The areas range from and manure into the surface layer improves tilth and 10 to 150 acres. Slopes are smooth, undulating, and 50 increases organic matter content. The use of proper to 800 feet long. The surface of the soil has stones 1 to stocking rates, deferred grazing, and pasture rotation 3 feet in diameter that are 30 to 100 feet apart. help maintain desirable pasture plant species. Typically, the surface layer is very friable, dark brown The soil is suitable for openland and woodland wildlife fine sandy loam about 6 inches thick. The subsoil is very habitat. It is poorly suited to timber production. Slope, friable fine sandy loam 27 inches thick. It is brown in the the instability of the sides of excavations in this soil, and upper 10 inches, yellowish brown in the next 11 inches, the rapid permeability of the substratum limit the soil for and light olive brown in the lower 6 inches. The substra- tum is loose, light brownish gray gravelly loamy sand to ost other nonfarm uses. a depth of 60 inches or more. This unit is in capability subclass Ille. Included with this soil in mapping are small areas of Ca®®Canton flee sandy loam, 15 t® 25 percent Scituate soils and Medisaprists, shallow, and soils with a surface layer and subsoil of silt loam. Included soils slopes. This deep, moderately steep, well drained soil is make up about 20 percent of this map unit. in irregularly shaped areas on the lower slopes of hills The permeability of this soil is moderately rapid in the throughout the survey area. The areas range from 5 to subsoil and rapid in the substratum. Available water ca- 30 acres. Slopes are 50 to 500 feet long. pacity is moderate, and reaction ranges from extremely Typically, the surface layer is very friable, dark brown acid to strongly acid. The rooting zone extends into the fine sandy loam about 5 inches thick. The subsoil is very substratum. friable fine sandy loam 22 inches thick. It is brown in the A few areas of this soil are farmed and are mainly upper 8 inches, yellowish brown in the next 8 inches, used for pasture. Some areas are wooded, and many are and light olive brown in the lower 6 inches. The substra- in urban and residential development (fig. 10). tum is loose, light brownish gray gravelly loamy sand to The stones on the surface make this soil poorly suited a depth of 60 inches or more. to cultivated crops. The use of proper stocking rates, Included with this soil in mapping are small areas of deferred grazing, and pasture rotation help maintain de- Charlton soils and Medisaprists, shallow. Inclusions sirable pasture plant species. make up about 15 percent of this map unit. p p p The permeability of this soil is moderately rapid in the The stony surface also limits the soil for most recre- subsoil and rapid in the substratum. Available water ca- ational uses other than picnic areas. The soil is suitable pacity is moderate, and reaction ranges from extremely for woodland wildlife habitat but is poorly suited to timber acid to strongly acid. The rooting zone extends into the production. The slope, stones on the surface, instability substratum. of the sides of excavations in the soil, and the rapid Most areas of this soil have been farmed. Some previ- permeability of the substratum limit the soil for most ously cleared areas have reverted to or been planted to other nonfarm uses. trees. Some of the acreage still is fanned, and some is This unit is in capability subclass Vls. in urban and residential development. very stun fine sandy loam, 8 to 15 This soil is suited to cultivated crops, hay, and pasture. y y good tilth is easily maintained in cultivated areas. The percent slopes, This deep, moderately sloping, well erosion hazard is severe, and controlling erosion is a drained soil is in irregularly shaped areas on the lower 70 ESSEX COUNTY, MASSACHUSETTS, NORTHERN PART 57 Wh—Whitman extremely stony loam. This deep, This soil is suitable for cultivated crops, hay, and pas- nearly level, very poorly drained soil is in depressions ture. The low available water capacity makes irrigation a and low areas. Slopes are smooth or very gently undulat- major management concern. Mixing crop residue and ing and are 100 to 400 feet long. The areas range from manure into the surface layer maintains tilth and in- 5 to 50 acres and are covered by stones and boulders 1 creases the organic matter content. The use of proper to 3 feet in diameter that are 5 to 100 feet apart. stocking rates, deferred grazing, and pasture rotation Typically, the surface layer is very friable, black loam help to maintain desirable pasture plant species. about 9 inches thick. The substratum extends to a depth The sandy texture of the surface layer limits the soil of 60 inches or more. It is firm, gray, distinctly mottled for most types of recreational 'development, and the soil sandy loam to a depth of 20 inches and very firm, gray, is poorly suited to most types of wildlife habitat. distinctly mottled loamy sand at a depth of more than 20 The soil is generally suitable for residential develop- inches. ment. The rapid permeability, however, limits the soil as Included with this soil in mapping are small areas of a site for sanitary landfills and causes a hazard of pollu- Ridgebury and Leicester soils and soils with slopes of 3 tion to wells and streams where the soil is used as a site to 8 percent. Included soils make up about 15 percent of for septic tank absorption fields. this map unit. This unit is in capability subclass Ille. The permeability of this soil is moderately rapid in the surface layer and upper part of the substratum and slow WnB—Windsor loamy sand, 3 to 8 percent slopes. in the lower part of the substratum. Available water ca- This deep, gently sloping, excessively drained soil is in pacity is low. Reaction is very strongly acid to medium irregularly shaped areas that range from 20 to 100 acres. acid. The rooting zone extends to the very firm part of Typically, the surface layer is very friable, very dark the substratum, but root growth is restricted by a sea- grayish brown loamy sand about 10 inches thick. The sonal high water table which is at or near the surface in subsoil is 18 inches thick. It is yellowish brown loamy winter and spring. sand in the upper part and yellowish brown and very Most areas of this soil are in woodland, but the soil is pale brown sand in the lower part. The substratum is poorly suited to tree production. pale yellow sand to a depth of 60 inches or more. The soil is suitable for wetland wildlife habitat, but the Included with this soil in mapping are small areas of se^­)nal high water table and stones on the surface Deerfield, Wareham, and Pipestone soils. Also included M the soil poorly suited to farming. The seasonal are areas of Windsor soils with stones and rock outcrops high water table and stones also limit the soil for recre- on the surface. Included soils make up about 20 percent ational and residential development and as a site for of this map unit. waste disposal facilities. The slow permeability in the The permeability of this soil is rapid or very rapid, and lower part of the substratum is an additional limitation for available water capacity is low. Reaction is very strongly waste disposal facilities. acid or strongly acid. The rooting zone extends into the This unit is in capability subclass Vlls. substratum, but root growth is often restricted by a lack of moisture. WnA—Windsor loamy sand, 0 to 3 percent slopes. Many areas of this soil are in residential and urban This deep, nearly level, excessively drained soil is in development. Some areas are in woodland, but the soil irregularly shaped areas that range from 5 to 25 acres. is poorly suited to tree production. Typically, the surface layer is very friable, very dark The soil is suitable for cultivated crops, hay, and pas grayish brown loamy sand about 10 inches thick. The ture, The low available water capacity makes irrigation a subsoil is 18 inches thick. It is yellowish brown loamy major management concern. Where this soil is farmed, sand in the upper part and yellowish brown and very minimum tillage, the use of cover crops and grasses and pale brown sand in the lower part. The substratum is legumes in the cropping system, and mixing crop residue pale yellow sand to a depth of 60 inches or more, and manure into the surface laver help maintain tilth and Included with this soil in mapping are small areas of increase the organic matter content. The use of proper Deerfield, Wareham, Pipestone, and Scarboro soils that stocking rates, deferred grazing, and pasture rotation make up about 15 percent of the map unit. help to maintain desirable pasture plant species. The permeability of this soil is rapid or very rapid, and The sandy texture of the surface layer limits the soil available water capacity is low. Reaction is very strongly for most types of recreational development, and the soil acid or strongly acid. The rooting zone extends into the is poorly suited to most types of wildlife habitat. substratum, but root growth is often restricted by lack of The soil is generally suitable for residential develop- moisture, ment. The rapid permeability, however, limits the soil as Most areas of this soil are in residential and urban a site for sanitary landfills and causes a hazard of pollu- devPlopment. Some areas are in woodland, but the soil tion to wells and streams where the soil is used as a site is )rly suited to tree production. Some areas are for septic tank filter fields. farm ed. This unit is in capability subclass Ills. 71 SOIL SURVEY 60 to strongly acid. A seasonal high water table is at a Mixing crop residue and manure into the surface layer depth of 1.5 to 3 feet during winter and spring. improves filth and increases the organic matter content Most areas of this soil have been farmed. Some previ- of the soil. Erosion is a moderate hazard in cultivated ously cleared areas have reverted to or been planted to areas. The use of proper stocking rates, deferred gran- trees. Some areas still are farmed, and many are in ing, and pasture rotation help to maintain desirable pas urban and residential development, ture plant species. This soil is well suited to cultivated crops, hay, and The soil is suitable for trees and openland wildlife pasture. The seasonal high water table is the main limita- habitat, but the slow permeability in the substratum is a tion, and providing drainage is a management concern. limitation for some types of recreational development. Mixing crop residue and animal manure into the surface The seasonal high water table limits use of the soil for layer improves tilth and increases the organic matter residential development and as a site for waste disposal content of the soil. The use of proper stocking rates, facilities. A susceptibility to frost action is an additional deferred grazing, pasture rotation, and restricted grazing limitation for residential development, and the slow per- when the soil is saturated help to maintain desirable meability in the substratum for waste disposal facilities. pasture plant species. This unit is in capability subclass Ilw. The soil is suitable for trees and openland wildlife habitat, but the slow permeability in the substratum is a WrC®Woodbridge fine sandy loam, 8 to 15 per- limitation for some types of recreational development, cent slopes. This deep, sloping, moderately well drained The seasonal high water table limits use of the soil for soil is in rectangular or oval areas on or near the tops of residential development and as a site for waste disposal drumloidal hills and is in irregularly shaped areas at facilities. A susceptibility to frost action is an additional lower elevations. The areas range from 5 to 25 acres. limitation for residential development, and the slow per- Slopes are 100 to 400 feet long. meability in the substratum for waste disposal facilities. Typically, the surface layer is friable, very dark grayish This unit is in capability subclass llw. brown fine sandy loam about B inches thick. The subsoil is friable fine sandy loam 17 inches thick. It is yellowish yVr���Voodlarldge fine sandy loam, 3 to � percent brown in the upper part, mottled olive brown in the P'npese This deep, gently sloping, moderately well middle part, and mottled olive in the lower part. The fined soil is in rectangular or oval areas on or near the substratum is mottled, very firm, light olive brown fine tops of drumloidal hills and is in irregularly shaped areas sandy loam to a depth of 60 inches or more. at lower elevations. The areas range from 5 to 25 acres. Included with this soil in mapping are small areas of Slopes are 100 to 400 feet long, Ridgebury and Paxton soils. Also included are areas of Typically, the surface layer is friable, very dark grayish soils with slopes of 15 to 25 percent and areas of soils brown fine sandy loam about 9 inches thick. The subsoil with a subsoil of loamy sand. is friable fine sandy loam 17 inches thick. It is yellowish The permeabiliy of this soil is moderate or moderately brown in the upper part, mottled olive brown in the rapid in the subsoil and slow in the substratum. Available middle part, and mottled olive in the lower part. The ,,rater capacity is moderate. The rooting zone extends to substratum-is mottled, very firm, light olive brown fine a depth of about 25 inches, where root growth is restrict- sandy loam to a depth of 60 inches or more. ed by the very firm substratum. Reaction ranges from Included with this soil in mapping are small areas of medium acid to strongly acid. A seasonal high water Ridgebury and Whitman soils. Also included are areas of table is at a depth of 1.5 to 3 feet during winter and soils with a subsoil of loamy sand. Included soils make p up about 20 percent of this map unit. spring. Most areas of this soil have been farmed. Some previ- The permeability of this soil is moderate or moderately rapid in the subsoil and slow in the substratum. Available ously cleared areas have reverted to or been planted to trees. Some areas still are farmed; and some are in water capacity is moderate. The rooting zone of plants extends to a depth of about 26 inches, where root residential development. This soil is suited to cultivated crops, hay, and pasture. growth is restricted by the very firm substratum. Reaction ranges from medium acid to strongly acid. A seasonal The erosion hazard is moderately severe. The seasonal high water table is at a depth of 1.5 to 3 feet during high water table is a limitation, and providing drainage is winter and spring. a major concern. Mixing crop residue and manure into Most areas of this soil have been farmed. Some previ the surface layer improves filth and increases the organ ously cleared areas have reverted to or been planted to is matter content of the soil. Minimum tillage, contour trees. Some areas still are farmed, and some are in cultivation, and incorporating grasses and legumes in the urban and residential development. cropping system help reduce runoff and control erosion. This soil is well suited to cultivated crops, hay, and The use of proper stocking rates, deferred grazing, and pasture. The seasonal high water table is the main limita- pasture rotation help to maintain desirable pasture plant tion, and providing drainage is a management concern. species. 72 Appendix oil Hydrologic Group 73 190 SOIL SURVEY TABLE 16.--SOIL AND WATER FEATURES ne definitions of "flooding" and "water table" in the. Glossary explain terms such as "rare," "brief," "apparent," and "perched." The symbol C means less than; > means more than, Absence of an entry indicates that the feature is not a concern] Flooding High water table Risk of corrosion Soil name and Hydro-I T— I !Potential', map symbol I logic! Frequency 1 Duration ',Months Depth Kind 1Months ' actoat 'Uncoated 1Concrete steel !group i 1 >6,0 awam !Lour------ILow------ (High. a o B (None--------! --- i --- --- AoA, AoB, AgC-----I Ag a C !None--------I --- --- 11 .0-2.51Apparent;Dec-Apr ;Moderate Ihloderate ! Moderate. AmA, AmB----------I I Amostown ! I Beaches ! ! BeA, BeB, BeC-----'I B (None--------! --- ; --- 11 .5-3.51Apparent'INov-Apr;High-----(Moderate Moderate. Belgrade a High-----1High, D ,None-------- i --- i --- i 0-1.O IApparentlOct-JullHioh----- Birdsall ! --- --- 110-30iPerched (Nov-4 ay,High-----' High-----!Moderate. BuA, BuB, BuC----- C !None-------_ I ! I Buxton BB*, BxC*_- -- -!! C ;None--------I --- I --- i1 .0-3.0!Perched Nov-May!High-----!High-----!Moderate. B Rock outcrop. i CaA, CaB, CaC, CaD, CbB, CbC, CbD, CcB, CcC, B 1lione--------i --- --- ! >6.0 ! --- --- ILo•7--°---ILow------lH-gh• Canton I CDE*: i i >6.0 'Low------ILow------!High. Canton----------- B 1 lion e-------- ! ! I ! ' , >6.0 , ;Low------I Low------!High. Charlton--------- B !None-------- I _-- --- Low------ILow------(High. CeA, CeB----------I A. !None-------- I >6 0 I Carver I I CmB, CmC, CmD, ' >6.0 ! --- i --- !Lo<<r------ILow------(High. --- ! --- CoB, CoC, CoD----I B !N ------- one- � Charlton I ! CrB*, CrC*, CrD*: I ' _-- >6.0 I - I --° ILow------ILow------(High. Charlton---------! B !None-------- --- ! Rock outcrop. � I -- >6.0 --- ; - (Moderate Low------!High. Hollis-----------! C/D INone-------- --- De----------------I B (None-------- 1 .0-3.01APParentl Dec-Apr l �loderate ;Low------IHig . Deerfield ! I I , I ' , Du Dumps C !!done-------- I --- ! --- 11 .0-3.0 Perched ;Nov-14aylHigh-----I Mod erate ;Moderate. El A, ElB----------I ! ; ; Elmwood '1oderate. ------- _________' g ;Occasional !Brief-----;Oct-Apr ',3.0-S.O;ApparentliJov-hlayiHigh----- L°�'r'-----i He ; Hadley HfA, HfB, HfC, ; i _I --' A !None------ I --- I --- I >6.0 --- --- Low------ILow- -°-!High. Hinckley ; ! I I 1 ' ! ! I I I See footnote at end of table. 74 . �. ESSEX COUNT, MASSACHUSETTS, NORTHERN PART 193 % TABLE 16 AND WATER E92;o-w:nti c,, \ wowing 9A water tab16 ; Risk Of Corrosion Soil name and \tiro-/ ; ; �w«:G 6 d� Dr2G: Rowhs2w: ; :Id I nth frost 2 ,::&6 \,crew ma: :yA2 . w96 Frequency y roue@ action ; steel i #, xn-------� , !None --- ' \332Perched \ep-a :High-----\G:---High. m:Wc . - A«Wn o---- ----- ! :None ---2 ' . y3 :,>e---1 Low------ High. \ , a Ger ) «,9, Roy: Windsor ------; ! Non e----- y3 -- !Low------%a------ H9&. . Rock outcrop. 2 ;w-------- B \w,6e,g \rie w---Sep—Apr\3-3.0\PPv en\,e:-pr\Qw--\w«,w !Moderate. } Winooski \ ;G, wrB, wrC, a% G% AS � Re, 3 w----- = %,a---- --- --- U.n«.,>em:w :;,tea«ewe--!Moderate 1Awrate. wow w G g • See description ,zt,he map unit for compositi a and behavior, characteristics of the en' unit. : }\ � \ � p . . � 71 . � . y � . � . ,Q � W � � /\ � . J ; \ \ � \ � / r \ � K � / \ \ \ it � $ 75 \ Appendix C-Runoff Curve Numbers 76 Table 2-2a.—Runoff curve numbers for urban areasr — Curve numhers f,Qr Cover descripti(,rl hydrologic soil kruup- Average percent Cove- type and hydrologic condition impervious areal A B L D Fully developed urban areas (tlegetatiou established) Open space (lawns, parks, golf courses, cemeteries, etc.)': Poor condition (grass cover < 50%) .. . . . .. . . . . . . . 68 79 86 89 Fair condition (grass cover 50% to 75%). . . . . . . . .. . 49 69 79 84 Good condition (grass cover > 75%) . . .. . . . . . . . . . . 39 61 74 s0 Impervious areas: Paved parking lots, roofs, driveways, etc. (excluding right-of-way). . .. . . .. . . . . . .. . . . . . .. . . . . 98 98 98 98 Streets and roads: Paved; curbs and storm sewers (excluding right-of-way). . . . . . . .. . .. .. . .. . . . .. . . .. . . . . . . . . 98 98 98 98 Paved; open ditches (including right-of-way) . . . .. .. 83 89 92 93 Gravel (including right-of-way) ... . . .. . . .. . . . . . . .. 76 85 89 91 Dirt (including right-of-way) . .. . . . . . . . . . . . . . . . . . . 72 82 81 89 Western desert urban areas: Natural desert landscaping (pervious areas only)"... 63 77 85 88 Artificial desert landscaping (impervious weed barrier, desert shrub with 1- to 2-inch sand or gravel mulch and basin borders). . .. . .. . . . . . . . . 96 96 96 96 Urban districts: Commercial and business. . .. . . . . . . . . . . . . . . . . .. . . . . 85 59 92 94 90 Industrial.. . . . ... . . .. . .. . .. . . . . . . . . . .. . .. . . . . . . . . 72 81 88 91 93 Residential districts by average lot size: 1/8 acre or less (town houses).. .. .. . . . . . . ... . .. . . . . 65 77 85 90(town 1/4 acre . . . . . . . . . . . .. . . . . . . . . .. .. . . . . . . .. . . . . . . .. 38 61 75 83 87 1/3 acre . .. . . . . . . . . . . . .. . . . . . .. .. . . . . . . .. . . .. .. .. 30 57 72 81 8(3 1/2 acre . .. .. . . . . . . .. .. . . . . .. .. .. . . . . . . . . .. .. . . . . 25 54 70 80 85 1 acre . . . . . . . . . . . . . .. . . . . . . .. .. .. . . . . . . . . . . .. . . . . 20 51 68 79 84 2 acres . . .. . . . . . . . . .. . .. . .... .. .. . . . . . . . . . . .. . . .. 12 46 65 77 82 Dereloping turban arms Newly graded areas (pervious areas only, no vegetation)5 .. . . . .. . . . . . . .. . . .. . . . .. . .. . . . . . . . . 77 86 91 94 Idle lands (CN's are determined using cover types similar to those in table 2-2c). 'Average runoff condition, and 1;, = 0.2S. The average percent impervious area shown was used to develop the composite CN's. Other assumptions are its Culluws: imperciuus areas are directly connected to the drainage system, impervious areas have a CN of 98, and pervious areas are considered equivalent to open space in good hydrologic condition. CN's for other combinations of conditions may be computed using Figure 2 f o 24. 'CN's shown are equivalent to those of pasture. Composite CN's may be computed for other combinations of open space cover type. 4Composite CN's for natural desert landscaping should be computed using figures 2-3 or 24 haled on the impervious area percentage WN = 98) and the pervious area CN. The pervious area CN's are assumed equivalent to desert shrub in poor hydrologic condition. 'Composite CN's to use for the design of temporary measures during grading and construction should be computed using figure 2-:3 or 2-4, based on the degree of development(impervious area percentage)and the CN's for the newly graded pervious areas. 77 i Table 2.21).—Runoff Curve numbers for cultivated agricultural lands' Curve numbers for Cover description hydrologic soil group— Hydrologic Craver type Treatment'- condition" A B C D Fallow Bare soil — 77 86 91 94 Crop residue cover (CR) Poor 76 85 90 93 Good 74 83 88 90 Row crops Straight row (SR) Poor 72 81 88 91 Good 67 78 85 89 SR + CR Poor 71 80 87 90 Good 64 75 82 85 Contoured (C) Poor 70 79 84 88 Good 65 75 82 86 C + CR Poor 69 78 83 87 Good 64 74 81 85 Contoured & terraced (C&T) Poor 66 74 80 82 Good 62 71 78 81 C&T + CR Poor 65 73 79 81 Good 61 70 77 80 { Small grain SR Poor 65 76 84 88 Good 63 75 83 87 SR + CR Poor 64 75 83 86 Good 60 72 80 84 C Poor 63 74 82 85 Good 61 73 81 84 C + CR Poor 62 73 81 84 Good 60 72 80 83 C&T Poor 61 72 79 82 Good 59 70 78 81 C&T + CR Poor 60 71 78 81 Good 58 69 77 80 Close-seeded SR Poor 66 77 85 89 or broadcast Good 58 72 81 85 legumes or C Poor 64 75 83 85 rotation Good 55 69 78 83 meadow C&T Poor 63 73 80 83 Good 51 67 76 80 'Average runoff condition, and 1;, �C'rp rr-.eilre cor�o applies only if residue is on at least 517 of the Surface throughout the year. :'H'•drologie condition is based on combination of factors that affect infiltration and runoff, including(a)density and canopy of vegetative areas, (b) amount of.%ear-round cover, (c)amount of grau`s or close-seeded legumes in rotations, (d) percent of residue cover on the land sur- face (good >_ 201/(), and(e) degree of surface roughness. l4iw: Factors impair infiltration and tend to increattie runoff. Good: Factors encourage average and better than average infiltration and tend to decrease runoff. 78 E Table 2-2c.—Runoff curve numbers for other agricultural lands' Carve numbers for Cover description hydrologic soil 91-OUP- Hydrologic Cover type condition A B C D Pasture, grassland, or range—continuous Poor 68 79 86 89 forage for grazing.' Fair 49 69 79 84 Good 39 61 74 80 Meadow—continuous grass, protected from — 30 58 71 i8 grazing and generally mowed for hay. Brush—brush-weed-grass mixture «6th brush Poor 48 67 77 83 the major elementa Fair 35 56 70 77 Good 430 48 65 73 Woods—grass combination (orchard Poor 57 73 82 86 or tree farm).s Fair 43 65 76 82 Good 32 58 72 79 Woods.6 Poor 45 66 77 83 Fair 36 60 73 79 f Good 430 55 70 77 Farmsteads—buildings, lanes, driveways, — 59 74 82 86 and surrounding lots. 'Average runoff condition, and L, s/'our: <ow1lc ground cover or heavil, grazed with no mulch. Fair: 50 to 75`k gruwr(I corer and not heavily gi-zed. (;owl: >75'1( ground cover and lightly or only occattiiunall} grazed. 1 J'oor: <50% ground cover. F(rir: 7YJ to 7W( ground cove". Goo(1: >7W ground cover. 'Actual curve number is less than 30: use CN = 30 for runoff computations. 5CN's shuv,n %vere computed for areas with 50% w(w(k and 5017( grass (pasture) cover. Other combinations of conditions may be computedI from the CN's for %voods and pasture. 6l'oor: Forest litter. small trees, and brush are destroyed by heavy grazing or regular btn Wing. Fuir: Woods are grazed but not h(mied, and some forest litter covers the soil. (;oud: Woods are protected from grazing, and litter and brush adequately cover the soil. 79 Table 2-2d.—runoff curve numbers for arid and semiarid rangelands' - Curve numbers for Cover description hydrologic soil group— Hydrologic Cover type condition' A3 B C D Herbaceous—mixture of gn•ass, weeds, and Poor 80 87 93 low-growing brush, with brush the Fair 71 81 89 minor element. Good 62 74 85 Oak-aspen—mountain brush mixture of oak brush, Poor 66 74 79 aspen, mountain mahogany, bitter brush, maple, Fair 48 57 63 and other brush. Good 30 41 48 Pinyon-juniper—pinyon, juniper, or both; Poor 75 85 89 grass understory. Fair 58 73 80 Good 41 61 71 Sagebrush with grass understory. Poor 67 80 85 Fair 51 63 70 Good 35 47 55 Desert shrub—major plants include saltbush, Poor 63 77 85 88 greasewood, creosotebush, blackbrush, bursage, Fair 55 72 81 86 palo verde, mesquite, and cactus. Good 49 68 79 84 _ 'Average runoff condition, and I;, = 0.25. For range in humid regions, use table 2-2c. "I' <30'/r gr•uund cover(litter, grass, and hrush overstory). Fo;r: aU to 705: ground Cover. (;marl: >799r ground Cover. "Curve numbers for group A have been developed only for desert shrub. 80 Appendix D®Rainfall Data Maps sl i cure 2 - P reci--)itution `:%aloes for -assacnuse'--ts 2.8 3.011 ESSEX FRA.lLIN 3.211 W MIDDLESEX SUFFOLK r 2 HAMPSHIRI ORCE$TER ul W co � 11 L 3.6 P S' S� O / RAINFALL DATA MAP BARNSTAS 2-YEAR, 24 HOUR PRECIPITATION (INCHES) NANTUCKET TP-A-0 ESSEX FIRANAUN 61 NIOOLESEX S x WORCESTER Y HA w Ct 4.211 0 4.4 s S O RAI ALA. DATA MAP / 9 9T 5- YFAR,24-HOUR P CIPITATION (INCHES) b NANTUCKET TP-40 82 icure Values i= ::assachusetts . 4.2 4.411 4.5 " I1 , 4. 3 ESSEX FRANKLIN _ / W MIDDLESEX SUFFOLK s WORCESTER 71I 2 HAMPSHIRE H Y 2 HAMPDEN HOP 0 O m `T G ,,qq ��yy 11 .O 9 1 s O RAINFALL DATA MAP BARNSTAB 10-YEAR, 24 HOUR PRECIPITATION (INCHES) DUKES NANTUCKET TP®40 5.311 5.0 R 5.111 5.211 5.411 ESSEX FRANKLIN 11 5.5 W MIDDLE EX SUFFOLK ..I r .WORCESTER H az HAMPS44IRE 4 W 5.5« HAMPDEN </- oG N p 5.7 0 BARNS ifs RAINFALL DATA MAP 1 5.n 25 - YEAR,24 ® HOUR PRECIPITATION (INCHES) � NApTU TP°-40 83 _ icure _ - °reci D,Cation values for "assac:—usetts u 5.� 5.6" 5.7 5.911 ESSEX FRANKLIN 6. 0 11 MI&OlE SEX SUFFOLK 6.111 *0A C£STER HAMPSHIRE N X m Qd+ 6.2" HAM®DEF9 ®�6 611 1'1 O G � 1 a RAINFALL DATA MAP ° ®AIiW9TA8l 6.41 50-°Y1=AR,2 4 HOUR PRECIPITATION (INCHES) 6. 11 DUK NANTUCKET '... TP-40 s>�z F 6.6 MIDDLESEX SUQ�K a ONCESTER W M N ?� - 11,04,11,04,- 7 ° IR A I ��Im WAim MAP r 100 -YEAR,24-OOR P CdPITATIOM (INCHES) e KANTUCv$T TP®4O 84