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HomeMy WebLinkAboutStormwater Report - 1915 GREAT POND ROAD 3/7/2006 DRAINAGE REPORT LOT 1 GREAT POND ROAD NORTH ANDOVER, MASSACHUSETTS PREPARED FOR: Great Pond Realty Trust John R. Keilty,Trustee 40 Lowell Street Peabody,MA 01960 IH OF�ASSq o�' cyGN BENJAMIN C. o OSGOOD, CIVIL cn NO.45891 GISTE� Sim 05 Revised are 7, 2006 TABLE OF CONTENTS INTRODUCTION 1 LOCUS MAPS 2 SITE SOILS MAP 3 DRAINAGE SYSTEM DESCRIPTION 4 PRE DEVELOPMENT ANALYSIS 5 POST DEVELOPMENT ANALYSIS 23 SUMMARY 77 APPENDIX 78 RUNOFF CURVE NUMBERS RAINFALL DATA MAPS INTRODUCTION The site described in this report is an existing undeveloped residential lot The property is located Great Pond Road,North Andover,MA.The lot size of the subject property is 45894 square feet. The site is wooded and rises from the edge of Great Pond Road and slopes gradually a total of ten feet to the rear of the property. The existing drainage flows in a northwest to southeast direction in to a large wooded wetland on the adjacent property on the east side of the lot.Water then flows under great pond road through a culvert in to lake Cochichewick. Proposed alterations to current conditions include razing the existing dwelling,dividing the property in two,and constructing two new dwellings with driveways and appurtenances.Portions of the property which are currently lawn will be converted to unused area to provide a buffer to the wetlands providing less runoff and nutrient loading than is occurring presently. Drainage calculations provided in this report depict both existing and proposed runoff for the 1 year,2 year, 10 year,and 100 year storms using the SCS TR20 Runoff Method. Soil classification on the site is Woodbridge series,which is classified as a SCS Hydrological Soil Group C. The proposed infiltration of roof runoff will help reduce the amount of runoff from the site in all storms so that the proposed peak flow rates for water leaving the site will be less than or equal to existing peak flow rates.In addition,a deep sump catch basin,sediment forebays and a wet detention pond have been designed.This system manages the stormwater and provides treatment of runoff to produce a clean stormwater discharge from the site.. All regulations of the Town of North Andover have been incorporated herein. 1. USGS LOCUS MAP \� LAWREN6, u: U ICIOAL AjR'P iz of BM `�'•.� / i ��,',t •:1133; Jif 0 •St - 2 Y WM i ME UN va AMR W A'tf �� �^f �' �(L- �`-i u-h�C�'�` � �'`�'rt�Lgz-� �i'�jCY�•°j..2 MDRA E i DRAINAGE SYSTEM DESCRIPTION The pre existing drainage area has been depicted as one drainage area flowing from the site.Area A-1 flows from northwest to southeast off the property along the easterly line and on to the neighboring property to the east.The water travels in to the wetlands on the adjacent property then through a culvert in to lake Cochichewick..The post development drainage has been divided in to four sub catchments which are routed through the drainage structures which are to be constructed on the site. The increases in runoff as a result of the increase in impervious area are being controlled by diverting all of the roof runoff in to infiltration systems.In addition a wet detention pond is being constructed to treat and detain water prior to its leaving the site. The infiltration and detention of the runoff causes a decrease in post development rate of water exiting the site. Pre and Post development drainage maps are included with this submittal.The drainage calculations are presented in the next section of this report. 4 PRE DEVELOPMENT ANALYSIS 5 PRE DEVE OPMENT SUMATION POND Drainage Diagram for LOT 1 GREAT POND ROAD,NORTH ANDOVER- PRE DEVELOPMENT Prepared by NEW ENGLAND ENGINEERING SERVICES INC. 12122/2005 HydroCAD®7.10 s/n 002248 ®2005 HydroCAD Software Solutions LLC LOT 1 GREAT POND ROAD, NORTH ANDOVER - PRE Type III 24-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 7 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 12/22/2005 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 A-1: PRE DEVELOPMENT Runoff Area=45,894 sf Runoff Depth=0.46" Flow Length=351' Tc=38.0 min CN=70 Runoff--0.22 cfs 1,741 cf Pond 1P: SUMATION POND Peak Elev=0.00' Storage=0.000 of Inflow--0.22 cfs 1,741 cf Outflow--0.22 cfs 1,741 cf Total Runoff.Area=45,894 sf Runoff Volume= 1,741 cf Average Runoff Depth=0.46" LOT 1 GREAT POND ROAD, NORTH ANDOVER - PRE Type 11124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 8 HydroCAD®7.10 s/n 002248 ©2005 HYdroCAD Software Solutions LLC 12/22/2005 Subcatchment A-1: PRE DEVELOPMENT Runoff = 0.22 cfs Q 12.63 hrs, Volume= 1,741 cf, Depth= 0.46" Runoff by SCS TR-20 method, UH=SCS,Time Span= 0.00-30.00 hrs, dt=0.01 hrs Type III 24-hr 1 year Rainfall=2.50" Area(sf) CN Description 45,894 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 28.3 100 0.0400 0.1 Sheet Flow, . Woods: Dense underbrush n=0.800 P2=3.20" 9.7 251 0.0300 0.4 Shallow Concentrated Flow, Forest w/Heavy Litter Kv=2.5 fps 38.0 351 Total Subcatchment A-1: PRE DEVELOPMENT Hydrograph 0.25 - - - t--I--`--- -- i t f 0.24 -r--1- -- - -- r- - . ----r-r- ---- - --!--r-:- - I--- -*- +----r-t- +-- ®Runoff 0.23 --- '1- -'I-- i 1 i t 2 , ------ --- --"------ -- 0.22 - --1---- - - --1--;-; --;- ;- - - -- hype-14124-Ir- -yap - 0.21 -; ---.- -----,---- - _- - ; -.--,--, - --,- -----r----------r-,-- 0.2 - - -- -;- -- - -- -- --'- ;- -; ;-- Rai of ati -2:50"-- i 0.19 - __i__ _-__ _ 0.18 ;RiAhoff Area=X45-894 sf-- 0.17 -r-,---:--�-_-�--r--r---- --�- �- - --- -- - 0.15 - - ----r -+- --I--r-+-y--r --t--I- t ; � , �f_ '-_1 1 0.14 -1 Q 0.,3 Runo _ epf T ,46�__ _;- _ 0.12 LL I ; 0.1 -T --1--1- -- i--r r --t- -r-:- -�--,--.--r- --rwr- o A --- 0.09 1 .t_._3_-.__L_ J G= $-*�■' ��__ V Y 7n 0.08 _ _,__;___r_.T 007 _L_ __t__L_ _ __1__L_i_ __t_ _ __!__L_ ! ____1__ _ .__t_ _1__ L_1_■y^i__ L 0.08 -y_- __ __ - __ _ __ _ _y_A___0.05 0,04 0.04 0.03 i r 0.02 0.01 0 0 1 2 3 4 b 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) 1 LOT 1 GREAT POND ROAD, NORTH ANDOVER - PRE Type III 24-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 9 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 12/22/2005 Pond 1 P: SUMATION POND Inflow Area= 45,894 sf, Inflow Depth= 0.46" for 1 year event Inflow = 0.22 cfs @ 12.63 hrs, Volume= 1,741 cf Outflow = 0.22 cfs @ 12.63 hrs, Volume= 1,741 cf, Atten=0%, Lag=0.0 min Primary - 0.22 cfs @ 12.63 hrs, Volume= 1,741 cf Routing by Stor-Ind method,Time Span=0.00-30.00 hrs, dt=0.01 hrs Peak Elev=0.00' @ 12.63 hrs Surf.Area=0.000 ac Storage=0.000 of Plug-Flow detention time=0.0 min calculated for 1,741 cf(100%of inflow) Center-of-Mass det.time=0.0 min (926.9-926.9) Volume Invert Avail.Storage Storage Description #1 0.00' 0.001 of Custom Stage Data Listed below Elevation Inc.Store Cum.Store (feet) (acre-feet) (acre-feet) 0.00 0.000 0.000 10.00 0.001 0.001 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' long x 9.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.46 2.55 2.70 2.69 2.68 2.68 2.67 2.64 2.64 2.64 2.65 2.64 2.65 2.65 2.66 2.67 2.69 Primary OutFlow Max=0.01 cfs @ 12.63 hrs HW=0.00' (Free Discharge) 'L1=13road-Crested Rectangular Weir (Weir Controls 0.01 cfs) LOT i GREAT POND ROAD, NORTH ANDOVER - PRE Type III 24-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 10 HydroCADO 7.10 s/n 002248 Q 2005 HydroCAQ Software Solutions LLC 12122/2005 Pond iP: SUMATION POND Hydrograph L -A 2 Inflow 0.25 a Primary 0.24 0.23 0.22 0.21 P6A Et6V— '�n--001 I-A 0.2 0.18 A- StorageF = 0.17 F 7 T 0.16 -7 0.15 -r- . I I -i- I 1.14 ----I----;= 013 j F T IS ( J-12 0 0*I 0.09 -f--1-t z T 7 1 om 0.07 I t I i I 0-0, 0.05 0.04 0.03 0.02 0.01 0 ......... ......... . 0 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER- PRE Type 11124-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 11 HydroCADO 7 10 sln 002248 ©2005 HydroCAD Software Solutions LLC _1212212005 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 A-1: PRE DEVELOPMENT Runoff Area=45,894 sf Runoff Depth=0.83" Flow Length=351' Tc=38.0 min CN=70 Runoff--0.46 cfs 3,167 cf Pond 1P: SUMATION POND Peak Elev=0.00' Storage=0.000 of Inflow=0.46 cfs 3,167 of Outflow--0.46 cfs 3,167 cf Total Runoff Area=45,894 sf Runoff Volume=3,167 cf Average Runoff Depth=0.83" LOT 1 GREAT POND ROAD, NORTH ANDOVER - PRE Type III 24-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 12 HydroCADV 7.10 sin 002248 ©2005 HydroCAD Software Solutions LLC 12122/2005 Subcatchment A-1: PRE DEVELOPMENT Runoff = 0.46 cfs @ 12.59 hrs, Volume= 3,167 cf, Depth= 0.83" Runoff by SCS TR-20 method, t.lH=SCS,Time Span= 0.00-30.00 hrs, dt=0.01 hrs Type III 24-hr 2 Year Rainfall=120" Area(sf) CN Description 45,894 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 28.3 100 0.0400 0.1 Sheet Flow, Woods: Dense underbrush n=0.800 P2=3.20" 9.7 251 0.0300 0.4 Shallow Concentrated Flow, Forest wll-leayy Litter Kv=2.5 fps 38.0 351 Total Subcatchment A-1: PRE DEVELOPMENT Hydrograph 1 -L_ _-1--'__`-_.a_. --- --- ®Runoff 0.48 / _ _ 0.46 _-;-_' _ __' _..; '__�==' yp0" 24 0.44 i 0.42 _ __� �__'�____ = ==t==1�= ='=Rain [C== 0.4 - ---- 0.38 - --; -;--; - -- -, --- ,--', - ,-- - - --:-- -'A `aT4 - -- -- -- -- 0.32 -- 0.3 T--I--;--r-Z- .- I----7- --( - .- '{ -;--,--i-T -T- 7--i-- - -1-- 0.28 - --'- ---- - --I- - -J--- - ;--L ;--I-Run6lf©eptti- .831, - ` T - - --- - 3 0.26 -L--.--,-- -; -- - : - - ,--,----, 0 0.24 - - --(--t - - a--'--=- -J--'- --'--'--' - --'--!-C `r�- u- 0.22 -;--,--, ---; ---,-- --,-- - ,- ;-;- ;--, -, - O.Z _1._J__:__L_1-J__i__L-.S-J__1_ _;__;_-L-J-_i.__:__1_ ! _ _' - I I I , f , 1 - i : ( L in 0.16 ` _1._.i__:__L_-.__-__i_-�,_1_J.__I_ _I_-i__ L.__I__!___I__ -1_ __..L-I•_J___�5■. 0.14 -- --{- -t--i--i--,---- �-7 ---i - r--i-�----.---- ---I--,--�-i--�- .} V 0.12 - -- �- -- - -- - - -- -'--- -'-- - -t-- -'-- 0.08 -'--' -=--'--I- L-=- -' -L-i - '- -'--'-- - '-- 7 { 1 1 1 I -t-�� i 0.06 0.04 0.02 . 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PRE Type III 24-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 13 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 12/22/2005 Pond M SUMATION POND Inflow Area= 45,894 sf, Inflow Depth= 0.83" for 2 Year event Inflow = 0.46 cfs @ 12.59 hrs, Volume= 3,167 cf Outflow = 0.46 cfs @ 12.59 hrs, Volume= 3,167 cf, Atten=0%, Lag=0.0 min Primary = 0.46 cfs @ 12.59 hrs, Volume= 3,167 cf Routing by Stor-Ind method,Time Span=0.00-30.00 hrs, dt= 0.01 hrs Peak Elev=0.00' @ 12.59 hrs Surf.Area=0.000 ac Storage=0.000 of Plug-Flow detention time= 0.0 min calculated for 3,166 cf(100% of inflow) Center-of-Mass det.time= 0.0 min (905.4-905.4) Volume Invert Avail.Storage Storage Description #1 0.00' 0.001 of Custom Stage Data Listed below Elevation Inc.Store Cum.Store (feet) (acre-feet) (acre-feet) 0.00 0.000 0.000 10.00 0.001 0.001 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0'long x 9.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.46 2.55 2.70 2.69 2.68 2.68 2.67 2.64 2.64 2.64 2.65 2.64 2.65 2.65 2.66 2.67 2.69 Primary OutFlow Max=0.04 cfs @ 12.59 hrs HW=0.00' (Free Discharge) t1=Broad-Crested Rectangular Weir (Weir Controls 0.04 cfs @ 0.1 fps) LOT I GREAT POND ROAD, NORTH ANDOVER- PRE Type III 24-hr 2 Year Rainfall=3.20' Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 14 HydroCADO 7.10 sln 002248 0 2005 HydroCAD Software Solutions LLC Pond iP: SUMATION POND Hydrograph T-1 i 1� FU lnmw c Primary nflow, Arlea-7-45,8 i J 0.45 I I et6if-0 00 ' ftak , 17 Storan e:;0.00 if 0.35 0 3 t 01.2 U. 0.2 jt­ -L _1_J__j- OA5 0.1 j I t 0.05 0 0 1 2 3 4 5 6 7 8 9 1.0 11 1-2 1-3 14 15 1.6 17 1*8 19 20 2v1 22 23 24 25 26 27 ii'29 iO Time (hours) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PRE Type 111 24-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 15 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 12/2212005 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 A-1: PRE DEVELOPMENT Runoff Area=45,894 sf Runoff Depth=1.74" Flow Length=351' Tc=38.0 min CN=70 Runoff--1.06 cfs 6,673 cf Pond 1P: SUMATION POND Peak Elev=0.00' Storage=0.000 of Inflow--1.06 cfs 6,673 cf Outflow--1.06 cfs 6,673 cf Total Runoff Area=45,894 sf Runoff Volume=6,673 cf Average Runoff Depth= 1.74" LOT 1 GREAT POND ROAD, NORTH ANDOVER- PRE Type III 24-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 16 HydroCAD®7A0 s/n 002248 ©2005 HydroCAD Software Solutions LLC 12/2212005 Subcatchment A-1: PRE DEVELOPMENT Runoff = 1.06 cfs @ 12.54 hrs, Volume= 6,673 cf, Depth= 1.74" 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 45,894 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 28.3 100 0.0400 0.1 Sheet Flow, Woods: Dense underbrush n=0.800 P2=3.20° 9.7 251 0.0300 0.4 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 38.0 351 Total Subcatchment A-1: PRE DEVELOPMENT Hydrogmph SaBSts, ; , ; I 1 - , ---r-, -,--f-- -- -, - . --!----;-- Pe cif -hr�1 }�( ar- Rainfall=4.60„ ` t Rblnoff,Area-=45 894 sf ;I unoff;VP11,ume='!6;6' 31 Cf Runoff be,Pth=1.7`4" 3 t t i i 3 � i i I ; 1 Leh LL Flo i ur co' th=351*' ! I ', I I T6=38',',0-1 --C 1� I 1 l 1 I t S 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER- PRE Type III 24-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 17 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 12/22/2005 Pond 1 P: SUMATION POND Inflow Area= 45,894 sf, Inflow Depth= 1.74" for 10 Year event Inflow = 1.06 cfs @ 12.54 hrs, Volume= 6,673 cf Outflow = 1.06 cfs @ 12.54 hrs, Volume= 6,673 cf, Atten=0%, Lag=0.0 min Primary = 1.06 cfs @ 12.54 hrs, Volume= 6,673 cf Routing by Stor-Ind method,Time Span=0.00-30.00 hrs,dt=0.01 hrs Peak Elev=0.00' @ 12.54 hrs Surf.Area=0.000 ac Storage=0.000 of Plug-Flow detention time=0.0 min calculated for 6,671 cf(100% of inflow) Center-of-Mass det.time=0.0 min(881.9- 881.9) Volume Invert Avail.Storage Storage Description #1 0.00, 0.001 of Custom Stage Data Listed below Elevation Inc.Store Cum.Store (feet) (acre-feet) . (acre-feet) 0.00 0.000 0.000 10.00 0.001 0.001 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0'long x 9.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.46 2.55 2.70 2.69 2.68 2.68 2.67 2.64 2.64 2.64 2.65 2.64 2.65 2.65 2.66 2.67 2.69 Primary OutFlow Max=0.12 cfs @ 12.54 hrs HW=0.00' (Free Discharge) L1=Broad-Crested Rectangular Weir (Weir Controls 0.12 cfs @ 01 fps) LOT I GREAT POND ROAD, NORTH ANDOVER- PRE Type III 24-hr 10 Year Rainfa11=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 18 HydroCADO.7.10 s/n 002248 0 2005 HydroCAD Software Solutions LLC 12/2212005 Pond iP: SUMATION POND Hydrograph FIB Inflow N Primary jnfloyv ►x�a=46;894- f. Peiak Ele��O.QO', 9for, ine, 40'.0,00, it I I T t • Kama ............ ............ 1 2--31, 4 5 6 7 8 9 10 11 12 13 1*4 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Time (hours) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PR Type 111 24-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 19 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 12/22/2005 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 A-1: PRE DEVELOPMENT Runoff Area=45,894 sf Runoff Depth=3.13" Flow length=351' Tc=38.0 min CN=70 Runoff--1.95 cfs 11,955 cf Pond 1P: SUMATION POND Peak Elev=0.00' Storage=0.000 of Inflow-0.95 cfs 11,955 cf Outflow--1.95 cfs 11,955 cf Total Runoff Area=45,894 sf Runoff Volume=11,956 cf Average Runoff Depth=3.13" LOT 1 GREAT POND ROAD, NORTH ANDOVER- PR Type 11124-hr 900 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 20 HydroCAD®7.10 s/n 002248 Q 2005 HydroCAD Software Solutions LLC 12/2212005 Subcatchment A-1: PRE DEVELOPMENT Runoff = 1.95 cfs @ 12.54 hrs, Volume= 11,955 cf, Depth= 3.13" 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 45,894 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (Rift) (ft/sec) (cfs) 28.3 100 0.0400 0.1 Sheet Flow, Woods: Dense underbrush n=0.800 P2=3.20" 9.7 251 0.0300 0.4 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 38.0 351 Total Subcatchment A-1: PRE DEVELOPMENT Hydrograph t1 I , t i 1 I I i I 1 t i i I I I i 1 1 E Runoff I;II , `r '10',0 I, 'a' Yp� - IYer t Rai f' 44.40 r- i Runoff Area=451894 sf 1 I I 1 1 S I I 1 t t l Runoff,Volurhe"11'966 cf F f �Rirnoff Mpfh=J.13" + f I I t I 1 , ! , -P- -,----� - T--f-- -i- -It'-, -=--I--I'- --I�jOT 1 - -t-n w.t -`351x. w I U. I 1 i i t 4 1 c=3$.0, mire CN-`70 I 1 . i � ! i 1 i t I 1 1 t I L ( I I I I I { 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER- PR Type III 24-hr 100 year Rainfal1=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 21 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 12122/2005 Pond 11P: SUMATION POND Inflow Area= 45,894 sf, Inflow Depth= 3.13" for 100 year event Inflow = 1.95 cfs @ 12.54 hrs, Volume= 11,955 cf Outflow = 1.95 cfs @ 12.54 hrs, Volume= 11,955 cf, Atten= 0%, Lag=0.0 min Primary = 1.95 cfs @ 12.54 hrs, Volume= 11,955 cf Routing by Stor-Ind method,Time Span=0.00-30.00 hrs, dt= 0.01 hrs Peak Elev=0.00' @ 12.54 hrs Surf.Area=0.000 ac Storage=0.000 of .Plug-Flow detention time= 0.0 min calculated for 11,951 cf(100% of inflow) Center-of-Mass det.time= 0.0 min(864.8-864.8) Volume Invert Avail.Storage Storage Description #1 0.00' 0.001 of Custom Stage Data Listed below Elevation Inc.Store Cum.Store (feet) (acre-feet) (acre-fMt 0.00 0.000 0.000 10.00 0.001 0.001 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' long x 9.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.46 2.55 2.70 2.69 2.68 2.68 2.67 2.64 2.64 2.64 2.65 2.64 2.65 2.65 2.66 2.67 2.69 Primary OutFlow Max=0.31 cfs @ 12.54 hrs HW=0.00' (Free Discharge) - t1=Broad-Crested Rectangular Weir (Weir Controls 0.31 cfs @ 0.1 fps) LOT i GREAT POND ROAD, NORTH ANDOVER- PR Type 11124-hr 100 year Rainfatf=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 22 HydroCAM7.10 s/n 002248 0 2005 HydroCAD Software Solutions LLC 12/22/2005 Pond IP: SUMATION POND Hydrograph a inflow I F i 11 Primary 2 Itifl' Ar�a' 45.,894 'S if Qw . Peak EleViii'"O.00', l 8 to r ! a'ge' :;' 0.6 0 6 'at I I I t i I i ol .......... .......... .............. ............... 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) POST DEVELOPMENT ANALYSIS 23 S CATCH A-2 x SUBCATCH 1 A4 INFI RATOR SYSTEM DETENTI N POND ' #y SUBCAT HMENT A-3 BCATCHMENT A-4 OUTLET STRUCTURE SUMATION POND L>fIJ('+a Reach Oh„ L111k Drainage Diagram for LOT 1 GREAT POND ROAD,NORTH ANDOVER- POST DEV - Prepared by NEW ENGLAND ENGINEERING SERVICES INC. 3/7/2006 HydroCAD®7.10 s/n 002248 0 2005 HydroCAD Software Solutions LLC LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 25 H droCADO 7.10 s/n 002248 ©2005 H droCAD Software Solutions LLC 3/7/2006 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment A-1: SUBCATCH A-1 Runoff Area=37,652 sf Runoff Depth=0.79" Flow Length=318' Tc=27.0 min CN=78 Runoff-0.44 cfs 2,472 cf Subcatchment A-2: SUBCATCH A-2 Runoff Area=2,681 sf Runoff Depth=2.27" Flow Length=150' Tc=1.1 min CN=98 Runoff=0.18 cfs 507 cf Subcatchment A-3: SUBCATCHMENT A-3 Runoff Area=3,062 sf Runoff Depth=0.46" Flow Length=110' Tc=15.5 min CN=70 Runoff=0.02 cfs 116 cf Subcatchment A-4: SUBCATCHMENT A-4 Runoff Area=2,517 sf Runoff Depth=0.46" Flow Length=55' Tc=13.3 min CN=70 Runoff--0.02 cfs 95 cf Pond P1: INFILTRATOR SYSTEM Peak EIev=125.90' Storage=507 cf Inflow--0.18 cfs 507 cf 6.0"x 35.0'Culvert Outflow--0.00 cfs 0 cf Pond P2: DETENTION POND Peak EIev=119.34' Storage=738 cf Inflow--0.44 cfs 2,472 cf Outflow=0.18 cfs 2,409 cf Pond P3: OUTLET STRUCTURE Peak EIev=119.10' Storage=3 cf Inflow=0.18 cfs 2,409 cf 15.0"x 20.0' Culvert Outflow=0.18 cfs 2,409 cf Pond P4: SUMATION POND Peak EIev=0.00' Storage=0.000 of Inflow--0.20 cfs 2,621 cf Outflow=0.20 cfs 2,625 cf Total Runoff Area=45,912 sf Runoff Volume=3,191 cf Average Runoff Depth=0.83" LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 1 year Rainfall=2.500 Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 26 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-1: SUBCATCH A-i Runoff = 0.44 cfs @ 12.41 hrs, Volume= 2,472 cf, Depth= 0.79" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 1 year Rainfall=2.50" Area (sf) CN Description 7,499 70 Woods, Good, HSG C 22,446 74 >75% Grass cover, Good, HSG C 3,506 98 PAVED DRIVEWAY 535 98 STONE WALL 1,916 98 DETENTION POND 1,750 98 POOL AREA 37,652 78 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 50 0.0200 0.0 Sheet Flow,WOODS Woods: Dense underbrush n= 0.800 P2= 3.20" 4.7 100 0.0200 0.4 Shallow Concentrated Flow, FLOW THROUGH WOODS Forest w/Heavy Litter Kv= 2.5 fps 0.6 125 0.0560 3.5 Shallow Concentrated Flow, GRASS SWALE Grassed Waterway Kv= 15.0 fps 0.0 10 5.7 Lake or Reservoir,SEDIMENT FOREBAY Mean Depth= 1.00' 0.2 33 0.0030 2.9 2.31 Circular Channel (pipe), FLOW UNDER DRIVE Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.011 Concrete pipe, straight,&clean 27.0 318 Total LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 27 HydroGAD®7.10 s/n 002248 Q 2005 HydroCAD Software Solutions LLC 317/2006 Subcatchment A-1: SUBCATCH A-1 Hydrograph 0.48. : 046 0.44-: 11124_--hr- 1, _year_ 0.42 - 0.38 Ra_infatf-2:50"_ _ - ,- _ Runo'ff Area;3-7 -5f=- 0.36 - - 0.34 p- - 0.32 - - - - -- Rut1O,,ff VOt1ume=L��#7L;.�'i -- 0.3 -- - 0.28 - 0.26 = --: -- Runoff-De`pf 0.24 - - - u, 0.22 ;-- f6W-Lengtl'` '318'-- 0.2 — - --; --- --- -- - 0.18 - - - TC=`17,;-0 t#1m- - 0.16 - - - - - - -- ---- 0.14 - - - - -- CN-7 8-- 0.12 - -.- -- -- - .- --. - - • - .------ - : 0.08 - - - --- - -- - ---- 0.06 -- --- - -- - - 0.04 = — - 0.02 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 28 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 317/2006 Subcatchment A-2: SUBCATCH A-2 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.18 cfs @ 12.02 hrs, Volume= 507 of, Depth= 2.27" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 1 year Rainfall=2.50" Area (sf) CN Description 2,681 98 DWELLING &GARAGE ROOF RUNOFF To Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.4 35 0,0366 1.4 Sheet Flow, ROOF RUNOFF Smooth surfaces n= 0.011 P2= 3.20" 0.7 115 0.0100 2.8 0.25 Circular Channel (pipe),4" PIPE FROM DOWNSPOUT TO INFIL Diam=4.0" Area= 0.1 sf Perim= 1.0' r= 0.08' n= 0.010 PVC, smooth interior 1.1 150 Total Subcatchment A-2: SUBCATCH A-2 Hydrograph 0.19 • ,-_. -- --- - - _ -_ _ _ -__ Ail ific 0.18 - - - - _ 0.17 Tp� 111-:24=hr - year_ 0.16-- - - - _ 0.15 0.14 - _ - Area-=-2.6-81 if 0.,3 -tunof - -- 0.12-: RU. 1 ff'VolLlt ;em -50 :cf-- 0.11: - - - --- - - -- -- 0os - - -- Runoff--DQpth=,2.27" - LL - - --- - --i - :-- - -- 0.06 - Flow Length 0.07 0.06 - - -T - -1' =1._1 min - 0.05 0.04 - - - 0.03 ; 0.02-' .- - ' - - - - --- 0.01 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 1'4­15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type Ill 24-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 29 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-3: SUBCATCHMENT A-3 Runoff - 0.02 cfs @ 12.26 hrs, Volume= 116 cf, Depth= 0.46" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 1 year Rainfall=2.50" Area (sf) CN Description 3,062 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (fs) 13.9 50 0.0590 0.1 Sheet Flow, FLOW IN WOODS Woods: Dense underbrush n=0.800 P2= 3.20" 1.6 60 0.0590 0.6 Shallow Concentrated Flow, FLOW IN WOODS Forest w/Heavy Litter Kv=2.5 fps 15.5 110 Total Subcatchment A-3: SUBCATCHMENT A-3 Hydrograph 0.023 - - - - - - _ ®Runoff 0.022 _ _ 0.02 cfs:°: - - - ' -- '-- 0021 - -Tyke Itt 24-fir 1 dear - 0.02 - - - - 0.017 - - - '`'3,062 S _- 0.016 -- - - -- -Runs Area- - 0.0,5 - Runof# Il�-knie= 0.014 - - -- -- :- Ac 0.013 0.012 -- - i e g11d ptt -' , 00.011 -; - — =- - - - - - lUermt 0.008 0.007 =Tc=:1 :5=main-_ 0.006 _ _ - -C-':N—�j 0.005 ii0 0.004 - - - - 0.003 - 0.002 - - •-- -- - - - -- - 0.001 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER- POST Type IN 24-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 30 H droCADO 7.10 s/n 002248 ©2005 H droCAD Software Solutions LLC 3/7/2006 Subcatchment A-4: SUBCATCHMENT A-4 Runoff - 0.02 cfs @ 12.22 hrs, Volume= 95 cf, Depth= 0.46" Runoff by SCS TR-20 method, UH=SCS, Time Span=0.00-30.00 hrs, dt=0.01 hrs Type III 24-hr 1 year Rainfall=2.50" Areas CN Description 2,517 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.3 55 0.0200 0.1 Sheet Flow, FLOW IN WOODS Woods: Light underbrush n= 0.400 P2= 3.20" Subcatchment A-4: SUBCATCHMENT A-4 Hydrograph -- _ - - ®Runoff 0.02 - - 0.019 0.018 pe ICI-24r -year - 0.017 - - 0.016 - Rai lnf ll=.2.50" - 0.015 _ - - - Rf Aea-2,51 7 Sfuao 0.0,4 - 0.0,2 - - Runoff_Volume , Cf- 0 EL 0.009 - Flow LIn fh—W- - 0.008 0.007 - -- - - - - - _ 0.006 - --- - - --TG=13. =min-- 0.005 0.004 - ,- - -- 0.003 : . 0.002 0.001 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 31 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P1: INFILTRATOR SYSTEM Inflow Area= 2,681 sf, Inflow Depth = 2.27„ for 1 year event Inflow = 0.18 cfs @ 12.02 hrs, Volume= 507 cf Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 100%, Lag=0.0 min Primary - 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt=0.01 hrs Peak Elev= 125.90' @ 24.07 hrs Surf.Area= 808 sf Storage= 507 cf Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Inv_ ert Avail Storage Storage Description #1 124.83' 576 cf Custom Stage Data (Prismatic) Listed below 1,883 cf Overall -442 cf Embedded = 1,440 cf x 40.0%Voids #2 125.33' 442 cf 28.9"W x 16.0"H x 7.12%StormTech SC-310 x 30 Inside#1 1,018 of Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 4 124.83 808 0 0 127.16 808 1,883 1,883 Device Routing Invert Outlet Devices #1 Primary 127.00' 6.0" x 35.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 123.00' S= 0.1143'P Cc= 0.900 n= 0.010 PVC, smooth interior Primary OutFlow Max--0.00 cfs @ 0.00 hrs HW=124.83' TW=118.90' (Dynamic Tailwater) t-1=Culvert (Controls 0.00 cfs) LOT I GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 32 HydroCADO 7.10 s/n 002248 0 2005 HydroCAD Software Solutions LLC 3/7/2006 Pond PI: INFILTRATOR SYSTEM Hydrograph FE inflow a Prima 0.19 16,81 0.1$ nfloww, 0.17 t126.90' 0.16 akfl, Ov. 0.14 07- 0.13 v 36J 0.12 ----- 0.1- 0.09- LL 0.07 _2 0.06 0.05 0.04 0.03 0*02 0 0 1 2 3 4 5 6 7 8 9 0 11 12 13 1 1 1 5 1 1 6 1 1 7 1 1 8 1 1 9 2 1 0 2 1 1 2 1 2 2 1 3 2'4 25 26 27 28 29 30 Time (hours) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type I//24-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 33 HydroCADO 7.10 s/n 002248 d 2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P2: DETENTION POND Inflow Area= 40,333 sf, Inflow Depth = 0.74" for 1 year event Inflow = 0.44 cfs @ 12.41 hrs, Volume= 2,472 cf Outflow = 0.18 cfs @ 12.92 hrs, Volume= 2,409 cf, Atten= 58%, Lag= 30.6 min Primary = 0.18 cfs @ 12,92 hrs, Volume= 2,409 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 119.34' C 12.92 hrs Surf.Area= 1,618 sf Storage=738 of Plug-Flow detention time= 99.0 min calculated for 2,408 cf(97% of inflow) Center-of-Mass det. time= 84.9 min (968.2-863.3) Volume Invert Avail.Storage Storage Description #1 118.90' 4,018 cf Custom Stage Data (Prismatic) Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 118.90 1,417 0 0 120.00 1,916 1,833 1,833 121.00 2,454 2,185 4,018 Device Routing Invert Outlet Devices #1 Primary 118.90' 4.0" x 1.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 118.90' S=0.0000'P Cc=0.900 n=0.011 #2 Primary 119.50' 8.0" x 1.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 119.50' S= 0.0000'P Cc=0.900 n= 0.011 Primary OutFlow Max=0.18 cfs @ 12.92 hrs HW=119.34' TW=119.10' (Dynamic Tailwater) LCulvert (Barrel Controls 0.18 cfs @ 2.1 fps) 2J=Culvert (Controls 0.00 cfs) LOT 1 GREAT POND ROAD, NORTH ANDOVER r POST Type N124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 34 HydroCAD®7.10 s/n 002248 0 2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P2: DETENTION POND Hydrograph - - - ®Inflow 0.48 ®Primary 044 = Inflow Ares=40,33 $-f. 0.42 - - Reak Elev=119.34' 0.4 0.38 - 0.36 a7fio'rage-738 cf 0.34 -- --- - - - - - 0.32 - 0.3 - - - J 0.28 --_ - - - - 0.26 - - - - -- - - - 0.24 0.22 - 0.2 0.18 - 0.16 - 0.14 -- - - - 0.12 -_- 0.1 - - 0.08 - - 0.06 - 0.04 0.02 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 35 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC - 3/7/2006 Pond P3: OUTLET STRUCTURE Inflow Area = 40,333 sf, Inflow Depth >Volume=0.72" for 1 year event 2 Inflow = 0.18 cfs @ 12.92 hrs, ,409 cf Outflow = 0.18 cfs @ 12.92 hrs, Volume= 2,409 cf, Atten= 0%, Lag=0.1 min Primary = 0.18 cfs @ 12.92 hrs, Volume= 2,409 cf Routing by Dyn-Stor-Ind method,Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 119.10' @ 12.92 hrs Surf.Area= 13 sf Storage= 3 cf Plug-Flow detention time= 0.4 min calculated for 2,408 cf(100% of inflow) Center-of-Mass det.time= 0.3 min ( 968.5-968.2) Volume Invert Avail Storage Storage Description #1 118.90' 34 cf Custom Stage Data(Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 118.90 13 0 0 121.50 13 34 34 Device Routing Invert Outlet Devices #1 Primary 118.90' 15.0" x 20.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 118.70' S=0.0100'P Cc=0.900 n= 0.011 Primary OutFlow Max=0.18 cfs @ 12.92 hrs HW=119.10' TW=0.00' (Dynamic Tailwater) t 1=Culvert (Barrel Controls 0.18 cfs @ 2.3 fps) Pond P3: OUTLET STRUCTURE Hydrograph _ - - 0 inflow -- - 0 Primary 0.2 _ - 0.,9 - - e #nlovv Area=40,,333 sf- 0.18 0.17 _ - - P-ea�c';-00=1-19.1 0.16 - 0.15 t©rage=3-cf - 0.14 - - -.. - - 0.13 - 15.0". -20.0' Ctl�rer# 0.12 0.11 - - - - -_ LL 0.09 0.07 0.06 , - 0.04 - 0.03- - 0.02 0.01 ' 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type /1124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 36 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P4: SUMATION POND Inflow Area= 45,912 sf, Inflow Depth > 0.68" for 1 year event Inflow = 0.20 cfs @ 12.85 hrs, Volume= 2,621 cf Outflow = 0.20 cfs @ 12.85 hrs, Volume= 2,625 cf, Atten=0%, Lag=0.0 min Primary = 0.20 cfs @ 12.85 hrs, Volume= 2,625 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt=0.01 hrs Peak Elev= 0.00' @ 12.85 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det.time= 0.4 min (963.8-963.4) Volume Invert Avail.Storage Storage Description #1 0.00' 0.001 of Custom Stage Data Listed below Elevation Inc.Store Cum.Store (feet) (acre-feet) (acr(tfeet) 0.00 0.000 0.000 10.00 0.001 0.001 _Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' long x 9.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.46 2.55 2.70 2.69 2.68 2.68 2.67 2.64 2.64 2.64 2.65 2.64 2.65 2.65 2.66 2.67 2.69 Primary OutFlow Max=0.20 cfs @ 12.85 hrs HW=0.00' (Free Discharge) t-1=13road-Crested Rectangular Weir (Weir Controls 0.20 cfs @ 0.1 fps) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 1 year Rainfall=2.50" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 37 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P4: SUMATION POND Hydrograph -_ - - - -- ®Inflow 0.21 o2ods 11 Primary 0.2 Infilow Q► a=45, a-2 sf- 0.19 0.16 - Peak-00V=01.00' - 0.17 - -- - --- - - 0.16 . y St0M,-- a=0.000 of- - 0.15 0.14 - - - - 0.13 0.12 - 3 0.11 - -- --- = - - 0 0.1 U. 0.09 - .. 0.08 - ,-- - - - - - - - 0.07 - 0.06 - 0.05 -. -- - - - 0.04 - - -. --:-- -- - --. 0.03 " , -- - - - , D.02 i - - ---, - 0.01 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 'rime (hours) LOT 1 GREAT POND ROAD, NORTH ANDOVER.- POST Type 11124-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 38 HydroCADD 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment A-1: SUBCATCH A-1 Runoff Area=37,652 sf Runoff Depth=1.27" Flow Length=318' Tc=27.0 min CN=78 Runoff=0.75 cfs 3,995 cf Subcatchment A-2: SUBCATCH A-2 Runoff Area=2,681 sf Runoff Depth=2.97" Flow Length=150' Tc=1.1 min CN=98 Runoff=0.23 cfs 663 cf Subcatchment A-3: SUBCATCHMENT A-3 Runoff Area=3,062 sf Runoff Depth=0.83" Flow Length=110' Tc=15.5 min CN=70 Runoff--0.05 cfs 211 cf Subcatchment A-4: SUBCATCHMENT A-4 Runoff Area=2,517 sf Runoff Depth=0.83" Flow Length=55' Te=13.3 min CN=70 Runoff--0.04 cfs 174 cf Pond P1: INFILTRATOR SYSTEM Peak Elev=126.19' Storage=663 cf Inflow--0.23 cfs 663 cf 6.0"x 35.0'Culvert Outflow--0.00 cfs 0 cf Pond P2: DETENTION POND Peak Elev=119,64' Storage=1,229 cf Inflow--0.75 cfs 3,995 cf Outflow=0.33 cfs 3,929 cf Pond P3: OUTLET STRUCTURE Peak Elev=119.17' Storage=3 cf Inflow=0.33 cfs 3,929 cf 15.0"x 20.0'Culvert Outflow--0.33 cfs 3,928 cf Pond P4: SUMATION POND Peak Elev=0.00' Storage=0.000 of Inflow=0.35 cfs 4,313 cf Outflow--0.35 cfs 4,318 cf Total Runoff Area=45,91129f Runoff Volume- 6,0430 Average Runoff Depth=1.32" LOT 1 GREAT POND ROAD, NORTH ANDOVER- POST Type 11124-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 39 HydroCADO 7.10 s/n 002248 0 2005 HydroCAD Software Solutions LLC 317/2006 Subcatchmeht A-1: SUBCATCH A-1 Runoff = 0.75 cfs @ 12.39 hrs, Volume= 3,995 cf, Depth= 1.27" 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 (M CN Description 7,499 70 Woods, Good, HSG C 22,446 74 >75% Grass cover, Good, HSG C 3,506 98 PAVED DRIVEWAY 535 98 STONE WALL 1,916 98 DETENTION POND 1,750 98 POOL AREA 37,652 78 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 50 0.0200 0.0 Sheet Flow,WOODS Woods: Dense underbrush n= 0.800 P2= 3.20" 4.7 100 0.0200 0.4 Shallow Concentrated Flow, FLOW THROUGH WOODS Forest w/Heavy Litter Kv= 2.5 fps 0.6 125 0.0560 3.5 Shallow Concentrated Flow,GRASS SWALE Grassed Waterway Kv= 15.0 fps 0.0 10 5.7 Lake or Reservoir, SEDIMENT FOREBAY Mean Depth= 1.00' 0.2 33 0.0030 2.9 2.31 Circular Channel (pipe),FLOW UNDER DRIVE Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n=0.011 Concrete pipe, straight&clean 27.0 318 Total LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr2 Year Rainfall=3,20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 40 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-1: SUBCATCH A-1 Hydrograph 0.8 ®Runoff - - - - -- - D 0.75 _ Type: lit 4-hr Yeah-- 0.7-' Rainfall"12 --, - 0.65 0.6 '.Runoff;Area V,652 sf-- 0.55 ' ' 0.5 Ru_r�off 1/olum =$,995;c - 0.45 - - t - - Runoff Qe i6p-117''__ 035 - Ftow Le th 318! ts - 0.25 -- '- -- - --GN-78-- 0.2 - - - - 0.15 -- 0.1 0.05 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type /I/24-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 41 HydroCADO 7.10 s/n 002248 4 2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-2: SUBCATCH A-2 [49] Hint: Tc<2dt may require smaller dt Runoff = 0.23 cfs @ 12.02 hrs, Volume= 663 of, Depth= 2.97" 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 2,681 98 DWELLING &GARAGE ROOF RUNOFF Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.4 35 0.0366 1.4 Sheet Flaw, ROOF RUNOFF Smooth surfaces n= 0.011 P2= 3.20" 0.7 115 0.0100 2.8 0.25 Circular Channel(pipe),4" PIPE FROM DOWNSPOUT TO INFIL Diam=4.0" Area= 0.1 sf Perim= 1.0' r=0.08' n= 0.010 PVC, smooth interior 1.1 150 Total Subcatchment A-2: SUBCATCH A-2 Hydrograph 015 -- 0.24 0.23 - - Runoff 0.22 - - - �' pe 1�1-24- it 2-Year-- 0.21 - - fa 0.19 - - --- 0.2 _ - _ - =Rai=lf�al,f= 2 ' 0.17 = _ __ _ _ =R0- ff Area=2681 sf = 0.16 - - 0.,5 Runo ff V6 1u Me=66� ef-- 0.14 - - -- -- - ------ -- . --. - - .---- - 0:;2 - -_ = Runb# th=2;97"'__ E 0.11 - - -- - o, - - F1o�v Leggth=1 SO! == 0.09 - 0:0� - - _ -- _ Tc= mein 0.06 - - - -- ----- 0.05 - - b►1V�7 - 0.04 --- 0.03 - 0.02 --'-- - - - 0.01 - - 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 42 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-3: SUBCATCHMENT A-3 Runoff = 0.05 cfs @ 12.24 hrs, Volume= 211 cf, Depth= 0.83" 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) ON Description 3,062 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.9 50 0.0590 0.1 Sheet Flow, FLOW IN WOODS Woods: Dense underbrush n=0.800 P2= 3.20" 1.6 60 0.0590 0.6 Shallow Concentrated Flow, FLOW IN WOODS Forest w/Heavy Litter Kv= 2.5 fps 15.5 110 Total Subcatchment A-3: SUBCATCHMENT A-3 Hydrograph 0.05 0.048-: - - - -- 0.046 0.044 - - ,Type EN-24-hr 2_ ear- 0.042 - ._ ; __ . - - -- 0.oa - - . - R' 10 0117 20"-- 0.038 - - - 0.036 - A - U.034 = '- -RU n Area =3,06 sf - 0.032 0.03 - - -- Runof#Volum' e-, 211 �# - 0 .028 -- r - Ruin -- - ;- ,n- -,- - 0.024 - ;-- M 0.022 - - - - - - --'- - FI&W Len - #h=110 0.02 - - 0.o16 - _ - -=----'- -- '-g--- - - - 0.016- ' - = - : - -- - - - c=.1 - - -- 0.012 - - - - - 0.01- - - ,-- - - 0.008 - 0.006 _ --- - - - --- ,- - - 00 4 0.002 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER- POST Type I// 24-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 43 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-4: SUBCATCHMENT A-4 Runoff - 0.04 cfs @ 12.20 hrs, Volume= 174 cf, Depth= 0.83" 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 2,517 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.3 55 0.0200 0.1 Sheet Flow, FLOW IN WOODS Woods: Light underbrush n= 0.400 P2= 3.20" Subcatchment A-4: SUBCATCHMENT A-4 Hydrograph 0.042 ®Runoff 0.04 -- - awns_ - 0.036 -- - 'type 01 24-hr 2-Year-- 0.036 - -=, - - --- --- - -- -- - O.034 - -- - - - - slll#11(=3«201' - 0.032 - - - -- 0.03 Runoff Area=2,57 s# 0.028 - -- - - ' - —=--'- :- ' -- - 0.026 - -- - - -- Runoff'Volum' 4' 1-74-cf- v0.024 _ - - -'- -- - - --' - -- 0.022 " 3 - - - 0 - 0.02 I v €f-Dept :.O i ' LL 0.01$ - Flow Length-5 -- 0.016 - - - - ----- -L- -- - 0.014 0.012 Ci 1- - - - -- �- ln,llj-- T 0.01 - - 0.008 C;N-7(�-- _ _ _,-_, 0+ 0.006 - - - 0.004 - - -- - 0.002 00 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type Ill 24-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 44 HydroCAD®7.10 s/n 002248 4 2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P1: INFILTRATOR SYSTEM Inflow Area = 2,681 sf, Inflow Depth = 2.97" for 2 Year event Inflow = 0.23 cfs @ 12.02 hrs, Volume= 663 cf Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 100%, Lag= 0.0 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method,Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 126.19' @ 24.07 hrs Surf.Area= 808 sf Storage=663 cf Plug-Flow detention time= (not calculated: initial storage excedes outflow) Center-of-Mass det.time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 124.83' 576 cf Custom Stage Data (Prismatic)Listed below 1,883 cf Overall -442 cf Embedded = 1,440 cf x 40.0%Voids #2 125.33' 442 cf 28.9"W x 16.0"H x 7.12%StormTech SC-310 x 30 Inside#1 1,018 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 124.83 808 0 0 127.16 808 1,883 1,883 Device Routing Invert Outlet Devices #1 Primary 127.00' 6.0" x 35.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 ^ Outlet Invert= 123.00' S= 0.11437 Cc=0.900 n= 0.010 PVC, smooth interior rimary OutFlow Max=0.00 cfs @ 0.00 hrs HW=124.83' TW=118.90' (Dynamic Tailwater) r­1=Culvert (Controls 0.00 cfs) LOT 'I GREAT POND ROAD, NORTH ANDOVER- POST Type 111 24-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 45 HydroCAD®7.10 s/n 002248_©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P1: INFILTRATOR SYSTEM Hydrograph - - - ®Inflow 0.25 o23sts' - - IM Primary 0.23 = - - Infl;ow Anew-, ;681 s#- - -- 0.22 -- -- --. -, , 0.21 _ 0.2 LL __ - - _Ptak-E;l 126. 19`- 0.19 - - 0:;7 - - S#t�rage663 of 0.16 - - 60.E _x 0.15,.. 0.15 - 0.14 --- -- - -- -- ---- -- 0.13 -T - - - - -- 3 0.12 - LL. 0.11 01 - - - -- 0.08 ---- - - - - -- - : - - 0.08 - - --- -- - x- 0.06 --- — -- - 0.05 0.04 - - - -- - --- -- 0.03 - -'--' -- --- - - 0.02 Mogan 0. 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 46 HydroCAM 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P2: DETENTION POND Inflow Area= 40,333 sf, Inflow Depth = 1.19" for 2 Year event Inflow = 0.75 cfs @ 12.39 hrs, Volume= 3,995 cf Outflow - 0.33 cfs @ 12.86 hrs, Volume= 3,929 cf, Atten= 56%, Lag=28.1 min Primary - 0.33 cfs @ 12.86 hrs, Volume= 3,929 cf Routing by Dyn-Star-Ind method,Time Span= 0.00-30.00 hrs, dt=0.01 hrs Peak Elev= 119.64' @ 12.86 hrs Surf.Area= 1,752 sf Storage= 1,229 cf Plug-Flow detention time= 84.7 min calculated for 3,929 cf(98% of inflow) Center-of-Mass det. time= 75.0 min (943.7-868.6) _Volume Invert Avail Storage Storage Description #1 118.90' 4,018 cf Custom Stage Data(Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubiafeet) (cubic-feet) 118.90 1,417 0 0 120.00 1,916 1,833 1,833 121.00 2,454 2,185 4,018 Device Routing� Invert Outlet Devices #1 Primary 118.90' 4.0" x 1.0' long Culvert RCP, square edge headwall, Ke=0.500 Outlet Invert= 118.90' S=0.0000 'P Cc= 0.900 n= 0.011 #2 Primary 119.50' 8.0" x 1.0' long Culvert RCP, square edge headwall, Ke=0.500 Outlet Invert= 119.50' S= 0.0000'P Cc=0.900 n=0.011 Primary OutFlow Max=0.33 cfs @ 12.86 hrs HW=119.64' TW=119.17' (Dynamic Tailwater) LCulvert (Inlet Controls 0.29 cfs @ 3.3 fps) 2=Culvert (Barrel Controls 0.04 cfs @ 1.2 fps) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 47 HydroCAD®7.10 s/n 002248 4 2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P2: DETENTION POND Hydrograph - ®Inflow 0.8 orsers. - - - ®Primary 0.75 Anf'low Area=40�,-333-S#- a 05 -Weak Elev#1'19.64'- 0.6 - - - = S_tora it:0 229 cf 0.55 0.5 : _L � 0.45 -- - -- - --- - ---- - -- - - - - - 0.4 a 0.35:35 b3dd_- 0.3 0.25 - -- 0.2 - 0.15 0.1 0.05 ' 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 48 HydroCADD 7.10 s/n 002248 0 2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P3: OUTLET STRUCTURE Inflow Area= 40,333 sf, Inflow Depth > 1.17" for 2 Year event Inflow = 0.33 cfs @ 12.86 hrs, Volume= 3,929 of Outflow - 0.33 cfs @ 12.86 hrs, Volume= 3,928 cf, Atten= 0%, Lag= 0.1 min Primary = 0.33 cfs @ 12.86 hrs, Volume= 3,928 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt=0.01 hrs Peak Elev= 119.17' @ 12.86 hrs Surf.Area= 13 sf Storage= 3 cf Plug-Flow detention time= 0.3 min calculated for 3,928 cf(100% of inflow) Center-of-Mass det. time=0.3 min (944.0-943.7) Volume Invert Avail Storage Storage Description #1 118.90' 34 cf Custom Stage Data(Prismatic) Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 118.90 13 0 0 121.50 13 34 34 Device Routing Invert Outlet Devices #1 Primary 118.90' 15.0" x 20.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 118.70' S= 0.0100'P Cc= 0.900 n= 0,011 Primary OutFlow Max=0.33 cfs @ 12.86 hrs HW=119.17' TW=0.00' (Dynamic Tailwater) t-1=Culvert (Barrel Controls 0.33 cfs @ 2.6 fps) Pond P3: OUTLET STRUCTURE Hydrograph - -- - ®Inflow 0.36 _ D83c(s _j j i - a Primary - - - - - -InfloW' Area-40; 33-0 - 0.32 - - 0.3. Pk.- �1 ' - , 0.28 ' 0.26 - - Storage=- cf 0.22 - - 5:Q.� x X0.6'-CU-Nei rt 0.18-: - ti 0.14 - - 0. --- 0.12 - - , 0.1 0.08 _ - 0.06 0.04 - - - 0.02 ' 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POST Type 11124-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 49 HydroCADO 7.10 s/n 002248 0 2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P4: SUMATION POND Inflow Area= 45,912 sf, Inflow Depth > 1.13" for 2 Year event Inflow = 0.35 cfs @ 12.84 hrs, Volume= 4,313 cf Outflow = 0.35 cfs @ 12.84 hrs, Volume= 4,318 cf, Atten= 0%, Lag= 0.0 min Primary = 0.35 cfs @ 12.84 hrs, Volume= 4,318 cf Routing by Dyn-Stor-Ind method, Time Span=0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.00' @ 12.84 hrs Surf.Area= 0.000 ac Storage=0.000 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det.time= 0.3 min (938.9-938.6) Volume Invert Avail.Storage Storage Description #1 0.00' 0.001 of Custom Stage Data Listed below Elevation Inc.Store Cum.Store (feet) (acre-feet) (acre-feet) 0.00 0.000 0.000 10.00 0.001 0.001 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' long x 9.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.46 2.55 2.70 2.69 2.68 2.68 2.67 2.64 2.64 2.64 2.65 2.64 2.65 2.65 2.66 2.67 2.69 Primary OutFlow Max=0.35 cfs @ 12.84 hrs HW=0.00' (Free Discharge) L9=Broad-Crested Rectangular Weir (Weir Controls 0.35 cfs @ 0.1 fps) LOT 1 GREAT POND ROAD, NORTH ANDOVER- POST Type 11124-hr 2 Year Rainfall=3.20" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 50 H droCAD®7.10 s/n 002248 ©2005 H droCAD Software Solutions LLC 3/7/2006 Pond P4: SUMATION POND Hydrograph - - -- ®Inflow 7"���a 10 Primary 0.38 assas, --I.n low "" ,,91--2-Sf- b.36 0.34 - - - - 0.32 - - - - eak-E�eu=V'-0W - b.3 _ Storage=x.000 of 0.28 -- 0.24 -- , - - 0.2 - .- 0 0.18 - 0.14 - - -- - - 0.12 " 0.1 - - - 0.08 --'- -- - -- 0.06 -- - -- - - - - 0.04 " 0.02 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type 11124-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 52 HydroCAD®7 10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-1: SUBCATCH A-1 Runoff = 1.43 cfs @ 12.39 hrs, Volume= 7,454 cf, Depth= 2.38" 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 7,499 70 Woods, Good, HSG C 22,446 74 >75% Grass cover, Good, HSG C 3,506 98 PAVED DRIVEWAY 535 98 STONE WALL 1,916 98 DETENTION POND 1,750 98 POOL AREA 37,652 78 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.5 50 0.0200 0.0 Sheet Flow,WOODS Woods: Dense underbrush n= 0.800 P2= 3.20" 4.7 100 0.0200 0.4 Shallow Concentrated Flow, FLOW THROUGH WOODS Forest w/Heavy Litter Kv=2.5 fps 0.6 125 0.0560 3.5 Shallow Concentrated Flow, GRASS SWALE Grassed Waterway Kv= 15.0 fps 0.0 10 5.7 Lake or Reservoir, SEDIMENT FOREBAY Mean Depth= 1.00' 0.2 33 0.0030 2.9 2.31 Circular Channel (pipe), FLOW UNDER DRIVE Diam= 12.0" Area= 0.8 sf Perim= 3.1' r=0.25' n=0.011 Concrete pipe, straight&clean 27.0 318 Total LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type 11124-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 53 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-1: SUBCATCH A-1 Hydrograph ®Runoff Type III '24-hr 10 Year Rainfall 4.60'' Runoff Area 37,652 sf Funoff;vol',ume=7,454';cf Runoff Depth=2.38'' LL Flow Length=318' Tc=27.0 min CN=78 OL 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type 11124-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 54 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3//2006 Subcatchment A-2: SUBCATCH A-2 [491 Hint: Tc<2dt may require smaller dt Runoff = 0.33 cfs @ 12.02 hrs, Volume= 975 cf, Depth= 4.36" 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 2,681 98 DWELLING &GARAGE ROOF RUNOFF Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.4 35 0.0366 1.4 Sheet Flow, ROOF RUNOFF Smooth surfaces n= 0.011 P2= 3.20" 0.7 115 0.0100 2.8 0.25 Circular Channel(pipe),4" PIPE FROM DOWNSPOUT TO INFIL Diam=4.0" Area= 0.1 sf Perim= 1.0' r= 0.08' n= 0.010 PVC, smooth interior 1.1 150 Total Subcatchment A-2: SUBCATCH A-2 Hydrograph 0.36 -- -- ? - FIB Runoff 0.34 aa -- - Yp `e 0.32 ; - , T e-III 2?4-h�-ib"_ ;ar-- 028 /air Falk 4.)60" - 0.24 - - Runoff Area=2,681 sf-_ 0,22: _- _ -- Ruoff Volume= 75 cf-- 3 0.16 -. - - - Ril'nbfi [�4ptlt=430-" - -- 0.14 v� 1_@n'athr- 50' FI O � -- - - - - 0.12 -- c-1 - - - - - .1 m,in 0.08 - N-9 -0.06-0.04-' - - 0.02 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type Ill 24-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 55 HydroCADO 7.10. s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-3: SUBCATCHMENT A-3 Runoff = 0.10 cfs @ 12.22 hrs, Volume= 445 cf, Depth= 1.74" 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 (sfl CN Description 3,062 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.9 50 0.0590 0.1 Sheet Flow, FLOW IN WOODS Woods: Dense underbrush n= 0.800 P2=3.20" 1.6 60 0.0590 0.6 Shallow Concentrated Flow, FLOW IN WOODS _ Forest w/Heavy Litter Kv= 2.5 fps 15.5 110 Total Subcatchment A-3: SUBCATCHMENT A-3 Hydrograph 7- - 7 0.11 0.105- ' - - - - -- -- 0.1 - pe-III, -hr-1D:_-Xear:. - 0.095 - - - -- - -- 0.09 - -- - - - - -- - - Rai fall=4,6 "-- 0.085 - 0.06 - - - Runoff Aea=3,06 f-- 0.075 -- -- -= --'-- --' --' -''--' - -- 0.07 -- - unnff Volume I Cf X0065 - =- _Ru' ,---- -------_ e -4461 ----. - 0.06 - -- RUno#�fl0-P_W 1- 74''-- 30.055 - - - --- -- - -- -- - E 0.05 ' - -- - --- h=1 0'-- �r , 0.045 -[-1O�►_Le4' t - _ 'C - _ - -- 0.04 0.0357: -. - - - - Tri= 1�•3-nl�n - 0.03 - - - - -- --' -- 0.025 -- = - -- = N�70-- 0.02 - ; -, -- -- -- - --,- --- 0.000 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER- POS Type 11124-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 56 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-4: SUBCATCHMENT A-4 Runoff — 0.09 cfs @ 12.19 hrs, Volume= 366 cf, Depth= 1.74" Runoff by SCS TR-20 method, UH=SCS, Time Span=0.00-30.00 hrs, dt=0.01 hrs Type 11124-hr 10 Year Rainfall=4.60" Area (sf) CN Description 2,517 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.3 55 0.0200 0.1 Sheet Flow, FLOW IN WOODS Woods: Light underbrush n=0.400 P2= 3.20" Subcatchment A-4: SUBCATCHMENT A-4 Hydrograph 0.1 - ; 0.095 0.09: 0.085 TYpe-�I124-h r 1�-Y'ear-- - - - - Q.oa - - - c , al� a n 0,075: 4.6 0.07 - - - - -F �roff Aroma=2;5-17-sf - 0.065 Q.06 nof#::1Vo rr a=36fi ef-- 0.055 c 0.05 _ __ U`nffEpth u -x1.-74" - .0.045 - - - - - - _ _ _ '-flow Leiagth 55' 0.04 -- 0.035 0.03 -- 0.025 - , 0.02 -- - - � 0_ 0.015 -- _ r-- , 0.005 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type 11124-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 57 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P1: INFILTRATOR SYSTEM Inflow Area = 2,681 sf, Inflow Depth = 4.36" for 10 Year event Inflow = 0.33 cis @ 12.02 hrs, Volume= 975 cf Outflow = 0.00 cfs @ 24.02 hrs, Volume= 7 of, Atten= 100%, Lag= 720.0 min Primary — 0.00 cfs @ 24.02 hrs, Volume= 7 cf Routing by Dyn-Stor-Ind method, Time Span=0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 127.02' @ 24.02 hrs Surf.Area= 808 sf Storage= 973 cf Plug-Flow detention time= 1,369.8 min calculated for 7 cf(1% of inflow) Center-of-Mass det. time=759.2 min ( 1,504.1 -744.9) Volume Invert Avail.Storage Storage Description #1 124.83' 576 cf Custom Stage Data(Prismatic) Listed below 1,883 cf Overall-442 cf Embedded = 1,440 cf x 40.0%Voids #2 125.33' 442 cf 28.9"W x 16.0"H x 7.12%StormTech SC-310 x 30 Inside#1 1,018 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 124.83 808 0 0 127.16 808 1,883 1,883 Device Routing Invert Outlet Devices #1 Primary 127.00' 6.0" x 35.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 123.00' S= 0.1143'/' Cc=- 0.900 n= 0.010 PVC, smooth interior Primary OutFlow Max=0.00 cfs @ 24.02 hrs HW=127.02' TW=119.06' (Dynamic Tailwater) 'L-1=Culvert (Inlet Controls 0.00 cfs @ 0.5 fps) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type //I 24-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 58 HydroCAD®7 10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P1: INFILTRATOR SYSTEM Hydrograph ®Inflow 0.36 0.33 crs I M Primary 0.34= Inflow Area=2,681 sf 0.32 0.3 Peak Elev=127.02' 0.28 0.26= Storage=973 cf 0.24' of 0.22 6.0 x 35.0 Culvert 0.2- 0.18 0 w 0.16: 0.14- 0.12 0.1 0.08 0.06- 0.04- 1 51i: 0.02-: o.00crs - 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 116'';'7"1'8­1'9"2'0 21 22 23 24 25 26 27 28 29 30 Time (hours) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type 11124-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 59 HydroCAD 8 7 10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P2: DETENTION POND Inflow Area = 40,333 sf, Inflow Depth = 2.22" for 10 Year event Inflow = 1.43 cfs @ 12.39 hrs, Volume= 7,461 cf Outflow = 0.91 cfs @ 12.68 hrs, Volume= 7,388 cf, Atten= 36%, Lag= 17.5 min Primary = 0.91 cfs @ 12.68 hrs, Volume= 7,388 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 120.06' @ 12.68 hrs Surf.Area= 1,949 sf Storage= 1,967 cf Plug-Flow detention time=66.2 min calculated for 7,386 cf(99% of inflow) Center-of-Mass det. time=60.4 min ( 911.4- 851.0) Volume Invert Avail.Storage Storage Description #1 118.90' 4,018 cf Custom Stage Data (Prismatic) Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 118.90 1,417 0 0 120.00 1,916 1,833 1,833 121.00 2,454 2,185 4,018 Device Routing Invert Outlet Devices #1 Primary 118.90' 4.0" x 1.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 118.90' S= 0,0000 '/' Cc= 0.900 n= 0.011 #2 Primary 119.50' 8.0" x 1.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 119.50' S= 0.0000'/' Cc=0.900 n= 0.011 Primary OutFlow Max=0.91 cfs @ 12.68 hrs HW=120.06' TW=119.38' (Dynamic Tailwater) �I=Culvert (Inlet Controls 0.35 cfs @ 4.0 fps) 2=Culvert (Barrel Controls 0.56 cfs @ 2.4 fps) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type 11124-hr 90 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 60 HydroCADS 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P2: DETENTION POND Hydrograph ®Inflow 1.43 as Primary Inflow Area=40,333 sf Peak Elev=120.06' Storage=1,967 cf . 1- Os�as 0 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type /II 24-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 61 HydroCADO 7 10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P3: OUTLET STRUCTURE Inflow Area= 40,333 sf, Inflow Depth> 2.20' for 10 Year event Inflow = 0.91 cfs @ 12.68 hrs, Volume= 7,388 cf Outflow = 0.91 cfs @ 12.68 hrs, Volume= 7,388 cf, Atten=0%, Lag= 0.1 min Primary = 0.91 cfs @ 12.68 hrs, Volume= 7,388 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 119.38' @ 12.68 hrs Surf.Area= 13 sf Storage= 6 cf Plug-Flow detention time= 0.3 min calculated for 7,388 cf(100% of inflow) Center-of-Mass det. time=0.2 min (911.6-911.4) Volume _Invert Avail Storage Storage Description #1 118.90' 34 cf Custom Stage Data(Prismatic) Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 118.90 13 0 0 121.50 13 34 34 Device Routing Invert Outlet Devices #1 Primary 118.90' 15.0" x 20.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 118.70' S= 0.0100'/' Cc=0.900 n= 0.011 Primary GutFlow Max=0.91 cfs @ 12.68 hrs HW=119.38' TW=0.01' (Dynamic Tailwater) t--1=Culvert (Barrel Controls 0.91 cfs @ 3.1 fps) Pond P3: OUTLET STRUCTURE Hydrograph - ®Inflow 1 0.91 ds 0 Primary Inflow Area=40,333 sf Peak Elev=119.38' Storage=6 cf 15.0" x 20.0' Culvert 3 0 LL 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type 11124-hr 10 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 62 HydroCADO 7 10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P4: SUMATION POND Inflow Area = 45,912 sf, Inflow Depth > 2.14„ for 10 Year event Inflow = 0.97 cfs @ 12.64 hrs, Volume= 8,199 cf Outflow = 0.97 cfs @ 12.64 hrs, Volume= 8,204 cf, Atten= 0%, Lag= 0.0 min Primary = 0.97 cfs @ 12.64 hrs, Volume= 8,204 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.01' @ 12.64 hrs Surf.Area= 0.000 ac Storage= 0.000 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.2 min (906.7-906.5) Volume Invert Avail Storage Storage Description #1 0.00' 0.001 of Custom Stage Data Listed below Elevation Inc.Store Cum.Store (feet) (acre-feet) (acre-feet) 0.00 0.000 0.000 10.00 0.001 0.001 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' long x 9.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.46 2.55 2.70 2.69 2.68 2.68 2.67 2.64 2.64 2.64 2.65 2.64 2.65 2.65 2.66 2.67 2.69 Primary OutFlow Max--0.97 cfs @ 12.64 hrs HW=0.01' (Free Discharge) 't1=Broad-Crested Rectangular Weir (Weir Controls 0.97 cfs @ 0.2 fps) LOT 1 GREAT POND ROAD, NORTH ANDOVER - POS Type ///24-hr 90 Year Rainfall=4.60" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 63 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P4: SUMATION POND Hydrograph - Inflow 0.970s U Primary 1 0.97ds Inflow Area=45,912 sf Peek Elev=0.01' Storage=0.000 of 3 0 LL 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type 111 24-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 64 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment A-1: SUBCATCH A-1 Runoff Area=37,652 sf Runoff Depth=3.93" Flow Length=318' Tc=27.0 min CN=78 Runoff--2.36 cfs 12,345 cf Subcatchment A-2: SUBCATCH A-2 Runoff Area=2,681 sf Runoff Depth=6.16" Flow Length=150' Tc=1.1 min CN=98 Runoff=0.46 cfs 1,377 cf Subcatchment A-3: SUBCATCHMENT A-3 Runoff Area=3,062 sf Runoff Depth=3.13" Flow Length=110' Tc=15.5 min CN=70 Runoff=0.19 cfs 798 cf Subcatchment A-4: SUBCATCHMENT A-4 Runoff Area=2,517 sf Runoff Depth=3.13" Flow Length=55' Tc=13.3 min CN=70 Runoff=0.17 cfs 656 cf Pond P1: INFILTRATOR SYSTEM Peak EIev=127.10' Storage=998 cf Inflow=0.46 cfs 1,377 cf 6.0"x 35.0'Culvert Outflow=0.03 cfs 409 cf Pond P2: DETENTION POND Peak EIev=120.47' Storage=2,865 cf Inflow--2.36 cfs 12,753 cf Outflow=1.65 cfs 12,676 cf Pond P3: OUTLET STRUCTURE Peak Elev=119.58' Storage=9 cf Inflow=1.65 cfs 12,676 cf 15.0"x 20.0'Culvert Outflow=1.65 cfs 12,676 cf Pond P4: SUMATION POND Peak EIev=0.01' Storage=0.000 of Inflow=1.77 cfs 14,129 cf Outflow--1.77 cfs 14,133 cf Total Runoff Area=45,912 sf Runoff Volume= 15,175 cf Average Runoff Depth=3.97" LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type 11124-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 65 HydroCADS 7.10 s/n 002248 ©2005 H,ydroCAD Software Solutions LLC 317/2006 Subcatchment A-1: SUBCATCH A-1 Runoff - 2.36 cfs c@ 12.38 hrs, Volume= 12,345 cf, Depth= 3.93" 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 7,499 70 Woods, Good, HSG C 22,446 74 >75% Grass cover, Good, HSG C 3,506 98 PAVED DRIVEWAY 535 98 STONE WALL 1,916 98 DETENTION POND 1,750 98 POOL,AREA 37,652 78 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) ffiec) (cfs) 21.5 50 0.0200 0.0 Sheet Flow,WOODS Woods: Dense underbrush n= 0.800 P2= 3.20" 4.7 100 0.0200 0.4 Shallow Concentrated Flow, FLOW THROUGH WOODS Forest w/Heavy Litter Kv=2.5 fps 0.6 125 0.0560 3.5 Shallow Concentrated Flow,GRASS SWALE Grassed Waterway Kv= 15.0 fps 0.0 10 5.7 Lake or Reservoir,SEDIMENT FOREBAY Mean Depth;- 1.00' 0.2 33 0.0030 2.9 2.31 Circular Channel (pipe), FLOW UNDER DRIVE Diam= 12.0" Area=0.8 sf Perim= 3.1' r= 0.25' _ n= 0.011 Concrete pipe, straight&clean 27.0 318 Total �I LOT I GREAT POND ROAD, NORTH ANDOVER - P0 Type I// 24-hr 100 year RainfaU=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 66 HydroCADS 7.10 s/n 002248 @ 2005 HydroCAD Software Solutions LLG 317/2006 Subcatchment A-1: SUBCATCH A-1 Hydrograph T ype 111 24-hr 100 ,yea r! ftinf =6.40"- 2- Runoff Area=37 662 sf Runoff V 011UM6=1 213461 cf 'Run'off D6pth' 3.9T• '30' flol 1 Length e 917 L .0, min CN=478 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 16 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type 11124-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 67 HydroCADO 7.10 s/n 002248 4 2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-2: SUBCATCH A-2 [49] Hint: Tc<2dt may require smaller dt Runoff C 0.46 cfs @ 12.02 hrs, Volume= 1,377 cf, Depth= 6.16" 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 2,681 98 DWELLING &GARAGE ROOF RUNOFF Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (fused) (cfs) 0.4 35 0.0366 1.4 Sheet Flow, ROOF RUNOFF Smooth surfaces n= 0.011 P2= 3.20" 0.7 115 0.0100 2.8 0.25 Circular Channel(pipe),4" PIPE FROM DOWNSPOUT TO INFII. Diam=4.0" Area= 0.1 sf Perim= 1.0' r= 0.08' n= 0.010 PVC, smooth interior 1.1 150 Total Subcatchment A-2: SUBCATCH A-2 Hydrograph 0.48 �4s - 0.46 Type111-24-hr-100_year = 0.44 -- -- 0.42 -- - - - - -- - Rafi faft;-6.40 0:36 Runoff-Area=,2,681 s#_ 0.34 - -- - -- -0.3.2-- - Run off V Iklrn ' *I 377 of- 03 0.28- ' - - - _ -4 Runoff Depth=6.1.6'' 0.26 - - - o 0:22 =150'=_ �'c- 1= 1 -f11in= - - _ _- - 0.167 7 0.14 -. -- 0.12 - - , 0.08 - - 0.04 ---'- -- - - - - - -_lip 0.02 0 1 2 3 4 5 6 7 8 9 10 11 12 13 4­1"5­1"6 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type 11124-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 68 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 317/2006 Subcatchment A-3: SUBCATCHMENT A-3 Runoff = 0.19 cfs @ 12.21 hrs, Volume= 798 cf, Depth= 3.13" 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 3,062 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) M/sec) (cfs) -- - 13.9 50 0.0590 0.1 Sheet Flow, FLOW IN WOODS Woods: Dense underbrush n=0.800 P2=3.20" 1.6 60 0.0590 0.6 Shallow Concentrated Flow, FLOW IN WOODS Forest w/Heavy Litter Kv= 2.5 fps 15.5 110 Total Subcatchment A-3: SUBCATCHMENT A-3 Hydrograph 0.21 - - - - -- - ®Runoff 0,2 -- Al - YP 0.19 4 00 year-_ 0.18 - - Q r:1 - 'F e. lII 24 h 0.17 - - __- - -R Wall 6. -- 0.16 - - - - - -- -- - -- -- 0.,5 - - Runoff 'Area=3;062-062 's - Runoff - -- - -- - - -- ------ 0.13 - - Rulrroff Volume 0.12 - --- - Runoff & Dept l3"-- 0 0.1 - - -- - - - LL 009 - -- 1?lav� Len, th=110' - 0.08 - - - - --- 0.07 -TC=1v.� mill- - 0.06 - - - - 0.05 - - CI�i-/-0- 0.04 - -- - -- - - - - - - -- - 0.03 - -- - 0.02 - - - - - -- -- - 0.01 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) LOT '1 GREAT POND ROAD, NORTH ANDOVER - PO Type 11124-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 69 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Subcatchment A-4: SUBCATCHMENT A-4 Runoff - 0.17 cfs @ 12.19 hrs, Volume= 656 cf, Depth= 3.13" 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 2,517 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.3 55 0.0200 0.1 Sheet Flow, FLOW IN WOODS Woods: Light underbrush n=0.400 P2= 3.20" Subcatchment A-4: SUBCATCHMENT A-4 Hydrograph 0.18 ®Runoff A_17sfi - 0.17 - - - - 0.16- , -- Type;=11124-h r-100 year: -- /�u__ 0.14 Rarnfal,l=64. a�2 0.,3 - - : -Runoff �4re ,§17 sf-- 0.12 - -- Rubdffi Volume=656cf- 3 0 - - - -= _Runoff_hepf =3:13 -- LL 0.08 - - - - C r, 0.07 f IoW Lengthw-L - 0.05 - -- --'--' -=--'- =--'-- - -` - 0.04 - -- - N=7 C , 0 0.03 0.02-: - - - - 0.01 0 gin 1=1 110 0 1 2 3 4 5 6 7 8 9­1'6' 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type Ill 24-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 70 HydroCAD®710 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P1: INFILTRATOR SYSTEM Inflow Area = 2,681 sf, Inflow Depth = 6.16" for 100 year event Inflow = 0.46 cis @ 12.02 hrs, Volume= 1,377 cf Outflow = 0.03 cfs @ 13.14 hrs, Volume= 409 cf, Atten= 94%, Lag=67.4 min Primary — 0.03 cfs @ 13.14 hrs, Volume= 409 of Routing by Dyn-Stor-Ind method, Time Span=0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 127.10' @ 13.14 hrs Surf.Area= 808 sf Storage=998 cf Plug-Flow detention time=458.5 min calculated for 408 cf(30% of inflow) Center-of-Mass det. time=254.5 min (994.2-739.7) Volume Invert Avail Storage Storage Description #1 124.83' 576 cf Custom Stage Data (Prismatic) Listed below 1,883 of Overall -442 cf Embedded = 1,440 cf x 40.0%Voids #2 125.33' 442 cf 28.9"W x 16.0"H x 7.12'L StormTech SC-310 x 30 Inside#1 1,018 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sg-ft) (cubic-feet) (cubic-feet) 124.83 808 0 0 127.16 808 1,883 1,883 Device Routing Invert Outlet Devices #1 Primary 127.00' 6.0" x 35.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 123.00' S= 0.1143'P Cc=0.900 n= 0.010 PVC, smooth interior Primary OutFlow Max=0.03 cfs @ 13.14 hrs HW=127.10' TW=120.13' (Dynamic Tailwater) 1t-I=Culvert (Inlet Controls 0.03 cfs @ 1.1 fps) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type /if 24-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 71 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P1: INFILTRATOR SYSTEM Hydrograph - - - - ®Inflow ®Primary Inflow Area=2,6,81 s# 0.45 _ 0.4 Peak ;EIev=127:10' 0.35 _ Storage=9;98 cf 0.3 S.O" x 35,0' Cu lvert - - - - - 0.25 - - - IL 0.2 _ - 0.15 0.05 D.o3dl- 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type 11124-hr 900 year Rainfall--6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 72 HydroCADO 7.10 s/n 002248 0 2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P2: DETENTION POND Inflow Area = 40,333 sf, Inflow Depth = 3.79" for 100 year event Inflow = 2.36 cfs @ 12.38 hrs, Volume= 12,753 of Outflow = 1.65 cfs @ 12.63 hrs, Volume= 12,676 cf, Atten= 30%, Lag= 14.9 min Primary = 1.65 cfs @ 12.63 hrs, Volume= 12,676 cf Routing by Dyn-Stor-Ind method,Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 120.47' @ 12.63 hrs Surf.Area=2,170 sf Storage=2,865 cf Plug-Flow detention time= 54.7 min calculated for 12,676 cf(99% of inflow) Center-of-Mass det.time= 51.0 min (892.0- 841.0) Volume Invert Avail Storage Storage Description #1 118.90' 4,018 cf Custom Stage Data(Prismatic) Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 118.90 1,417 0 0 120.00 1,916 1,833 1,833 121.00 2,454 2,185 4,018 Device „Routing Invert Outlet Devices - #1 Primary 118.90' 4.0" x 1.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 118.90' S= 0.0000? Cc=0.900 n= 0.011 #2 Primary 119.50' 8.0" x 1.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert-- 119.59 S= 0.0000'P Cc=- 0.900 n= 0.011 Primary OutFlow Max=1.65 cfs @ 12.63 hrs HW=120.47' TW=119.58' (Dynamic Tailwater) Lulvert (Inlet Controls 0.40 cfs @ 4.6 fps) 2Zulvert (Barrel Controls 1.25 cfs @ 3.6 fps) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type 11124-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 73 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P2: DETENTION POND Hydrograph ®Inflow zaaaa ®Primary Inflow Area=40,333 sf ak EIOV"120'.47', 2- Storage-2,865 cf LL 0 0 1 2 3 4 5 8 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type 11124-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 74 HydroCADO 7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P3: OUTLET STRUCTURE Inflow Area = 40,333 sf, Inflow Depth > 3.77" for 100 year event Inflow — 1.65 cfs @ 12.63 hrs, Volume= 12,676 cf Outflow = 1.65 cis @ 12.63 hrs, Volume= 12,676 cf, Atten=0%, Lag= 0.1 min Primary = 1.65 cfs @ 12.63 hrs, Volume= 12,676 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt=0.01 hrs Peak Elev= 119.68' @ 12.63 hrs Surf.Area= 13 sf Storage= 9 cf Plug-Plow detention time=0.2 min calculated for 12,672 cf(100% of inflow) Center-of-Mass det. time=0.2 min (892.1 - 892.0) Volume Invert Avail Storage Storage Description #1 118.90' 34 cf Custom Stage Data(Prismatic) Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 118.90 13 0 0 121.50 13 34 34 Device Routing Invert Outlet Devices #1 Primary 118.90' 15.0" x 20.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 118.70' S= 0.0100'P Cc= 0.900 n= 0.011 Primary OutFlow Max=1.65 cfs @ 12.63 hrs HW=119.58' TW=0.01' (Dynamic Tailwater) t-1=Culvert (Barrel Controls 1.65 cfs @ 3.5 fps) Pond P3: OUTLET STRUCTURE Hydrograph a inflow InfloW Areat'40,333 sf ..Pear Elev=119.58' storage=9 cf -20.01-4�ulVert- i (} 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) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type 11124-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 75 HydroCADO 710 s/n 002248 ©2005 HydroCAD Software Solutions LLC 317/2006 Pond P4: SUMATION POND Inflow Area= 45,912 sf, Inflow Depth > 3.69" for 100 year event Inflow = 1.77 cfs @ 12.59 hrs, Volume= 14,129 cf Outflow = 1.77 cfs @ 12.59 hrs, Volume= 14,133 cf, Atten=0%, Lag= 0.0 min Primary - 1.77 cfs @ 12.59 hrs, Volume= 14,133 cf Routing by Dyn-Stor-Ind method, Time Span=0.00-30.00 hrs, dt= 0.01 hrs Peak Elev= 0.01' @ 12.59 hrs Surf.Area= 0.000 ac Storage=0.000 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time=0.1 min (887.2-887.1 ) Volume Invert Avail Storage Storage Description #1 0.00' 0.001 of Custom Stage Data Listed below Elevation Inc.Store Cum.Store (feet) (acre-feet) (acre-feet) 0.00 0.000 0.000 10.00 0.001 0.001 Device Routing Invert Outlet Devices #1 Primary 0.00' 999.0' long x 9.0'breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.46 2.55 2.70 2.69 2.68 2.68 2.67 2.64 2.64 2.64 2.65 2.64 2.65 2.65 2.66 2.67 2.69 Primary OutFlow Max=1.77 cfs @ 12.59 hrs HW=0.01' (Free Discharge) 't-1=13road-Crested Rectangular Weir (Weir Controls 1.77 cfs @ 0.2 fps) LOT 1 GREAT POND ROAD, NORTH ANDOVER - PO Type 11124-hr 100 year Rainfall=6.40" Prepared by NEW ENGLAND ENGINEERING SERVICES INC. Page 76 HydroCAD®7.10 s/n 002248 ©2005 HydroCAD Software Solutions LLC 3/7/2006 Pond P4: SUMATION POND Hydrograph ®Inflow i ®Primary In' 1: Area=46,912 sf Peak Elev=0.01' Storage=0.000 of 3 1 LL 0 0 1 2 3 d 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) SUMMARY The following tables summarize the pre development vs.post development runoff flow for the 1,2, 10, and 100 year storms.Due to the proposed construction of the infiltration facilities and detention pond the post development flow rates are lower than the pre development flow rates.Because the flow rates are reduced and a large portion of the volume increases are infiltrated,no down stream properties will be adversely affected by this project. In the summary table below the pre and post development flows are shown. PRE VS.POST DEVELOPMENT DRAINAGE FLOW SUMMARY TABLE Design Pre Dev. Post Dev. Change Storm (cfs) (cfs) (cfs) 1 0:22 0.20 (0.02) 2 0.46 0.35 (0.11) 10 1.06 0.97 (0.07) 100 1.95 137 (0.18) 77 APPENDIX 78 100 SOIL SURVEY The C horizon has hue of 7.5YR to 5Y, value of 5 to 7, The C horizon has hue of 10YR to 5Y, value of 3 to 5, and chroma of 2 to 4. It is medium sand or fine sand. and chroma of 3 or 4. It is very fine sandy loam, silt Winooski series loam, or loamy very fine sand. The Winooski series consists of coarse-silty, mixed, Woodbridge series nonacid, mesic Aquic Udifluvents. These deep, moder- The Woodbridge series consists of coarse-loamy, ately well drained soils are on flood plains. The soils mixed, mesic Typic Fragiochrepts. These deep and mod- formed in acid alluvium derived mainly from mica schist. erately well drained soils are on uplands. The soils Slopes range from 0 to 3 percent. In this survey area the formed in compact glacial till derived mainly from schist soils are a taxadjunct to the Winooski series because and granite. Slopes range from 0 to 25 percent. mottles with chroma of 2 or less are at a greater depth Woodbridge soils formed in the same kind of material than is defined in the range for the series. This differ- as well drained Paxton soils, poorly drained Ridgebury ence does not significantly affect the use and manage- soils, and very poorly drained Whitman soils. They are ment of the soils. similar to the Scituate and Sutton soils. Woodbridge soils Winooski soils formed in the same kind of material as have less sand in the substratum than the Scituate soils. well drained Hadley soils, poorly drained Limerick soils, They have a fragipan, which the Sutton soils do not and very poorly drained Saco Variant soils. They are have. similar to the Belgrade and Ninigret soils. Winooski soils Typical pedon of Woodbridge fine sandy loam, 3 to 8 have a substratum that has more stratification and more Percent slopes, in the town of Georgetown, in a field 700 silt than the Belgrade soils. They have more very fine feet southwest of the junction of Andover and West sand and silt throughout the profile than the Ninigret Streets: -soils. Ap-0 to 9 inches; very dark grayish brown (10YR 3/2) Typical pedon of Winooski very fine sandy loam, in the fine sandy loam; very weak fine and medium granu- town of Groveland, in a field 150 feet east of Main Street lar structure; friable; many fine roots; 10 percent and 1,400 feet south of its junction with Gardiner Street: angular coarse fragments 2 to 20 millimeters in di- Ap-0 to 8 inches; very dark grayish brown 10YR ameter; medium acid; abrupt smooth boundary. 3/2 ( ) 1321=9 to 16 inches; yellowish brown (10YR 5/4) fine very fine sandy loam, light brownish gray (10YR 6/2) sandy loam that fades to light olive brown (2.5Y dry; very weak fine and very fine granular structure; 5/4) with depth; very weak fine and medium granu- very friable; many fine roots; medium acid; abrupt lar structure; friable; common fine roots; many small smooth boundary. worm holes filled with very dark grayish brown mate- C1-8 to 24 inches; light olive brown (2.5Y 5/4) very fine rial from Ap horizon; 10 percent angular sandy loam; massive; friable; common fine roots; medium acid; clear wavy boundary. gravel; neutral; clear-smooth boundary. B22-16 to 23 inches; olive brown (2.5Y 4/4) fine sandy C2-24 to 38 inches; light olive brown (2.5Y 5/4) very loam; common fine distinct gray. to tight gray (5Y fine sandy loam; few fine distinct light brownish gray 6/1) and yellowish brown (10YR 5/6) mottles; weak (10YR 6/2) and strong brown (7.5YR 5/6) mottles; medium subangular blocky structure; friable; few fine massive; friable;.slightly acid; clear wavy boundary. 10 percent angular gravel, 3 per- C3-38 to 60 inches; light olive brown (2.5Y 5/4) varved herbaceous roots; cent stones; medium acid; abrupt wavy boundary. very fine;sand and silt loam; many,medium promi- A'2-23 to 26 inches; light olive gray (5Y 6/2):fine sandy nent gray (10YR 6/1), dark yellowish brown (10YR loam; common fine distinct strong brown (7.5YR 4/4), and reddish yellow (5YR 618) mottles; mas- 5/6) and yellowish red (5YR 5/6) mottles; weak sive; friable; slightly acid. medium subangular blocky structure; firm; few fine roots; 15 percent angular and subrounded gravel, 3 The thickness and number of horizons below the A percent stones; strongly acid; abrupt wavy boundary. horizon are variable and correspond to the thickness and Cx-26 to 60 inches; light olive brown (2.5Y 514) fine variability of the alluvial deposits. The depth to mottling sandy loam; common fine distinct strong brown ranges from 20 to 26 inches. Reaction ranges from very (7.5YR 5/6) mottles; moderate to strong thick platy strongly acid to neutral above a depth of 35 inches and structure; very firm; 10 percent angular gravel, 2 medium acid to neutral below a depth of 35 inches. Percent stones; strongly acid. Typically, there are no coarse fragments in this soil, but some pedons are u to 5 The depth to the firm or very firm fragipan ranges fron P percent coarse fragments. 21 to 29 inches. The depth to mottling ranges from 16 tc The Ap horizon has hue of 10YR, value of 3 or 4, and 29 inches. The content of coarse fragments in the solun chroma of 2 or 3. It is very fine sandy loam or silt loam. and substratum ranges from 5 to 30 percent. The reac __79 ESSEX COUNTY, MASSACHUSETTS, NORTHERN PART 101 tion ranges from strongly acid to medium acid. The sur- meaning brittle horizon, plus ochrept, the subo]great f face layer is slightly acid to neutral where limed. Inceptisols that have a pale surface). The Ap horizon has hue of 10YR, value of 3 or 4, and SUBGROUP. Each great group may be dividto chroma of 2 or 3. The Al horizon is 1 unit lower in value three subgroups: the central (typic) concept of that or chroma or both. The texture of the A horizon is fine groups, which is not necessarily the most extensib- sandy loam or loam. group; the intergrades, or transitional forms ter The B21 horizon has hue of 7.5YR or 10YR, value of 4 orders, suborders, or great groups; and the extras, or 5, and chroma of 4 to 6. It is fine sandy loam or loam. which have some properties that are representof The B22 horizon has hue of 10YR or 2.5Y with value the great groups but d6-not indicate transitions ny and chroma of 4 to 6 and is distinctly mottled. It is sandy other known kind of soil. Each subgroup is idenby loam, fine sandy loam, or loam. Some pedons do not one or more adjectives preceeding the name of teat have an A'2 horizon. group. The adjective Typic identifies the subgrout is The Cx horizon has hue of 2.5Y or 5Y, value of 4 or 5, thought to typify the great group. An example pic and chroma of 3 or 4. It is sandy loam, fine sandy loam, Fragiochrepts. or loam or thin gravelly analogues. FAMILY.families are established within a subgroup on the basis of similar physical and chemical properties that affect management. Among the.properties considered in Classification of the soils horizons of major biological activity below plow depth are The system of soil classification currently used-was particle-size distribution, mineral content, temperature adopted by the National Cooperative Soil Survey in regime, thickness of the soil penetrable,by roots, consis- tense, moisture equivalent, soil slope, and permanent 1965. Readers interested in further details about the cracks. A family name consists of the name of a sub- system should refer to "Soil taxonomy".(6). group and a series of adjectives. The adjectives are the The system of classification has six categories. Begin- class names for the soil properties used as family differ- ning with the broadest, these categories are the order, entiae. An example is coarse-loamy, mixed, mesic Typic suborder, great group, subgroup, family, and series. In Fragiochrepts. this system the classification is based on the different SERIES. The series consists of soils that formed in a soil properties that can be observed in the field or those particular kind of material and have horizons that, except that can be inferred either from other properties that are for .texture of the surface soil or of the underlying sub- observable in the field or from the combined data of soil stratum, are similar in differentiating characteristics and science and other disciplines. The properties selected in arrangement in the soil profile. Among these charac- for the higher categories are the result of soil genesis or teristics are color, texture, structure, reaction, consis- -of factors that affect soil genesis. In table 17,the soils of tense, and mineral and chemical composition. the survey area are classified according to the system. Categories of the system are discussed in the following paragraphs. References ORDER. Ten soil orders are recognized as classes in the system. The properties used to differentiate among (1) Allan, P. F., L. E. Garland; and R. Dugan. 1963. orders are those that reflect the kind and degree of Rating northeastern soils for their suitability for wild- dominant soil-forming processes that have taken place. life habitat. 28th North Am. Wildl.*Nat. Resour. Each order is identified by a word ending in sol. An Cont. Wildl. Manage. Inst., pp. 247-261, illus. example is Inceptisol. (2) American Association of State Highway and Trans- SUBORDER. Each order is divided into suborders portation Officials. 1970. Standard specifications for based primarily on properties that influence soil genesis highway materials and methods of sampling anc and are important to plant growth or that are selected to testing. Ed. 10, 2 vol., illus. reflect the most important variables within the orders. (3) American Society for Testing and Materials. 1974 The last syllable in the name of a suborder indicates the Method for classification of soils for engineerinc order. An example is Ochrept (Ochr, meaning pale, plus purposes. ASTM Stand. D 2487-69. In 1974 Annua ept, from Inceptisol). Book of ASTM Standards, Part 19, 464 pp., illus GREAT GROUP. Each suborder is divided into great (4) MacConnell, William, W. Cunningham, and R. Blan groups on the basis of close similarities in kind, arrange- chard. 1974. Remote sensing, 20 years of chang, ment, and degree of expression of pedogenic horizons; in Essex County, Mass., 1951-1971. Plann. an soil moisture and temperature regimes; and base status. Resour. Dev. ser. no. 26. Univ. Mass. Pub. 98. 10 Each great group is identified by the name of a suborder pp. and a prefix that suggests something about the proper- (5) United States Department of Agriculture. 1951. Sc ties of the soil. An example is Fragiochrepts (Frag, survey manual. U.S. Dep. Agric. Handb. 18, 503 pp _ �Q ESSEX COUNTY, MASSACHUSETTS, NORTHERN PART 193 TABLE 16.--SOIL AND WATER FEATURES--Continued Flooding , High water table , Soil name and ;Hydro- , , Risk of corrosion ! ;Potential; map symbol ; logic; Frequency ; Duration ;Months ! Depth ! Kind . !Months ! frost ',Uncoated ',Concrete !group ! ' ! ! , , , action , steel ; Wg, Wh------------1 D None--------! _-- ; --- 10.0-0.5!Perched !Sep-Jun!High-----;High-----!High. Whitman , , WRA, WnB, WnC, , WnD--------------! A !None--------! --- ' --- >6.0 1 1 i,L I g --- --- ow------,Low------lH1 h. Windsor , , � , It It , It , ; ; WO C*, WOD*• ! ! i I I 'It ! ! � � � It A None--------! ! ! >6.0 ' Low------ Low------;, High. Rock outcrop. WP----------------1 B !Occasional Brief-----!Sep-April.0-3.OlApparent!Dee-Apr!High-----!Moderate ;Moderate. Winooski It 11 11 1 WrA, WrB, WrC, WsB, WsC, Ws;, WtB, WtC-----------i C !None--------! --- ; --- 11.5-3.0!Perched ;Nov-Mar!High-----!Moderate !Moderate. Woodbridge , _ ! ! i ! It * See description of the map unit for composition and behavior characteristics of the map .unit. i �II V i C9, SUMMARY The following tables summarize the pre development vs.post development runoff flow for the 1,2, 10, and 100 year storms. Due to the proposed construction of the infiltration facilities and detention pond the post development flow rates are lower than the pre development flow rates. Because the flow rates are reduced and a large portion of the volume increases are infiltrated,no down stream properties will be adversely affected by this project. In the summary table below the pre and post development flows are shown. PRE VS.POST DEVELOPMENT DRAINAGE FLOW SUMMARY TABLE Design Pre Dev. Post Dev. Change Storm (cfs) (cfs) (cfs) 1 0:22 0.20 (0.02) 2 0.46 0.35 (0.11) 10 1.06 0.97 (0.07) 100 1.95 1:77 (0.18) 77 APPENDIX 78