HomeMy WebLinkAbout20230119 Planning III-Stormwater Report Salem Forest 3DEFINITIVE SUBDIVISION PLAN
HYDROLN REPORT
TOWN OF NORTH ANDOVER
SALEM FOREST III
DECEMBER 81 1986
PREPARED BY
NEVE ASSOCIATES, INC.
447 BOSTON STREET
TOPSFIELD, MA 01983
TABLE OF CONTENTS
I. APPLICATION FOR APPROVAL OF DEFINITIVE PLAN
II. DESIGNERS CERTIFICATE
III. STATEMENT OF ENVIRONMENTAL IMPACT
IV. CONSTRUCTION SCHEDULE
V. ABUTTERS LIST
VI. HYDROLOGY AND DRAINAGE REPORT
FORM D
DESIGNER'S CERTIFICATE
November 25
TO THE PLAWtZING BOARD OF THE TOWN OF NORTH ANDOVER:
, 19 86
In preparing the plan entitled Salem Forest III
I hereby certify that the above named plan and accompanying data is true
and correct to the accuracy required by the current Rules and Regulations
Governing the Subdivision of Land in North Andover, Massachusetts, and
my source of information about the location of boundaries shown on said
plan were one or more of the following:
1. Deed from Sohn Bolten to George H & Wanda H. Farr
dated 1967 and recorded in the
North Essex Registry in Book 1087 page 314
2. Other plans, as follows
3. Oral information furnished by No one
4. Actual measurement on the ground from a starting point established
by Thomas E. Neve Associates, Inc., 447 Boston St., Topsfield MA
5. Other Sources
(Seal of Engineer or
Surveyor)
(Registered Professional Engineer or
Registered Land Surveyor)
Thomas E. Neve Associates, Inc.
447 Boston St., Topsfield, MA 01983
Address
SALEM FOREST III
ENVIRONMENTAL IMPACT STATEMENT
PHYSICAL ENVIRONMENT
The topography of the site is moderately sloping, having slopes
averaging 3% to 20%. (See Sheet #3). The vegetation is medium;
the site primarily contains small trees averaging 30-50 feet.
The site is bordered on the North and West by typical woodland
areas, on the North and East by seasonal wetlands and Boston Brook,
and to the East and South by residential areas of Patton Lane,
Salem Forest II.
The developer proposes to construct a roadway from Patton Lane
through the forested area over Boston Brook and along the bordering
wetland. The road shall be constructed at an acceptable grade
and shall not pose a significant impact to the physical
environment. This new roadway is approximately 650 feet long
and shall serve five (5) lots.
SURFACE WATER AND SOILS
As previously mentioned, this site is bordered by Boston Brook
and a wetland area that is subject to seasonal flooding. Boston
Brook flows from Northwest to Southeast. The drainage pattern
of the uplands is from South to North, ultimately discharging
into Boston Brook. The underlying soils of the site are moderately
drained, i.e., during rainfall the runoff is medium since 60 -
70% of the rainfall percolates into the existing soil.
During the construction of the proposed road, erosion and
sedimentation control measures shall be implemented.
Conventionally staked hay bales shall be installed along the
Northerly edge of the Right of Way to prevent any siltation, as
a result of the road construction, from entering the wetlands
areas. The proposed sideslopes of the roadway fill areas are
within the regulation criteria. These areas shall be stabilized,
loamed, and seeded once installed.
Each of the five lots shall dispose of their sewage by conventional
subsurface methods. Each dwelling shall have a leach field
designed in strict accordance with the State Environmental Code
and the local Board of Health Regulations. The areas of the leach
field is subject to the percolation rate of the soil. Several
percolation tests and deep hole observation test pits were
conducted with their rates being acceptable.
SUBSURFACE CONDITIONS
The existing subsurface soil conditions consist of soils which
have a medium infiltration rate. This soil classification was
verified in the field by excavating test pits throughout the site.
The pits were excavated during the permitted periods as required
by the local Board of Health.
The water tables observed were within acceptable ranges and do
not pose a limitation on the development of this land. This soil
is acceptable for both the construction of dwellings with basements
as well as the construction of local roads and streets.
TOWN SERVICES
The proposed subdivision shall have insignificant impact regarding
traffic and parking. These lots shall generate an average of
60 auto trips per day. Each dwelling shall have a garage and
driveway for off street parking.
The subdivision shall require the services of the Town Fire
Department, Police Department, and Public Works Department. Town
water and fire hydrants will be installed in the proposed road
with a recommended cul-de-sac at the end of the road. Street
drainage and appurtenances shall be installed in conformance with
the Town of North Andover Subdivision Rules and Regulations. All
wetland disturbance shall be submitted to the local Conservation
Commission for their review and approval.
CONCLUSION
The general environmental impact of this proposed subdivision
is minimal. All attempts have been made to blend good engineering
design concepts with the Subdivision Rules and Regulations to
generate a development which correlates with the character of
the area and the attitude of the Town of North Andover.
CONSTRUCTION SCHEDULE
The developer anticipates the subdivision to be constructed within
24 months.
Month
1:
Clear and grub roadway,
rough grade
Month
2-7:
Install all utilities,
bring road up to subgrade.
Month 8-9: Gravel roadway and install binder coat, rough grade
and install sideslopes.
Month 2-24: Clear lots, construct dwellings.
Month 12-24: Finish landscape all portions of the roadway
and sideslopes, install finish pavement, install
road monuments.
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HYDROLOGY
AND
DRAINAGE
SALEM FOREST III
NORTH ANDOVER, MASSACHUSETTS
November 11, 1986
Prepared For:
Thomas E. Neve Associates, Inc.
447 Old Boston Road
Topsfield, Massachusetts
Prepared By:
IEP, Inc.
6 Maple Street
Northborough, Massachusetts
,EPnc.
Salem Forest III is a proposed 5-lot subdivision on a single cul-de-sac road
off existing Patton Lane. The 12 + acre site is traversed by Boston Brook
which must be crossed at one location by the proposed Hawkins Lane. A
crossing presently exists at this location for a dirt road referred to as Wood
Road. The existing crossing is sub -standard and would result in over -topping
of Wood Road by the peak 100-year discharge of Boston Brook.
The purpose of this analysis is threefold: 1) to establish the existing
100-year flood plain elevation and peak discharge in Boston Brook, 2) to
design a crossing culvert to convey the peak discharge with no increase in
peak flood stage and, 3) to size the proposed storm drain pipes for the
10-year storm and compare existing and post -development discharge in Boston
Brook for both the 10-year and 100-year storms.
SCS methods (NEH-4) were used to derive the peak discharge in Boston Brook
from USGS gaging/frequency records for the Ipswich River to which Boston Brook
is tributary. The HYDRP computer model was used to evaluate the peak stage of
Boston Brook based on the hydraulic performance of the existing Wood Road
crossing. The resulting peak stage (100 year floodplain elevation) was
calculated to be 106.2 ft. NGVD, over -topping the road. It must be noted the
FEMA-designated floodplain (A -Zone) is not based on a detailed study and
therefore does not specify a flood stage.
The HYDRP model was further used to aid in designing an improved crossing
culvert. The optimal design selected was a 10' wide x 5' high precast
concrete box culvert with a beveled entrance. This structure would result in
a 0.4 foot decrease in the peak flood stage and would avoid over -topping the
proposed road.
Qi�
The proposed storm drains were designed by use of the DRAINCALC program.
Subcatchments 3, 4 and 5 are tributary to the proposed storm drains.
Composite Curve Numbers (CN) were developed from the areal distribution of
proposed impervious surface (including roods and driveways), other surface
cover types and SCS-mapped soils groups.
The DRAINCALC program was also used to generate composite hydrographs for the
entire site. Subcatchment 1 represents the site in its existing condition
whereas Subcatchment 2 represents the developed site. A 100-year hydrograph
for Boston Brook was manually constructed using other SCS methods (NEH-4)
because the watershed size exceeds the working limits of DRAINCALC.
Comparison of these hydrographs shows that the peak discharge (10-year and
100-year) of Boston Brook would only be increased by 0.2 cfs as a result of
site development. This increase is negligible owing to the significant
difference in timing between the hydrograph peak of the site and that of
Boston Brook.
-2-
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6 Maple Street
Northborough, MA 01532
393-8558
Job No. Sheet_ of
By Date
Ckd.�_ Rev.
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6 Maple Street
Northborough, MA 01533
393-8558
Client 70M Alf ViE lob No. Sheet— of
Subject bell) IF6 J•UB.DiU/J/a/(/ By J2— Date
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(iPSTREff/i'/ .f/ICE OG Gt/Oo/J /?lJ/il�� ,pO.fTDA/ &'.Plo/,�
V—
g of swamps will'fbr`fher Supply Paper (in preparation).
r withdrawals. 'Sammel, E. A., and Baker, J. A.,1962, Record of wells, materials
der from the basin, mainly tests, and chemical analyses of water in the lower Ipswich River
i, amount to about 5 per- basin, Massachusetts: U.S. Geol. Survey open -file report, 47 p.
streamflow by 50 percent U.S. Geological Survey,1930-60, Surface -water supply of the United
and 1957 this pumpage States, pt. 1, North Atlantic slope basins: U.S. Geol. Survey
r short periods near the Water -Supply Papers 696, 711, 726, 741, 756, 781, 801, 821, 851,
871, 891, 921, 951, 971, 1001, 1031, 1051, 1081, 1111, 1141, 1171, 1201,
surface water in the basin 1231, 1271, 1331, 1381, 1431, 1501, 1651, 1621, and 1701.
Ithough some water may
�nganese. 'Available in duplicated form from U.S. Geol. Survey, Boston, Mass.
I
1.1 1.5 2 3 5 7 li
RECURRENCE INTERVAI
Frequency of flood:
Flood -frequency curves can be used to predict
similar hydrologic conditions continue. Thus, if
given magnitude is 10 years, there is a 10 pere
one year.
"PSWICH RIVER B
and W. N. Palmquist, Jr.
20 30 50 100
IN YEARS
at Ipswich
he probabilities of flood occurence if
is recurrence interval of a flood of a
it probability of its occurence in any
.1
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200
z 100
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RECURRED
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Low -flow frequency curves can bi
flows assuming no change in hydro
2.5 million gallons a day for 60 coi
of once every 10 years, indicating a
occur in any year.
ODS And LOW FLOWS -Extremes Of Streamflows
INTERIOR -OEM '
MASSACHUSETTS
fG S
f/1R- i94
HYDRAULIC HATING PROGRAM (C) Copyright 1.9831 Peter J. Singhofen, P.E.
STRUCTURE DATA lvaoG eMb C,POJJ//UG � I?OJTON 8k001f�
F!'iJ7-/1V6
y
ELEMENT # 1
-> Box Culvert <-
Span (inches)
- 100.2
Rise (inches)
--'> 49.2
Length (feet)
--. 14.8
Manning's n
--. .015
HW Invert (Fmsl)
--. 99.5
TW Invert (fmsl)
--% 99.28
Energy Loss Coef
--. 1
Entrnc Loss Coef
--. .5
# of Culverts/Channels
--> 1
ELEMENT # 2
/76.7V k-N07Cft �POAl
J /�Fs7CC�
-` Broad Crested Weir/r_.+o
and nr;f;,-o <_
�
Crest elevation (fmsl)
105.21
Crest length (feet)
--;` 35.58
�30-
93
Discharne coefficient
-- 3.1
Weir exponent --> 2.5
to effective submergence - 67
Gate opening (feet) --> 999
# of end contractions --. c)
Discharge coef for gate on -> 0
Circular orifice cntrin (ft) 999
Orifice diameter (ft) --:1. 0
Orifice dischrg coef --> 0
# identical orifices --> 0
fOh LD = 3s, s,F
HYDRAULIC RATING PROGRAM (C) Copyright 198.3, Peter J. Singhofen, P.E.
FLOW RATES (CFS)
HW
TW
ELEM i
ELEM 2
&OX
V-Ai07(1!
99.500
99.280
0.00
0.00
100.000
99.280
7.21
0.00
101.000
99.280
37.60
0.00
102.000
99.280
80.85
0.00
103.000
99.2BO
133.92
0.00
104.000
99.280
195.24
0.00
105.000
99.280
263.82
0.00
106.000
99.280
330.94
61.1S
107.000
99.2BO
413.38
472.B3
D TOT
0.00
7.21
37.60
80.65
133.92
195.24
263.82
400.13
BB6.21
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6 Maple Street
Northborough, MA 01532
393-8558
Jab No, Sheet_ of
By_ Date
Chtl. Rev.
ZL, /JEJ'/6XI c;ejPdjr, ,Po.90 C�'cUs/r�/6 CUL UE/PT
/�,4 e FG 0 o.D J 7-19 G C A1V16 NU U VFI? rUP/'/N 6
of Pk4l),00irb /2a1}OGv4v
HYDRAULIC RATING PROGRAM (C) Copyright 1963, Peter J. Ginghofen, P.E.
STRUCTURE DATA
/ /
ELEMENT # I le)
-> Box Culvert <-
Span (inches)
'-> 120
Rise (inches)
^~> 6O
Length (feet)
--> 60
Manning's n
--> .013
UW Invert (fmsl)
--> 99,5
TW Invert (fmsl)
-~> 99"28
Energy Loss Coef
Entrnc Loss Coef
# of Culverts/Channels
-11-
HYDRAULIC RATING PROGRAM (C) Copyright 1903, Peter J. SinghoFen, P.E.
HW TW
99. 500 99.280
100.000 99.2BO
101..000 99.2BO
102.000 99.200
103.000 99.280
1.04.000 99.280
1.05.000 99.2BO
106.000 99.200
107.000 99.280
FLOW RATES (CFS)
ELEM 1
0 TOT
0. 00
0.00
10.41
10.41
53.96
53.96
1.16.10
116.10
192.44
192.44
200.55
280.555
379.09
379.09
457.04
487.04
604.45
604.45
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Northborough, MA 01532
393-8558
Job No. Sheet_ of
Date
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SUBCATCHMENT/WATERSHED DATA IC1�
SUBCATCHMENT NO. r l?-r) befit A ON SITE /Z,:(?
PROJECT: 11mnll AOFF SITE 0
CONDITION: jFX1,f71N6 ATOTAL
CN CALCULATION
COVER TYPE
SOILS
CN
AON SITE
AOFFSITE
ATOTAL
CNA
f�i2� rr
-
A
217
Q , `7¢
0.7 %
/B,S-
B
si-
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A
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B
9k
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9k
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B
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A
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A
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C
D
TOTALS
1760,a'
CN=boo„>'/12,s3
CN'=
HYDRAULIC LENGTH, L= 16eC
CALC. BY:
DATE:
SUBCATCHMENT SLOPE, S= 7 Y /
CHECK BY:
DATE:
TIME OF CONCENTRATION To
SOURCES:7-01POa�o
-15-
SUBCATCHMENT/WATERSHED DATA ICP
SUBCATCHMENT NO. 2 (",rNr1,QE .1rl7£) /Rcv A ON SITE
PROJECT: 4/4,P7H 1gNbovE,P ; JACfin F0,01--fr-Za AOFF SITE
CONDITION: ATOTAL
CN CALCULATION
COVER TYPE
SOILS
CN
AON SITE
AOFFSITE
ATOTAL
CNA
B
si-
c,
-76
9F
D
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A
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D
TOTALS
/2,13
iz,53
PZo.k
JCN
HYDRAULIC LENGTH, L= MY?
CALC. BY: 2
DATE:
SUBCATCHMENT SLOPE,S= U °/
CHECK BY:
DATE:
TIME OF CONCENTRATION, Tc = l Sl
SOURCES:S rc Tom f
UdGl 0✓AD
�•� - c .,;t -16-
SUBCATCHMENT/WATERSHED DATA IC�
SUBCATCHMENT NO. 3 (7,e/a 7o rllrrlv6 <8J, PgWN LN)
A ON SITE 6
PROJECT: vm7#
AOFF SITE Z/,71
CONDITION: ��IWN6 ti PdJ7-e�Fa
ATOTAL y,7/
CN CALCULATION
COVER TYPE
SOILS
CN
AON SITE
AOFFSITE
ATOTAL
CNA
FU/2f:T
-
A
2S
B
si-
c
-7D
D -
77
ouj,
A
9p
B
9F
C
9�
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Reel 6FN7/A1
A
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O,a9F Z,/
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D 99
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-79
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1,60.
04,y
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D
TOTALS
4, 7/
30/•8
CN=3o/,8/q,71= 64./
CN`_
HYDRAULIC LENGTH, L= 6,5T
CALC. BY: Z
DATE:
SUBCATCHMENT SLOPE, S= 4•tle/u
CHECK BY:
DATE:
TIME OF CONCENTRATION, To = �C/
SOURCES:s is 70� I
U.f/•I QUAD
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SUBCATCHMENT/WATERSHED DATA ICP
SUBCATCHMENT NO.4 (7,els io ,aPooatED CBf,J'>vorz4�) AON SITE D,/S/
PROJECT: 41OP7N .gN4omce)Z46fln foPF'(T--zzz AOFF SITE 0,o73
CONDITION: I'oJT- 4r�l ATOTAL
CN CALCULATION
COVER TYPE
SOILS
CN
AON SITE
AOFFSITE
ATOTAL
CNA
FU/?�tT
-
A
Zs-
!'t2 6,dIS
0,073
/,Y-?
B
si-
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77
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0,079
1174
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A
B
C
D
TOTALS
CN=//Y7/0-7Z9=S3,0
CN'=
HYDRAULIC LENGTH, L= 160'
CALC. BY:.7-
DATE:
SUBCATCHMENT SLOPE, S= 2.4 o
CHECK BY:
DATE:
TIME OF CONCENTRATION, Tc = (P
SOURCES:S rc
!/d'GJ Q✓AD
SUBCATCHMENT/WATERSHED DATA
ICP
SUBCATCHMENT NO, s(7PIE 70 R-`4POJFG eTsl r�4 2
A ON SITE Z 7 4
PROJECT: 2/am, 4N4oVE',P) S44 E,,n
AOFF SITE
CONDITION: POST- Lev
ATOTAL 2.7 y
CN CALCULATION
COVER TYPE
SOILS
CN
AON SITE
AOFFSITE
ATOTAL
CNA
FU/2�:T
-
A
2,7
B
SJ-
-0,13
29,/
C
76
D
77
lm�Ewi0as
(�nc� Z NUUJeJ y'�,�, r�
A
9P
6'a 00/
D,0/
h0
B
9k
4-?d
C
13, 7
D
Fo1?E,rr11'4 11v
A
Y F
0 • / 1 Deli
U/ o/
U --?
B
SF
I 39,?J- /- -T d
/,37
W'-
C
'12
33; ;, d, i, 1
d,z
19, f
D
7�
A
B
C
D
A
B
C
D
TOTALS
? Z4
D s3
7'
/g72
HYDRAULIC LENGTH, L= 7
CALC. BY: -7-
DATE:
SUBCATCHMENT SLOPE, S= Co, S %
CHECK BY:
DATE:
TIME OF CONCENTRATION, Tc = //
SOURCES: ri Tom f
UdGJ 0✓AD
-19
I.E.P., Inc.
PROJECT:SALEM FOREST III 10YR
------------------
SUBCATCHMENT DATA
SUBCAT # 1
AREA= 1.2.53 ACRES
CN= 60.7
TC= 21. MIN
PEAL. FLOW= 12.7 CFS
RAINFAL..L= 4.5 INCHES
VOL.= 1..01. AC.FT.
SUBCAT #
AREA= 4.71. ACRES
CN- 64.1.
TC= 16 MIN
PEAK FLOW= 6.1 CFS
RAINFALL.== 4.5 INCHES
VOL.== .45 AC.FT.
SUBCAT # 5
AREA 2.79 ACRES
CN= 67.1.
TC= 11 MIN
PEAK FLOW= 4.9 CFS
RAINFALL_== 4.5 INCHES
VOL...= .3 AC.FT.
ROUTING DATA
REACH # 1
PEAL+. FLOW= 6.1. CFS
MAX. FLOW POSSIBLE= 6 CFS
MAX. WATER DETAINED= 0 AC.FT.
REACH # _
PEAK FLOW 6.2 CFS
MAX. FLOW POSSIBLE:= 6 CFS
MAX. WATER DETAINED= 0 AC.FT.
MEMORY DATA
SUBCAT # 2
AREA= 12.53 � ACRES
CN= 63.5
TC= 18 MIN
PEAK FLOW= 17.4 CFS
RAINFALL== 4.5 INCHES
VOL== 1.3 AC.FT.
SUBCAT # i4
AREA= ..224 ACRES
CN= 53
TC=; 6 MIN
PEAK FLOW= CPS
RAINFAL..L.= 4.5 INCHES
VOL- 0 AC.FT.
REACH # 2
PEAK FLOW= 6.2 CFS
MAX. FLOW POSSIBLE= 6 CFS
MAX. WATER DETAINED= 0 AC.FT.
REACH # 4
PEAK FLOW= 4.9 CFS
MAX. FLOW POSSIBLEi= 6 CFS
MAX. WATER DETAINED= 0 AC.FT.
-20 -
------------
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Northborough, MA 01532
393-0550
Job No. Sheet_ of
By Date
ljfl/FGOP /00-5�E%�P� SC..f h'/�O.t'OG,Z'i9PH Leh'
fj= 4,Z.�- lkii 2 = 2720 a<kf
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Z116 L= �-/)0,7- (27)750)O,Y(3G8i
07
1906 %°'s 19oo (0,9)0,
L = S-,/7 hrl
T(= S?L 7)= Gz Gas
D6l2s17/401V OF "F(/P ZWFrf�) D --0,/3,7 T = 0,/,? 40 z,
L = /S ti%r
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—22-
is?r�
6 Maple Street
Northborough, MA 01532
393-8558
,E',g77oJ OF 7H5- S(J
Job No. Sheet_ of
By- Date
Ckd. Rev.
7/111,t-- ,9.UD ,O)JC//.9/?64'
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f
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0,476
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0,(nG U
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0,7
4oz
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le/,5y
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0,930
43,?,/%
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S./7
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0,5I0
40•/11
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s•79
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/,0aa
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/,/
6121
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0,990
plc!/y
/,z
6189
/X,7 o
D-93D
4.7?, /9
/,3
7
4U0•s9
0,7F0
3G3,3z
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016.74
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9,/8
20,41
0,500
2(1d•BS
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0.4Ga
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-231-
I.E.P., Inc.
PROJECT:SALEM FOREST" III 100YR
-----------------
SUBCATCHMENT DATA
SURCAT # 1
AREA= 12.53 ACRES
CN= 60.7
TC= 21. MIN
PEAK F=LOW== 27.6 CFS
RAINFALL= 6.5 INC:HES
VOL== 2.21 AC.FT.
SUBCAT .p
AREA= 4.71 ACRES
CN= 64.1.
TC= 16 MIN
PEAK FLOW- 1.2.7 CFS
RAINFALL= 6.5 INCHES
VOL- .94 AC.FT.
SUHCAT # 5
AREA== 2.79 ACRES
CN= 67.1
TC= 1.1 MIN
PEAK FLOW== 9.7 CFS
RAINFALL== 6.5 INCHES
VOL= .61 AC.FT,.
SUPCAT # 2
AREA= 12.53 ACRES
CN= 65.5
TC= iS MIN
PEAK FLOW= 35.7 CFS
RAINFALL 6.5 INCHES
VOL._ 2.65 AC.FT.
SUHCAT # 4
AREA= .224 ACHES
CN= 53
TC= 6 MIN
PEAK FLOW .6 CFS
RAINFALL= 6.5 INCHES
VOL.= .01 AC.FT.
ROUTINE; DATA
------------
MEMORY DATA
PONDING DATA
-24-
I.E.F., Inc.
PROJECT:SALEH FOREST III I('OVR
HYDROORPFH FOR SUOCATCHMENI k 1 ENi//2E f/%E- EXIPYA16
CUBIC FEET PER SECOND
k xxxxxxkk xxx xkxxxxxwN
HOUR
10.0 * 0.5
10.1 * 0.5
10.2 * 0.6
10.3 x 0.6
10.4 * 0.7
10.5 * 0.7
10.6 * 0.7
10.7 * U.e
10.0 x 0.0
L).9 N* 0.9
11.0 N* 0.9
11.1 Nx 1.0
11.2 *x 1.0
11.3 vxk 1.7
11.4 xxx 1.5
11.5 *xN* 1.9
11.6 xxxx.. 2.8
11.7 kxxxk%%kk kxkk 5.5
11.8 kxxx NN xxxNNkx wx kNNxxxxx vx kxxx 12.4
11.9 kkNkNkkkk XkXkXxx x%NCxk xkXxNMxx Xkkxkkkkw kk kxwX Y.xMXk%%xw 22.8
12.0 kMM%XkrxX kx%xk%kxkkXM xN kxxxXkxxxkk%xkxM%k%Mxx%Mx%kN kkkkkxXx xxkk wxk 27.6
12.1 kXXXxXNNM xk kxM kN kNXYMxXYkrNkkxMNkXXMxXkx xx wxM kMkkX krkX NXxM%x 25.2
12.2 NXN kkM kxxxkkkkx NNNMxk kx kM xXxX%kxkx kkNNNkxxkk IH.7
12.7, xXNxxxxxXkkkk kY kkxN%XN kkkxX kkwk 13.2
12.4 xk***xxxrvXwxux k**Y xxxx 9.8
12.5 kXkkkMMNkk kxN Nk wkx 7.7
12.6 xxNkx%N kx kk xxxx 6.3
12.7 XkM kxx%NNxxk 5.2
12.8 NxNxx.k xxx 4.3
12.9 xxX%x%Xkx 1.8
13.0 *xx***** 3.4
1311 ******k 3.2
13.2 kkxx k* 2.9
13.3 kkxx*. 2.7
13.4 xN*** 2.5
13.g *.*** 2.4
13.6 xxkkk2.2
13.7 k*k*x 2.1
13.B k*** 2.0
13.9 x.x* 1.9
14.0 kk** 1.9
14.1 *N*x 1.8
14.2 *xx. 1.7
14.3 %xxx 1.7
14.4 xNx 1.6
14.5 xkN 1.6
14.6 **k 1.5
14.7 *xk 1.5
14.8 xxx 1.4
14.9 kxX 1.4
15.0 xx* 1.4
15.1 xx* 1.7
15.2 *x* 1.3
15.3 kkx 1.3
15.4 x* 1.2
15.5 ** 1.2
15.6 ** 1.2
15.7 *k 1.1
15.8 xN 1.1
15.9 *k 1.1
16.0 *x 1.1
16.1 wk 1.1
16.2 N* 1.1
16.3 X* 1.0
16.4 k* 1.0
16.5 N* 1.0
16.6 *x 1.0
16.7 w* 1 0
16.0 xx 1.0
x I O
17. U x*
1, x* f.0
17.2 kN 0.9
17.3 wk 0.9
17.4 Nx 0.9
17. f, xx n.9
17.6 wN 0.1
17.7 *k 1i,9
17.6 kx 0.9
17.9 * 0.8
1 B.0 x 0.8
18.1 k ,.0
10.2 Y 0.0
IS." * J.0 -25-
I8.4 * O.S
S.E.F., Inc.
FROJECT:SRLEM FOREST III 10OYR
HYDROGRAPH FOR 5UBCAICHMEMT N 2 1-/171ef lr/TF
CUBIC FFET FER SECOND
kx xk kxkXXkkkk%kkxxk%x
HOUR
10.0 x 0.6
10.1 w 0.7
10.2 x 0.7
10.3 N 0.0
10.4 k II,B
10.5 x 0.9
10.6 x 0.9
10.7 X I 0
I C..S x I
10.9 kx 1.1
I I.0 kx 1.1
11.1 xk 1.2
11.2 %x 1.3
11.3 kk 1.6
11.4 kkk 2.0
11.5 wxXx 2.3
11.6 kkkkx xx 3.0
11.% xkNxMww Xw%%k kw 7.6
I1.A %kwk xx k%xxkXw ww%Xk kkkx kx kkxkkx%w 17.6 f
11.9 Xkwwkxkx kkXwkk%%xkwwXXkkkx xwkwXkkxkw wx xkkkk kkwx wX wxkk kxkww 31.8
12.0 XNk kXY%xkkXNkx kM%YM XN xYk XXX xNNNk%MxkX kwxNNkkkMxXxNX kXxk wk xXx%xkXkk 35.7
12.1 xkkXwwkkkkk xw xw%kkxMww%kkwkk%xkM kkNkkw kkkNxkkxwwww k%k 29.11
12.2 YXkX xkX xwkkkkkkkwXxNkkk xXXwxwk kk%kx xX 20.2
12.3 kkxw wN kx N%kkxxkxkk YkwYxYx 13.6
12,4 xXkk%N kNXxXx%NY Nkk 111, 11
12.5 XXYx%%k%YXx xkk 13.0
12.6 NNXk XXxXx kkk 6.7
12.7 kXY%%k kkww
Ma4.7 NkYX XMXk •J
12.9 xxYkXkk 4.2
13.(, %kx Nxkk 3.8
13.1 kkxwxx3.5_
13.2_-
13.3
13.4 XkN kk 7.9
13.5 xxx kx 2.8
13.6 Xx%% 2.6
13.7 xxNw 2.4
13.8 kwwx 2.3
13.9 kkkk 2.3
14.0 kNkx 2.2
14.1 kwkx
14.2 wxk 2..1�
14.3 kX% 2.1
14.4 xxk 7.0
14.5 xwx 1.6
14.6 xxx 1.0
14.7 xxk 1.7
14.H xxk 1.7
14.9 wx 1.6
15.C, kk 1.6
15.1 wx 1.6
15.2 kx 1.6
15.$ xk 1.5
15.4 xX 1.5
15.5 kt 1.4
15.6 kx 1.4
15.7 Mk 1.4
15.8 xk 1.4
15.9 xk 1.3
16.0 ww 1.3
16.1 xw 1.3
16.2 kx 1.3
16.3 xw 1.2
16.4 xx 1.2
16.5 kx 1.2
16.6 wX 1.2
16.7 kk 1.2
16.8 kk 1.2
16.9 Xk 1.2
7.0 k%
17.1 ww 1.1
17.2 xx 1.1
17.3 kx L. i
17.4 xx 1.1
17'.5 Nk I.i
17.6 kw 111
17.7 kx 1.1
17.8 kk 1.1
17.9 k 1.0
I B.0 x 1.0
IB.1 x 1.0
10.3 x I.0 _26_
I H.4 x 1.0
PkOJ ECT:5HLEM FOREST I11 tOVf2
HYDROGRHF'H FOR SUBCHTCHMENT 0 1 r V 7/RE d/ 7E - r,,k 7//V 6
-------------------------------
CUBIC FEET PER SECOND
N kx wwkkxk kkN xxXNM*kwk
HOUR
I0.0 * 0.2
10.1 * 0.2
10.2 x 0.3
10.3 * 0.3
10.4 w 0.3
10.5 k 0.3
10.6 k 0.7
10.7 xk 0.4
10.El ** 0.4
10.9 ** 0.4
11.0 x* 0.4
11.1 ** 0.5
11.7 w* J.5
t1.3 XXX 0.6
11.4 *** 0.7
11.5 XkYN 0.9
11.6 *NN*xk 1.3
11.7 *xxkwwkkN**xx 2.6
I I.H xk*%k kXxNw kXY *xNXX Wx x**xx WMx*N $.[i
11.9 xxNNxw*w*Xxx*wkM%xx Xwkkk %xYwX kw kkN *xwwNxwkk; xxNww W*kxXx 10.6
12.11 NX wY wXXkN xxwX%XxXxNwWNM wNNxXkkxNxXxxXwMXN NN xY Yxxk xNMxNx%MX X%kYX kxY 12.7
12,1 xwww Mk*W*xN%XkkXXXM x%N XNx X%%N %xXxw X%xkkk xN NWww wk kN *MX kNkNkN 11.5
12.2 kxX*XxXxkWk XXNN%YYN Y.X kx%*xxYXXkW**YNNNxWkWXW G.5
12.7, kkxk Xx XMXkXN MAXX NxXNX NM %M NY *Xkx 6.0
12.4 XXN MX XY XM NXYXNMYXMXkXX 4.4
12.5 kNXXWM xMNNkNXXxMYX ,�
12.6 NXxxx WXxxNXXx%k 2.9�
12.7 xNX kxXY xx xk% 2.4
12.0 XXXNXNNX XN 2.0
12.9 XkN NkXYk 1.7
13.0 kkrN*x** 1.6
j 1. ( ***Yx** 1.5
13.2 %*N*** I.3
13.3 kN**** 1.2
17.4 kx*Xxk 1.2
13.5 N***x 1.1
13.6 -KKK* L 0
13.7 ***** i.0
13.9 XYXX 0.9
13.9 *Y** 0.9
14.0 k*** 0.9
14.1 ***x 0.8
14.2 NxwW Cl.6
14.3 k*** 0.0
14.4 W*X 0.7
14.5 *** 0.7
14.6 *Nw 0.7
14.7 k** 0.7
14.8 *w* 0.7
14.9 **w 0.6
I5.i, **x 0.6
15.1 *k* 0.6
15.2 **x 0.6
15.3 N*X 0.6
15.4 **k 0.6
15.5 *x 0.5
15.6 *X 0.5
15.7 %X 0.5
15.8 Xk 0.5 1
15.9 *X 0.5
j6.0 *x 0.5
16.1 ** 0.5
16.2 ww 0.5
16.3 k* 0.5
16.4 *X 0.5
16.5 ** 0.�,
16.6 X* 0.5
16.7 wx 0.5
16.8 x* 0.4
16.9 X* O.4
** 4
17.2 ** 0.4
17.3 x* 0.4
17.4 ** 0.4
17.5 ww 0.4
17.6 xW 0.4
17.7 ** 0.4
17.6 ** 0.4
17.9 ww 0.4 _27_
18.(1 wk 0.4
18.1 ** 0.4
18.2 NW 0.4
IB.3 kw 0.4
111.4 rx 0.4
18.5 kk 0.4
I.E.F., Inc.
PROOECT:SPLEM FOREST III IOYR
HYDROBRAPH FOR SOBCRTCHMENT It 2 FN?/,eC .rlrr- ?os -dEi/Fiella4i Nr
CLINIC FEET TER SECOND
X kwkNkkkkkXkXXMXXx kXk
HOAR
10.0 N 0.3
10.1 k 0.3
10.2 N 0.3
10.3 + 0.4
10.4 w 0.4
10.5 w 0.4
111.6 k 11.5
10.7 X 0.5
/0.8 k 0.5
10.9 X 0.5
I1.0 YN 0.6
11.1 kk 0.6
11.2 wx 11.6
11.3 wwk 0.8
11.4 rNN 1.0
11.5 kNxX 1.1
11.6 XkXkNX 1.0
11.7 Xx xw NNw x-X kkNkk 3.7
11.8 iFXN kx kwwwwwkwkkxk kkkxxXN kkkkXwww 8.5
11.9 XX4N Y.x xXkkxXM kN XkkkNk kMNkk kXX XXXMYXXM MN kNwkkXwXkN NX kkN Yk%X 15.4
12.0 kkX wXxkXxkkkXk kMX kk kwkM NkXXkkNXxx XxN XNkxwxw MN kkN kk kN N'-kkkkM kXNkxkxN 17.4
12.1 XkXXXXNX kNNk XXNxk NXXXXxxkk Y.NX XX XXkXwkkkX%XkXXXxNkkX%XX 14.3
12.2 NwxkkkMkNx kkXkNNXXM kMxXwkkkXkXkXXXkxN TO..)
12.3 XX kN%Mkkkw YkX%NXXx kNN Xk kk 6.3
12.4 xN XMkXXx NkXMXXwMNX S.0
12.5 MxXYN NX Y.N kM MkXY 4.11
12.6 wMN NM xN kXMkk 3.4
12.7 Y.X kXMX CxXk 2.8
12.0 XYN YxNNN
12.9 kkM YNXN 2.1'
171.0 xXMkNMx 1.9
13.1 kXNNXk 1.8
13.2 kxr Nkk 1.6
17.3 XMxkkw 1.6
13.4 xwxxx 1.4
13.5 kkX%♦ 1.4
13.6 wxXw 1.3
13.7 XXkN 1.2 '
1 �•.B wkkk 1.1
13.9 kXNk 1.1
14.0 Xkkk 1.1
14.1 wwwk 1.1
14.2 kXk 1.0
14.3 XXX 1.0
14.4 Nxx 1.0
14.5 XXk 0.9
14.6 wwX 0.9
14.7 rXx 0,9
14.8 XXx 0.8
14.9 Xkw 0.0
15.0 wNk 0.8
15.1 kwX 0.8
15.2 wXk 0.8
15.3 xX 0.7
15.4 wx 0.7
15.5 XX 0.7
15.6 XN 0.7
M.7 Xx 0.7
15.8 k% 0.7
15.9Nw 0.6
16.0 NX 0.6
16.1 kw 0.6
16.2 kx 0.6
16.3 XX 0.6
16.4 xX 0.6
16.5 Yx 0.6
16.6 xN 0.6 ,
16.7 xX 0.6
16.6 xk 0.6
16.9 wk 0.6
.0 Nw
17.1 XX 0.6
17.2 Nx 0.6
17.3 0.6
17.4 kN 0.6
17.5 k 0.5
17.6 w 0.5
17.7 X 0.5
17.8 N 0.5
17.9 X 0.5
18.0
I8.1
IB. k 0.5
18.3 r 0.3 -2$-
18.4 x 0.5
18.5 X 0.5
Subject
iC?�
6 Maple Street
Northborough, MA 01532
393-8558
Jet) ND. Sheet_ of
By Date
Ckd. Bev.
%�UYyOFF //�/C,PCf�f'F CDA/CL UJ'/0/t/
80J74N B,P44/� A r e✓ 04-O Rd/IL4) ,rriJ7/N6 4�ploe) = #Gj r, CC 17DS/lrr
so.?7,P,W r F, IsrIA)6 JITF 4)1,10P 1704 �-v
4G4•� ��s
l,Z c{J AD.1) RO fr IFS JirE Q/V6 /7aa ti f
q6G• 0 Cc�J IONT dl�✓• Q4J701V ,F,t'o0/i,�
o IJO b1,1(/NR/2Gr/NI1"1IJ'F — 0, 2 cvJr POJT-Ofy�G���FNT
f//hiLfi2L /� /D YR 41SO14 edt /tie e4'l9.tc = 0,4 -0,4 = 0,2 CV.r
—29—