HomeMy WebLinkAboutStormwater Report - 701 SALEM STREET 5/1/1996 SITE DESCRIPTION
AND
DRAINAGE IS
FOR
PROPOSED I
FACILITY
STREET AT
ABBOTT AND SALEM S
NORTH ANDOVER9 MASSACHUSETTS
SYSTEM BUILDERS, INC.
202 SUTTON STREET
NORTH ANDOVER, MASSACHUSETTS
AY, 1996
MERRIMACK ENGINEERING SE VICES, INC.
66 PARK STREET
ANDOVER, MASSACHUSETTS 01810
WLEY
cfvtt
.,
TABLE OF CONTENTS
SITE DESCRIPTION
METHODOLOGY
PRE-DEVELOPMENT
DRAINAGE ANALYSIS
POST-DEVELOPMENT
DRAINAGE ANALYSIS
DESIGN SUMMARY
CHARTS AND TABLES
SOIL TEST RESULTS
SITE DESCRIPTION
SITE DESCRIPTION
EXISTING CONDITIONS
The project site is located at the corner of Abbott Street and Salem Street in North
Andover. At the present time the site is in a developed state on which a commercial building
occupies about 3,500 square feet of floor area, and a two story wood-frame dwelling occupies
about 1500 square feet.
The area of the property is 42,086 square feet (0.97) acres). There is about 7,000 square
feet of pavement for access and parking for the commercial building and about 750 square feet of
pavement for the dwelling. These buildings are serviced by Town water via a 12" C.L.D.I.
watermain and 6" high pressure gas. A subsurface sewage disposal system is located in the rear
of the buildings and handles the sewage flows for both buildings, which discharge sewage into a
septic tank, then to a pump chamber, through a two inch forcemain, to a slightly raised leaching
facility.
The topography of the land is a gradient of 2 to 4 percent slope from the northwest to
the southeast portion of the property, where virtually allow of the runoff from the site flow to
and then beyond onto Salem Street in a southeasterly direction, after flowing across Abbott
Street. No catch basins were found along the Abbott Street frontage.
A copy of a Topographic Plan from the South Groveland Quadrangle (1" = 2083'), a
portion thereof, showing the location of the project site and vicinity, is included in this report.
The soils on the site are entirely"Sudbury - SrA", based on the soil maps prepared by the
U.S.D.A. Soil Conservation Service. This soil type is a loamy sand to a sandy gravel in texture.
This was verified by actual deep hole tests done on May 3, 1995. The test results are included in
this report. The permeability of the parent soil can range between 2 and 20 inches per hour. A
portion of the Soils Map (1" = 1320') showing the location of the project site and vicinity, is
included in this report. A soil of the Sudbury description is suitable for subsurface drainage
system'given the high permeability of the parent material. The only foreseeable restriction would
be the seasonal high water table. However, the water table were found to range between 60"
and 90", as the observed water tables throughout the site, at five different locations, and
assuming the seasonal high water table(S.H.W.T.) to be potentially up to 24" above the
observed level witnessed on the date of testing.
PROPOSED SITE DEVELOPMENT
. Based on a preliminary site design prepared for our client by John Daly, Project
Architect, we further developed an overall site plan for the proposed 7680 square foot
- commercial building to be constructed. Site development shall occur shortly after the existing
buildings are razed and demolition is completed, in the preparation of site for all proposed
earthwork and appurtenant construction activity, including water service connection and a sewer
service connection, which will require a sewer extension from the vicinity of Summer Street to
Abbott Street..
Also, in order to mitigate the increase in potential runoff from the new site, at least three
subsurface infiltration facilities are proposed on the site. These systems will store the runoff
from the new building roof area as well as large portions of the paved areas to be built around
the new building for access and parking provisions. The stored water will infiltrate into the
ground below and surrounding each subsurface system, as they are engineered and designed to
capture, detain, and percolate 100% of the runoff, back into the ground based on an inflow
volume from a 100 year storm event. The remaining areas of the site will not drain into these
facilities. This runoff will flow unmitigated to the lowest part of the property(Design Point#1)
at the southeasterly corner.
. Along the perimeter of the site, adjacent to abutting residential properties, a landscaped
buffer strip will be constructed to provide sufficient"green" space between the commercial and
residential properties. A landscaping plan has been designed to provide a variety of trees,
shrubbery, and other plantings throughout the site, in mulched islands, for visual aesthetics. The
remaining areas will be loamed and seeded or sodded.
Along the edge of pavement will be sloped granite and bituminous concrete curbing,
which will serve adequately in channelizing and directing surface water runoff into catch basins
or swales, as proposed, to ensure that each facility will receive all of the runoff based on the
design:
The net effect and intent of this subsurface drainage system is to produce an overall
reduction in the peak rate of runoff from the site when comparing pre-development to post-
development conditions.
METHODOLOGY
METHODOLOGY
The method of analysis for determining stormwater runoff rates is based on the Soil
Conservation Service TR-20 procedures. This method takes into account the following
information: watershed area, soil type, ground cover condition, topography, time of
concentration. Using this information for input, the HydroCAD computer program contains a
statistical Type Iii rainfall distribution, which then internally generates a separate hydrograph for
each watershed being considered, called a subcatchment area. Rainfall rates on the basis of a 24
hour total rainfall are provided as input data, i.e. 2 year storm - 3.1", 10 year - 4.5", and 100 year
- 6.5". For the subcatchments, the peak rates of runoff are calculated. The post-development
rates shall not exceed the predevelopment rates. In order to mitigate any increase, we must
design either a retention facility, such as the subsurface infiltration facilities d e signed for this
project, or a detention facility. Runoff from the subcatchments are routed to or through these
types of facilities. Doing this enables the engineer to meet the specific objective, which-is not to
create any increase in runoff beyond the limits of the project.
The Summary Chart within this report is based on the combination of all hydrographs of
subcatchments and ponds, which are the subsurface infiltration systems by description. This is
done to account for the time during the storm event, given that all of the peak flows do not occur
simultaneously, when the runoff exits the project site.
A
R E- DEVELOPMENT
i
R DEVELOPMENT
2-YEAR
PRE- DEVELOPMENT
Data for SYSTEM BUILDERS,INC-ABBOTT ST. ,NORTH ANDOVER Page 73
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 1 PRE-DEVEL. TOTAL SITE, 2-YEAR STORM
PEAK= .76 CFS @ 12.23 HRS, VOLUME= .08 AF
PERCENT CN SCS TR-20 METHOD
35.00 98 PAVED SURFACE AREA TYPE III 24-HOUR
45.00 61 GRASS SURFACE AREA RAINFALL= 3. 1 IN
5.00 58 LANDSCAPED AREAS SPAN= 10-20 HRS, dt=.1 HRS
15.00 58 WOODED AREA
100.00 73 TOTAL AREA = 1.09 AC
Method Comment Tc (min)
TR-55 SHEET FLOW OVER WOODED AREA 12.5
Woods : Light underbrush n=.4 L=50' P2=3.1 in s=.02
SHALLOW CONCENTRATED/UPLAND FLOW OVER GRASSED AREA 4.2
Short Grass Pasture Kv=7 L=250' s=.02 '/' V=.99 fps
CHANNEL FLOW IN GUTTER TO D.P.# 1 .8
a=1.4 sq-ft Pw=12.2' r=. 115'
s=.02 ' /' n=.016 V=3.1 fps L=150' Capacity=4.3 cfs
Total Length= 450 ft Total Tc= 17.5
SUBCATCHMENT 1 RUNOFF
PRE-DEUEL , TOTAL SITE , 2-YEAR STORM
. 75
70 AREA- 1 . 09 AC
. 65 Tc= 17 . 5 MIN
. 60 CN= 73
. 55
55 SCS TR-20 METHOD
45 TYPE III 24-HOUR
u �� RAINFALL= 3 , 1 IN
' 35 PEAK= . 76 CFS
a 130 @ 12 , 23 HRS
. 25 UOLUME= 08 AF
�-
. 20
. 15
. ] a
. 05
0 . 03 CD
TIME (hours )
10-Y AR
PRE- DEVELOPMENT
Data for SYSTEM BUILDERS, INC-ABBOTT ST-NORTH ANDOVER Page 72
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4 51 000899 (c) 1986-1996 Applied Microcomputer ystems
SUBCATCHMENT 1 PRE-DEVEL. TOTAL SITE,10-YEAR STORM
PEAK= 1.67 CFS @ 12.21 HRS, VOLUME= .16 AF
PERCENT CN SCS TR-20 METHOD
35.00 98 PAVED SURFACE AREA TYPE III 24-HOUR
45.00 61 GRASS SURFACE AREA RAINFALL= 4.5 IN
5.00 58 LANDSCAPED AREAS SPAN= 10-20 HRS, dt=.1 HRS
15.00 58 WOODED AREA
100.00 73 TOTAL AREA = 1.09 AC
Method Comment Tc (min)
TR-55 SHEET FLOW OVER WOODED AREA 12.5
Woods : Light underbrush n=.4 L=50' P2=3.1 in s=.02
SHALLOW CONCENTRATED/UPLAND FLOW OVER GRASSED AREA 4.2
Short Grass Pasture Kv=7 L=250' s=.02 '/' V=.99 fps
CHANNEL FLOW IN GUTTER TO D.P.# 1 .8
a=1.4 sq-ft Pw=12.2' r=.115'
s=.02 '/' n=.016 V=3. 1 fps L=150' Capacity=4.3 cfs
Total Length= 450 ft Total Tc= 17.5
SUBCATCHMENT 1 RUNOFF
PRE-DEUEL , TOTAL SITE , 10-YEAR STORM
1 . 6
1 , 5 AREA= 1 . 09 AC
1 , 4 Tc= 17 . 5 MIN
1 , 3 CN= 73
1 . 2
LO 1 . 1 SCS TR-20 METHOD
1 O TYPE III 24-HOUR
u g RAINFALL= 4 . 5 IN
. 7 PEAK= 1 . 67 CFS
0 . 6 e 12 , 21 HR5
-� . 5 UDLUME= 16 AF
. 4
. 3
, 2
. 1
O l e m t r- as rn CD
TIME (hours )
100-YEAR
PRE- DEVELOPMENT
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 74
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4 51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 1 PRE-DEVEL. TOTAL SITE, 100-YR STORM
PEAK= 3. 14 CFS @ 12.21 HRS, VOLUME= .29 AF
PERCENT CN SCS TR-20 METHOD
35.00 98 PAVED SURFACE AREA TYPE III 24-HOUR
45.00 61 GRASS SURFACE AREA RAINFALL= 6.5 IN
5.00 58 LANDSCAPED AREAS SPAN= 10-20 HRS, dt=. l HRS
15.00 58 WOODED AREA
100.00 73 TOTAL AREA = 1.09 AC
Method Comment Tc (min)
TR-55 SHEET FLOW OVER WOODED AREA 12.5
Woods: Light underbrush n=.4 L=50' P2=3.1 in s=.02
SHALLOW CONCENTRATED/UPLAND FLOW OVER GRASSED AREA 4.2
Short Grass Pasture Kv=7 L=250' s=.02 '/' V=.99 fps
CHANNEL FLOW IN GUTTER TO D.P.# 1 .8
a=1.4 sq-ft Pw=12.2' r=.115'
s=.02 ' /' n=.016 V=3. 1 fps L=150' Capacity=4.3 cfs
Total Length= 450 ft Total Tc= 17.5
SUBCATCHMENT 1 RUNOFF
PRE-DEVEL , TOTAL SITE , 100-YR STORM
3 . e
2 S AREA= 1 , 09 AC
2 . 6 Tc= 17 . 5 MIN
2 . 4 - CN= 73
2 ' 2 SCS TR-20 METHOD
2 ' 6 TYPE III 24-HOUR
1 , 6 RAINFALL= 6 . 5 IN
1 . 4 PEAK= 3 . 14 CFS
CD 1 . 2 @ 12 , 21 HR5
1 . 8 UOLUME= . 29 AF
, 6
. 4
2
1310
N M st- to kD ao 0') m
TIME (hours )
{
POST- DEVELOPMENT
Oat for SYSTEM BUILDERS,INC-ABBOTT ST. ,NORTH ANDOVER
Prepared by Merrimack Engineering Services, Inc.
HydrQCAD 4.51 000899 (c) 1986-1996 ARolied Microcom inter Systems
7 6 5 4 3 z 1
0 a
SUBCATCHMENT ❑ REACH APOND LINK
w
SUBCATCHMENT 1 = POST-DEV.- FLOW TO CB#1 -> POND 1
SUBCATCHMENT 2 = POST-DEVEL. ROOF AREA -> POND 1
SUBCATCHMENT 3 = POST-DEVEL. REAR ROOF & PAVEMENT -> POND 3
SUBCATCHMENT 4 = POST-DEVEL. FRONT ROOF & CB#3 AREAS -> POND 4
SUBCATCHMENT 5 = POST-DEVEL.. LOW PARK'G AREA -> REACH 1
SUBCATCHMENT 6 = POST-DEVEL. REAR PARKING & SWALE -> REACH 1
SUBCATCHMENT 7 = POST-DEVEL. FRONTAGES & WEST SWALE -> REACH 1
REACH 1 = DESIGN POINT FOR SUBCATS 5,6,&7 ->
POND 1 = INFILT.SYSTEM FOR CB#1 & .04 AC ROOF ->
POND 3' = INFILT.SYSTEM FOR SUBCAT# 3 ->
POND 4 = INFILT.SYSTEM FOR SUBCAT # 4 ->
SUBCAT AREA Tc WGT'D Tpeak
NUMBER (ACRE) (MIN) --GROUND COVERS (RCN) -- CN (HRS)
1 .06 1.4 100%98 - - - 98 11.98
2 .04 .2 100%98 - - - 98 11.96
3 .12 1.9 100%98 - - - 98 111.99
4 .21 1.7 100%98 - - - 98 11.99
5 .11 1.2 100%98 - - - 98 11.98
6 .17 8.7 46%98 20%61 34%58 - 77 12.09
7 .38 4.5 32%98 57%61 11%58 - 73 12.02
2-YEAR
POST- DEVELOPMENT
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 50
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 1 POST-DEV. , 2-YR FLOW TO CB#1
PEAK= .18 CFS @ 11.98 HRS, VOLUME= .01 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 PAVED SURFACE AREA TYPE III 24-HOUR
TOTAL AREA = .06 AC RAINFALL= 3.1 IN
SPAN= 10-20 HRS, dt=.l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS PAVEMENT 1.0
n=.016 L=50' P2=3. 1 in s=.02 ' / '
CHANNEL FLOW IN GUTTER, TO CB#1 .4
a=1.4 sq-ft Pw=12.2' r=. 115'
s=.01 '/' n=.016 V=2. 19 fps L=50' Capacity=3. 1 cfs
Total Length= 100 ft Total Tc= 1.4
SUBCATCHMENT 1 RUNOFF
POST-DEU , 2-YR FLOW TO CB# 1
17
. 16 AREA= 06 AC
1 Tc= 1 . 4 MIN
14 CN= 98
13
r, . 12 SCS TR-20 METHOD
. 11 TYPE III 24-HOUR
u
. 10 RAINFALL= 3 . 1 IN
. 09
. 08 PEAK= 18 CFS
CD . 86 @ 11 , 98 HRS
VOLUME= 01 AF
LL_ . 05
. 04
. 03
. 02
01
0CD M d- in 0 r- co a) 0
TIME ( hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST—NORTH ANDOVER Page 51
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 2 POST-DEVEL. , 2-YR,ROOF AREA
PEAK= .11 CFS @ 11.96 HRS, VOLUME= .01 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 ROOF SURFACE TYPE III 24-HOUR
TOTAL AREA = .04 AC RAINFALL= 3.1 IN
SPAN= 10-20 HRS, dt=.l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW TO ROOF GUTTER 1
Smooth surfaces n=.011 L=35' P2=3.1 in s=.5
CHANNEL FLOW IN GUTTER, TO SYSTEM#1 l
a=.2 sq-ft Pw=1' r=.2'
s=.02 ' /' n=.01 V=7. 19 fps L=60' Capacity=1.4 cfs
Total Length= 95 ft Total Tc= .2
SUBCATCHMENT 2 RUNOFF
POST-QEUEL , , 2-YR , ROOF AREA
. 11
1O AREA= . 04 AC
Tc= . 2 MIN
09 CN= 98
. �8
SCS TR-20 METHOD
� , 07 TYPE III 24—HOUR
U . 06 RAINFALL= 3 , 1 IN
3
. 85 PEAK= 11 CFS
O , 04 @ 11 . 96 HRS
—� UOLUME= 01 AF
. 02
, 81
M d' In tD r- CO O} CD
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 61
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomp t� er Systems
POND 1 INFILT.SYSTEM FOR CB#1 & .04 AC ROOF, 2-YR
Qin = .29 CFS @ 11.98 HRS, VOLUME= .02 AF
Qout= . 10 CFS @ 12.24 HRS, VOLUME= .02 AF, ATTEN= 66%, LAG= 15.7 MIN
Qpri= 0.00 CFS @ 14.60 HRS, VOLUME= -0.00 AF
Qsec= . 10 CFS @ 12.24 HRS, VOLUME= .02 AF
ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD
(FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 160 CF
0.0 0 0 0 0 PEAK ELEVATION= .5 FT
.l 396 13 13 396 FLOOD ELEVATION= 3.0 FT
1.5 396 554 568 495 START ELEVATION= 0.0 FT
2.5 50 196 763 844 SPAN= 10-20 HRS, dt=.1 HRS
3.0 60 27 791 861 Tdet= 9.8 MIN ( .02 AF)
# ROUTE INVERT OUTLET DEVICES
1 S 0.0' EXFILTRATION
V= .014 FPM over WETTED AREA
Primary Discharge
Secondary Discharge
�--1=Exfiltration
POND 1 INFLOW & OUTFLOW
INFILT , SYSTEM FOR CB# 1 & 04 PC ROOF , 2-YR
, 28
. 26 STOR-IND METHOD
. 24 PEAK STOR= 160 CF
22 PEAK ELEU= . 5 FT
20 Qin= 29 CFS
c+ 1 Qout= . 1 0 CFS
U . 16 Qpri = 0 . 00 CFS
. 14 Q5(--c= . 10 CFS
12 LAG= 15 . 7 MIN
C 10 �.
IL . 08
l 1
1
. 04 7.
. 02
',I- Ln �D r- co 0) m
TIME ( hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 52
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 3 POST-DEVEL. , 2-YR,REAR ROOF & PAVEMENT
PEAK= .36 CFS @ 11.99 HRS, VOLUME= .02 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 ROOF & PAVEMENT TYPE III 24-HOUR
TOTAL AREA = . 12 AC RAINFALL= 3. 1 IN
SPAN= 10-20 HRS, dt=. l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW OVER ROOF /PAVVEMENT 1 .0
n=.016 L=50' P2=3. 1 in s=.02 '/ '
SHALLOW CONCENTRATED/UPLAND FLOW ALONG GUTTERS .4
Paved Kv=20.3282 L=50' s=.01 '/ ' V=2.03 fps
CHANNEL FLOW ALONG GUTTER TO CB#2 .5
a=1.4 sq-ft Pw=12.2' r=.115'
s=.01 '/' n=.016 V=2. 19 fps L=60' Capacity=3. 1 cfs
Total Length= 160 ft Total Tc= 1 .9
SUBCATCHMENT 3 RUNOFF
POST-DEUEL , , 2-YR , REAR ROOF & PAUEMENT
. 36
34 AREA= . 12 AC
. 32 Tc= 1 . 9 MIN
. S0
CN= 98
26
24 SCS TR-20 METHOD
� .
22 TYPE III 24-HOUR
u , 20 RAINFALL= 3 , 1 IN
`-' . 18
. 16 PEAK= . 36 CFS
CD . 14 @ 11 . 99 HRS
-� . 1 UOLUME= . 02 AF
i- . ] a
. 08
. 06
. 04
, 02
0 '
00
CD M d u7 w r- ao a) r�
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 60
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
POND 3 2 YR STORM,INFILT.SYSTEM FOR SUBCAT# 3
Qin = .36 CFS @ 11.99 HRS, VOLUME= .02 AF
Qout= .13 CFS @ 12.23 HRS, VOLUME= .02 AF, ATTEN= 65%, LAG= 14.2 MIN
Qpri= 0.00 CFS @ 11.00 HRS, VOLUME= 0.00 AF
Qsec= . 13 CFS @ 12.23 HRS, VOLUME= .02 AF
ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD
(FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 173 CF
0.0 0 0 0 0 PEAK ELEVATION= .4 FT
. 1 528 18 18 528 FLOOD ELEVATION= 3.0 FT
1.5 528 739 757 642 START ELEVATION= 0.0 FT
2.5 50 247 1004 1123 SPAN= 10-20 HRS, dt=. 1 HRS
3.0 60 27 1031 1140 Tdet= 8.1 MIN ( .02 AF)
# ROUTE INVERT OUTLET DEVICES
1 S 0.0' EXFILTRATION
V= .014 FPM over WETTED AREA
Primary Discharge
Secondary Discharge
-1=Exfiltration
POND 3 INFLOW & OUTFLOW
2 YR STORM , INFILT , SYSTEM FOR SUBCAT# 3
. 36
. 34 STOR-IND METHOD
' 32 PEAK STAR= 173 CF
, 30 PEAK ELEU= . 4 FT
. 28
. 26
' O , 24 Qin= 36 CFS
, 22 Qout= 13 CFS
U 20 Qpri = 0 . 00 CFS
`-` . 18 05ec= . 13 CFS
. 16 LAG= 14 . 2 MIN
O 14
12 �.
. aS �
. 04
7
. 02
am T M d- n r�
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST-NORTH ANDOVER Page 53
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 4 POST-DEVEL. , 2-YR. ,FRONT ROOF & CB#3 AREAS
PEAK= .63 CFS @ 11.99 HRS, VOLUME= . 04 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 ROOF/PAVED AREA TYPE III 24-HOUR
TOTAL AREA = .21 AC RAINFALL= 3.1 IN
SPAN= 10-20 HRS, dt=. 1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS IMPERVIOUS SURFACES .8
n=.016 L=50' P2=3.1 in s=.03 '/ '
SHALLOW CONCENTRATED/UPLAND FLOW ALONG GUTTER .3
Paved Kv=20.3282 L=40' s=.01 '/' V=2.03 fps
CHANNEL FLOW ALONG GUTTER TO CB#3 .6
a=1.4 sq-ft Pw=12.2' r=. 115'
s=.01 '/' n=.016 V=2.19 fps L=80' Capacity=3.1 cfs
Total Length= 170 ft Total Tc= 1.7
SUBCATCHMENT 4 RUNOFF
POST-DEUEL , , 2-YR , , FRONT ROOF & CB#3 AREAS
' 55 AREA= . 21 AC
55 Tc= 1 . 7 MIN
. 50 CN= 98
45 SCS TR-20 METHOD
� 40 TYPE III 24-HOUR
u . 35 RAINFALL- 3 . 1 IN
30 PEAK= 63 CFS
0 25 @ 11 . 99 HRS
-� . 20 UDLUME- 04 AF
15
. 10
. 05
0 , 0 am T ni M It Ln co 0) CD
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 59
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
POND 4 2-YR STORM, INFILT.SYSTEM FOR SUBCAT# 4
Qin = .63 CFS @ 11.99 HRS, VOLUME= .04 AF
Qout= .24 CFS @ 12.19 HRS, VOLUME= .04 AF, ATTEN= 61%, LAG= 12.4 MIN
Qpri= 0.00 CFS @ 12.30 HRS, VOLUME= 0.00 AF
Qsec= .24 CFS @ 12.19 HRS, VOLUME= .04 AF
ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD
(FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 270 CF
0.0 0 0 0 0 PEAK ELEVATION= .3 FT
. 1 1020 34 34 1020 FLOOD ELEVATION= 3.0 FT
1 .5 1020 1428 1462 1179 START ELEVATION= 0.0 FT
2.5 50 432 1894 2151 SPAN= 10-20 HRS, dt=.1 HRS
3.0 60 27 1921 2167 Tdet= 6.7 MIN ( .04 AF)
_# ROUTE INVERT OUTLET DEVICES
1 S 0.0' EXFILTRATION
V= .014 FPM over WETTED AREA
Primary Discharge
Secondary Discharge
-1=Exfiltration
POND 4 INFLOW & OUTFLOW
2-YR STORM , INFILT , SYSTEM FOR SUBCAT# 4
, 5
5 STDR-IND METHOD
PEAK STDR= 270 CF
. 50 PEAK ELEU= . 3 FT
. 45
'-` Q in= , 63 CFS
(4- . 40 - Qout= 24 CFS
u . 35 Qpr i = 0 . 00 CFS
`-` , 30 Qsec= . 24 CFS
LAG= 12 . 4 MIN
0 25 �.�
-J , 2e l
15 S
1 ti
10
. e5
ale 0 M r- m
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 54
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 5 POST-DEVEL. , 2-YR. ,LOW PARK'G AREA
PEAK= .32 CFS @ 11.98 HRS, VOLUME= .02 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 PAVED PARKING AREA TYPE III 24-HOUR
TOTAL AREA = . 11 AC RAINFALL= 3.1 IN
SPAN= 10-20 HRS, dt=. l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS PAVEMENT .8
n=.016 L=50' P2=3. 1 in s=.03 ' /'
SHALLOW CONCENTRATED/UPLAND FLOW ACROSS PAVEMENT TO GUTTER .2
Paved Kv=20.3282 L=40' s=.03 ' /' V=3.52 fps
CHANNEL FLOW ALONG GUTTER .2
a=1.4 sq-ft Pw=12.2' r=.115'
s=.02 ' /' n=.016 V=3.1 fps L=40' Capacity=4.3 cfs
Total Length= 130 ft Total Tc= 1 .2
SUBCATCHMENT 5 RUNOFF
POST-DEUEL , , 2-YR , , LOW PARK ` G AREA
3
, 30 AREA= . 11 AC
. 28 Tc= 1 . 2 MIN
. 26 CN= 98
. 24
. 22 SCS TR-20 METHOD
20 TYPE III 24-HOUR
U 18 RAINFALL= 3 . 1 IN
16
. 14 PEAK= 32 CFS
0 12 @ 11 , 98 HRS
-� 10 UOLUME= , 02 AF
. 08
. 06
, 04
, 02
0 , 000 T N M n 0 �-
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 56
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 6 POST-DEVEL. , 2-YR. ,REAR PARKING & SWALE
PEAK= . 19 CFS @ 12. 10 HRS, VOLUME= .01 AF
PERCENT CN SCS TR-20 METHOD
46.00 98 PAVEMENT TYPE III 24-HOUR
20.00 61 GRASS SWALE RAINFALL= 3. 1 IN
34.00 58 LANDSCAPED SPAN= 10-20 HRS, dt=.1 HRS
100.00 77 TOTAL AREA = .17 AC
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS PAVEMENT .9
Smooth surfaces n=.011 L=50' P2=3.1 in s=.01
SHALLOW CONCENTRATED/UPLAND FLOW ACROSS PAVEMENT TO GUTTER .6
Paved Kv=20.3282 L=60' s=.007 '/ ' V=1.7 fps
SHALLOW CONCENTRATED/UPLAND FLOW WITHIN GRASS SWALE 2.2
Grassed Waterway Kv=15 L=140' s=.005 '/ ' V=1 .06 fps
CHANNEL FLOW WITHIN GRASS SWALE 5.0
a=8 sq-ft Pw=12.2' r=.656'
s=.005 ' / ' n=.24 V=.33 fps L=100' Capacity=2.6 cfs
Total Length= 350 ft Total Tc= 8.7
SUBCATCHMENT 6 RUNOFF
POST-DEUEL , , 2-YR , , REAR PARKING & SWALE
19
. 18
17 AREA= . 17 AC
16 Tc= 8 , 7 MIN
. 15 - CN= 77
. 14
r, 13 SCS TR-20 METHOD
' 12 TYPE III 24-HOUR
u , 11 RAINFALL= 3 . 1 IN
. 89
3 , 08 PEAK= . 19 CFS
CD 07 C 12 , 1 HRS
-� , 06 UOLUME= , @ 1 AF
�-
. 05
, 04
. a3
, 02
, O1
' @ am N M T Ln tD r- CC)
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 57
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 7 POST-DEVEL. , 2-YR. ,FRONTAGES & WEST SWALE
PEAK= .36 CFS @ 12.03 HRS, VOLUME= .03 AF
PERCENT CN SCS TR-20 METHOD
32.00 98 PAVEMENT TYPE III 24-HOUR
57.00 61 GRASS RAINFALL= 3. 1 IN
11.00 58 LANDSCAPED SPAN= 10-20 HRS, dt=.1 HRS
100.00 73 TOTAL AREA = .38 AC
Method Comment Tc (min)
TR-55 SHEET FLOW OVER PAVEMENT 1 .2
Smooth surfaces n=.011 L=50' P2=3.1 in s=.005
SHALLOW CONCENTRATED/UPLAND FLOW WITHIN GRASS SWALE 1.7
Grassed Waterway Kv=15 L=150' s=.01 '/ ' V=1.5 fps
SHALLOW CONCENTRATED/UPLAND FLOW ALONG GUTTER LINE .9
Paved Kv=20.3282 L=150 ' s=.02 '/ ' V=2.87 fps
CHANNEL FLOW WITHIN GUTTER .7
a=1.5 sq-ft Pw=12.2' r=.123'
s=.02 '/' n=.016 V=3.25 fps L=140' Capacity=4.9 cfs
Total Length= 490 ft Total Tc= 4.5
SUBCATCHMENT 7 RUNOFF
POST-DEUEL , , 2-YR , , FRONTAGES & WEST SWALE
. 36
. 34 AREA= . 38 AC
. 32 Tc= 4 , 5 MIN
. 30
. 28 CN= 73
. 26
r, 24 SCS TR-20 METHOD LO 22 TYPE III 24-HOUR
u 20 RAINFALL= 3 . 1 IN
�f 18
16 PEAK= 36 CFS
0 14 @ 12 , 03 HRS
-� 12 UOLUME-- 03 AF
I� 10
. O8
. 06
. 04
, 02
0 , 00CS) T rp to ca � C D,
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 58
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
REACH 1 DESIGN POINT FOR SUBCATS 5,6,&7 < 2-YR >
Qin = .82 CFS @ 12.02 HRS, VOLUME= .06 AF
Qout= .74 CFS @ 12.07 HRS, VOLUME= .06 AF, ATTEN= 10%, LAG= 2.9 MIN
DEPTH END AREA DISCH
(FT) (SO-FT) (CFS) 20' x .8' CHANNEL STOR-IND+TRANS METHOD
0.0 0.0 0.00 SIDE SLOPE= .01 ' /' PEAK DEPTH= .02 FT
. l 2.2 3.27 n= .016 PEAK VELOCITY= 1.5 FPS
.2 5.8 12.34 LENGTH= 90 FT TRAVEL TIME = 1.0 MIN
.2 10.6 28.33 SLOPE= .01 FT/FT SPAN= 10-20 HRS, dt=. l HRS
.3 18.7 61.55
.5 32.6 130. 17
.6 53.8 254. 18
.8 80. 0 432.70
REACH 1 INFLOW & OUTFLOW
DESIGN POINT FOR SUBCATS 5 , 6 , &7 < 2-YR >
. 0
. 75 20' x . 8' CHANNEL
. 70 r� SIDE SLOPE- . 01 ' l'
. 65 4 n= . 016 L=90' S= . 01
60 5
n 55 STOR-IND+TRANS METHOD
LO 150 1 VELOCITY= 1 , 5 FPS
u . 45 TRAVEL= 1 MIN
. 35 f Q i n= . 82 CFS
o 30 Gout= 74 CFS
, 25 LAG- 2 , 9 MIN
. 20
. 15
. 10
05
' (DID r-�
M in � as a-) m
TIME (hours )
10-YEAR
POST- DEVELOPMENT
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 41
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 1 POST-DEV. ,10-YR FLOW TO CB#1
PEAK= .26 CFS @ 11.98 HRS, VOLUME= .02 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 PAVED SURFACE AREA TYPE III 24-HOUR
TOTAL AREA = .06 AC RAINFALL= 4.5 IN
SPAN= 10-20 HRS, dt=. 1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS PAVEMENT 1 .0
n=.016 L=50' P2=3.1 in s=.02 '/ '
CHANNEL FLOW IN GUTTER, TO CB#1 .4
a=1.4 sq-ft Pw=12.2' r=. 115'
s=.01 ' /' n=.016 V=2. 19 fps L=50' Capacity=3.1 cfs
Total Length= 100 ft Total Tc= 1.4
SUBCATCHMENT 1 RUNOFF
POST-DEU , , 10-YR FLOW TO CB# 1
. 26
. 24 AREA= . 66 AC
. 22 Tc= 1 . 4 MIN
20 CN= 98
,� 18 SCS TR-20 METHOD
16 TYPE III 24—HOUR
U 14 RAINFALL= 4 . 5 IN
12 PEAK= . 26 CFS
0 . 1e @ 11 . 98 HRS
—� • 88 UOLUME- 02 AF
06
. 04
, 02
0 , 0 am T cv r� d r~ ca 0) CD
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 36
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 2 POST-DEVEL. ,10-YR,ROOF AREA
PEAK= . 16 CFS @ 11.96 HRS, VOLUME= .01 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 ROOF SURFACE TYPE III 24-HOUR
TOTAL AREA = .04 AC RAINFALL= 4.5 IN
SPAN= 10-20 HRS, dt=. l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW TO ROOF GUTTER . 1
Smooth surfaces n=.011 L=35' P2=3.1 in s=.5
CHANNEL FLOW IN GUTTER, TO SYSTEM#1 . 1
a=.2 sq-ft Pw=1' r=.2'
s=.02 ' /' n=.01 V=7. 19 fps L=60' Capacity=1.4 cfs
Total Length= 95 ft Total Tc= .2
SUBCATCHMENT 2 RUNOFF
POST-DEVEL , , 10-YR , RO0F AREA
. 16
. 15 AREA= . 04 AC
. 14 Tc- 2 MIN
13 CN= 96
12
. 11 SCS TR-20 METHOD
L 10 TYPE III 24-HOUR
u . 09 RAINFALL- 4 . 5 IN
. 08
. 07 PEAK= 16 CFS
o . 06 @ 11 , 96 HRS
. 05 UOLUME- . 01 AF
04
. 03
. 02
. 01
e , @e@ T , r'7 �- m
TIME (hour5 )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 37
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4. 51 000899 (c) 1986-1996 Applied Microcomputer Systems
POND 1 INFILT.SYSTEM FOR CB#1 & .04 AC ROOF,100YR
Qin = .42 CFS @ 11.98 HRS, VOLUME= .03 AF
Qout= . 11 CFS @ 12.33 HRS, VOLUME= .03 AF, ATTEN= 75%, LAG= 21.5 MIN
Qpri= 0.00 CFS @ 11.80 HRS, VOLUME= -0.00 AF
Qsec= .11 CFS @ 12.33 HRS, VOLUME= .03 AF
ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD
(FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 325 CF
0.0 0 0 0 0 PEAK ELEVATION= .9 FT
. 1 396 13 13 396 FLOOD ELEVATION= 3.0 FT
1.5 396 554 568 495 START ELEVATION= 0.0 FT
2.5 50 196 763 844 SPAN= 10-20 HRS, dt=. 1 HRS
3.0 60 27 791 861 Tdet= 19.7 MIN ( .03 AF)
# ROUTE INVERT OUTLET DEVICES
1 S 0.0' EXFILTRATION
V= .014 FPM over WETTED AREA
Primary Discharge
Secondary Discharge
�-1=Exfiltration
POND 1 INFLOW & OUTFLOW
INFILT , SYSTEM FOR CB# 1 & , 04 PC ROOF , 100YR
4B STOR-IND METHOD
. 35 PEAK STOR= 325 CF
PEAK ELEU= 9 FT
'� 38 Qin= 42 CFS
25 Qout= . 11 CFS
U Qpri = 0 , 00 CFS
. 20 Qsec= , 11 CFS
LAG= 21 . 5 MIN
0 15
V_
r �.t
.y
TIME (fours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST-NORTH ANDOVER Page 42
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 3 POST-DEVEL.10 -YR,REAR ROOF & PAVEMENT
PEAK= .53 CFS @ 11.99 HRS, VOLUME= .03 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 ROOF & PAVEMENT TYPE III 24-HOUR
TOTAL AREA = . 12 AC RAINFALL= 4.5 IN
SPAN= 10-20 HRS, dt=. l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW OVER ROOF /PAVVEMENT 1.0
n=.016 L=50' P2=3. 1 in s=.02 '/ '
SHALLOW CONCENTRATED/UPLAND FLOW ALONG GUTTERS .4
Paved Kv=20.3282 L=50' s=.01 '/' V=2.03 fps
CHANNEL FLOW ALONG GUTTER TO CB#2 .5
a=1.4 sq-ft Pw=12.2' r=.115'
s=.01 ' /' n=.016 V=2. 19 fps L=60' Capacity=3.1 cfs
Total Length= 160 ft Total Tc= 1.9
SUBCATCHMENT 3 RUNOFF
POST-DEUEL , 10 -YR , REAR ROOF & PAUEMENT
' 50 AREA= 12 AC
45 Tc= 1 . 9 MIN
CN= 98
. 40
35 SCS TR-20 METHOD
LO TYPE III 24-HOUR
4
U . 30 RAINFALL- 4 . 5 IN
U
25 PEAK= . 53 CFS
cD . 20 e 11 . 99 HR5
I 15 VOLUME= 03 AF
1 0
. 05
010 0m N M � Ln to co rn
TIME ( hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST-NORTH ANDOVER Page 47
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HYdroCAD 4. 51 000899 (c) 1986-1996 Applied Microcomputer Systems
POND 3 10 -YR INFILT.SYSTEM FOR SUBCAT# 3
Qin = .53 CFS @ 11.99 HRS, VOLUME= .03 AF
Qout= .14 CFS @ 12.33 HRS, VOLUME= .03 AF, ATTEN= 74%, LAG= 20.4 MIN
Qpri= 0.00 CFS @ 17.10 HRS, VOLUME= -0.00 AF
Qsec= . 14 CFS @ 12.33 HRS, VOLUME= .03 AF
ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD
(FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 365 CF
0.0 0 0 0 0 PEAK ELEVATION= .8 FT
. 1 528 18 18 528 FLOOD ELEVATION= 3.0 FT
1.5 528 739 757 642 START ELEVATION= 0.0 FT
2.5 50 247 1004 1123 SPAN= 10-20 HRS, dt=. 1 HRS
3.0 60 27 1031 1140 Tdet= 16.7 MIN ( .03 AF)
# ROUTE INVERT OUTLET DEVICES
1 S 0.0' EXFILTRATION
V= .014 FPM over WETTED AREA
Primary Discharge
Secondary Discharge
�1=Exfiltration
POND 3 INFLOW & OUTFLOW
10 -YR INFILT , SYSTEM FOR SUBCAT# 3
' 50 STDR-IND METHOD
. 45 PEAK STDR= 365 CF
, 40 PEAK ELEU= . S FT
• S5 Qin= . 53 CFS
'LO Qout- . 14 CFS
L) 30 Qpri = 0 . 00 CFS
L)
Qsec- . 14 CFS
LAG= 20 . 4 MIN
cD . 20 -
J
It ' 15
05 t
t
e 0 Bm ni d do Co 0-)
TIME ( hours )
Data for SYSTEM BUILDERS,INC-ABBOTT ST. ,NORTH ANDOVER Page 43
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 4 POST-DEVEL.10 -YR. ,FRONT ROOF & CB#3 AREAS
PEAK= .92 CFS @ 11.99 HRS, VOLUME= .06 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 ROOF/PAVED AREA TYPE III 24-HOUR
TOTAL AREA = .21 AC RAINFALL= 4.5 IN
SPAN= 10-20 HRS, dt=.l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS IMPERVIOUS SURFACES .8
n=.016 L=50' P2=3. 1 in s=.03 ' / '
SHALLOW CONCENTRATED/UPLAND FLOW ALONG GUTTER .3
Paved Kv=20.3282 L=40' s=.01 ' / ' V=2.03 fps
CHANNEL FLOW ALONG GUTTER TO CB#3 .6
a=1.4 sq-ft Pw=12.2' r=. 115'
s=.01 ' /' n=.016 V=2. 19 fps L=80' Capacity=3.1 cfs
Total Length= 170 ft Total Tc= 1.7
SUBCATCHMENT 4 RUNOFF
POST-DEUEL , 10 -YR , , FRONT ROOF & CB#3 AREAS
, 90
, 85 AREA= . 21 AC
. 80 Tc= 1 . 7 MIN
. 75 CN= 98
. 70
65 SCS TR-20 METHOD
. 60 -
55 TYPE III 24-HOUR
U , 50 RAINFALL= 4 , 5 IN
'-'
. 145
, 40 PEAK-- 92 CFS
0 . 35 @ 11 , 99 HRS
J • 30 VOLUME= 06 AF
25
. 20
. 15
. 10
. 05
M �r Ln w r- ao a) m
TIME ( hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 48
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HvdroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
POND 4 10 -YR INFILT.SYSTEM FOR SUBCAT # 4
Qin = .92 CFS @ 11.99 HRS, VOLUME= .06 AF
Qout= .25 CFS @ 12.31 HRS, VOLUME= .06 AF, ATTEN= 73%, LAG= 19.3 MIN
Qpri= 0.00 CFS @ 10. 10 HRS, VOLUME= -0.00 AF
Qsec= .25 CFS @ 12.31 HRS, VOLUME= .06 AF
ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD
(FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 595 CF
0 .0 0 0 0 0 PEAK ELEVATION= .6 FT
. 1 1020 34 34 1020 FLOOD ELEVATION= 3.0 FT
1 .5 1020 1428 1462 1179 START ELEVATION= 0.0 FT
2.5 50 432 1894 2151 SPAN= 10-20 HRS, dt=. l HRS
3.0 60 27 1921 2167 Tdet= 14.3 MIN ( .06 AF)
# ROUTE INVERT OUTLET DEVICES
1 S 0.0' EXFILTRATION
V= .014 FPM over WETTED AREA
Primary Discharge
Secondary Discharge
�1=Exfiltration
POND 4 INFLOW & OUTFLOW
10 -YR INFILT , SYSTEM FOR SUBCAT # 4
. 90
. 85 STOR-IND METHOD
PEAK STOR= 595 CF
, 75 PEAK ELEU= . 6 FT
. 70
65 Qin= . 92 CFS
LO . 60
t,- . 55 Qout= 25 CFS
L) . 50 Qpri = 0 , 00 CFS
'-`
. 45 Qsec= . 25 CFS
40 LAG- 19 . 3 MIN
O 35
1 . SO
LL . 25
20 i
15
. 10 y
. 05
O 0 00 N M 'r D ca M CD
ERROR 900
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 44
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomp to er Systems
SUBCATCHMENT 5 POST-DEVEL.10 -YR. ,LOW PARK'G AREA
PEAK= .47 CFS @ 11.98 HRS, VOLUME= .03 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 PAVED PARKING AREA TYPE III 24-HOUR
TOTAL AREA = . 11 AC RAINFALL= 4.5 IN
SPAN= 10-20 HRS, dt=. l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS PAVEMENT .8
n=.016 L=50' P2=3.1 in s=.03 '/ '
SHALLOW CONCENTRATED/UPLAND FLOW ACROSS PAVEMENT TO GUTTER .2
Paved Kv=20 .3282 L=40' s=.03 ' /' V=3.52 fps
CHANNEL FLOW ALONG GUTTER ,2
a=1.4 sq-ft Pw=12.2' r=.115'
s=.02 '/' n=.016 V=3. 1 fps L=40' Capacity=4.3 cfs
----------
Total Length= 130 ft Total Tc= 1.2
SUBCATCHMENT 5 RUNOFF
POST-DEUEL , 10 -YR , , LOW PARK ' G AREA
. 45
AREA= . 11 AC
. 40 Tc= 1 , 2 MIN
CN= 98
. 35
SCS TR-20 METHOD
c 30 TYPE III 24-HOUR
U 25 RAINFALL= 4 . 5 IN
v
, 20 PEAK= . 47 CFS
O 8 11 . 98 HRS
-� . 15 UOLUME= 03 AF
. 1 �
. �5
' �m cv M d' Ln tD r- co Q1 @
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 45
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 6 POST-DEVEL.10 -YR. ,REAR PARKING & SWALE
PEAK= .38 CFS @ 12.09 HRS, VOLUME= .03 AF
PERCENT CN SCS TR-20 METHOD
46.00 98 PAVEMENT TYPE III 24-HOUR
20.00 61 GRASS SWALE RAINFALL= 4.5 IN
34.00 58 LANDSCAPED SPAN= 10-20 HRS, dt=.l HRS
100.00 77 TOTAL AREA = .17 AC
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS PAVEMENT .9
Smooth surfaces n=.011 L=50' P2=3.1 in s=.01
SHALLOW CONCENTRATED/UPLAND FLOW ACROSS PAVEMENT TO GUTTER .6
Paved Kv=20.3282 L=60' s=.007 '/ ' V=1.7 fps
SHALLOW CONCENTRATED/UPLAND FLOW WITHIN GRASS SWALE 2.2
Grassed Waterway Kv=15 L=140' s=.005 '/ ' V=1.06 fps
CHANNEL FLOW WITHIN GRASS SWALE 5. 0
a=8 sq-ft Pw=12.2' r=.656'
s=.005 '/ ' n=.24 V=.33 fps L=100' Capacity=2.6 cfs
Total Length= 350 ft Total Tc= 8.7
SUBCATCHMENT 6 RUNOFF
POST-DEUEL , 10 -YR , , REAR PARKING & SWALE
, 36
. 34 AREA= , 17 AC
. 32 Tc= 8 . 7 MIN
38 CN= 77
. 28
26 SCS TR-20 METHOD
. 22 TYPE III 24-HOUR
u 20 RAINFALL= 4 . 5 IN
`-` . 18
16 PEAK= 38 CFS
CD , 14 @ 12 , 09 HRS
-� . 12 UOLUME= 03 AF
. 18
. 08
. 06
, 84
. 02
Om M d- Ln �D r- co a) m
TIME ( hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 46
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HvdroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 7 POST-DEVEL.10 -YR. ,FRONTAGES & WEST SWALE
PEAK= .80 CFS @ 12.02 HRS, VOLUME= .06 AF
PERCENT CN SCS TR-20 METHOD
32.00 98 PAVEMENT TYPE III 24-HOUR
57.00 61 GRASS RAINFALL= 4.5 IN
11.00 58 LANDSCAPED SPAN= 10-20 HRS, dt=. l HRS
100.00 73 TOTAL AREA = .38 AC
Method Comment Tc (min)
TR-55 SHEET FLOW OVER PAVEMENT 1.2
Smooth surfaces n=.011 L=50' P2=3. 1 in s=.005
SHALLOW CONCENTRATED/UPLAND FLOW WITHIN GRASS SWALE 1 .7
Grassed Waterway Kv=15 L=150' s=.01 ' /' V=1.5 fps
SHALLOW CONCENTRATED/UPLAND FLOW ALONG GUTTER LINE .9
Paved Kv=20.3282 L=150' s=.02 '/' V=2.87 fps
CHANNEL FLOW WITHIN GUTTER .7
a=1.5 sq-ft Pw=12.2' r=. 123'
s=.02 '/' n=.016 V=3.25 fps L=140' Capacity=4.9 cfs
Total Length= 490 ft Total Tc= 4.5
SUBCATCHMENT 7 RUNOFF
POST-DEUEL , 10 -YR , , FRONTAGES & NEST SWALE
80
. 75 AREA= . 38 AC
' 70 Tc= 4 . 5 MIN
' 65 CN= 73
. 60
. 55 SCS TR-20 METHOD
50 TYPE III 24-HOUR
U 45 RAINFALL= 4 . 5 IN
u . 40
135 PEAK-- 80 CFS
Ca . 30 - 8 12 . 02 HRS
-� . 25 UOLUME= 06 AF
20
15
. 10
. 05
0 ,
08
CS)
TIME ( hour5 )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 49
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
REACH 1 DESIGN POINT FOR SUBCATS 5,6,&7 <10-YR>
Qin = 1.56 CFS @ 12.02 HRS, VOLUME= .12 AF
Qout= 1.40 CFS @ 12.06 HRS, VOLUME= .12 AF, ATTEN= 10%, LAG= 2.8 MIN
DEPTH END AREA DISCH
(FT) (SO-FT) (CFS) 20' x .8' CHANNEL STOR-IND+TRANS METHOD
0.0 0.0 0.00 SIDE SLOPE= .01 ' /' PEAK DEPTH= .03 FT
. 1 2.2 3.27 n= .016 PEAK VELOCITY= 1,5 FPS
.2 5.8 12.34 LENGTH= 90 FT TRAVEL TIME = 1.0 MIN
.2 10.6 28.33 SLOPE= .01 FT/FT SPAN= 10-20 HRS, dt=.1 HRS
.3 18.7 61.55
.5 32.6 130. 17
.6 53.8 254. 18
.8 80.0 432.70
REACH 1 INFLOW & OUTFLOW
DESIGN POINT FOR SUBCATS 5 , 6 , &7 C10-YR>
1 . 5
1 . 4 20' x . 8' CHANNEL
SIDE SLOPE= 01 ' /'
1 , 2 f1 n= , 016 L=90' S= , 01
1 . 1 STOR-IND+TRANS METHOD
1 , e
VELOCITY= 1 . 5 FPS
5 TRAVEL= 1 MIN
. 7 Din= 1 . 56 CFS
0 6 Gout= 1 , 40 CFS
-� . 5 LAG= 2 . 8 MIN
, 4
. 3
. 2
. 1
0 . 0 M rn m
TIME (hours )
100-YEAR
POST- DEVELOPMENT
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 32
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 1 POST-DEV.100-YR FLOW TO CB#1
PEAK= .38 CFS @ 11.98 HRS, VOLUME= .02 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 PAVED SURFACE AREA TYPE III 24-HOUR
TOTAL AREA = .06 AC RAINFALL= 6.5 IN
SPAN= 10-20 HRS, dt=. 1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS PAVEMENT 1.0
n=.016 L=50' P2=3.1 in s=.02 '/ '
CHANNEL FLOW IN GUTTER, TO CB#1 .4
a=1.4 sq-ft Pw=12.2' r=. 115'
s=.01 ' /' n=.016 V=2.19 fps L=50' Capacity=3. 1 cfs
Total Length= 100 ft Total Tc= 1 .4
SUBCATCHMENT 1 RUNOFF
POST-DEU , 100-YR FLOW TO CB# 1
. 38
. 36
34 AREA= . 06 AC
. 32 Tc- 1 . 4 MIN
, 30 CN= 98
. 28
. 26 SCS TR-20 METHOD
LO ' 24 TYPE III 24-HOUR
u RAINFALL= 6 , 5 IN
18
. 16 PEAK= . 38 CFS
0 14 @ 11 , 98 HRS
-j 12 UOLUME= 02 AF
10
. 08
. 06
. 04
. 02
cu M co o) m
TIME (hour5 )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 34
Prepared by Merrimack Engineering Services, Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 2 POST-DEVEL.100-YR,ROOF AREA
PEAK= .24 CFS @ 11.96 HRS, VOLUME= .02 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 ROOF SURFACE TYPE III 24-HOUR
TOTAL AREA = .04 AC RAINFALL= 6.5 IN
SPAN= 10-20 HRS, dt=.l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW TO ROOF GUTTER . 1
Smooth surfaces n=.011 L=35' P2=3. 1 in s=.5
CHANNEL FLOW IN GUTTER, TO SYSTEM#1 l
a=.2 sq-ft Pw=1' r=.2'
s=.02 '/' n=.01 V=7.19 fps L=60' Capacity=1.4 cfs
Total Length= 95 ft Total Tc= .2
SUBCATCHMENT 2 RUNOFF
POST-DEUEL , 1O0-YR , RO0F AREA
' 22 AREA= . 04 AC
. 20 Tc= . 2 MIN
. 1S CN= 98
r, 16 SCS TR-20 METHOD
LO 14 TYPE III 24—HOUR
u RAINFALL- 6 . 5 IN
12
. 10 PEAK= 24 CFS
CD @ 11 , 96 HRS
08
LL 1 VOLUME= 02 OF
06
. 04
. 02
0 , 0 0m N M 73- Ln to ti co o� m
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 35
Prepared by Merrimack Engineering Services , Inc. 16 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
POND 1 INFILT.SYSTEM FOR CB#1 & .04 AC ROOF,100YR
Description changed since last calculation
Qin = .61 CFS @ 11.98 HRS, VOLUME= .04 AF
Qout= .12 CFS @ 12.40 HRS, VOLUME= .04 AF, ATTEN= 80%, LAG= 25.3 MIN
Qpri= 0.00 CFS @ 11.60 HRS, VOLUME= 0.00 AF
Qsec= . 12 CFS @ 12.40 HRS, VOLUME= .04 AF
ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD
(FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 584 CF
0 .0 0 0 0 0 PEAK ELEVATION= 1.6 FT
. 1 396 13 13 396 FLOOD ELEVATION= 3.0 FT
1.5 396 554 568 495 START ELEVATION= 0.0 FT
2.5 50 196 763 844 SPAN= 10-20 HRS, dt=.l HRS
3.0 60 27 791 861 Tdet= 36.3 MIN ( .04 AF)
# ROUTE INVERT OUTLET DEVICES
1 S 0.0' EXFILTRATION
V= .014 FPM over WETTED AREA
Primary Discharge
Secondary Discharge
�1=Exfiltration
POND 1 INFLOW & OUTFLOW
INFILT , SYSTEM FOR CB# 1 & 04 AC ROOF , 10OYR
. 60 Description changed since last calculation
155 STOR-IND METHOD
50 PEAK STOR= 564 CF
PEAK ELEU= 1 . 6 FT
. 45
, 40 Q i n- . 61 CFS
Qout= . 12 CFS
U 35 Qpri = 0 . 00 CFS
`-'
. 30 Qsec= . 12 CFS
25 LAG= 25 . 3 MIN
O
-1
. 20
� . 15
. 05
�t
1
TIME (hours )
Data for SYSTEM BUILDERS, INC-ABBOTT ST-NORTH ANDOVER Page 17
Prepared by Merrimack Engineering Services, Inc. 14 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 3 POST-DEVEL 100 YR,REAR ROOF & PAVEMENT
PEAK= .77 CFS @ 11.99 HRS, VOLUME= .05 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 ROOF & PAVEMENT TYPE III 24-HOUR
TOTAL AREA = .12 AC RAINFALL= 6.5 IN
SPAN= 10-20 HRS, dt=. 1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW OVER ROOF /PAVVEMENT 1.0
n=.016 L=50' P2=3. 1 in s=.02 ' / '
SHALLOW CONCENTRATED/UPLAND FLOW ALONG GUTTERS .4
Paved Kv=20 .3282 L=50' s=.01 ' / ' V=2.03 fps
CHANNEL FLOW ALONG GUTTER TO CB#2 .5
a=1.4 sq-ft Pw=12.2' r=. 115'
s=.01 ' /' n=.016 V=2. 19 fps L=60' Capacity=3. 1 cfs
Total Length= 160 ft Total Tc= 1.9
SUBCATCHMENT 3 RUNOFF
POST-DEUEL 100 YR, REAR ROOF & PAVEMENT
.75
.70 AREA= . 12 AC
.65 Tc= 1 .9 MIN
.60 CN= 98
55 SCS TR-20 METHOD
j 50 TYPE III 24-HOUR
u ,40 RAINFALL= 6.5 IN
35 PEAK= .77 CFS
p •30 C 11 ,99 HRS
J .25 UOLUME= .05 AF
'j- .20
15
10
05
0,0am - co M
TIME (hours)
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 20
Prepared by Merrimack Engineering Services , Inc. 14 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
POND 3 100 YR INFILT.SYSTEM FOR SUBCAT# 3
Qin = .77 CFS @ 11.99 HRS, VOLUME= .05 AF
Qout= . 15 CFS @ 12.41 HRS, VOLUME= .05 AF, ATTEN= 81%, LAG= 25.2 MIN
Qpri= 0.00 CFS @ 10.50 HRS, VOLUME= -0.00 AF
Qsec= .15 CFS @ 12.41 HRS, VOLUME= .05 AF
ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD
(FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 674 CF
0 .0 0 0 0 0 PEAK ELEVATION= 1.3 FT
. 1 528 18 18 528 FLOOD ELEVATION= 3.0 FT
1.5 528 739 757 642 START ELEVATION= 0.0 FT
2.5 50 247 1004 1123 SPAN= 10-20 HRS, dt=.1 HRS
3.0 60 27 1031 1140 Tdet= 31.7 MIN ( .05 AF)
# ROUTE INVERT OUTLET DEVICES
1 S 0.0' EXFILTRATION
V= .014 FPM over WETTED AREA
Primary Discharge
Secondary Discharge
1-1=Exfiltration
POND 3 INFLOW & OUTFLOW
100 YR INFILT , SYSTEM FOR SUBCAT# 3
75
.70 STOR-IND METHOD
.65 PEAK STOR= 674 CF
.60 PEAK ELEU= 1 .3 FT
.55
j 50 Qin= .77 CFS
+ .45 Gout= . 15 CFS
U 40 Qpri= 0,00 CFS
Gsec= . 15 CFS
35 LAG= 25.2 MIN
p .30
J .25
L- .20 -
. 15 --- -�._.
. 10
.e5 ,
0.0
TIME (hours)
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 26
Prepared by Merrimack Engineering Services , Inc. 14 May 96
HYdroCAD 4 51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 4 POST-DEVEL.100-YR. ,FRONT ROOF & CB#3 AREAS
PEAK= 1.34 CFS @ 11.99 HRS, VOLUME= .09 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 ROOF/PAVED AREA TYPE III 24-HOUR
TOTAL AREA = .21 AC RAINFALL= 6.5 IN
SPAN= 10-20 HRS, dt=. l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS IMPERVIOUS SURFACES .8
n=.016 L=50' P2=3. 1 in s=.03 '/ '
SHALLOW CONCENTRATED/UPLAND FLOW ALONG GUTTER .3
Paved Kv=20.3282 L=40' s=.01 '/' V=2.03 fps
CHANNEL FLOW ALONG GUTTER TO CB#3 .6
a=1.4 sq-ft Pw=12.2' r=.115'
s=.01 '/ ' n=.016 V=2. 19 fps L=80' Capacity=3.1 cfs
Total Length= 170 ft Total Tc= 1.7
SUBCATCHMENT 4 RUNOFF
POST-DEUEL . 100-YR , , FRONT ROOF & CB#3 AREAS
1 .3
1 .2 AREA= .21 AC
1 . 1 Tc= 1 .7 MIN
CN= 98
1 ,0
.9 SCS TR-20 METHOD
O g TYPE III 24-HOUR
RAINFALL= 6.5 IN
v
3 6 PEAK= 1 .34 CFS
o .5 C 11 .99 HRS
-i 4 UOLUME= .09 AF
3
.2
. I
TIME (hours)
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 27
Prepared by Merrimack Engineering Services , Inc. 14 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
POND 4 100 YR INFILT.SYSTEM FOR SUBCAT # 4
Qin = 1.34 CFS @ 11.99 HRS, VOLUME= .09 AF
Qout= .27 CFS @ 12.40 HRS, VOLUME= .09 AF, ATTEN= 80%, LAG= 24.6 MIN
Qpri= 0.00 CFS @ 17.60 HRS, VOLUME= -0.00 AF
Qsec= .27 CFS @ 12.40 HRS, VOLUME= .09 AF
ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD
(FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 1131 CF
0 .0 0 0 0 0 PEAK ELEVATION= 1.2 FT
. 1 1020 34 34 1020 FLOOD ELEVATION= 3.0 FT
1 .5 1020 1428 1462 1179 START ELEVATION= 0.0 FT
2.5 50 432 1894 2151 SPAN= 10-20 HRS, dt=.1 HRS
3.0 60 27 1921 2167 Tdet= 28.5 MIN ( .09 AF)
# ROUTE INVERT OUTLET DEVICES
1 S 0.0' EXFILTRATION
V= .014 FPM over WETTED AREA
Primary Discharge
Secondary Discharge
�1=Exfiltration
POND 4 INFLOW & OUTFLOW
100 YR INFILT , SYSTEM FOR SUBCAT # 4
1 .3
1 .2 STOR-IND METHOD
1 1 PEAK STOR= 1131 CF
PEAK ELEU= 1 .2 FT
1 ,0
.9 Qin= 1 ,34 CFS
4 •g Qout= .27 CFS
U 7 Qpri= 0.00 CFS
Qsec= .27 CFS
3 6 LAG= 24.6 MIN
O .5
J 4
LL
.3
. 1 t
N
TIME (hours)
Data for SYSTEM BUILDERS, INC-ABBOTT ST-NORTH ANDOVER Page 28
Prepared by Merrimack Engineering Services , Inc. 14 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 5 POST-DEVEL.100-YR. ,LOW PARK'G AREA
PEAK= .69 CFS @ 11.98 HRS, VOLUME= .05 AF
PERCENT CN SCS TR-20 METHOD
100.00 98 PAVED PARKING AREA TYPE III 24-HOUR
TOTAL AREA = .11 AC RAINFALL= 6.5 IN
SPAN= 10-20 HRS, dt=. l HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS PAVEMENT .8
n=.016 L=50' P2=3. 1 in s=.03 ' /'
SHALLOW CONCENTRATED/UPLAND FLOW ACROSS PAVEMENT TO GUTTER .2
Paved Kv=20.3282 L=40' s=.03 ' /' V=3.52 fps
CHANNEL FLOW ALONG GUTTER .2
a=1.4 sq-ft Pw=12.2' r=. 115'
s=.02 ' /' n=.016 V=3. 1 fps L=40' Capacity=4.3 cfs
Total Length= 130 ft Total Tc= 1.2
SUBCATCHMENT 5 RUNOFF
POST-DEUEL , 100-YR, , LOW PARK'G AREA
.65 AREA= . 11 AC
,60 Tc= 1 .2 MIN
.55 CN= 98
.50
j 45 SCS TR-20 METHOD
�+ .40 TYPE III 24-HOUR
U 35 RAINFALL= 6.5 IN
3 30 PEAK= .69 CFS
O .25 e 11 .98 HRS
20 VOLUME= .05 AF
Lj_ 15
. 10
.05
0,eem - N M - U) w r O1 m
TIME (hours)
Data for SYSTEM BUILDERS, INC-ABBOTT ST-NORTH ANDOVER Page 32
Prepared by Merrimack Engineering Services , Inc. 14 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 6 POST-DEVEL.100-YR. ,REAR PARKING & SWALE
PEAK= .67 CFS @ 12.09 HRS, VOLUME= .05 AF
PERCENT CN SCS TR-20 METHOD
46.00 98 PAVEMENT TYPE III 24-HOUR
20.00 61 GRASS SWALE RAINFALL= 6.5 IN
34.00 58 LANDSCAPED SPAN= 10-20 HRS, dt=. 1 HRS
100.00 77 TOTAL AREA = .17 AC
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS PAVEMENT .9
Smooth surfaces n=.011 L=50' P2=3.1 in s=.01
SHALLOW CONCENTRATED/UPLAND FLOW ACROSS PAVEMENT TO GUTTER .6
Paved Kv=20.3282 L=60' s=.007 '/ ' V=1.7 fps
SHALLOW CONCENTRATED/UPLAND FLOW WITHIN GRASS SWALE 2.2
Grassed Waterway Kv=15 L=140' s=.005 '/' V=1 .06 fps
CHANNEL FLOW WITHIN GRASS SWALE 5.0
a=8 sq-ft Pw=12.2' r=.656'
s=.005 '/ ' n=.24 V=.33 fps L=100' Capacity=2.6 cfs
Total Length= 350 ft Total Tc= 8.7
SUBCATCHMENT 6 RUNOFF
POST-DEUEL , 100-YR . , REAR PARKING & SWALE
.65
.60 AREA= . 17 AC
.55 Tc= 8.7 MIN
.50 CN= 77
.45 SCS TR-20 METHOD
c� .40 TYPE III 24-HOUR
v
35 RAINFALL= 6.5 IN
3 •30 PEAK= .67 CFS
0 25 e 12,09 HRS
20 UOLUME= .05 AF
15
, 10
.05
N
TIME (hours)
Data for SYSTEM BUILDERS, INC-ABBOTT ST-NORTH ANDOVER Page 39
Prepared by Merrimack Engineering Services, Inc. 14 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
SUBCATCHMENT 7 POST-DEVEL.100-YR. ,FRONTAGES & WEST SWALE
PEAK= 1.50 CFS @ 12.02 HRS, VOLUME= . 10 AF
PERCENT CN SCS TR-20 METHOD
32.00 98 PAVEMENT TYPE III 24-HOUR
57.00 61 GRASS RAINFALL= 6.5 IN
11.00 58 LANDSCAPED SPAN= 10-20 HRS, dt=. l HRS
100.00 73 TOTAL AREA = .38 AC
Method Comment Tc (min)
TR-55 SHEET FLOW OVER PAVEMENT 1.2
Smooth surfaces n=.011 L=50' P2=3. 1 in s=.005
SHALLOW CONCENTRATED/UPLAND FLOW WITHIN GRASS SWALE 1.7
Grassed Waterway Kv=15 L=150' s=.01 '/' V=1.5 fps
SHALLOW CONCENTRATED/UPLAND FLOW ALONG GUTTER LINE .9
Paved Kv=20.3282 L=150' s=.02 ' /' V=2.87 fps
CHANNEL FLOW WITHIN GUTTER .7
a=1.5 sq-ft Pw=12.2' r=. 123'
s=.02 ' / ' n=.016 V=3.25 fps L=140' Capacity=4.9 cfs
Total Length= 490 ft Total Tc= 4.5
SUBCATCHMENT 7 RUNOFF
POST-DEUEL . 100-YR , , FRONTAGES & WEST SWALE
1 .5
1 .4 AREA= .38 AC
1 ,3 Tc= 4.5 MIN
1 .2 CN= 73
1 . 1
1 ,0 SCS TR-20 METHOD
4- g TYPE III 24-HOUR
U 8 RAINFALL= 6.5 IN
7 PEAK= 1 ,50 CF5
3 '6 C 12.02 HR5
of •5 UOLUME= . 10 OF
�- .4
,3
.2
. I
M
TIME (hours)
Data for SYSTEM BUILDERS, INC-ABBOTT ST. ,NORTH ANDOVER Page 1
Prepared by Merrimack Engineering Services, Inc. 14 May 96
HydroCAD 4.51 000899 (c) 1986-1996 Applied Microcomputer Systems
REACH 1 DESIGN POINT FOR SUBCATS 5,6,&7
Qin = 2.72 CFS @ 12.02 HRS, VOLUME= .20 AF
Qout= 2.45 CFS @ 12.06 HRS, VOLUME= .20 AF, ATTEN= 10%, LAG= 2.8 MIN
DEPTH END AREA DISCH
(FT) (SO-FT) (CFS) 20' x .8' CHANNEL STOR-IND+TRANS METHOD
0.0 0.0 0.00 SIDE SLOPE= .01 ' / ' PEAK DEPTH= .06 FT
. 1 2.2 3.27 n= .016 PEAK VELOCITY= 1.5 FPS
.2 5.8 12.34 LENGTH= 90 FT TRAVEL TIME = 1.0 MIN
.2 10.6 28.33 SLOPE= .01 FT/FT SPAN= 10-20 HRS, dt=. l HRS
.3 18.7 61.55
.5 32.6 130.17
.6 53.8 254. 18
.8 80.0 432.70
REACH 1 INFLOW & OUTFLOW
DESIGN POINT FOR SUBCATS 5 , 6 , &7
2 . 6
2 . 4 20' x . S' CHANNEL
SIDE SLOPE-- 01 '/'
2 . 2 r ti n= , 016 L=90 ' S= . 01
2 , O ti
1 STOR-IND+TRANS METHOD
cO 1 6 UELOCITY- 1 , 5 FPS
`u 1 4 y TRAVEL= 1 MIN
:13 1 . 2 Qin= 2 . 72 CFS
O 1 . O Qout= 2 , 45 CFS
-� LAG= 2 , 8 MIN
L�
. 6
. 4
. 2
O , Om T M M CS)
TIME (hours )
STORM WATER INFILTRATION FACILITY DESIGN
Based on U.S.D.A. Soil Conservation Services Soil Maps for the project, the soil type is
100% Sudbury"SrA', hydrologic soil group"B", consisting of loamy sand and sandy gravel in
the C Horizon, well drained soil, with permeability up to 20" per hour.
The soil classification based on actual test pits done on May 3, 1996, revealed a sandy to
coarse sand and gravel parent material.
From this information, a permeability rate of 10" per hour(0.014 FPM) was used as the
exfiltration rate over the contact area within the perimeter and bottom of the facility for each
system.
The combined action of storage volume and exfiltration has been evaluated to contain the
peak flow and maximum runoff volume up to and through the peak rate period to the greatest
extent feasible and within economic reason.
i
t
SHEA
CONCRETE PRODUCTS
P.O. Box 520
773 Salem St., Route 62
No. Wilmington; Mass. 01887
Tel. (508) 658-2645
500 GALLON DRYWEL
H-20-44
MANHOLE
18 OLA
I
I �i
i
g� �
PLAtJ
4"—4 2 DlA
7° TOP NTS INLETS
DRAINAGE HOLES
NOTES: 1„ N.T.5.
i. ALL WALLS ARE 2— THICK AND „
HAVE DRAINAGE HOLES 4" DIA TO 22 DIA TAPER.
2. REINFORCED WITH 6"X6"X NO. 10 WIRE THROUGHOUT
AND NO.4 RE—BAR IN TOP 6 I ON CENTER.
DESIGN SUMMARY
DESIGN SUMMARY
As determined by analysis and design, the proposed subsurface infiltration facilities
proposed in three location on the site will completely eliminate all runoff from the contributory
areas which they will serve. Each facility has additional reserve capacity, even for the 100 year
storm event, for which we anticipate a probable, though minimal, reduction in the infiltration rate
through the wetted perimeter over time. To minimize this reduction, each catch basin will have a
2' - 6" sump, to collect any sediment in the runoff water, and a gas/oil trap, to retain any oils,
grease, gas, or floating debris. Periodic inspection and maintenance of the catch basins will
ensure a long operational expectancy of the facilities.
SUMMARY CHART
PRE- VS. POST-DEVELOPMENT
FLOW COMPARISON
TO DESIGN POINT #1
Pre-D Post-D
Storm Flow Flow Difference
Event (CFS) (CFS) (CFS)
2 0.76 0.82 +0.06 (+8%)
10 1.67 1.56 -0.11 (-7%)
100 3.14 2.72 -0.42 (-13%)
CHARTS AND TABLES
� �•
TOPOGRAPHIC MAP
/ - Opt?�l _\,j �r^'l o` 'C'/„�``,.0 - `� ._ �,.- "•
Cerri
� L —
No � over ;�o' - Q°
r I. den r /.° v
g C as \•oO
.� o DAL —.- O� �• �� i _ ����_.\ \O :,jA o ^'�� 1,
./ - -
Ll-
\,J /` `'�' I •� o
••�� , 1 •� � • , �1 - \ _ v ,i! �L ( u� ° ,per '
j O I
ST
�y� 3 '•�T•, +.u, R,E',�' r� \ I,r •� �o � ,DER
RFJ�• % —X770. �• °� 90 ;Y�
do uC
1 ATS FOREST - 00
AA
I
y . '� ✓/ .� 0 1 :,' °may P a
169 174
191 v. ! - III
MERRIMACK ENGINEERING SERVICES,INC. 66 PARK STREET ANDOVER, MASSACHUSETTS 01810
.0 -J
2 8 3 &
ES;IfX
FRANKUN MIDDLESEX 3.2"
SUFFOLK
HAMPSHIRE WORCESTER
HAMPDEN 3.4"
eA 3.6
RAINFALL DATA MAP
BARNSTA E
2-YEkti, 24 HOUR PRECIPITATION (INCHES)
DUKES
NANTUCKET
4.2
4.3' 4.5
ESSEX 4 6"
FRANKLIN
IM11100LESEX
X
SUFFOLK
4.7"
HAMPSHIRE RE V-
WORCESTER
HAMPDEN vo 0
j,
o' 4.8
RAINFALL DATA MAP
10.YEAR, 2-1 HOUR PRECIPITATION (INCHES)
419
DUKES
NANTUCKET
6.0" 6.2 6.4"
PRANKUN ESSE
X
WIODLESEX 6.6"
SUFFOLK
y WAMPS141RE WORCESTER 6.8"
r, HALIPOEN i -7
RAINFALL DATA MAP Rainfall Data Map
j BARNST^IL,
100—YEAR, 24 HOUR PRECIPITATION (INCHES)
7.2
(scs)
NANTUCKET
MERRIMACK ENGINEERING SERVICES,INC 66 PARK STREET ANDOVER, MASSACHUSETTS 01810
Appendix E: CULVERT ENTRANCE LOSS COEFFICIENTS
Entrance Loss Coefficients.
Type of Structure and Design of Entrance Coefficientke
Pipe, Concrete
Projecting from fill,groove end. . . . . . . . . . . . . . . . . . . . . . 0.2
Projecting from fill,sq.cut end. . . . . . . . . . . . . . . . . . . . . . 0.5
Headwall or headwall and wingwalls
Grooveend of pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2
Square-edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5
Rounded(radius= 1/120) 0.1
Mitered to conform to fill slope 0.7
End-Section conforming to fill slope'. . . . . . . . . . . . . . . . . . 0.5
Pipe,or Pipe-Arch,Corrugated Metal
Projecting from fill (no headwall) 0.9
Headwall or headwall end wingwalls t
Square-edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5
Mitered to conform to fill slope . . . . . . . . . . . . . . . . . . . . . 0.7
End-Section conforming to fill slope*. . . . . . . . . . . . . . . . . . 0.5
Box, Reinforced Concrete
Headwall parallel to embankment(no wt ils)
Square-edi.ed on 3 edges. . . . . . . . . . . . . . . . . . . . . . . . 0.5
Rounded in 3 edges to radius of 1/12 barrel dimension. . . . . . . 0.2
Wingwai' .,s0'to 75' co Darrel
Sq,; -edged at crown. . . . . . . . . . . . . 0.4
Crown edge rounded to radius of 1/12 barrel - nsion . . . . . 0.2
Wingwalls at 100 to 300 to barrel
Square-edged at crown. . . . . 0.5
Wingwalls oarallel (extension of sides)
Square-edged at crown. . . ... . . . . . . . . . . . . . . . . . . . . 0.7
Appendix F: SHEET FLOW ROUGHNESS COEFFICIENTS
Surface Description n Appendix G: VELOCITY FACTORS
Smooth surfaces .011
Fallow .05 Surface Description Kv
Cultivated: Residue< =20% .06 Paved 20.3282
Cultivated: Residue>20% .17 Unpaved 16.1345
Grass: Short .15 Grassed Waterway 15.0
Grass: Dense .24 Nearly Bare & Untilled 10.0
Grass: Bermuda .41 Cultivated Straight Rows 9.0
Range I .13 Short Grass Pasture 7.0
Woods: Light underbrush .40 Woodland 5.0
Woods: Dense underbrush 80 Forest w/Heavy Litter 2.5
Memmack Engineering Services, Inc.
Appendix A: RUNOFF CURVE NUMBERS
Runoff curve numbers for urban areas)
Cure numbers for
Cover description h}•drologic soil group—
Average percent
Cover type and hydrologic condition impervious areaz A )s C D
Fully developed urban areas Negetation established)
Open spay ,: (lawns, parks, golf courses, cemeteries,
etc.)':
Poor condition (grass cover < 50%) .............. 68 7C) 86 89
Fair condition(grass cover 50% to 7570)......... .. 49 69 79 84
Good condition(grass cover > 75%) .............. 39 61 74 SO
Impervious areas:
Paved parking lots, roofs, driveways, etc.
(excluding right-of-way). ........... .............. 93 98 93 98
Streets and roads:
Paved; curbs and storm sewers (excluding
right-of-way)........................... ..... 98 98
98 98
Runoff curve numbers for other agricultural lands'
Curve numbers for
Cover description hydrulogic soil group—
Hydrologic
Cover type condition A B C D
Pasture,grassland, or range—continuous Poor 68 79 86 89
foi age for grazing.2 Fair 49 69 79 84
Good 39 61 A— 74 80
Meadow—continuous grass, protected from — 30 58 4-- 71 78
grazing and genes ally mowed for hay.
Brush—brush-weed-grass mixture with brush Poor 48 67 77 S3
the major element.3 Fair 35 56 e-- 70 77
Good 430 48 65 73
Woods—grass combination (orchard Poor 57 73 32 86
or tree farm).5 Fair 43 65 76 82
Good 32 58 4- 72 79
Woods.' Poor 45 66 77 83
Fair 36 60 73 79
Good 430 5.3 70 77
Merrimack Engineering Services, Inc.
SOIL TEST RESULTS
SYSTEMS BUILDERS,INC.
PROPERTY AT ABBOTT AND SALEM STREETS
NORTH ANDOVER,MASSACHUSETTS
TEST PIT RESULTS -MAY 3, 1996
TP#1
0"- 8" "A"Br.L.S.
8"-24"'S"Br.L.S.
24"-70""C"Br. Sand w/graveUsome small cobbles
Water @ 70"
TP#2
0"- 14""A"B.L.S.
14"-20""B"Br. Coarse Sand
20"-68""C"Br. Loose-line sandy gravel
Water @ 60"
TP#3
0"- 12""A!,B.L.S.
12"- 18"'S"Br/Samd
18"-66""C"Med Br. Sand/IGravel(loose-live)
No Water @ 66"
TP#4
07"- 8" "A"B.S.L.
8"-30""B"Lt. Br. S.L.
30"-90""C" Br. Sand w/losse live gravel
Water @ 80"
TP#5
0" - 12" "A" Br. S.L.
12" - 18" "B" B.S.L.
18"- 90" "C" B. Sand w/losse coarse gravel
No Water @ 90"
� i
Or'-lb
mail r
\\
e.
v \
t5vr=/s6.of
V
z `'1\
jo NN C SpSTANIA
�+ r
LET 31 � \ It ,..
\
4-2,086 s F .�' \
'97 AC s�f �4
• h 1�
" itr ALE
Zl
/ I \
If, 0 S�C1L
J9- 2 j\
16
O 1e1.. 4
ONE O ' / 'f lrws Kt. �A
ca
ltwt-C rT I CG \ CENT,c 150.BJ
Mi
ss..s
� 79'56' 5' S 79 56
\ • �/r'm� -- -a
W /
277.8 / ——— —is4 — —
—
as 4 /r
E 12~
YR/AME OV1H R.O.WJ CB WA�RMA/N STRE r 3a5 CENr150.17 A L950 T T Ng2
c \
MI I lea \
51.57 - 68.7"S ss�\ S \�1,4E
I�
E5 16 IJ.I .1...\ -p �
r Ip,�\ \
PO i NT
kI41 ! \
\ -is �- A V E L 0 F MT
A(yiEtlED,WT/GT.l'AT/O•(/SACK/TYAZ \ .^ 6 a9
NIT
C/ZP/TJ- TOT.ILJ °�\ �� //\�U /�•
JOHN CRISOSTANIA — \
AM
,l„ RL"TE.VT/O.V/N 6�fA.SS may,CQ•E
SH'AGE •CSI/•/SC.O \ pA
New" r4—
.-T 1101
"Or
•asp* ,u•+I `
"' /I' / � -... PiPOPOSED •Y \ 79,
ARP/ �P�t� t' ,�T x,f.,a• fN' , \ �,.z '..
ot 1 \ \
Z CD 11Y47 AU��1 �C�C L/ //I(5 yy�
n Z ,' p S/6$ N✓�/ Z /YY
rs
tjb
Cl
',. -_` -__ __ / ''\ \� ` �Yl' � C r^f.N.IN 7J '.` 'i �, F�✓-IF/O -, f � �.
✓AR/AB '7M� 1` 6 W _ ,}^ s� CC.j .
5! c.•,. - . . 1 Pn.3r2 !E�OIH /x• _• I ."A. � \\ CB
RIH t FR. R►FSe� /956 pp� K, \ �ENT"SC
d1� w �• � \\ / �\ Al
8 q r \\ \
ry r;
DES IGW y ` �
POI NT _ °F
..p