UNIVERSITY OF MASSACHUSETTS BOSTON
Restoring Eelgrass to the
Neponset River Estuary
Watershed Characteristics
Ashley Bulseco-McKim
10/15/2012
ABSTRACT: This document synthesizes information gathered for the purpose of restoring eelgrass to the Neponset
River Estuary. Phase one focuses on the physical and chemical aspects of the Neponset River Watershed, covering
topics such as watershed area, basic river characteristics, land use types within the watershed, topography, surficial
geology, bedrock lithology, atmospheric deposition, water supply and interbasin transfer, and aquatic habitat.
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PROBLEM STATEMENT
The Neponset River Watershed has a complex history of social, cultural, and economic
development that has led to subsequent deterioration of its receiving estuary. The current goal of
this semester’s class is to restore eelgrass to its estuary, in turn improving its overall health.
Eelgrass performs a number of ecosystem services, including altered water flow, nutrient
cycling, maintaining food web structure, providing a source of food and nursery habitat for upper
trophic levels, stabilizing sediments, and contributing to the detritus pool. Unfortunately,
multiple stressors, specifically sediment and nutrient run off, have caused massive seagrass
decline (Orth et al. 2006).
The Neponset River Watershed Association (NepRWA) was originally formed in 1967 as
the “Neponest Conservation Association” by a group of people who were concerned about the
development and extension of Rt. 95 into Boston. They hold an everlasting commitment to an
integrated, water-shed based approach that focuses on the protection and restoration of the
physical, biological, and chemical integrity of the Neponset River. This report will help to
answer a number of questions posed by the NepRWA, with the ultimate goal of restoring
eelgrass and its corresponding ecosystem services to the Neponset River estuary.
In order to restore eelgrass to the Neponset River estuary, we must first grasp a number
of fundamental characteristics regarding the watershed that feeds it. This report will focus on the
physical and chemical aspects of the Neponset River Watershed, covering topics such as (in no
particular order) watershed area, basic river characteristics, land use types within the watershed,
topography, surficial geology, bedrock lithology, atmospheric deposition, water supply, and
aquatic habitat.
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WATERSHED DELINEATION
The Neponset River Watershed (total area = 340-km2) covers the western portion of the
Boston Harbor watershed (Fig. 1), draining into the Neponset River and eventually reaching the
coastal ocean at Boston Harbor (Zhu & Olsen 2009). The watershed itself consists of 14 cities
and towns, including at least parts of Boston, Canton, Dedham, Dover, Foxborough, Medfield,
Milton, Norwood, Randolph, Quincy, Sharon, Stoughton, Walpole, and Westwood (Fig. 2), and
houses approximately 330,000 people (Neponset River Watershed Association – hereby
NepRWA 2004). It is important to note that this calculation was likely performed using data
from the 2000 U.S. Census, and will underestimate the current total population within the
watershed. Current estimates may be more accurate using the 2010 U.S. Census. From the 1990
to the 2000 U.S. Census alone, population grew by around 6% in towns predominantly
comprising the Neponset River Watershed, so it is clear that current population estimates should
be used when considering the social aspects of this problem later in the semester.
The Neponset River Watershed can be further delineated into sub-watersheds or subregions (Fig. 3). Although they have not been given geographical names, they each correspond to
a significant, nearby hydrological feature (e.g. Mill Brook; Table 1). Table 1 provides
information on each sub-region, its total area in mi2, and the percent area of forest, residential
area, and “other” (NepRWA 1999). This information is useful because it provides a high
resolution dataset of land cover, which is important in assessing overall impacts on watersheds
and their receiving estuaries (see Land Use/Land Cover, pg. 3).
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RIVER/STREAMS
The headwaters of the Neponset River originate in Foxborough at the Neponset
Reservoir, a man-made impoundment (approximately 321 acres). After traveling 30 miles
(48km) in a northeasterly direction, the river discharges into Dorchester Bay and Boston Harbor.
The river faces impoundment by 12 dams, and passes through a number of private reservoirs
before reaching its ultimate destination. There are a number of streams listed in Table 1
according to corresponding town and county, and Fig. 4, which provides a good visualization of
the river’s branching patterns (NepRWA). For more details regarding river characteristics, please
refer to Sarah Feinman’s assessment report.
LAND USE/LAND COVER
The Neponset River Watershed consists primarily of five major land cover types (as
calculated from MassGIS data and ArcGIS 9.2 by Huang & Chen 2009): 38% of the watershed is
residential, 34% is forested (together they make up 72% of the entire watershed land cover), 5%
is industry, 4% is wetlands, and 3% is golf courses (Huang & Chen 2009) (Fig.5). It is therefore
safe to assume that there are relatively low levels of agriculture and horticulture in this area, and
that the primary application of fertilizer will occur upon golf courses and residential lawns/parks.
These proportions of land use have undoubtedly shifted dramatically from pre-industrial
times to modern day, showing a clear intensification of human alterations with population
increase and urbanization (Bhaduri et al. 2000; Paul & Meyer 2008). Change in land use over
time is perhaps the most significant human impact on hydrologic systems at the local, regional,
and global scale (Bhaduri et al. 2000). Land use alterations have been shown to impact a number
of bio- and chemical factors within the watershed, including Dissolved Organic Matter (DOM)
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quality and quantity (Wiegner & Seitzinger 2004; Huang & Chen 2009), average annual runoff
(Bhaduri et al. 2000), species diversity (Minshall et al. 1985), and stream bed erosion (Schlosser
1991). In a study using the Little Eagle Creek watershed (Indianapolis, IN, USA) as a model, an
18% increase in urban or impervious areas led to an approximate 80% increase in annual average
runoff and more than 50% in average annual loads for lead, copper, and zinc (Bhaduri et al.
2000). In light of such impacts, it is crucial that we continue to assess land use changes in the
Neponset River Watershed (specifically a transition from forested/wetlands to
urbanized/impervious areas) and their corresponding ecological consequences. Therefore, we
may gain the ability to identify environmentally sensitive areas throughout the watershed, while
evaluating alternative land use scenarios to reduce annual runoff and non-point source (NPS)
pollution. Considering such a large proportion of the US population lives in metropolitan areas, it
is inevitable that urban and industrial areas will continue to expand and human activity will
continue to alter the environment (Clark 1967; Chinitz 1991). Understanding the impacts of land
use change over a spatial and temporal scale will allow for prediction of environmental
consequences and the development potential mitigation strategies.
One major consequence of urban development is the increased percentage of impervious
surfaces, which can include roads, rooftops, sidewalks, patios, parking lots, and buildings, or any
other material that prevents the infiltration of water into the soil (Arnold et al. 1996). These
surfaces contribute to the environmental impacts of urbanization by inhibiting the natural process
of groundwater recharge, thereby lowering water tables, and resulting in intermittent or dry
stream beds during low flow conditions (Harbor 1994). Without the ability to infiltrate the soil,
the water instead flows at a greater velocity and volume on the surface, resulting in large
sediment deposits and aggravated downstream erosion (Arnold et al. 1996). Additionally, runoff
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contains a wide array of pollutants, including nutrients, pesticides, pathogens, oil, grease,
sediment, and heavy metals, which accumulates from these same impervious surfaces, and
eventually feeds into its receiving estuary (Arnold et al. 1996; Bhaduri et al. 2000).
Approximately 24% of the Neponset River Watershed’s total acreage consists of
impervious surfaces (NepWRA 2004b; Fig. 6); however, the degree of imperviousness
inherently differs between and within cities/towns. Much of this variation depends on the total
amount of development, and the distribution of land use throughout the watershed. Based on
work by the Massachusetts office of Coastal Zone Management (MCZM), the NepRWA
described the degree of imperviousness according to land use for the Neponset River Watershed
as: 54% imperviousness for Residential Less than ¼ acre, 30% imperviousness for Residential
Multi-family ¼ to ½ acre, 30% imperviousness for Residential Multi-family over ½ acre, 58%
imperviousness for Commercial/Industrial land use, and 51% imperviousness for Transportation
(NepRWA 2004b). Should it then assumed that forest accounts for the remaining percentage of
land cover in residential areas?
By understanding how impervious surfaces are distributed throughout the Neponset River
Watershed, we may gain a better understanding of the degree to which they are impacting the
receiving estuary. Studies have found a strong correlation between a drainage basin’s
imperviousness and the physical/chemical health of its receiving stream (Klein 1979; Griffin et
al. 1980; Schueler 1992), and according to information from the Center for Watershed
Protection, expected watershed impacts worsen as percent imperviousness increases. At 0%-10%
imperviousness, channels are stable, and support high water quality and excellent biodiversity.
At 11-25% imperviousness, there may be some signs of degradation, some channel erosion and
widening, some elevated nutrients and pathogens, and fair to good biodiversity. Lastly, at 26%
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or more imperviousness, there may be stream bank erosion, channel instability, high nutrient
levels, low biodiversity, and limited human contact with water supply due to high bacteria levels
(NepRWA 2004b). Therefore, we must continue to consistently record percent imperviousness
and changes in land use within the watershed as urban development continues at high enough
resolution to allow for the continued analysis of watershed impacts.
TOPOGRAPHY/LITHOLOGY
The topography, surficial geology, and bedrock lithology can also play a role in
watershed characteristics by influencing watershed boundaries, and water infiltration, flow, and
chemistry, respectively (Fetter 2001). The topography of the Neponset River Watershed is fairly
mild, with the steepest topography occurring at Buck Hill (Quincy; 496 ft), Chickatawbut Hill
(Milton; 470 ft), Houghton Hill (Milton; 420 ft), Tucker Hill (Quincy; 499 ft), and Wolcott Hill
(Milton; 470 ft) (http://www.franklinsites.com; note, site may not be reputable). The Neponset
River Watershed is delineated using these topographical features, and is defined separately from
Boston Harbor Watershed’s other sub-watersheds (Fig. 1).
Precipitation that falls onto a watershed may travel as surface runoff, shallow interflow,
flow through surficial features, or groundwater through bedrock fractures (Newton et al. 1987).
Surficial geology of the Neponset River Watershed consists primarily of sand and gravel, large
sand deposits, and to a lower extent, floodplain alluvium (OLIVER MassGIS). Sand and gravel
ranges from 20-35% porosity, or the percent of void spaces between solid fragments, and
between 10-2 to 103 intrinsic permeability (in darcys), representing the degree of ease with which
a porous medium can transmit a liquid under a potential gradient. It is also tends to have a higher
hydraulic conductivity, which is a coefficient that helps to define the rate at which water can
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move through a permeable medium (Fetter 2001). These characteristics suggest that water will
be capable of infiltrating the surface soil in the absence of impervious surfaces; although, more
research should be conducted on the available literature to gain a better understanding of the
interaction between surficial geology and water flow. This could have tremendous implications
on the vertical and horizontal movement of groundwater, as well as velocity, which will
eventually translate to groundwater discharge impacts to the Neponset River Watershed streams
and estuary.
Bedrock lithology, or mineral composition/classification of rocks, can also play a role in
defining water flow and water chemistry. The Neponset River Watershed is comprised of
primarily granite (which groundwater cannot infiltrate), basin sedimentary rock, and
metamorphic rock near the coastline. The extent of fractures within the bedrock and the degree
of porosity can ultimately influence the residence time of the water underground, while the
mineral composition can lead to a number of chemical transformations of the groundwater itself.
These characteristics can further be applied to the analysis of water quality in both surface water
and shallow groundwater, along with the investigation of stream sediments in regards to bedrock
lithogeochemistry (Fetter 2001). Additionally, rare earth elements (REE) have been used to study
a variety of geological processes regarding chemical weathering and water-rock interactions
(Hannigan 2005). Again, more research needs to be conducted on the existing literature to
understand the complex interaction between bedrock lithology and water features to further
characterize the essential information required to restore eelgrass to the Neponset River estuary.
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WATER SUPPLY AND INTERBASIN TRANSFER
Approximately 220,000 people use water that at least partly depends on groundwater
from the Neponset Valley (NewRWA). Of that pumped water, 21% is pumped back into the
Neponset River Watershed as septic system effluent, and 65% is relocated outside the basin via
sewer systems (NepRWA 1998). Along the way, water is lost to a number of sources; however,
aging sewage infrastructure exacerbates the extent to which groundwater is lost by leaking and
infiltration (NepRWA 2004b). Due to these losses, the Neponset experiences an annual net loss
of 9 billion gallons water per year, a volume approaching ¼ of the river’s annual discharge.
The NepRWA attributes this extensive net loss to a number of factors: 1. The extension
of sewer lines for service of both new and existing development (formerly septic), 2. The
municipal development of new water supply sources throughout the Neponset River Watershed
to sustain increasing water demand due to population rise or increased per capita demand, 3. The
development of new Neponset water supply sources instead of MWRA (due to a rise in cost and
compliance with the Federal Safe Drinking Water Act), and 4. The installation private irrigation
wells in attempts to avoid compliance with water use restrictions opposed during periods of
drought (NepRWA 2004b).
Table 4 presents current Neponset Municipal Water Supply Sources and Wastewater
Infrastructure according to town as either ‘Neponset’, ‘MWRA’, or ‘other’. It is interesting to see
the different trends in water supply dependence (e.g. Canton relies heavily on the MWRA while
Sharon relies more so on their local supply). An important social aspect of this project to be
researched further is the individual attitudes and rationale from each town, leading to patterns in
water usage and dependence. There is also a knowledge gap (especially in my own knowledge)
in wastewater infrastructure and its current status (e.g. pipe integrity and age) throughout our
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watershed per municipal. We need to determine the distribution of sewage or septic systems
(perhaps in light of Title V to consider social aspects), evaluate the extent of failing sewage
systems, and further research processes of inflow and infiltration to the best of our ability,
although a number of assumptions will have to be made due to the lack of availability of this
type of information. These steps will help us to determine rates and distribution of sewage
disposal, calculate inputs lost to sewage and septic systems (e.g. nitrogen loads), and investigate
a number of other environmental impacts of NPS pollution.
ATMOSPHERIC DEPOSITION
Atmospheric deposition is the transfer of pollutants from the air to the earth’s surface
(EPA 2012), and can occur in two methods: wet deposition and dry deposition. Wet deposition is
when aerosols or other gases are dissolved/suspended in precipitation (e.g. rain, snow, sleet).
This can typically be measured directly by analyzing trace quantities of pollutants via
Inductively Coupled Plasma Mass Spectrometry (ICP-MS), or other analytical instrumentation,
and multiplying the resulting concentration by the total volume of precipitation over a specified
time period. Dry deposition, on the other hand, consists of suspended particles or gaseous
contaminants which gravitationally settle onto land or water surfaces. Once deposited onto the
earth’s surface, the contaminants quickly adsorb to vegetation, soils, or any other surfaces
present in that given area (Zhu & Olsen 2009). As suggested by a smaller volume of literature,
dry deposition is more difficult to directly measure. Generally, investigators will collect particles
using an artificial surface that represents a naturally occurring surface, or will take the
concentration of contaminants present in the air and multiply that by the values of deposition
velocities as found in the current literature (Golomb 1999).
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In the Valiela et al. 1996 article we covered in class, authors created and implemented a
model to estimate nitrogen loading from a coastal watershed to its receiving estuary. Nitrogen
loading to the coastal waters is of major concern, particularly because primary production is
limited by nitrogen availability (Valiela 1995; Howarth 1988). As a result, it is not only
important to enumerate nitrogen loading from fertilizer and wastewater disposal, but it is also
important to know how much of that nitrogen is being deposited in residential areas (impervious
surfaces), forests, or various other surfaces via wet and dry atmospheric deposition. In the
WBLMER model, atmospheric deposition was estimated to be twice that wet deposition (in kg N
ha-1 yr-1) due to the lack of studies covering dry deposition. A handful of studies have
investigated the rate of dry deposition in the Boston area (e.g. Zhu & Olsen 2009 looked at 7Be
deposition from the roof of UMass Boston; Golomb 1999 looked at toxic metals Cd, Co, Al, Cr,
Cu, Fe, Mn, Ni, Ph, Zn, Hg biweekly in Massachusetts Bay); however, I suggest a number of
atmospheric deposition studies be conducted directly in our estuary. Because a large portion of
the Neponset “airshed” is urban, to what extent will dry deposition contribute to total
atmospheric deposition as a whole?
It is clear that atmospheric deposition plays an important role in loading of various trace
metals and pollutants to the coastal ocean (Valiela et al. 1996); however, it must be readily
monitored over long time scales in order to capture its spatial and temporal variability. Rates of
wet deposition depend on precipitation and its particular chemistry, while rates of dry deposition
depend on wind velocity and direction. Therefore, an understanding of climate is required to
fully interpret effects of atmospheric deposition – climate has not been fully discussed in this
assessment report, but Table 3 provides the precipitation rates (inches per month) for East
Boston and Milton (representing the NE Region) and Foxborough and Milton (representing the
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SE Region). More detailed climate characteristics, including information regarding wind, should
be further researched. USGS or NOAA NCDC will likely report reliable data from which we can
infer climate and atmospheric deposition rates.
AQUATIC HABITAT
The final link in the watershed chain is the conservation of aquatic habitats, including
wetlands, vernal pools, riparian shoreline buffers, and other vegetated landscapes, all of which
serve a number of critical functions to the maintenance of natural stream processes. As
development continues to transition forested land to urban areas, the physio-chemical
relationships with adjacent streams and brooks are altered and their integrity compromised (Roth
et al. 1996). It is therefore crucial that we synthesize studies regarding the effects of
physical/chemical alterations on aquatic habitat integrity.
The Neponset River Watershed in particular houses a number of special habitat types (for
sake of brevity, see maps in NepRWA (2004b) pg. 66-72). Various habitats include the BioMap
core map, which focuses NHESP (Natural Heritage and Endangered Species Program) listed rare
species and communities, estimated habitats for rare wildlife, priority habitats for state protected
rare species, living water core habitats, as well as anadromous fisheries, vernal pools, areas of
critical environmental concern, outstanding resource waters, cold and warm water fisheries, and
wetlands. According to the Massachusetts Executive Office of Environmental Affairs (EOEA),
key topics to further research include salt marshes, wetland wildlife habitat, flood storage,
invasive species, cold water fisheries, and groundwater recharge and stream baseflow (NepRWA
2004b). These aquatic habitats face degradation, primarily due to channelization, removal of
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riparian buffer zone, thermal modification as a result of impoundments, and dumping into the
habitats themselves.
The final type of aquatic habitat denoted by the NepRWA is called “open space,” which
is protected through the ownership of a governmental or non-profit organization. This habitat
type allows for rain water to infiltrate the groundwater and recharge underground aquifers, while
also providing shelter for hundreds of species of plants and animals – the NepRWA reported
over 900 species of “visible” species in one town alone. The Neponset River Water has
approximately 20.7% of the total acreage that is considered open space, with an additional 4.3%
owned with private, for-profits. Future research should consider assessing various habitats, and
determining if they may be intact enough to be acquired as permanent open space. At this point,
the NepRWA doesn’t know how much of the watershed’s land can be labeled as permanent, and
hasn’t determined how much land is available for open space acquisition (NepRWA 2004b). It
can only be assumed that while population growth is inevitable, so is land development. As more
and more land is used, the total acreage of open space will be lost. Further assessments should
take into account the ecological importance of these habitats, and emphasize the need for open
space throughout the Neponset River Watershed.
CONCLUSION
To restore eelgrass to the Neponset River Estuary, a number of characteristics need to be
further researched (either within the current literature, or through newly designed experiments).
These include 1. continued monitoring of land use changes over time to understand and predict
ecological consequences incurred by sensitive environmental areas, 2. continued monitoring of
imperviousness, 3. an investigation of the relationship between topography and bedrock
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lithology to understand how groundwater flow and chemistry may be affected, 4. a survey of
wastewater infrastructure of municipals included in the Neponset River Watershed and the
overall status of these systems, 5. An investigation into atmospheric deposition processes
affecting the Neponset River Watershed (with a particular focus on dry deposition), and 6. An
assessment of available open space throughout the watershed and its potential for acquisition and
conservation.
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References
Arnold Jr CL, Gibbons CJ (1996) Impervious surface coverage: the emergence of a key
environmental indicator. Journal of the American Planning Association 62:243-258
Bhaduri B, Harbor J, Engel B, Grove M (2000) Assessing watershed-scale, long-term hydrologic
impacts of land-use change using a GIS-NPS model. Environmental Management
26:643-658
Chinitz B (1991) A framework for speculating about future urban growth patterns in the US.
Urban Studies 28:939-959
Clark C (1967) Population growth and land use. Population growth and land use
EPA (2012) Atmospheric Deposition of Toxic Pollutants.
http://www.epa.gov/glindicators/air/airb.html
Fetter C (2001) Applied Hydrogeology. Prentice Hall New Jersey
Golomb D, Ryan D, Eby N, Underhill J, Zemba S (1997) Atmospheric deposition of toxics into
Massachusetts Bay-I metal. Atmos Environ 31:1349-1359
Griffin Jr D, Grizzard T, Randall C, Helsel D, Hartigan J (1980) Analysis of non-point pollution
export from small catchments. Journal (Water Pollution Control Federation):780-790
Hannigan R (2005) Rare earth, major, and trace element geochemistry of surface and geothermal
waters from the Taupo Volcanic Zone, North Island New Zealand. Rare Earth Elements
in Groundwater Flow Systems 51:67-88
Harbor JM (1994) A practical method for estimating the impact of land-use change on surface
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Howarth R (1988) Nutrient limitation of net primary production in marine ecosystems. Annual
Review of Ecology and Systematics 20:256-260
Huang W, Chen RF (2009) Sources and transformations of chromophoric dissolved organic
matter in the Neponset River Watershed. Journal of Geophysical Research 114:G00F05
Klein RD (1979) Urbanization and stream quality impairment. Journal of the American Water
Resources Association 15:948-963
Lovett GM (1994) Atmospheric deposition of nutrients and pollutants in N. America: an
ecological perspective. Ecol Appl 4:629-650
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Minshall GW, Cummins KW, Petersen RC, Cushing CE, Bruns DA, Sedell JR, Vannote RL
(1985) Developments in stream ecosystem theory. Canadian Journal of Fisheries and
Aquatic Sciences 42:1045-1055
Neponset River Watershed Association (1998) Neponset Basin Water Use Efficiency Report.
Neponset River Watershed Association (2004) Boston Harbor South Watersheds 2004
Assessment Report. Urban Harbors Institute Publications.
http://www.neponset.ord/Low%20Resolution/BostonHarborAssesLoRes.pdf
Neponset River Watershed Association (2004) Neponset River Watershed 2004 Assessment
Report. University of Massachusetts, Urban Harbors Institute.
http://www.neponset.org/BasinPlan/Low%20Resolution/NeponsetAssessLoRes.pdf>
Neponset River Watershed Association (2010) Neponset River Watershed. Accessed October 12,
2012. http://www.neponset.org/Watershed.htm
Neponset River Watershed Association (2006) Neponset River Watershed Association strategic
plan, 2006-2011. http://www.neponset.org/Reports/NepRWAStrategicPlan06-11.pdf
Neponset River Watershed Association (1999) Neponset River Subwatershed-River and Estuary
Segment Assessments. http://www.mass.gov/dep/water/resources/70wqar3b.pdf
Neponset River Watershed Association (2004) Neponset River Watershed 2004 Water Quality
Assessmnet Report. http:..www.mass.gov/dep/water/resources/wqassess.htm
Neponset River Watershed Association, and Executive Office of Environmental Affairs. 1997.
Neponset River watershed basin-wide action plan. Boston, MA.
Newton RM, Weintraub J, April R (1987) The relationship between surface water chemistry and
geology in the North Branch of the Moose River. Biogeochemistry 3:21-35
Orth RJ, Carruthers TJB, Dennison WC, Duarte CM, Fourqurean JW, Heck Jr KL, Hughes AR,
Kendrick GA, Kenworthy WJ, Olyarnik S (2006) A global crisis for seagrass ecosystems.
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Pack DH (1980) Precipitation chemistry patterns: A two-network data set. Science 208:11431145
Paul MJ, Meyer JL (2008) Streams in the urban landscape. Urban Ecology:207-231
Schlosser IJ (1982) Fish community structure and function along two habitat gradients in a
headwater stream. Ecological Monographs 52:395-414
Schueler TR (1992) Mitigating the adverse impacts of urbanization on streams: A comprehensive
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strategy for local government. Watershed Restoration Sourcebook, Publication 92701:2131
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York, USA
Valiela I, Collins G, Kremer J, Lajtha K, Geist M, Seely B, Brawley J, Sham C (1997) Nitrogen
loading from coastal watersheds to receiving estuaries: new method and application.
Ecological Applications 7:358-380
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Stewart PM (2003) Watershed, reach, and riparian influences on stream fish assemblages
in the Northern Lakes and Forest Ecoregion, USA. Canadian Journal of Fisheries and
Aquatic Sciences 60:491-505
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nitrogen from pristine and polluted freshwater wetlands. Limnol Oceanogr 49:1703–
1712
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the Neponset River estuary, Massachusetts, USA. J Environ Radio 100:192-197
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FIGURES
Fig. 1. Delineation of Boston Harbor Watershed, including the City of Boston Watershed, Fore
River Watershed, Back River Watershed, Weir River Watershed, and Neponset River Watershed
(NepRWA 2004a).
Fig. 2. Delineation of the Neponset River Watershed and relevant town/city boundaries
(NepRWA 2004b)
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Fig 3. River and estuarine segments in the Neponset River Subwatershed.
Fig. 4. Streams and major ponds of the Neponset Watershed (NepRWA 2004), from which
subregions are hydrologically linked.
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Table 1. List of streams/brooks associated with subwatersheds within the Neponset River
Watershed. Segment #’s can be referenced in Fig. 3. Total area given in mi2, and area of forest,
residential, and other given in total percent (NepRWA 1999)
Subwatershed
School Meadow
Brook
Tubwreck Brook
Mill Brook
Mine Brook
Unnamed tributary
Mill Brook
Bubbling Brook
Unnamed tributary
Unnamed tributary
Germany Brook
Hawes Brook
Unnamed tributary
Traphole Brook
Neponset River
Unnamed tributary
Steep Hill Brook
Beaver Brook
Unnamed tributary
Massapoag Brook
Pequid Brook
E. Branch Nep. River
Plantingfield Brook
Purgatory Brook
Pencuit Brook
Ponkapoag Brook
Neponset River
Mother Brook
Pine Tree Brook
Neponset River
Unquity Brook
Gulliver Creek
Neponset River
City
Seg. #
Walpole
MA73-06
Dover
MA73-07
Medgield
MA73-08
Walpole
MA73-10
Walpole
MA73-09
Westwood
MA73-12
Walpole/Westwood
MA73-11
Walpole/Westwood
MA73-13
Norwood
MA73-14
Norwood
MA73-15
Norwood
MA73-16
Norwood
MA-73-33
Sharon/Norwood
MA73-17
Foxboro/Canton
MA73-01
Stoughton
MA73-32
Canton
MA73-18
Sharon/Norwood
MA73-19
Sharon/Norwood
MA73-31
Sharon/Canton
MA73-21
Canton
MA73-22
Canton
MA73-05
Westwood/Norwood MA73-23
Westwood/Norwood MA73-24
Canton
MA73-25
Canton
MA73-27
Canton/Boston
MA73-02
Dedham/Boston
MA73-28
Milton
MA73-29
Milton/Boston
MA73-03
Milton
MA73-26
Milton
MA73-30
Boston/Quincy
MA73-04
19
Area
(mi2)
Forest
(%)
Residential
(%)
Open
Land (%)
1.7
1.6
2.3
3.0
1.1
3.1
1.1
0.0
0.4
2.0
1.1
0.7
3.5
13.7
1.0
1.0
3.5
0.2
4.0
3.8
3.2
2.0
4.9
1.7
3.2
7.9
3.1
4.7
3.7
1.4
0.0
1.0
59
58
58
55
51
54
83
54
46
50
45
70
42
40
55
56
58
43
44
42
40
42
35
37
34
37
59
47
37
62
x
x
15
33
33
33
32
39
23
34
37
30
37
14
32
35
22
23
27
33
37
28
37
31
33
23
25
35
14
41
36
15
x
x
7
5
5
5
5
3
14
7
7
10
7
8
10
8
8
8
7
6
7
9
7
10
11
20
17
8
12
8
9
14
x
x
Watershed Characteristics
Bulseco-McKim
Table 2. List of stream segments within the Neponset River Watershed, separated by
town/county (NepRWA 2004b).
Town
County
Stream Segments
Boston
Canton
Suffolk
Norfolk
Mother Brook; Neponset River middle and lower mainstems and estuary
Beaver Meadow Brook; East Branch mainstem (aka Canton River),
Massapoag Brook; Neponset River middle mainstem; Pecunit Brook; Pequit
Brook; Ponapoag Brook
Dedham
Dover
Foxboro
Medfield
Milton
Norfolk
Norfolk
Norfolk
Norfolk
Norfolk
Mother Brook, Neponset River middle mainstem
Mill Brook (off Germany Brook) and Mill Brook (off Mine Brook)
Neponset River upper mainstem, School Meadow Brook
Mine & Mill brooks
Gulliver Creek; Neponset River middle & kiwer mainstem and estuary; Pine
Tree Brook; Unquity Brook
Norwood
Norfolk
Germany Brook; Hawes Brook; Meadow Brook; Neponset River upper &
Middle mainstem; Plantingfield Brook; Purgatory Brook; Traphole Brook
Quincy
Randolph
Sharon
Norfolk
Norfolk
Norfolk
Neponset River estuary; Gulliver Creek
Pequit Brook, Ponkapoag brook
Massapoag & Beaver Brooks; Steep Hill Brook; School Meadow Brook ,
Traphole Brook
Stoughton
Walpole
Norfolk
Norfolk
Beaver Meadow Brook; Steep Hill Brook
Mine Brook, Neponset River upper mainstem; School Meadow brook;
Spring Brook; Traphole Brook
Westwood Norfolk
Germany Brook, Mill Brook (off Germany Brook); Neponset middle
mainstem; Plantingfield Brook; Purgatory Brook
20
Watershed Characteristics
Bulseco-McKim
Fig. 5. Land use within the Neponset River Watershed. Residential area, forested area, industry,
wetlands, and golf courses are the five major types of land cover according to Huang & Chen
2009 (NepRWA 2004b)
21
Watershed Characteristics
Bulseco-McKim
Table 3. Precipitation rates (inches per month) for East Boston and Milton (representing the NE
Region) and Foxborough and Milton (representing the SE Region) from
<http://www.mass.gov/dcr/watersupply/rainfall/precipdb.htm>.
22
Watershed Characteristics
Bulseco-McKim
Table 4. Neponset Municipal Water Supply Sources and Wastewater Infrastructure (NepRWA
2004b)
Water Supply Sources
Town
Neponset
MWRA
Boston
None
100
Canton
44
56
Dedham
71
None
Dover
66
None
Foxboro
58
None
Medfield
79
None
Milton
None
100
Norwood
None
100
Quincy
None
100
Sharon
None
None
Stoughton
47
None
Walpole
45
None
Westwood
100
None
TOTAL
71
34
Other
None
None
29
34
42
33
None
None
None
53
55
None
29
19
23
Wastewater Infrastructure
Septic
MWRA
Other
None
100
None
30
70
None
8
92
None
100
None
None
95
None
5
67
None
33
10
90
None
2
98
None
None
100
None
98
None
2
36
61
None
36
64
None
13
87
None
21
56
23