The Charles River at South Natick, Massachusetts.

Human activity has profoundly altered the Charles River and its watershed over the past 375 years. Restoration of 

environmental quality in the watershed has become a high priority for private- and public-sector organizations across 

the region. The U.S. Environmental Protection Agency and the Massachusetts Executive Office of Environmental 

Affairs worked together to coordinate the efforts of the various organizations. One result of this initiative has been a 

series of scientific studies that provide critical information concerning some of the major hydrologic and ecological 

concerns in the watershed. These studies have focused upon:

Streamflows—Limited aquifer storage, growing water demands, and the spread of impervious surfaces are some of 

the factors exacerbating low summer streamflows in headwater areas of the watershed. Coordinated management of 

withdrawals, wastewater returns, and stormwater runoff could substantially increase low streamflows in the summer. 

Innovative approaches to flood control, including preservation of upstream wetland storage capacity and construction 

of a specially designed dam at the river mouth, have greatly reduced flooding in the lower part of the watershed in 

recent decades. 

Water quality—Since the mid-1990s, the bacterial quality of the Charles River has improved markedly, because 

discharges from combined sewer overflows and the number of illicit sewer connections to municipal storm drains 

have been reduced. Improved management of stormwater runoff will likely be required, however, for full attainment 

of State and Federal water-quality standards. Phosphorus inputs from a variety of sources remain an important waterquality problem. 

Fish communities and habitat quality—The Charles River watershed supports a varied fish community of about 20 

resident and migratory species. Habitat conditions for fish and other aquatic species have improved in many parts of 

the river system in recent years. However, serious challenges remain, including the control of nutrients, algae, and 

invasive plants, mitigation of dam impacts, addressing remaining sources of bacteria to the river, and remediation of 

contaminated bottom habitat and the nontidal salt wedge in the lower river.

•

•

•

Prepared in cooperation with the

Massachusetts Executive Office of Environmental Affairs 

General Information Product 47

The Charles River, Eastern Massachusetts: 

Scientific Information in Support of 

Environmental Restoration

By Peter K. Weiskel
BOSTON

EASTON

STOW

ACTON

SHARON

FRANKLIN

SUDBURY

CONCORD

HOPKINTON

CANTON

WALPOLE

NATICK

DOVER

QUINCY

NEWTON

MENDON

WESTON

FRAMINGHAM

MILLIS

WRENTHAM

BROCKTON

MANSFIELD

MILTON

LINCOLN

HOLLISTON

MILFORD

WAYLAND

NORFOLK

BELLINGHAM

MEDFIELD

FOXBOROUGH

LEXINGTON

SHERBORN

WOBURN

MARLBOROUGH

HUDSON WALTHAM

ASHLAND

SAUGUS

MEDWAY

STOUGHTON

NEEDHAM

DEDHAM

PLAINVILLE

NORWOOD

RANDOLPH

WESTWOOD

SOUTHBOROUGH

WELLESLEY

BLACKSTONE

MEDFORD

AVON

REVERE

MALDEN

CAMBRIDGE

STONEHAM

BROOKLINE

MAYNARD

BELMONT

HOPEDALE

MELROSE

WINCHESTER

ARLINGTON

EVERETT

SOMERVILLE

WATERTOWN

CHELSEA

Stony Brook

Muddy

 River

Charles

Charles River

Charles

River

River

Charles

River

Faneuil 

Brook

Laundry

Brook

Middle watershed

Upper watershed (headwaters)

Lower

watershed

Watertown Dam

Base map coverages from: Mass GIS,

City of Boston – Water and Sewer Department,

City of Newton – MIS Department,

Massachusetts State Plane Projection, NAD 1983

EXPLANATION

SURFACE-WATER WITHDRAWAL

GROUND-WATER WITHDRAWAL

WETLANDS

LAKES, PONDS, AND RESERVOIRS

STREAMS

CULVERTED STREAMS

BASIN BOUNDARY

2 MILES

0 2 KILOMETERS

0

71°30' 71°

42°20'

42°10'

71°15'

0 50 MILES

0 50 KILOMETERS

MASSACHUSETTS Charles

Basin

73°00'

42°30'

42°00'

41°30'

72°00'

71°00'

70°00'

Figure 1. The Charles River watershed, eastern Massachusetts.


Introduction

The Charles River flows for 83 miles from its source 

in Hopkinton, Massachusetts to its mouth at Boston Harbor 

(fig. 1). The longest stream entirely within the Commonwealth 

of Massachusetts, the Charles River drains a watershed of 

308 square miles populated by about 1 million people in 

the heart of the Boston metropolitan region. About 20,000 

people a day use the lower river for recreation in the warm 

season, and the Charles River is known internationally for 

its fall rowing regatta and spring canoe-and-kayak race. 

In addition to recreation, the streams, aquifers, lakes, and 

wetlands of the watershed provide many other human and 

ecological benefits, including aquatic habitat, water supply, 

and wastewater assimilation.

In the upper and middle portions of the watershed, 

changes in land- and water-use patterns have begun to affect 

streamflow and aquatic habitat (DeSimone and others, 

2002; Parker and others, 2004). The lower watershed, by 

contrast, has a long history of water-quality and aquatichabitat impairment linked to over 375 years of modern 

human settlement in Boston and adjacent urban communities 

(Seasholes, 2003; Weiskel and others, 2005). In response to 

both the recent and historic environmental challenges facing 

the residents of the watershed, efforts have been initiated 

in recent years by citizens’ groups, the private sector, and 

government agencies to restore the environmental quality of 

the Charles River and its tributaries.

In conjunction with these efforts, scientific studies 

have been conducted in recent years to better define the 

streamflow, water-quality, fish communities, and habitats 

in the river system, and the potential benefits of restoration 

alternatives. This report summarizes the principal findings 

of these studies, and the major scientific questions that 

remain to be answered. The studies described here were 

conducted by several organizations and agencies, including 

the Charles River Watershed Association (CRWA), the 

U.S. Environmental Protection Agency (USEPA), the 

Massachusetts Executive Office of Environmental Affairs 

(EOEA), the Massachusetts Department of Environmental 

Protection (MDEP), the Massachusetts Water Resources 

Authority (MWRA), the Massachusetts Department of Fish 

& Game (MDFG), and the U.S. Geological Survey (USGS).

Streamflow

Low flows in the upper watershed. Streamflow in the 

watershed is affected by human land- and water-use patterns, 

and the effects differ in different portions of the watershed. 

The upper watershed, which includes a major portion of 

the Interstate 495 corridor, underwent rapid development 

during the 1990s, with population increases of over 30 

percent in some towns. Annual water withdrawals grew by 

similar amounts (DeSimone and others, 2002). Most of these 

withdrawals are taken from production wells screened in thin 

valley aquifers closely connected to the streams, ponds, and 

wetlands of the watershed (fig. 2). Ground-water discharge 

from these aquifers, plus wastewater return flow, provides 

sustained flow or baseflow for the mainstem Charles River and 

its tributaries during the summer months.

Till and Bedrock Uplands Sand and Gravel Lowlands

A

B

D

2

3

E

C

E

A

A

INFLOWS AND INTERNAL FLOWS

A. Precipitation recharge to till-covered uplands

B. Precipitation recharge to sand- and gravel-filled lowlands

C. Seepage from streams

D. Wastewater discharge

E. Septic-system return flow

OUTFLOWS

1. Discharge to streams, ponds, wetlands

2. Ground-water evapotranspiration

3. Ground-water withdrawals

4. Surface-water withdrawals 

Sandy

 Aquifer 

Till

Fractured

Bedrock

1

Water 

table

Schematic diagram, not to scale

4

Vegetated

Surface

Figure 2. The water cycle of the upper Charles River watershed (modified from DeSimone and others, 2002 and Randall and 

others, 1988).


In the upper watershed, more water is withdrawn in 

the summer than during any other season (fig. 3), in part, to 

supply water for lawn irrigation and other outdoor uses. From 

1989 to 1998, summer withdrawals in the upper watershed 

increased by about 35 percent (DeSimone and others, 2002).

This increase in summer withdrawals is having a disproportionate effect on streamflows, because (1) streamflows are 

naturally at their lowest in the summer, and (2) the portion of 

withdrawn water that is lost to the watershed (consumptive 

use) is highest in the summer because outdoor uses are more 

subject to evapotranspiration losses. 

Recent modeling studies by the USGS in the upper watershed have shown that certain water management strategies 

could substantially increase summer low flows (DeSimone 

and others, 2002; Eggleston, 2004). Such management actions 

include returning treated municipal wastewater flows and 

stormwater runoff to watershed aquifers, minimizing summer withdrawals from production wells near streams, regional 

sharing of water supplies, reducing ground-water infiltration 

to sewer networks, and improved water-conservation practices. 

Increased operational flexibility and regional sharing of water 

supplies, in particular, have the potential to increase summer 

streamflows in the mainstem Charles River substantially while 

preserving additional supply capacity for future increases in 

demand (Eggleston, 2004). Such approaches take advantage 

of the fact that wells distant from streams generally have less 

short-term impact on streamflow than wells near streams.

Flooding in the lower watershed. In contrast to the 

rapidly developing upper watershed, the lower watershed 

downstream of the Watertown Dam has long been heavily 

urbanized. From about 1870 to 1950, the percentage of 

impervious area in the lower watershed increased greatly, and 

extensive storm-drain networks were constructed to convey 

runoff from streets, roofs, and other impervious areas to the 

lower Charles River and its tributaries (Weiskel and others, 

2005). At the same time, the flood-storage capacity of the 

lower watershed was reduced, as wetlands and ponds were 

filled and natural stream networks were culverted (figs. 1, 4A). 

As a result, flooding adjacent to the lower reaches of Stony 

Brook and Muddy River became more common. An example 

of this type of urban flooding is shown in figure 4B. Although 

Boston park designer Frederick Law Olmsted made allowance 

for the storage of Muddy River and Stony Brook flood waters 

in his 1879 design for the Back Bay Fens (Seasholes, 2003), 

he apparently did not anticipate the tremendous growth in 

impervious watershed area—and the loss of available channel 

storage—in these tributary watersheds during the next century. 

In October 1996, a 5.5-inch rainstorm severely flooded the 

Muddy River and lower Stony Brook corridor, causing over 

$70 million in damage and disabling a portion of the regional 

transit system for several weeks. In response, the City of 

Boston and the Town of Brookline have recently developed a 

flood-mitigation strategy to remove undersized culverts and 

accumulated bottom sediment in this corridor (City of Boston/

Town of Brookline, 2003).

The other major flood hazard in the lower watershed 

is associated with the Charles River itself. In August 1955, 

Hurricane Diane dropped over 12 inches of rain on the lower 

watershed and flooded about 1,700 acres in Boston, Cambridge, and Watertown (U.S. Army Corps of Engineers, 1968). 

An innovative, twofold approach to this flood hazard was 

designed jointly by CRWA, the U.S. Army Corps of Engineers, and the Commonwealth of Massachusetts in the 1960s. 

First, 8,500 acres of nearstream or riparian wetland area in the 

middle and upper watershed were acquired and protected as 

natural valley storage for flood waters (Spirn, 1984). Second, 

a new dam was planned for the mouth of the Charles River. 

Large-capacity pumps in the dam were designed to maintain 

a constant water level in the freshwater basin behind the dam, 

even under extreme flood and tide conditions. This combination of structural and nonstructural approaches proved highly 

effective in preventing flood damage by the Charles River 

during the October 1996 storm, and during other large storms 

over the past 25 years.

AVERAGE MONTHLY RATES

MILLION GALLONS PER DAY

15

10

5

0

J F M A M J J A S O N D

TOTAL MUNICIPAL WITHDRAWALS

MUNICIPAL WASTEWATER DISCHARGES

Figure 3. Average monthly municipal withdrawals and 

wastewater discharges in the upper Charles River watershed, 

eastern Massachusetts, 1989-98 (modified from DeSimone and 

others, 2002). 


B

A

Figure 4. (A) The culverting of Stony Brook at Forest Hills, about 1900. (B) Urban flooding, 

lower Stony Brook watershed, Boston, about 1900 (Photographs courtesy of the Boston Water 

& Sewer Commission).


Remaining scientific information needs—low flows and 

flooding. More research is needed to assess the capacity of 

structural and nonstructural approaches to increase infiltration of rainfall, increase low flows, and reduce flooding in all 

parts of the watershed. Such approaches include low-impact 

development (LID) practices that preserve natural areas, use 

pervious paving materials, and recharge stormwater runoff 

through rain gardens and other infiltration methods. Because irrigation 

of residential lawns and golf courses 

accounts for a large fraction of 

consumptive water use in the upper 

watershed, the potential benefits 

of natural landscaping and highefficiency irrigation practices must 

also be carefully evaluated. Finally, 

the benefits, costs, and feasibility 

of regional water-supply sharing in 

the upper watershed need further 

evaluation.

Water Quality

The water quality of the 

Charles River has been a matter of public concern for at least 

the last 125 years. In 1878, the 

Boston Board of Health gave a 

vivid description of the sewagecontaminated tidal flats where the 

Stony Brook and the Muddy River 

join the Charles:

Large areas have been at once, 

and frequently, enveloped in an 

atmosphere of stench so strong as 

to arouse the sleeping, terrify the 

weak, and nauseate and exasperate nearly everybody... (City of 

Boston, 1878).

Construction of a dam at the 

mouth of the river converted the 

estuary into a freshwater basin and 

improved conditions substantially 

(Haglund, 2003). However, the 

lower Charles still experienced 

Combined Sewer Overflows 

(CSOs), or discharges of sewage 

combined with stormwater. They 

occur when stormwater and wastewater are conveyed through the 

same pipe and the pipe capacity is 

exceeded. By the 1960s, CSOs discharges had become quite frequent 

because of large increases in sewage flows over the course of 

the 20th century.

The resulting public concern led, in part, to the founding of the CRWA in 1965. Since the mid 1990s, sewer-system 

upgrades by local communities and the MWRA have greatly 

reduced CSO discharges to the lower river and thus have 

enhanced recreational values. In addition, many illicit sewage 

connections to the storm-drain 

networks of the lower watershed have been eliminated by the 

river communities. These efforts, 

coordinated by the USEPA and 

EOEA agencies, have measurably 

improved water quality over the 

past decade (fig. 5). Nevertheless, 

regular monitoring by the CRWA, 

USEPA, and MWRA has shown 

that all reaches of the river continue to be affected by bacteria 

concentrations in excess of State 

swimming and boating standards, 

especially after major rain storms.

To help answer some of the 

remaining water-quality questions 

on the lower river, USGS recently 

quantified the relative amounts 

or loads of contaminants entering 

the river from upstream and from 

tributary streams and storm drains 

downstream of the Watertown Dam 

(Breault and others, 2002; Zarriello 

and Barlow, 2002). On an annual 

basis, bacterial loads to the lower 

river were found to be dominated 

by wet-weather inputs from Stony 

Brook and Muddy River, with 

substantial additional bacterial 

inputs from areas of the watershed 

upstream of the Watertown Dam 

(fig. 6A). Improvements of sewage infrastructure now underway in 

the Stony Brook and Muddy River 

sub-watersheds, improved stormwater management in the middle- and 

lower watershed communities, and 

treatment of the remaining large 

CSO discharges to the lower river 

are expected to further reduce wetweather bacterial loads (Massachusetts Water Resources Authority, 

2004; Zarriello and others, 2003).

Phosphorus loading to 

the Charles River is also a 

Muddy River, Back Bay Fens, Boston, Massachusetts.



Laundry Brook, Newton Center, Massachusetts
major concern because it stimulates excessive growth of 

phytoplankton and other types of algae (eutrophication). 

Phosphorus loads to the lower river are dominated by dryweather inputs from upstream, although wet-weather inputs 

are also substantial (fig. 6B). The upstream dry-weather loads 

likely originate from municipal wastewater treatment plants 

in the middle and upper watershed (Charles River Watershed 

Association, 2004a), and non-point sources such as residential 

lawn fertilizer. In addition, internal loading of phosphorus 

from the sediments and stagnant bottom waters of the 

lower river is thought to be large and is just beginning to be 

quantified (Breault and others, 2000b).

Figure 6. Relative size of the (A) fecal coliform bacteria, and 

(B) phosphorus loads to the lower Charles River from upstream 

sources and from tributary subbasins downstream of Watertown 

Dam. The total bacterial load from the largest source, Stony 

Brook, was 4,200 trillion colony forming units per year during the 

2000 study period. The total phosphorus load from the largest 

source, upstream inputs, was 9,900 kilograms per year (Breault 

and others, 2002).

0

0.5

1

1.5

2

2.5

3

3.5

4

1998 1999 2000 2001 2002 2003 2004 2005

WATER CLARITY IN FEET

B

0

10

20

30

40

50

60

70

80

90

100

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Swimming

Boating

PERCENTAGE OF TIME MEETING STANDARD

A

Figure 5. (A) Percentage of time that the lower Charles River 

meets Massachusetts swimming and boating standards for 

bacteria, 1995-2005 (Charles River Watershed Association, 2004b). 

(B) Average summer clarity of water in the lower Charles River 

at Boston University Bridge, as measured by the maximum depth 

at which a black-and-white patterned disk (Secchi disk) remains 

visible (U.S. Environmental Protection Agency, 2003).

A. Fecal Coliform Bacteria

A B C

D E

F

B. Phosphorus, Total

A B C

D E

F

PIE-CHART AREAS

Dry-weather portion

 Stormwater portion

MAP AREAS

 Gaged subbasins

 Ungaged area

 Water

EXPLANATION

A Upstream of Watertown dam

B Laundry Brook subbasin 

C Faneuil Brook subbasin

D Muddy River subbasin

E Stony Brook subbasin 

F Ungaged area

AREAS FOR WHICH ANNUAL

 LOADS WERE CALCULATED


Other contaminants affecting water quality in the 

Charles River include trace metals and organic compounds. 

Dissolved trace-metal concentrations in the water column 

are generally below both Acute and Chronic Ambient 

Water Quality Criteria for aquatic life (U.S. Environmental 

Protection Agency, 2003). Through reconnaissance 

sampling in the lower watershed, the USGS found detectable 

concentrations of many trace-organic contaminants, including 

wastewater-derived human pharmaceuticals and personalcare products. Such compounds are common in urban 

streams affected by treated or untreated sewage effluent 

(Barnes and others, 2002; Kolpin and others, 2002).

Remaining scientific information needs—water 

quality. More refined techniques of bacterial source tracking 

are needed so that the remaining sources of bacteria to the 

river, including sewage, wildlife, and domestic pets, can be 

better differentiated, quantified, and mitigated. In order to 

reduce eutrophication in the river, the CRWA and USEPA 

are presently quantifying the maximum amount or Total 

Maximum Daily Load (TMDL) of phosphorus that can be 

absorbed by the river without violating water quality standards 

in the upper and lower portions of the river, respectively 

(Charles River Watershed Association, 2004a). Finally, the 

effects of the highly contaminated bottom sediments of the 

river (see next section) upon the quality and ecological health 

of the overlying water column need further investigation.

Fish Communities and Habitat Quality

The Charles River supports a rich aquatic community, 

including about 20 species of resident and migratory fish 

(Charles River Watershed Association, 2003). Because the 

main-stem river is a low-slope stream with many dams and 

impounded reaches, most of the resident fish are considered 

macrohabitat generalists (Armstrong and others, 2004) 

adapted to both ponded and flowing-water conditions (fig. 7). 

Recent sampling by MDFG and CRWA at several sites from 

Medway to Newton indicates that macrohabitat generalists 

such as bluegill, redfin pickerel, American eel, and largemouth 

bass dominate the fish community (Charles River Watershed 

Association, 2003). Important migratory species in the Charles 

River include alewife and blueback herring; historically, 

eel and smelt populations were also important. The Charles 

River main stem has 20 dams along its length; the 7 most 

downstream dams have fish ladders or have been breached 

to promote fish migration, although the actual success of fish 

passage varies at these structures.

The quality of aquatic habitat in the upper and middle 

watershed was recently found by CRWA to be suboptimal 

to marginal with respect to physical and hydrologic 

characteristics (Charles River Watershed Association, 2003). 

Habitat quality is governed by many factors, including summer 

streamflows, water quality, dams, invasive species, and 

bottom-sediment quality. Low summer streamflows restrict 

available cover and fish habitat, raise water temperatures, 



Impounded freshwater basin, lower Charles River, Boston and Cambridge, Massachusetts. 
Figure 7. The 15 most common fish species in the mainstem 

Charles River and tributaries, on the basis of a sample of 3,320 

fish collected in the summer of 2002 by CRWA and MDFG (written 

commun., 2005, Charles River Watershed Association and 

Massachusetts Department of Fish & Game).

wastewater-treatment-plant discharges, stormwater runoff, 

and other sources tend to affect the more sensitive fluvialspecialist species more than the more tolerant, generalist 

fish species. Such impairments may contribute to the low 

numbers of fluvial-specialist fish in the river. In the lower 

river, water quality is further impaired by a bottom layer of 

salt water (a salt wedge) which is associated, especially during 

the summer, with boat-lock operations at the New Charles 

River Dam at Boston Harbor (Breault and others, 2000a). 

The salt wedge, which extends as far as 4 miles upstream 

during summer low-flow periods, depresses DO and elevates 

dissolved sulfide concentrations in the bottom water; these 

chemical conditions degrade the habitat for bottom-dwelling 

(or benthic) biota, including fish.

and reduce both dissolved oxygen (DO) concentrations and 

the capacity of the river to assimilate wastewater-effluent 

discharges (Parker and others, 2004; Charles River Watershed 

Association, 2003). Extreme low flows are most common in 

the tributaries and headwater reaches of the main-stem river 

(DeSimone and others, 2002). Water-quality impairments from 



0 5 10 15 20 25 30

 Bluegill

Redfin Pickerel

Largemouth Bass

American Eel

Redbreast Sunfish

Pumpkinseed

Yellow Perch

Golden Shiner

Yellow Bullhead

Chain Pickerel

White Sucker

Brown Bullhead

White Perch

Common Carp

Black Crappie

RELATIVE ABUNDANCE IN PERCENT
Although dams on the Charles River have reduced 

migratory fish populations from their historic numbers, dambreaching and fish-ladder installations on the most downstream dams have likely increased migratory fish numbers 

in recent decades. Invasive plant species, such as water 

chestnut, affect habitat and recreational quality by displacing native species, shading the water column, and impeding 

navigation. Water chestnut is particularly widespread in the 

impounded Lakes District section of the river in Newton and 

Waltham, and in Watertown near a yacht club and boathouse. 

Finally, the benthic habitat of the lower river is contaminated by a suite of inorganic and organic constituents which 

have accumulated since the 1908 construction of the Old 

Dam, located about 0.5 miles upstream of the New Dam at 

Boston Harbor (Breault and others, 2000b). Median concentrations of bottom-sediment lead and total polychlorinated 

biphenyls (PCBs) substantially exceed median concentrations found in a recent national USGS survey of urban 

river sediment (fig. 8), and also exceed Probable Effects 

Levels (PELs) for adverse effects on benthic organisms.

The effects of bottom-sediment and water-column 

contamination are evident in a recent USEPA survey of fish 

contaminants in the lower Charles River (U.S. Environmental 

Protection Agency, 2001). More than 100 fish were sampled 

for trace metals, PCBs, organochlorine pesticides, and dioxins. 

Although contaminants were commonly detected in the fish, 

contaminant concentrations in the target species (largemouth 

bass, yellow perch, and carp) were generally below the Human 

Consumption Action Levels of the U.S. Food and Drug 

Administration (FDA). PCB concentrations in carp, however, 

were found to exceed the FDA Action Level of 2 parts per 

million at two sampling sites. This finding is consistent with 

the high PCB concentrations in lower-river bottom sediments, 

the bottom-feeding habits of carp, and the tendency of PCBs 

to accumulate in the fatty tissue of carp and other high-lipid 

fish species. In addition, USEPA investigators found internal 

abnormalities in some of the carp, and noted that fish health 

may be compromised at tissue PCB levels considerably below 

the FDA Action Level for human consumption (U.S. Environmental Protection Agency, 2001).

Remaining scientific information needs—fish 

communities and habitat quality. In order to guide ecosystem 

restoration efforts in the Charles River, several scientific 

questions need to be addressed. These include the assessment 

of (1) the target communities of both resident and migratory 

fish that are sought for the river; (2) the ecological and 

human-health risks of wastewater-derived, trace-organic 

contaminants; (3) the relative benefits of dam removal 

compared to fish ladder construction to extend fish passage 

farther upstream and improve passage at the lower dams; 

(4) the vertical extent of bottom-sediment contaminants 

in the lower river, their uptake by benthic organisms, and 

their potential for transfer to the water column and uptake 

by aquatic organisms; (5) the potential benefits of bottom0 100 200 300 400 500 600 700 800 900

LEAD

PARTS PER MILLION

CHARLES RIVER

U.S. URBAN RIVERS

10th percentile

25th percentile 75th percentile

90th percentile

Median

EXPLANATION

(135)

(92)

(number of samples)

(35)

(72)

0 500 1,000 1,500 2,000 2,500 3,000

TOTAL PCBs

CHARLES RIVER

U.S. URBAN RIVERS

PARTS PER BILLION

PEL (FRESHWATER) 

A.

B.

PEL (FRESHWATER) 

Figure 8. (A) Lead and (B) total PCB concentrations in bottom sediments of the lower Charles River, in comparison to other 

U.S. urban rivers. Probable Effects Levels (PELs) for each contaminant are also shown. At least 75% of the U.S. urban river 

samples used for comparison purposes had total PCB concentrations below detection. Data from Breault and others (2000b).

10
sediment removal or capping; (6) the role played by native and 

invasive macrophytes (large plants) in the phosphorus cycle 

of the river; and (7) alternatives for reducing or eliminating 

salt-water intrusion through the New Dam and improving fish 

passage through this dam. 

References Cited

Armstrong, D.S., Parker, G.W., and Richards, T.A., 2004, 

Evaluation of streamflow requirements for habitat protection by comparison to streamflow characteristics at index 

streamflow-gaging stations in southern New England: U.S. 

Geological Survey Water-Resources Investigations Report 

03-4332, 108 p. http://pubs.usgs.gov/wri/wri034332/.

Barnes, K.K., Kolpin, D.W., Meyer, M.T., Thurman, E.M., 

Furlong, E.T., Zaugg, S.D., and Barber, L.B., 2002, Waterquality data for pharmaceuticals, hormones, and other 

organic wastewater contaminants in U.S. streams, U.S. 

Geological Survey Open-File Report 02-94 (on-line only) 

http://toxics.usgs.gov/pubs/OFR-02-94/index.html

Breault, R.F., Barlow, L.K., Reisig, K.D., and Parker, G.W., 

2000a, Spatial distribution, temporal variability, and 

chemistry of the salt wedge in the lower Charles River, 

Massachusetts, June 1998 to July 1999: U.S. Geological 

Survey Water-Resources Investigations Report 00-4124, 1 

pl. http://water.usgs.gov/ pubs/wri/wri004124/.

Breault, R.F., Reisig, K.R., Barlow, L.K., and Weiskel, P.K., 

2000b, Distribution and potential for adverse biological 

effects of inorganic elements and organic compounds in 

bottom sediment, lower Charles River, Massachusetts: U.S. 

Geological Survey Water-Resources Investigations Report 

00-4180, 70 p., 1 pl.

Breault, R.F., Sorenson, J.R. and Weiskel, P.K., 2002, Streamflow, water quality, and contaminant loads in the lower 

Charles River watershed, Massachusetts, 1999–2000: U.S. 

Geological Survey Water-Resources Investigations Report 

02-4137, 131 p. http://water.usgs.gov/pubs/wri/wri024137.

Charles River Watershed Association, 2003, Assessment of 

fish communities and habitat in the Charles River watershed, final report: Waltham, Mass., Charles River Watershed 

Association, 30 p.

Charles River Watershed Association, 2004a, Upper Charles 

River watershed total maximum daily load project, phase 

I final report: Waltham, Mass., Charles River Watershed 

Association, 231 p.

Charles River Watershed Association, 2004b, Water-quality 

monitoring program: Accessed March 2, 2004 at http://

charlesriver.org/wq/wq.html

City of Boston, 1878, Sixth annual report of the Board of 

Health, May 1, 1878, City Document no. 68., p. 3.

City of Boston/Town of Brookline, 2003, Final environmental 

impact report, phase I Muddy River flood control, water 

quality and habitat enhancement, and historic preservation 

project, volume 1, main report (EOEA #11865): Cambridge, 

Mass., Camp, Dresser, and McKee, Inc., variously 

paginated.

DeSimone, L.A., Walter, D.A., Eggleston, J.R., and Nimroski, 

M.T., 2002, Simulation of ground-water flow and evaluation of water-management alternatives in the upper Charles 

River basin, eastern Massachusetts: Water-Resources Investigations Report 02-4234, 94 p. http://water.usgs.gov/pubs/

wri/wri024234/.

Eggleston, J.R., 2004, Evaluation of strategies for balancing 

water use and streamflow reductions in the upper Charles 

River basin, eastern Massachusetts: U.S. Geological Survey 

Water-Resources Investigations Report 03-4330, 85 p.

Haglund, K., 2003, Inventing the Charles River: Cambridge, 

Mass., MIT Press, 493 p.

Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M., 

Zaugg, S.D., Barber, L.B., and Buxton, H.T., 2002, Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000—A national reconnaissance: Environmental Science & Technology: v. 36, no. 6, 

p. 1202-1211.

Massachusetts Water Resources Authority, 2004, Cottage 

Farm CSO facility assessment report, (EOEA # 10335): 

Mass. Water Resources Authority, Boston, Mass., variously 

paginated.

Parker, G.W., Armstrong, D.S., and Richards, T.A., 2004, 

Comparison of methods for determining streamflow 

requirements for aquatic habitat protection at selected sites 

on the Assabet and Charles Rivers, Eastern Massachusetts, 

2000-2002: U.S. Geological Survey Scientific Investigations Report 2004-5092, 72 p. http://water.usgs.gov/pubs/

sir/2004/5092/.

Randall, A.D., Francis, R.M., Frimpter, M.H., and Emery, 

J.M., 1988, Northeastern Appalachians, in Back, W., Rosenshein, J.S., and Seaber, P.R., Hydrogeology: Boulder, CO, 

The Geological Society of America, The Geology of North 

America, v. O-2, p. 177-187.

Seasholes, N.S., 2003, Gaining ground—A history of landmaking in Boston: Cambridge, Mass., MIT Press, 533 p.

Spirn, A.W., 1984, The granite garden—Urban nature and 

human design: New York, N.Y., Basic Books, 334 p.

U.S. Army Corps of Engineers, 1968, Interim report on the 

Charles River for flood control and navigation: Waltham, 

Mass., Department of the Army, New England Division, 

Corps of Engineers, variously paginated.

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U.S. Environmental Protection Agency, 2001, Charles River 

Fish Contaminant Survey: Lexington, Mass., U.S. Environmental Protection Agency, New England Regional Laboratory, variously paginated.

U.S. Environmental Protection Agency, 2003, Clean Charles 

2005 water quality report–2002 core monitoring program: 

North Chelmsford, Mass., U.S. Environmental Protection 

Agency, Region 1, Office of Environmental Measurement 

and Evaluation, 27 p. Accessed April 2, 2004 at http://www.

epa.gov/NE/lab/reportsdocuments/charles/report2002.pdf

Weiskel, P.K., Barlow, L.K., Smieszek, T.W., 2005, Water 

resources and the urban environment, lower Charles River 

watershed, Massachusetts, 1630–2005: U.S. Geological 

Survey Circular 1280, 46 p.

For more information about the Charles River, consult the following 

Web sites:

Charles River Watershed Association: http://charlesriver.org

Charles River Conservancy: http://www.charlesriverconservancy.org/ 

Massachusetts Department of Conservation and Recreation: http://www.mass.gov/dcr/parks/metroboston/charlesR.htm

U.S. Geological Survey: http://ma.water.usgs.gov

U.S. Environmental Protection Agency: http://www.epa.gov/NE/charles/index.html

For more information about USGS programs in Massachusetts, contact:

Wayne H. Sonntag, Director

U.S. Geological Survey

Massachusetts-Rhode Island Water Science Center

10 Bearfoot Road

Northborough, MA 01532

1-800-696-4042

Zarriello, P.J., and Barlow, L.K., 2002, Measured and simulated runoff to the lower Charles River, Massachusetts, 

October 1999–September 2000: U.S. Geological Survey 

Water-Resources Investigations Report 02-4129. http://

water.usgs.gov/pubs/wri/wri024129/.

Zarriello, P.J., Breault, R.F., and Weiskel, P.K., 2003, Potential 

effects of structural controls and street sweeping on stormwater loads to the lower Charles River, Massachusetts: U.S. 

Geological Survey Water-Resources Investigations Report 

02-4220, 48 p. http://water.usgs.gov/pubs/wri/wri024220/.

Unnumbered Photo (Charles002): Laundry Brook, Newton 

Center, Massachusetts

Charles River, Wellesley, Massachusetts Photographs by P. Weiskel

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