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Region 1: EPA New England

History of Human Impacts on Charles River

Urbanization and associated degradation of the Charles River has occurred over a four-hundred year period starting in the early 1600s. EPA and its partners have been working to reverse that degradation since 1995. The improvement in the river's health is an extraordinary accomplishment.

Year Grade Overall* Dry* Wet*
  Boating Swimming Boating Swimming Boating Swimming
2013 A- 96 70 97 84 95 63
2012 B+ 87 67 99 93 81 53
2011 B 82 54 96 89 74 35
2010 B+ 86 66 94 86 82 54
2009 B+ 93 62 92 69 94 58
2008 B+ 95 48 91 58 92 42
2007 B++ 100 63 100 84 100 50
2006 B+ 90 62 100 80 84 51
2005 B+ 97 50 97 59 96 32
2004 B+ 96 54 94 38 97 62
2003 B- 85 46 91 56 81 41
2002 B 91 39 100 71 86 21
2001 B 82 54 97 80 74 40
2000 B 92 59 94 82 91 46
1999 B- 90 65 100 71 85 62
1998 C+ 83 51 98 85 74 31
1997 C 70 34 87 56 61 22
1996 C- 57 21 94 40 45 15
1995 D 39 19        

2007 use e coli single sample number of 235 for swimming and a multiplier of 5 (=1175) for boating.

The general standards for the grade at the outset were as follows:

A: always meets standards
B: all boating and some swimming
C: some boating and swimming
D: some boating and no swimming
F: no standards

The way the numbers have been calculated depends on a gross level on the general descriptors.

The grade is then refined by looking at past years and seeing how the numbers stack up against those.

*Figures represent the percentage of time that state bacterial standards are met.

Water Resources and the Urban Environment, Lower Charles River Watershed, Massachusetts, 1630–2005

Full-color printable PDF of Charles River timeline (PDF) (1 pg, 717 K, about PDF)

Date Human Activity Impact on River
4000 BC to 1617 AD Native Americans inhabit watershed Only known impact is remains of fishing weirs discovered in Back Bay
1625 John Blaxton becomes first settler in Boston, building his home near freshwater spring on western flank of Beacon Hill  
1630 John Winthrop and Massachusetts Bay Colony joins Blaxton; additional springs used for water supply  
1634 Grist mill dam erected at Watertown, first of 43 industrial mills to be built on lower Charles Dam changes flow of river, captures sediments, limits fish migration
1640 First printing press, public park, public school, college in colonies established on Charles  
1643 Dam and mill constructed on current Causeway St. Mill ponds become repositories of industrial waste; 1656 ordinance allows dumping of "beast entralls and garbidg" at North St. w/out fine
late 1700s Boston streets are paved with cobblestones; underground drainage system for gray water created Paving eliminates recharge of aquifer; springs dry up and become contaminated by privies; private water company brings water into Boston from Jamaica Pond; in 1840 Boston constructs enlarged water supply at lake Cochituate in Natick
1790-present Paving of street surfaces and creation of other impervious surfaces continues; turns an "absorbent" landsurface into a "waterproof" land surface; for example, some residential areas of Cambridge are 73% impervious Runoff carries away contaminants such as bacteria, phosphorus lead and PCBs degrading river uses, poisoning fish and increasing algal growth; increases flooding; lowers water table in Boston; creating host of problems. Even today, buildings on pilings at risk due to dry rot; see Globe story of Feb. 2004
1799 First filling of marshes occurs by lopping of top of Trimountain (now Tremont) to make Charles St. Filling eliminates natural esturine habitat, limits water available for assimilating wastes
1840 Introduction of public water supply spurs develop of internal plumbing for waste; waste is conveyed directly to Charles through pre-existing street drains and through newly constructed common sewers carrying storm and sewer water Bacteria load to river increases dramatically; waste on exposed mudflats causes stench thought to spread disease (before germ theory of disease, illnesses thought to be spread by odors or "miasma"
1855-1880s 738 acres of tidal marsh in Back Bay is filled with material from Boston drumlins and then Needham quarries Goal was to eliminate stench from poorly flushed tidal flats: results in reduced esturine environment, limits assimililative capacity of basin
1878 Construction of first metropolitan sewer creates additional concern over lowered groundwater table; network of groundwater observation wells initiated Sewer lines begin to drain the groundwater of Boston; in later years, tunnels, subways and increased impervious areas add to problem
1879 Boston adopts Olmsted's "Sanitary Improvement of Back Bay; Fens is created by filling 90% of 190 acre section of Back west of Gavelly point. Stony Brook wet weather flow designed to overflow into fens, an artificial marsh with tide gate to keep water elevated; Muddy River diverted to culvert under Brookline Ave to Charles Riverine habitat of Muddy lost. CSO discharge into fens remains today; constriction of flow causes flooding in lower Muddy, a problem being ameliorated by $100 million Muddy River Restoration project currently underway
1884 All of back bay other than portion at entrance of Stony Brook and Muddy River filled. Reduced river area in combination with sewage load from drains raises public health concerns Sewer interceptors parallel to shore line conveying waste to Moon Island constructed to address sewage discharge to tidal flats and waters; interceptors designed to overspill into surface waters in large storms, creating "combined sewer overflows"
late 19th, early 20th century Stoney Brook, largest tributary to Charles is culverted; many of the other major Charles tributaries, including Fanueil Brook, Village Brook, Tannery Brook and parts of Laundry Brook, are also culverted over time Project to protect public from sewage disease. Culverting of streams eliminates habitat value; sets up streams as sewer conduits
1903 Increasing CSO flows into basin along with burgeoning population leads to creation of committee to examine sewage problem; committee decides upon creation of freshwater basin to flood the flats See Dam Construction below
1908 Dam constructed between Boston and E. Cambridge at the locus of the current Museum of Science. This dam is replaced by New Dam at Boston harbor in 1978; Intended to alleviate sewage threat by covering tidal flats, dam eliminated esturine environment in total and created a settling basin for suspended sediments in water: results in heavily contaminated bottom sediment; anoxic zone created by salt water intrusion from harbor;also eliminates tidal flushing in river and makes the "fens solution" unworkable as a result
early 20 th century 200 acres of marshes in Allston filled to make land for RR yards, Harvard Business School, Harvard athletic fields  
1978 Dam constructed at mouth of harbor to control flooding and enhance fish passage  
1988 MWRA creates its CSO program Lower Charles had 19 CSOs discharging 1.7 billion gallons per year into lower Charles, 150 mgy untreated
1995 Clean Charles Initiative Launched  
1995 EPA issues illicit connection orders to Watertown, Newton, Waltham, Brookline, Needham, Dedham  
1997 MWRA's Long Term Plan Approved Plan requires closure of 7 CSOs and reduction of discharges to 162 mgy, 2.3mgy untreated
2000 Deer Island Plant and outfall tunnel complete Greatly expanded capacity and secondary treatment at Deer Island reduces CSO flows to Charles and improves water quality in Boston Harbor. CSO
Earth Day 2005 Most Known Elicits Removed

Well over 1MGD of illicits have been removed.


MWRA has completed most of its 1997 CSO control plan

Under orders issued in the fall of 2004, Waltham, Watertown, Newton and Brookline required to eliminate all known connections by 2005; CSO flows in lower Charles have been reduced by 90%
September 2006 Separation of Stoney Brook completed Stony Brook is the largest remaining source of bacteria to the lower Charles
2007 EPA and MassDEP establish TMDL for lower Charles River to reduce levels of phosphorus  
2013 Projected date of completion of MWRA CSO long-term control plan for Charles River  

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