The Ipswich River flows through 21 communities in northeastern Massachusetts and supplies drinking water to more than 330,000 people. It frequently runs dry and experiences fish kills during periods of peak summer demand, due to rapid suburban sprawl that has increased water use and over-burdened streams and aquifers in the watershed. Because of these stresses and their effects on streamflow, especially baseflow, the Ipswich River is recognized as one of the most endangered rivers in the nation (American Rivers 2003), “highly stressed” by the MA Water Resources Commission (2001) and “impaired” under S. 303(d) of the Clean Water Act.
In addition to streamflow problems, stormwater pollution is the principal cause of shellfish bed closures and occasional beach closures. The lower Ipswich River and Plum Island Sound are listed as impaired due to pathogens on the 2002 Integrated List of Waters, and the MA Department of Environmental Protection has drafted a pathogen TMDL for the Ipswich River.
Approximately 70 dams and more than 500 bridges and culverts in the watershed further degrade habitat quality by altering natural flow patterns, drowning critical riffle habitats, and creating impediments to fish passage. The combined effect of extreme low flow conditions and the impoundments of dams and poorly designed culverts has been to transform the Ipswich River from a healthy, free-flowing river to a series of stagnant ponds, particularly during low-flow periods.
As a result, the Ipswich River suffers from low dissolved oxygen and unnaturally warm summertime temperatures. The river’s native community of herring, shad, brook trout, and other anadromous and fluvial dependent fish species has been nearly extirpated, replaced by macrohabitat generalist fish species adapted to ponded conditions (USGS 2001, Assessment of Habitat, Fish Communities, and Streamflow Requirements for Habitat Protection, Ipswich River, Massachusetts, 1998-99).