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Ch. 3 Figure 8. Integrated Water Quality Monitoring Assessment IWQMA Impaired Waters
3.3.2 Major Watersheds in Rhode Island
Not only is each of Rhode Island’s watersheds affected by different stressors, but management of each watershed must be framed within a unique set of policy goals informed by
these stressors. Plans to establish hydropower facilities on any of Rhode Island’s rivers likewise
should consider the unique ecological, cultural, and regulatory context of each watershed. The following watershed status summaries are based on information from RIDEM, the Rhode Island
Rivers Council, and local watershed councils. More information on watershed characteristics and the potential impacts of hydropower on each watershed is available in RIDEM’s Draft
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Management Guidance on Siting Considerations for Development of New Hydropower Facilities RIDEM 2012.
Blackstone River The Blackstone River stretches 46 miles 74 km. Its watershed of 640
square miles 1658 km
2
spans most of northern Rhode Island down to Pawtucket, with the majority of the area located in Massachusetts. A series of steep drops along the length of the
Blackstone River provided ideal conditions for the historical development of dams for mill power, and by 1914 nearly every appropriate site along the Blackstone River was occupied by a
mill dam. The intensive development of the Blackstone River gave rise to the Industrial Revolution, but at a high environmental cost: pollution of waters, alterations to the river course,
and damage to fish populations Blackstone River Valley National Heritage Corridor Commission 1998. Now classified as a National Heritage River, the Blackstone River is one of
RIDEM’s highest priorities for anadromous fish restoration, and its four lower dams are scheduled to be modified for fish passage in the near future RIDEM 2012. Maintenance of
streamflow is important due to recreational use of the river. Because of the river’s long history of industrial pollution and the presence of wastewater discharges on the river, it is designated by
RIDEM as impaired for bacteria, copper, lead, biodiversity impacts, ammonia, nutrients, and dissolved oxygen RIDEM 2012. The river has been placed on the
EPA’s 303d list of impaired and threatened waters. Contaminated materials are potentially situated in the sediment collected
behind the dams at former mill sites on the river. In addition, a Superfund site at the PetersonPurina landfill is bordered by the Ashton Dam to the North and the Pratt Dam to the
south. This landfill contains chlorinated solvents and volatile organic compounds USEPA 2012, and may make it unwise to pursue hydropower development at the Pratt Dam CLF
2010. The Blackstone River has the greatest hydropower potential of any river in Rhode Island.
Currently, three FERC-licensed or FERC-exempt hydropower plants operate on the Blackstone, with a combined capacity of 4.8 MW. Four preliminary permits have been filed with FERC to
develop new projects on the Blackstone, representing a total of 4 MW of additional capacity. There is interest in increasing the number of hydropower facilities on the Blackstone. In 2010,
several towns along the river convened with the Rhode Island Economic Development Corporation, RIDEM, and other Blackstone Valley stakeholders to form the Northern Rhode
Island Municipal Energy Collaborative. The purpose of the Collaborative is “to explore opportunities to develop renewable energy in Northern Rhode Island for municipal benefit while
at the same time protecting important historic, cultural, and ecological values Essex Partnership 2012.” In a 2010 feasibility study, the Conservation Law Foundation and Essex Partnership
examined the Pratt, Ashton, Albion, Manville, and Elizabeth Webbing dams for possible
hydropower development. These groups concluded that four of the five dams “show sufficient
promise in terms of energy generation and associated development CLF 2010.”
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Ten Mile River The Ten Mile River drains 52 square miles 135km
2
, passing though part of Massachusetts, Pawtucket, and East Providence, before emptying into the Seekonk River. The
three dams on this river are of interest as sites for potential hydropower development Essex Partnership 2011. One of these, Hunt’s Mill, has been granted a FERC preliminary permit to
explore development of a 300 kW hydropower facility FERC 2012. The Ten Mile River supports a small trout fishery RI Rivers 2012b, and is one of RIDEM’s highest priorities for
anadromous fish restoration RIDEM 2012. The three dams on this river are undergoing or have
completed modification for fish passage RIDEM 2012. During industrialization, the river received waste from numerous textile and metal plating mills, and to this day water quality is
considered impaired RI Rivers 2012b. In addition, the river receives effluents from two Massachusetts wastewater treatment plants RIDEM 2012. All impoundments along the river
show signs of eutrophication, and Turner Reservoir and Omega Pond are classified as impaired for dissolved oxygen RIDEM 2012. RIDEM is currently developing a TMDL to limit
pollutants entering the Rhode Island portion of the river RIDEM 2012. Two dam ponds Turner Reservoir and Omega Pond contain wetlands along the impoundment shorelines Essex
Partnership 2011. Two of the riv er’s dams Hunt’s Mill and Omega Pond are considered low-
hazard; the third Turner Reservoir is considered high-hazard RIDEM 2010a. Wood-Pawcatuck River
The Wood-Pawcatuck River drains most of southwestern Rhode Island and a portion of southeastern Connecticut. About 65 of the watershed remains
undeveloped and about 70 of Rhode Islands globally rare species are found within the watershed RI Rivers 2012c. Although 28 historic dams are found on this river, most were used
for milling grain, and did not discharge heavily polluted effluents into the water RI Rivers 2012c. This watershed is one of RIDEM’s highest priorities for anadromous fish restoration
because of the prime spawning habitat contained in its upstream reaches. Federal legislation has
been submitted that would list the Pawcatuck River under the Wild and Scenic rivers designation RIDEM 2012; see also Section 3.2.2.
Pawtuxet River The Pawtuxet River watershed encompasses the Scituate Reservoir, 64
ponds, 93 brooks, 7 tributary rivers, and 18 dams RI Rivers 2012a. The banks of the river are lined with historic dams, mills, and mill villages dating to the industrial era. Most of the dams on
the Pawtuxet are privately owned Essex Partnership. In 2011, the lowest dam on the river was partially removed to enhance fish passage, and other dams may be targeted for fish passage
improvements at a later date RIDEM 2012. The Pawtuxet River receives wastewater treatment discharges from three treatment plants, all of which have undergone extensive upgrades in recent
years in order to improve water quality RIDEM 2012. RIDEM de-listed the Pawtuxet River as impaired for dissolved oxygen in 2008 RIDEM 2012. Contaminated sediments derived from
historical use of the river as a disposal site for industrial effluents continue to present water quality threats RIDEM 2012, and with highways I-95 and I-295 crossing the watershed,
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pollution from runoff is now a leading concern RI Rivers 2012a. Interest exists in developing recreational opportunities along the Pawtuxet River. In 1987, the Pawtuxet River Authority
drafted a plan for a series of river walks, canoe access sites, and significant natural areas, but progress towards this goal has been incremental due to lack of funding RI Rivers 2012a. In
2010, the Essex Partnership was commissioned by the Rhode Island Economic Development Council to evaluate the hydropower potential of fourteen dams on the Pawtuxet River, and
concluded that hydropower development would be feasible on all fourteen but economically justified at only nine Essex Partnership 2010. Dams on the Pawtuxet represent a range of
RIDEM hazard classifications, and many are in states of disrepair Essex Partnership 2010. Woonasquatucket River
The Woonasquatucket River is 19 miles 31 km long and drains an area of 50 square miles 129 km
2
in northern Rhode Island Woonasquatucket Watershed Council 2012. The watershed is characterized by varied land use, with the upper river flowing
through rural areas and the lower river emptying into the urbanized Providence River RIDEM 2012. It has a rich history, and in 1998 was federally designated as an American Heritage River
RI Rivers 2012d. Fish passage efforts are currently underway on the first four obstructions on the lower Woonasquatucket RIDEM 2012. Water quality varies according to the degree of
urbanization along the river, with the urbanized lower reaches considered impaired for fecal coliform, copper, lead, and zinc RIDEM 2012. RIDEM’s 2007 TMDL for the
Woonasquatucket documented stormwater runoff, dry and wet weather, combined sewer
overflows, wastewater treatment discharges and other non-point sources of pollution as causes of impaired water quality RIDEM 2012.
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