The Hunt River Basin is centrally located in Rhode Island on the westerly side of Narragansett Bay. The watershed drains approximately 25 square miles (15,445 acres) and includes parts of seven Rhode Island communities: Exeter, North Kingstown, East Greenwich, West Greenwich, Coventry, West Warwick, and Warwick. The watershed includes Hunt River, Potowomut River, and four major tributaries. The major tributary sub-watersheds are Sandhill Brook (2,352 acres), Frenchtown Brook (4,487 acres), Scrabbletown Brook (1,653 acres), and Fry Brook (1,986 acres). TMDLs are also under development for the latter two tributaries, Scrabbletown Brook and Fry Brook.
In August 2005, an average of 4.8 million gallons per day (MGD) was withdrawn from the Hunt River basin by public water suppliers. As a direct consequence of this withdrawal, for nearly half of August, the flow in the Hunt River was at or below two cubic ft/sec. and fell to 10% of the average August flow (1.1 cubic ft./sec.). While the summer of 2005 was relatively dry, it never reached the stage of drought advisory, the lowest level of drought designation. The two cubic ft/sec flow is only a quarter of the lowest natural flow that would be expected for the driest week in a ten-year period (the 7Q10) - far too low to be protective of the aquatic environment.
For 2006, water suppliers have indicated the intention to withdraw large amounts of water from their Hunt River wells. This level of withdrawal in August 2005 would have nearly stopped all flow. We view the environmental situation in the Hunt River as critical, requiring immediate attention from the legislature and action by DEM and the WRB.
Currently there are no standards that define the minimum flows in the Hunt that would be protective of the aquatic environment. DEM has the legal authority to adopt such standards, but its current practice is to set flow standards only on a case-by-case basis, after an application is made for a new well. As a consequence, because there is no pending application for a new well in the Hunt River, the DEM has set no protective standards for the Hunt, despite the low flows in the river and the projected substantial increases of withdrawals. The USGS has completed a detailed study of this river basin, so high quality information is available for use in setting standards. We believe that this Commission’s report should recommend legislative direction to DEM to set protective standards for the Hunt River by no later than July 2006.
The Hunt River and two of its tributaries, Fry Brook and Scrabbletown Brook, have been identified by DEM as being impaired by pathogens (i.e., bacteria). During the summer of 1999, DEM staff carried out extensive water quality monitoring in the Hunt River watershed under wet and dry weather conditions. The data collected was used to support the development of water quality restoration plans known as Total Maximum Daily Loads (TMDLs). These TMDLs are aimed at reducing pathogen levels and returning the streams to a condition that meets state standards. The TMDLs have undergone a public review and were given final approval by EPA in January 2001. DEM is now working with Towns and state agencies to implement the recommendations of the TMDL to reduce pollutant loads to the streams.Priority Ranking
The Hunt River, Fry Brook, and Scrabbletown Brook are listed as Group 1 (highest priority) water bodies on the State of Rhode Island's 303(d) list of water quality impaired water bodies.Pollutant of Concern
The Hunt River TMDL has been developed for fecal coliform, as measured fecal coliform concentrations have been found to exceed the state’s water quality standards. Both dry and wet weather water quality data have been collected in the Hunt River watershed, revealing elevated fecal coliform concentrations at both instream and tributary stations. Based on this data, Hunt River, Fry Brook, and Scrabbletown Brook were placed on the state’s 1998 303(d) list of water quality impaired waterbodies.Pollutant Sources
RIDEM has identified 5 major sources of fecal coliform bacteria in the Hunt River watershed. These include storm water runoff from highways and residential/commercial areas, a dairy farm, pigeons roosting under Route 4, a horse farm, and resident waterfowl, domestic pets, and wildlife. All sources are summarized below in Table 1. The largest dry weather sources of bacteria are the dairy farm, pigeons roosting under the Route 4 overpass, and domestic pets, resident waterfowl, and other wildlife. The largest wet weather source of bacteria to the watershed is storm water runoff. Although other sources are significant during wet weather, storm water runoff has a greater cumulative impact in the watershed.