Sodium and chloride from road salt:
Wintertime road maintenance with sodium and chloride deicing materials may be impacting freshwater systems in Rhode Island. This problem is discussed in a USGS study of the Scituate Reservoir watershed which evaluated the sources of sodium and chloride to the reservoir during water year 2000 (October 1999 – September 2000). Sodium concentrations in the reservoir have been increasing, despite the use of reduced sodium deicing materials on state owned roads in the watershed. The study concluded that deicing of state and local roads was the major source of sodium and chloride in the drainage basin during the 2000 water year, accounting for 67 % of the 1,000 tons of sodium and 90 % of the 2,300 tons of chloride introduced into the basin.
URI Watershed Watch volunteers have monitored chloride since 1988. None of the measurements exceed the state water quality aquatic life criteria for chloride of 860 mg/l (acute), 230 mg/l (chronic), but many of the stations show a trend of increasing concentration over time.
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Fig. FW.8: Average lake chloride concentrations (mg/l) in all URI Watershed Watch lakes, 1993 – 2007 suggest increasing levels over time. (L. Green, year?)
Animal impacts:
Animal waste also impacts water quality in rivers and streams. Natural sources such as wildlife and water fowl were found to be important in most of the state’s TMDL studies addressing impairments due to elevated levels of bacteria and pet waste is well documented as a source of contamination in stormwater discharges. Farming operations in proximity to streams an wetlands without utilization of appropriate best management practices can also be a significant source of water pollution. According to the USDA Economic Research Service, 9.2 % of Rhode Island’s total land area was used for farmland in 2002. Most of these farms (78.2 %) were small, between 1 and 99 acres in size, and most (57.7 %) generated less than $9,999 in sales. The US Department of Agriculture Natural Resources Conservation Service (USDA NRCS) in Rhode Island has recently completed an assessment with the assistance of the Southern Rhode Island Conservation District (SRICD) of livestock operations in portions of South County. The survey identified a large number of horse operations, as well as small farms, particularly in the Saugatucket, Beaver, Queen, Uppper and Lower Wood watersheds (Mike Kenyon, personal communication). All of these farms could potentially have impacts on rivers and streams but since some of these land owners are not eligible for USDA financial assistance through various funding programs, such as the Environmental Quality Incentives Program (EQIP), due to program policy, the landowners are unable to implement the recommendations on their own because of financial issues. Technical assistance from USDA NRCS is always available to landowners in identifying their natural resource issues and recommending various best management practices to assist in addressing them. The URI Cooperative Extension Healthy Landscapes program also provides technical information and assistance to small acreage livestock owners.
Protection of Headwater Streams:
Headwater streams and wetlands are essential components of riverine ecosystems. They provide natural flood control, play a critical role in ensuring a continual flow of water downstream to our water supplies, and trap sediments and recycle nutrients. Headwater streams are the most biologically diverse of all riverine ecosystems, providing a wide range of habitats for plants and animals. Headwater streams are also fragile and are easily influenced by human activities in their watersheds. Since they are difficult to find and map, they are often threatened by new development.
Maintaining and Restoring River and Stream Continuity: Throughout the Narragansett Bay watershed the natural flow of rivers and streams are blocked or altered by dams and road crossings. The University of Massachusetts River and Stream Continuity Project provides valuable information on the importance of stream continuity. There are over 500 dams in Rhode Island alone and unnumbered road crossings throughout the watershed. These blockages significantly alter river habitats and disrupt river and stream continuity.
Over the past decade, attention has focused on dams and the impact they have on fish passage. Throughout the Narragansett Bay watershed, projects are moving forward to remove dams or install fish ladders to restore fish passage. Less attention has been focused on the impacts of road crossings and culverts on river ecosystems. The movement of organisms within rivers and streams is an important ecological process and can be significantly affected by road crossings. If not properly designed, road crossings can block animal movements, delay migration, and cause physiological stress as animals expend energy passing both natural and artificial obstacles.
In Massachusetts, the Riverways program is working with local communities to evaluate and restore the impacts of stream crossings and culverts to river segments. MA Riverways has developed a handbook, “Massachusetts Stream Crossings Handbook” and technical standards for stream crossings. They are working with partners to restore river continuity in several river watersheds.
In Rhode Island, the Wood-Pawcatuck Watershed Association with volunteers and partners including the USDA NRCS program and the RIRC& D Council and Trout Unlimited worked with the MA Riverways program and UMASS Extension on a study of stream continuity in the upper and lower Wood Rivers. The study evaluated 291 stream crossings covering 268 miles of streams. Of these, 230 were identified as actual road and stream crossings, and 107 presented severe barriers to wildlife, 72 were moderate barriers, 36 were minor barriers while only 5 met general or optimum standards for stream crossings. The project team assessed the relative habitat impacts of the barriers and prioritized restoration projects. On-the-ground restoration is completed or in progress at several sites.