Scituate Reservoir Watershed
The largest fresh waterbody in Rhode Island, the Scituate Reservoir is the source of Providence Water’s supply. The Y-shaped reservoir is nearly 6 miles long and has a storage capacity of nearly 37 billion gallons at the Gainer Dam spillway elevation. Its average depth is about 32 feet, while it reaches a depth of 90 feet just upstream of the dam.
Water flows into the Scituate Reservoir from five smaller tributary reservoirs (Barden, Moswansicut, Ponaganset, Regulating, and Westconnaug) and an extensive network of rivers and smaller streams. In total, Providence Water owns surface reservoirs covering about 5,000 acres and another 13,000 acres of surrounding forestland.
Providence Water works to conserve the entire Scituate Reservoir watershed, or area of land that water flows across or under on its way to the main reservoir. The watershed is located primarily within the rural towns of Scituate, Foster, and Glocester, and also includes parts of western Cranston and Johnston. The total drainage area covers 93 square miles or nearly 60,000 acres.
Land use influences the water quality in the reservoir and private wells within the watershed. Maintaining forest cover and practicing and promoting wise stewardship help ensure cleaner water entering the reservoirs. Since Providence Water only owns about one third of the land in the watershed, it relies on local municipalities and private landowners as stewardship partners.
Protecting the source of the water supply saves ratepayers’ money by reducing treatment costs, while providing many other benefits.