The Scituate Reservoir is the largest inland body of water in the state of Rhode Island. It has an aggregate capacity of 39 billion US gallons (150,000,000 m3) and a surface area of 5.3 square miles (13.7 km²). It and its six tributary reservoirs—which make up a total surface area of 7.2 square miles (18.6 km²)—supply drinking water to more than 60 percent of the state population, including Providence.