It and its six tributary reservoirs—which make up a total surface area of 7.2 square miles (19 km2)—supply drinking water to more than 60 percent of the state population, including Providence.

The surrounding drainage basin that provides water to the reservoir system covers an area of about 94 square miles (240 km2), which includes most of the town of Scituate and parts of Foster, Glocester, Johnston, and Cranston.

By 1910, with Providence's heavy industry growing and the supply system being expanded to surrounding communities, people realized that the flow from Pettaconsett would soon fall short of the rising demands.

A new Water Supply Board was appointed in 1915 with powers to enact the legislation that cleared the way for construction of the reservoir.

At that time, it was the largest project ever undertaken in Rhode Island, and workers were housed in a temporary village established nearby.

[4] On February 21, 1982, Pilgrim Airlines Flight 458 crash-landed on the frozen reservoir due to an in-flight fire.

Most residents of this area were forced to move out of Scituate and received compensation from the city for the property they lost.

Some individuals such as businessman and farmer Arthur Steere sold hundreds of acres for the creation of the Reservoir.

The Joslin family, which owned large mills in the doomed villages, fought a long legal battle, which they eventually lost.