The Pawtuxet River watershed, located in central-western Rhode Island, is the largest 
watershed in the state. The river flows generally from west to east. Its headwaters are in 
the hills of western Rhode Island. Its mouth is in historic Pawtuxet Village between the 
cities of Warwick and Cranston, the state's second and third largest cities. The watershed 
encompasses all or portions of the following communities: Coventry, Cranston, East 
Greenwich, Exeter, Foster, Glocester, Johnston, Providence, Scituate, Warwick, West 
Greenwich, and West Warwick. The Pawtuxet River watershed comprises the Scituate 
Reservoir and its tributaries, the North Branch of the Pawtuxet, the Pocasset River, the 
Big River and its tributaries, the Flat River Reservoir and its tributaries. the South Branch 
of the Pawtuxet, and the main stem of the Pawtuxet. In total, the watershed contains 64 
ponds, 93 brooks, 7 tributary rivers, and 18 dams.

The watershed is heavily influenced by the devel-
opment patterns of the 19th and 20th centuries. 
With the second largest volume of water in Rhode 
Island and a substantial drop in elevation from its 
headwaters to Narragansett Bay, the Pawtuxet 
River watershed became a center of textile manu-
facturing plants. Numerous impoundments were 
created along the river and its tributaries, and 
along the banks were a series of mills and mill 
villages, many of which now have historical signif-
icance. In the late 19th century, this development 
was so intensive that an urban area emerged in 
the eastern Coventry-West Warwick area. Factories 
and villages both discharged their effluent and 
waste in the river, degrading water quality in the 
lower portions of the watershed. As the city of 
Providence's population increased through the 
industrial era, public health became a major 
concern. 

It was decided that the northern and western portions of the Pawtuxet River watershed would 
be used as the source for the City's drinking water. The Scituate Reservoir water system 
completed in the 1920's, now provides drinking water to nearly two-thirds of the state's pop-
ulation. The Big River, a major tributary of the South Branch of the Pawtuxet, was also 
recognized as another potential drinking water resource. The development of this project 
was dropped largely because of the loss of wetlands that would have resulted.