In 1989, the Rhode Island Water Resources Board approved Providence Water's Water Quality Protection Plan to comply with the Rhode Island Water Quality Protection Act of 1987. Components of this plan include watershed land use management, forest management, reservoir management, security and enforcement, and maintenance activities necessary to protect the Scituate Reservoir.

The Watershed Land Acquisition Program, enacted by the the Rhode Island State Legislature in 1989 as part of the Water Quality Protection Plan, generates approximately $2.2 million annually for the purpose of acquiring land and protecting our raw water supply. Since 1990, the PWSB has purchased over 1,440 acres of critical watershed land.

The watershed surrounding the reservoir system covers nearly 60 thousand acres (92.8 sq mi) of mostly rural, well forested land; this represents about 9 per cent of the total land area of the state. Of this watershed, nearly 17 thousand acres (25.4 sq mi)  is controlled by Providence Water, an area roughly 30 percent greater than the area of the city itself. The six reservoirs cover a surface area of 4,563 acres and have a combined capacity of 41.268 billion gallons. Over 12 thousand acres (about 19 sq mi) of managed forestland provide protection to a water resource renowned for its high quality.

The privately owned portion of the watershed must also be monitored and protected through vigorous land use control and cooperative land use planning with local communities. In 1994, Providence Water re-authorized primary funding for the Scituate Reservoir Watershed Education Program conducted in the reservoir communities of Scituate, Foster and Glocester for the 1995 school year.

The classes educate school children and reach out to their families to show them what steps they can take to protect the watershed. The ongoing program, initiated in 1994, has been presented to more than 2,000 students from over 50 classrooms.

Scituate Reservoir 3,390 acres 37.011 Billion gals.
Moswaniscut Reservoir 282 acres 1.781 Billion gals.
Regulating Reservoir 243 acres 428 Million gals
Barden Reservoir 245 acres 853 Million gals
Westconnaug Reservoir 173 acres 453 Million gals
Ponaganset Reservoir 230 acres 742 Million gals
TOTAL 4,563 41.268 Billion gals
An average of over 40 billion gallons of water flows into the system each year


The yearly run-off, or actual water collected in the reservoirs, based on the same average period, is 25.08 inches.

Average reporting year rainfall (1917-2008) 50.57 inches
Maximum reporting year rainfall (2006) 71.37 inches
Minimum reporting year rainfall (1930) 33.43 inches
2008 reporting year rainfall 47.75 inches

Forest Management

The primary goal of the Forest Management Program is to manage forests on the watershed to optimize water production and profit from the sale of timber in a manner that is environmentally sensitive to the local communities. Forest management activities on the more than 12 thousand acres of forest land include:

Forest Management Activities

  • Plan Development
  • Computerized forest stand mapping and database
  • Development of an economic model to support the sustainability of the forest resource base
  • Proactive harvesting program utilizing Best Management Practices to protect water quality
  • Support of private landowner's forest management efforts
  • Support of public education and research efforts

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The long range plan is to establish a diverse forest of tree species native to this area that will provide for maximum profitability. read more

Land Protection

Providence Water has practiced aggressive watershed management and source protection since its inception in order to protect and maintain the high quality of source water for the System. This management program is structured to protect the raw water sources before they can be polluted. The focus of the watershed protection and land management program is: to acquire land as needed, control the use of the land in the watershed, provide close surveillance of the entire watershed, enforce rules and regulations to protect water resources, and sample and gauge tributary streams and reservoirs. Providence Water currently owns nearly all the land immediately proximate to the Scituate Reservoir.

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Providence Water is working in cooperation with the United States Environmental Protection Agency ("EPA") and the Rhode Island Department of Health ("DOH") to conduct an assessment and inventory of the watershed area to identify chemical use and transportation patterns within the watershed. Providence Water has also worked to develop a cooperative planning process with local and state agencies through the local Comprehensive Community Planning process.