Water Quality

Rhode Island enjoys an abundance of water resources that support vital uses such as drinking water, recreation, habitat and commerce, among others. The state has approximately 1,420 miles of rivers, 20,749 acres of lakes and ponds, and approximately 15,500 acres of freshwater swamps, marshes, bogs and fens as well as close to 72,000 acres of forested wetlands. Estuaries, including Narragansett Bay and the coastal ponds, cover approximately 159 square miles. Underlying the state are 22 major stratified drift (sand and gravel) aquifers as well as usable quantities of groundwater in almost all other locations from the bedrock aquifers. The Office of Water Resources (OWR) implements a variety of programs aimed at protecting and restoring the state's surface waters, groundwaters and wetlands.

With the monitoring conducted under the state's Water Monitoring Strategy and following the new Integrated Water Quality Monitoring and Assessment Reporting process, 79% of the river miles, 84% of the lake acres and nearly 100% of the estuarine waters in the state have enough data available to assess at least some of their designated uses. The state has documented water quality impairments in 192 Assessment Units (Waterbody ID Numbers) (see 2022 Section 303(d) Impaired Waters Report and continues to develop restoration plans, based upon thorough water quality assessments, for these areas in order to restore healthy aquatic habitats and reduce public health threats associated with fishing and water recreation.

Over 90% of the state's groundwater is considered suitable for drinking water use. Approximately 26% of the state's population depends on groundwater for their water supply and approximately two-thirds of the communities in the state depend on groundwater for all or a significant portion of their water supply needs. As of September 2007, there were 663 public wells in the state. In addition, groundwater quality affects surface waters since a significant portion of stream flow (almost all of it in dry periods) is derived from groundwater flow to the stream.

Office of Water Resources' programs play a pivotal role in controlling wastewater discharges, promoting nonpoint source abatement, preventing groundwater pollution and averting alterations to freshwater wetlands. New watershed based initiatives are helping to build partnerships and enhance management of water resources at both the state and local level through better land use planning, collaborative projects and other means. The targeting of activities, ranging from permitting to financial assistance, to priority watersheds is expected to improve overall effectiveness. New emphasis is being placed on restoring both freshwater wetland and coastal habitats. Permit streamlining measures have begun to improve efficiency. Additional progress is expected after further actions, including data system improvements.