Bay and Watershed Facts


By the Numbers:

The Bay

  • In 1987, the United States Congress named Narragansett Bay an “Estuary of National Significance”
  • Narragansett Bay is one of New England’s largest estuaries, it includes 196 square miles of estuarine waters
  • The Bay’s coastline is more than 560 miles long – farther than a round trip car ride between Boston and New York
  • There are 37 licensed marine beaches in the Bay
  • Narragansett Bay has 3,321 acres of salt marsh, and 513 acres of seagrass
  • Climate change is affecting air and water temperatures, precipitation, sea level, and fish in the Narragansett Bay

The Watershed

  • The Narragansett Bay Watershed lies 40% in Rhode Island and 60% in Massachusetts
    • The Watershed is home to 1.95 million people (as of 2010)
  • The Narragansett Bay watershed includes 1,091,112 acres of land (1,705 square miles) of which 35% is urban land (378,661 acres) and 39% is forested land (424,612 acres)
  • Major cities within the watershed include: Worcester, MA, Taunton, MA, Fall River, MA, Providence, RI, Newport, RI
  • There are 37 Wastewater Treatment Facilities that drain into the Bay
  • There are 3,578 miles of streams and rivers that carry water into the Bay
  • The Narragansett Bay watershed includes 4 river basins:
    • Taunton River Basin 338,871 acres (529 square miles)
    • Blackstone River Basin 303,734 acres (475 square miles)
    • Coastal Narragansett Basin 300,124 acres (469 square miles)
    • Pawtuxet River Basin 148,404 acres (232 square miles)

There are two other sub watersheds that make up the study area of the Narragansett Bay Estuary Program:

  • The Little Narragansett Bay Watershed includes 202,920.80 acres (317.10 square miles)
  • The Southwest Coastal Ponds Watershed includes 35,922.80 acres (56.10 square miles)


For more information, check out our 2017 State of Narragansett Bay and Its Watershed report!

NASA satellite photo of Narrgansett Bay
NASA satellite photo of Narragansett Bay - NASA