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LakeQuality
A red sun low over Slim Lake through wildfire haze, its reflection a column of orange on the water

Updated Aug 2026

Rhode Island Lake Water Quality

134 lakes across 5 counties, 5 with a recent water-quality reading.

Lake Map

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New water-quality readings for Rhode Island lakes as RIDEM publishes them. Unsubscribe anytime.

Where to stay near Rhode Island's major lakes

Cabins, resorts, and vacation rentals around Scituate Reservoir and the other major Rhode Island lakes pinned on the map. Live availability and prices.

Top-rated places to stay near Scituate Reservoir

Prices for Oct 9–11, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Reservoirs in Rhode Island

View all 2 reservoirs →

2 of 134 Rhode Island lakes (1%) are man-made reservoirs in the USACE National Inventory of Dams. 2 carry a High or Significant hazard rating. The oldest matched dam dates to 1885.

Hydroelectric (1)Recreation (1)

EPA-Impaired Lakes in Rhode Island

View all 86 impaired lakes →

86 of 134 Rhode Island lakes (64%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 42 have an approved Total Maximum Daily Load (TMDL) restoration plan.

Nuisance exotic species (48)Mercury (40)Nutrients (phosphorus, nitrogen) (34)Oxygen depletion (low DO) (24)Algal growth (8)Metals (other than mercury) (7)Pathogens (E. coli, fecal) (6)Hydrologic alteration (6)

Rhode Island Fishing & Recreation

Licenses, regulations, records, and where to fish across Rhode Island.

Counties

All 5 Rhode Island counties, ranked by average lake water quality. Compare them against every county nationwide in the county rankings, browse the full directory of lakes, or pick a different state.

Rhode Island lists 134 lakes across 5 counties, 5 of them with a recent clarity, phosphorus or algae reading. The rest are here because they are real named lakes, listed for their size, depth and location.

By surface area the largest lake here is Scituate Reservoir, at about 2,340 acres, and 4 of the lakes in this index cover more than 500 acres. Size is worth knowing before you go: a large deep basin buffers nutrient inputs by sheer volume, while a shallow one warms quickly and can turn over its whole water column in a single summer storm.

Lake Match

Which lake suits how you actually use one?

Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of lakes that fit, with the water quality behind each one.

Take the quiz →

Source: EPA National Aquatic Resource Surveys and the EPA Water Quality Portal.