The Rhode Island Department of Health (RIDOH) and the Rhode Island Department of Environmental Management (DEM) have recommended lifting the recreational advisories at Upper J.L. Curran Reservoir in Cranston, Wenscott Reservoir in North Providence, Mashapaug Pond in Providence, and three lakes in Roger Williams Park (Pleasure, Cunliff, and Elm) in Providence. These advisories were put in place due to high levels of blue-green algae, also known as cyanobacteria.
While blue-green algae are generally less active in the winter due to seasonal changes that reduce light and temperature, there is still a risk of recurring blooms and toxins, even in iced-over conditions. The DEM has ended its monitoring for the year, but advises the public to avoid contact with any body of water that appears bright green or has a dense, floating scum. Blue-green algae blooms may resemble green paint or thick pea soup.
Three other water bodies in Roger Williams Park remain under advisories (Roosevelt, Polo, and Willow Lakes) due to continued visual evidence of blue-green algae. For more information and a list of historical advisories, visit www.dem.ri.gov/bluegreen. If you suspect a blue-green algae bloom, please send reports and photographs, if possible, to DEM.OWRCyano@dem.ri.gov.