Beaches at Cedar Lake in Minneapolis closed due to blue-green algae

The Minneapolis Park and Recreation Board has issued a hazardous algae warning for all three beaches at Cedar Lake. 

The board says blue-green algae can grow quickly and form blooms that can be toxic to people and to animals. The city is asking people to avoid swimming at the lake.

While a water test at the Cedar Lake South Beach triggered the closure, the board also closed the lake's two other beaches as the bloom is expected to move around the lake based on weather and wind conditions. 

MPRB says the bloom has to do with the summer weather. Sunshine and water temperatures higher than 75 degrees make for ideal conditions for the algae to grow. 

"Blue-green algae blooms are often described as looking like pea soup or spilled green paint," the MPRB website says. "They can also appear as a brown or rust color in the water."

Three other beaches are also closed in Minneapolis: two on Bde Maka Ska and one on Lake Hiawatha. E. coli, not algae, is the culprit in those closures.

Minneapolis tracks beach closures and advisories in an online water quality map that's updated weekly.