Dead fish floating in water that looks like green pea soup and stinks like a swamp might tell the story of a blue-green algae contamination.

Mitchell Lake in Eden Prairie is contaminated, and the Riley Purgatory Bluff Creek Watershed District is taking actions this summer to begin correcting it. Two floating, stainless steel, solar-powered water circulation machines, called Solar Bees, were installed in Mitchell Lake last Wednesday as part of a pilot study to treat the harmful algae.

The study has wide implications because watershed officials will base its results on the solutions they offer for other area lakes with blue-green algae problems, including Lotus Lake, Riley Lake and Lake Susan in Chanhassen and Round Lake in Eden Prairie.

“Most of the lakes have problems with harmful algae blooms,” said David Austin from CH2M Hill, the engineering company that’s heading up this effort for the watershed district. “The blooms happen in mid-to-late summer. Lake Susan definitely has a harmful algae bloom problem. By contrast, Lake Ann (Chanhassen) is in great shape. It’s a real gem… I believe there are also blue-green algae in Riley. It’s probable. Looking at the data, I see that the water clarity gets poor in Riley in late summer.”

Do you have concerns about blue-green algae in any Chanhassen lakes?