This summer, Illinois’ rivers could turn red ... with algae.
The Illinois Environmental Protection Agency has advised that foam and red color in some branches of the Kishwaukee and Rock Rivers are from a chemical reaction caused by the breakdown of a rare algae.
When the algae breaks down, it releases an enzyme that turns the water red and foamy.
IEPA Communication Manager Maggie Carson said the algae – which appears when both the weather and the water are warm, water levels are low, and there is little rainfall – is not
“There can be situations in which algae is harmful, but those are not common situations,” Carson.
Carson was unable to say if Friday’s brief rainstorm, or the storms the National Weather Service has predicted would hit this weekend, will cause the red algae to dissipate.
“It very much depends on the conditions of the river and how much it rains,” Carson said.
Carson said there could be more of this kind of algae in the area if the weather continues to be hot and there is no rainfall.
Carson said the IEPA staff was first alerted to the algae when they received a call saying that a creek in Rockford was turning red.
“Our inspectors do respond – they check and make sure it is a harmless algae,” Carson said. “If they find something different, they will put out a public notice.”