Warnock lake near Atchison is one of several lakes across Kansas under a public health warning.

The Kansas Department of Health issued the warning Wednesday after detecting high levels of the toxic blue-green algae.

The warning means water is unsafe for direct water contact, including swimming or wading. Kansas health officials said you should not drink the lake water or swim in Warnock lake. They also advise to keep pets out of the lake.

State officials advise it may take weeks or several months for the algae to die out to normal, safe levels.

“The reason we get these algae blooms is most likely due to the lake’s shallow depth, its lack of circulation, and its agricultural surroundings,” said Clinton McNemee, Parks Superintendent with the City of Atchison. “Fertilizers and chemicals create a nutrient-rich lake, perfect for algae.”

City officials report the Atchison water supply is unrelated to the algae and remains safe.

Fishing is still permitted at Warnock Lake, though there have been studies indicating that consumption of a large number of fish from lakes with high toxin levels should be limited.

They advised the best approach is to wait it out, as attempting to kill the algae would only make conditions worse.