The city is prohibiting swimming, tubing, wakeboarding and operating watercraft on the lake, which lies between Guthrie and Edmond.

Until the algae bloom recedes, people and their pets should avoid direct contact with the water, but land-based activities around the lake are still fair game.

The city said normal springtime algae growth has been spurred on by low lake levels and warm waters. In a news release, officials said the timing of rains this year may have caused more runoff from surrounding fields.

When fertilizer runs off into streams and lakes, it can feed algae instead of the plants it was intended for. The city says it expects this bloom to fizzle out when it uses up all those available nutrients, but it’s using treatments to speed up that process.

Normally, Guthrie draws some of its drinking water from Liberty Lake. But until this issue is resolved, the city said it will rely on other water sources to ensure the drinking water stays safe. The Oklahoma Department of Environmental Quality has visited Liberty Lake and is working with the city.

This algae bloom isn’t the only effect Guthrie has felt from the ongoing drought. The city closed its pools and lakeside boat ramps for the summer due to low water levels, and a listener wrote KOSU about a bad taste in the water earlier this month.