Casper Closes Lake McKenzie After Cyanobacteria Blooms Confirmed

The City of Casper closed Lake McKenzie at least until spring after testing confirmed the presence of harmful cyanobacteria blooms, the City of Casper said in a news release.

Last week, the Wyoming Department of Environmental Quality confirmed the presence of blooms in the lake at the dog park after city employees found an algae-like substance in late September.

The City then immediately closed the lake to public use, fenced off the area and placed signs warning of potential hazard at the park at the rest of the park, 1691 Bryan Stock Trail.

The blooms look similar to algae.

The DEQ says cyanobacteria can produce toxins and other irritants that can cause adverse health effects in people and animals including rashes, itching, numbness, fatigue, disorientation, abdominal pain, vomiting, and diarrhea. The toxins can be fatal. Blooms also may cause fish kills due to depleted oxygen levels.

The water will remain closed, but park users should remain largely unaffected until the next testing cycle, according to the news release.

As the water freezes during the winter months, the cold will naturally kill the HCBs, according to the DEQ.

Parks Supervisor Katy Hallock encouraged pet owners to watch their dogs closely to ensure they don't dig through fencing and drink or enter the water.

“As long as you and your pets stay out of the water and away from the shoreline, the rest of the park is completely safe," Hallock said.

The City will work with the DEQ next spring to conduct more testing, though DEQ representatives are confident that the problem will be clear next spring.