CPW warns public to avoid contact with water at Deweese Reservoir due to algae bloom

CUSTER COUNTY, Colo. (KRDO) -- Colorado Parks and Wildlife (CPW) is warning the public about a growing bloom of toxic blue-green algae at the DeWeese Reservoir State Wildlife Area in Custer County.

Visitors should avoid contact with the water in the reservoir, and that includes pets.

“The algae can be harmful to people and pets if touched. It can give sensitive people a bad rash, for example. And it’s possibly fatal if ingested," CPW District Wildlife Manager Justin Krall said.

CPW said there are signs posted at the reservoir warning visitors to avoid the water and explaining the dangers of the algae. If anyone or their pet comes into contact with the algae, the signs urge them to shower immediately with fresh, clean water.

According to CPW, the warning was issued after testing found dangerous levels of toxicity in the water, and elevated levels of algae were observed in a turquoise-colored film on the reservoir. 

The DeWeese Reservoir State Wildlife is primarily used by fishermen.

You can still fish during an algae bloom,” Krall said. “But there should be no skin-to-water contact. It’s also important to take care when handling and cleaning any fish caught in DeWeese. Toxins accumulate in the liver and guts of fish. So it’s important any fish taken is properly cleaned and thoroughly cooked before eating it.” 

According to CPW, algae are an important part of aquatic food webs, but some types of blue-green algae are capable of producing toxins that may cause negative health impacts for humans and pets at elevated concentrations.

More information on blue-green algae is available from the CDPHE's website.