A ‘full-body contact’ closure has been issued at Colorado’s DeWeese Reservoir State Wildlife Area after algae with the potential to be deadly has been detected in the lake.

The algae that was found was toxic blue-green algae, which can be harmful to people and pets if touched. Sensitive people will more commonly get a rash from the algae, though it can be fatal if ingested. This is one reason why it’s particularly problematic for dogs.

The detection came after water was tested when a turquoise-colored film was spotted on the reservoir.

While fishing is still allowed at the destination, all recreation involving contact with the water has been banned, including but not limited to swimming, skiing, paddle-boarding, and wading.

“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,” said CPW District Wildlife Manager Justin Krall.

“Algae has become a seasonal problem at DeWeese, forcing CPW in recent summers to close the water to all activity except fishing to prevent the risk of exposure to humans and their pets,” said Krall. “This year, the algae bloom was delayed. But now it’s happening and people need to take precautions.”

Those who may be exposed to blue-green algae should shower immediately.

Algae blooms tend to occur when temperature rise in the summer. Frequent samples are taken on many bodies of water around the state to monitor water quality and to detect dangerous substances. CPW will continue to test water at DeWeese and water activities will reopen once algae levels have returned to a safe level.

DeWeese Reservoir State Wildlife Area spans 300 acres near Westcliffe and is best known for fishing, though other common recreation activities at the destination include hiking, wildlife spotting, camping, and picnicking.

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