WINDSOR, Colo. -- Windsor Lake was closed on Tuesday after a water sample tested positive for the harmful bacteria blue-green algae, the town of Windsor said.
The swim beach has been closed and roped off and the dog beach has been locked.
No swimming, bathing and pets are allowed in the northern Colorado lake. Tubing and water skiing are also not allowed.
Rentals and concessions have been shut down. Annual permitted motorized and nonmotorized boaters are allowed to help in agitating the water.
A test sample was taken Thursday after an increase in the algae was noticed. The Colorado Department of Public Health and Environment confirmed the presence of the bacteria.
“Out of an abundance of caution last week we issued a precautionary health advisory. Given (Tuesday's) positive test, we have closed the lake for usage," Windsor Parks, Recreation and Culture director Eric Lucas said in a statement.
"A new sample has been sent to the state laboratory (Tuesday) and we will continue to test weekly until the bacteria clears up."
Blue-green algae is common in Colorado lakes. It multiplies rapidly to form blooms and scums.
Exposure to people can cause symptoms such as sore throat, headache, skin irritation, vomiting, diarrhea, fever, nausea and stomach cramps.