The City of Boulder is asking residents to keep themselves and their pets out of the water at the Boulder Reservoir due to a possible harmful algae bloom.

Although the swim beach is closed for the season, watercraft are still allowed on the reservoir. City officials said anglers should clean any fish they catch thoroughly and dispose of fish waste appropriately. They warned against any contact with the water in areas where an active bloom is present.

Blue-green algae bloom spotted in Boulder reservoir City of Boulder

At high concentrations, blue-green algae, or cyanobacteria, can cause rashes, gastrointestinal issues, muscle weakness, or even vomiting. They can be particularly harmful to pets , and the city asked residents to keep dogs away from the reservoir.

Areas where cyanobact

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