Algae is common and natural to our waters in Colorado. But a certain type of algae can produce toxins that can harm people, animals, and the local environment.
Toxic algae or harmful algae blooms are made up of what many people call blue-green algae. Technically, these organisms are a special type of bacteria called cyanobacteria or cyanoHABs. Although these organisms naturally occur in Colorado waters, they become a problem when they multiply rapidly, resulting in a dense cyanobacteria concentration or bloom. The blooms can become harmful when the cyanobacteria produce toxins. Learn more below.
Toxic Algae FAQ What toxic algae looks like, how to test your water, health impacts, and more
Toxic Algae in Colorado Some bodies of water in Colorado are routinely monitored and tested for algal toxins to protect the health and safety of water users. Our toxic algae dashboard displays historic harmful algal bloom information submitted to the department. Data is voluntarily reported and does not represent all recreational bodies of water in Colorado. They do not represent current conditions of the water body so we recommend to always examine a body of water for warning signs before allowing children, pets, or yourself to come into contact with water.