Prospect Lake in Colorado Springs closed due to presumed blue-green algae
COLORADO SPRINGS, Colo. (KRDO) - The City of Colorado Springs has closed Prospect Lake in Memorial Park effective immediately and until further notice due to the presumed return of blue-green algae.
The city said the closure was put in place following a visual inspection by Parks and Recreation staff and a water sample test performed by Colorado Springs Utilities on Wednesday, July 24. The test confirmed the presence of microcystin toxin, which is produced by cyanobacteria, also known as blue-green algae, the city said.
According to the city, testing will be performed on a weekly basis with at least a required two-week closure to ensure the lake is up to the recreational water quality levels set by CDPHE and the EPA before the lake reopens to the public.
During the closure, the following activities are prohibited: swimming, bathing, paddle boarding, tubing, water skiing, and non-motorized boating of any kind. No pets are allowed. Fishing areas will remain open, though anglers are urged to clean fish well and remove guts.
According to the city, Prospect Lake was closed in the summer of 2020 due to blue-green algae. Since that time, staff has taken proactive measures, including the application of an enzyme-based, non-pesticide treatment that consumes the biomass at the bottom of the lake and helps oxygenate the water. Parks and Recreation is also moving forward with Timberline Building Systems to install an aeration system in Prospect Lake, tentatively scheduled for fall of 2024.
BLUE-GREEN ALGAE BACKGROUND
According to the city, blue-green algae are a type of bacteria common in lakes throughout Colorado. When conditions are right, blue-green algae multiplies quickly. Those conditions include sustained hot weather, stagnant water, and polluted stormwater runoff.
These conditions result in too much nitrogen, potassium, and phosphorus in the water. This causes the harmful bacteria to grow faster than the ecosystem can handle. The increased bacteria harm water quality, decrease the amount of oxygen available to animals living in the water and can produce a toxin that is harmful to humans and pets.
Blue-green algae are self-limiting, naturally-occurring bacteria, which means they eventually phase themselves out of bodies of water.
The Colorado Department of Public Health and Environment (CDPHE) offers additional information about blue-green algae on its website.
