Colorado Parks and Wildlife warns of potentially toxic algae blooms
Kara Van Hoose
July 28, 2023
CPW warns of elevated, harmful algae levels in northeast reservoirs
STERLING, Colo. – Colorado Parks and Wildlife is warning of increased presence of potentially toxic algae found in reservoirs in northeastern Colorado. CPW has observed algae blooms at North Sterling State Park, Jackson Lake State Wildlife Area, Prewitt State Wildlife Area and Jumbo (Julesburg) State Wildlife Area.
During the summer, CPW visually inspects water bodies weekly for algae blooms. When algae is spotted, CPW collects water samples weekly, bi-weekly or monthly, and the Colorado Department of Public Health and Environment tests the cyanobacteria samples for microcystin, an algal toxin. Weekly or bi-weekly testing continues until the algae bloom dissipates.
The threshold for water recreational closure set by CDPHE is 8 micrograms per liter (ug/L) of algal toxin (microcystin) and above. This is considered a “red” level. Samples testing below 8 ug/L are considered at a “yellow” level, where recreation is not restricted but visitors should take precautions.
Samples collected from North Sterling reservoir on July 17 showed concentrations of 7.3 ug/L at the swim beach and 4.6 ug/L at the marina. The swim beach will stay closed, out of the abundance of caution, and the marina is at a yellow level. Samples were collected again on July 24, and those results are pending. Jumbo SWA samples had low concentrations of toxins. Yellow caution signs have been posted. Prewitt SWA and Jackson Lake SWA’s test results are pending. Those state wildlife areas are currently operating at a “yellow” level.
The swim beach at North Sterling, which represents 20 of the 3,000 acres of the reservoir, first closed last week, and swimming, paddleboarding and wade fishing are not permitted. These activities are allowed on the rest of the reservoir outside of the swim beach area. Boating and kayaking are not restricted. Walking paths and roads leading to the swim beach have been marked off by cones to restrict access. Signs have been placed around the park warning visitors of the algae. Staff have been conducting boat patrols to enforce the swimming ban and provide education to visitors.
“It’s especially important to keep dogs on a leash by the swim beach, so they aren’t tempted to drink from the water while we’re experiencing an algae bloom,” said North Sterling Park Manager David Piper.
After additional testing, updates to water recreation restrictions will be posted to the park’s Facebook page and website.
While water recreation is not currently restricted at Prewitt, Jumbo and Jackson Lake State Wildlife Areas, visitors should take precautions after going into the water by thoroughly washing off with fresh water afterwards and not drinking the water. Dogs and other leashed pets should not come into contact with water where toxic algae blooms may be present.
According to CDPHE, symptoms of toxic algae exposure include skin irritation, fever, diarrhea, headache, muscle and joint pain, and liver damage. Contact a healthcare provider or Poison Control at 1-800-222-1222 if suspected exposure has occurred.
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PHOTO CUTLINES:
Top: The North Sterling swim beach, which is 20 acres of the reservoir, will remain off limits to recreation.
Bottom: Pathways and roads leading to the swim beach have signs posted detailing toxic algae bloom information and education.
Colorado Parks and Wildlife (CPW) is an enterprise agency, relying primarily on license sales, state parks fees and registration fees to support its operations, including: 43 state parks and more than 350 wildlife areas covering approximately 900,000 acres, management of fishing and hunting, wildlife watching, camping, motorized and non-motorized trails, boating and outdoor education. CPW's work contributes approximately $6 billion in total economic impact annually throughout Colorado.