Good news for swimmers and boaters headed to Lake Billy Chinook this Fourth of July weekend: the Oregon Health Authority (OHA) has downgraded its recreational use health advisory for the Jefferson County reservoir, saying water monitoring now confirms that cyanotoxin levels have fallen below guideline values for humans.

The original advisory was issued June 12, after testing detected cyanobacteria blooms with toxin levels above OHA’s Recreational Use Values. At the height of the advisory, the Crooked River arm near the Cove Palisades day-use area was visibly bright green.

Pets Still at Risk

While the advisory for humans has been lifted, the precaution for pets remains in effect. Cyanotoxin levels detected in the most recent testing are still above OHA’s educational guideline values for dogs. Pet owners are urged to keep animals away from any areas where blooms are visible.

Signs that a bloom may be present include:

  • Foamy, scummy, or paint-like surface water
  • Pea-green or blue-green coloring
  • Thick brownish-red mats visible on or just below the surface
  • Bright green clumps suspended in the water

OHA cautions that cyanotoxins can persist in water that appears clear, particularly near the edges of a dying bloom where toxins may have dispersed into surrounding water.

Community Frustration with OHA Communication

The advisory triggered frustration among Jefferson County business owners and local officials who say OHA’s communication process lacks the transparency and local input needed to minimize economic harm. Jefferson County leaders and businesses called on OHA last week to better involve communities before and during advisories that affect recreation at one of Central Oregon’s most-visited lakes.

Cove Palisades State Park and Lake Billy Chinook draw tens of thousands of visitors each summer, and extended advisories during prime recreation season have direct consequences for local tourism and businesses.

Staying Safe Going Forward

OHA reminds visitors that only a fraction of Oregon’s water bodies are actively monitored for cyanobacteria blooms, and that blooms can develop or disappear rapidly depending on temperature, sunlight, and nutrient conditions. Visitors should always check OHA’s cyanobacteria advisory page before heading out.

For updates, visit the OHA Cyanobacteria (Harmful Algae) Blooms website or call the Jefferson County Public Health office.