OHA Downgrades Health Advisory for Lake Billy Chinook Recreational Use, Risk for Pets Remains

MADRAS, Ore. (KTVZ) -- The Oregon Health Authority has downgraded the recreational use health advisory for Lake Billy Chinook in Jefferson County, signaling reduced risk for people. While cyanotoxin levels are now below recreational guideline values for humans, a precaution remains in place for pets.

The Oregon Health Authority (OHA) originally issued the health advisory for Lake Billy Chinook on June 12, 2026. Water monitoring has since confirmed that cyanotoxin levels are safe for human recreational activities.

Despite the reduced risk for humans, cyanotoxin levels detected are still above the OHA's educational guideline values for dogs. Pet owners should keep their animals away from areas where cyanobacteria blooms are present.

The Problem Solvers recently highlighted the concerns local community leaders and members have with the advisories at Lake Billy Chinook. You can learn more about their perspective here.

The OHA advises recreational visitors to continually be alert to signs of cyanobacteria blooms. This is because blooms can develop and disappear on any water body at any time when conditions are favorable.

Only a fraction of water bodies in Oregon are monitored for blooms and toxins. The OHA recommends people become familiar with signs of a bloom, exposures and symptoms by visiting its Cyanobacteria (Harmful Algae) Blooms website.

When recreating, people and especially small children and pets should avoid areas where the water is foamy, scummy, thick like paint, pea-green or blue-green. Individuals should also avoid areas if thick brownish-red mats are visible or bright green clumps are suspended in the water.

If these signs are present, people should avoid activities that cause them to swallow water or inhale droplets, such as swimming or high-speed water activities. Pets should be kept out of these areas.

Cyanotoxins can still exist in clear water. When a bloom dies, toxins released may reach into clear water around the bloom. Blooms can also be pushed into other areas, leaving toxins behind. Some species of cyanobacteria anchor themselves at the bottom of a water body, live in the sediment or can grow on aquatic plants and release toxins into clear water.

For health information or to report an illness, individuals can contact the OHA at 971-673-0482 or visit www.healthoregon.org/hab.