Skip to main content Homepage

Current Cyanobacteria Advisories

The table below is continually updated with the most current information on recreational use health advisories issued and lifted throughout the season for monitored and sampled water bodies.

Remember: Only a fraction of all water bodies in Oregon are visually monitored or sampled due to limited physical and monetary resources. A water body with no recreational health advisory is not an indication that a bloom is not present. You are your own best advocate when ensuring your safety, and that of your family and pets. Be aware and "when in doubt, stay out."

advisory= Advisory in effect  lifted= Advisory has been lifted  permanent= Permanent advisory

Toxin  Data (ppb)
Malheur Reservoir
liftedRecreational Use Advisory LIFTED

November 5, 2021

Ross Island Lagoon and Holgate Channel of Willamette River

liftedRecreational Use Advisory LIFTED
October 12, 2021

Upper Klamath Lake 

liftedRecreational Use Advisory LIFTED

November 2, 2021

JC Boyle Reservoir
liftedRecreational Use Advisory LIFTED

September 28, 2021

South Umpqua River and mainstem Umpqua River permanentPermanent Recreational Use Advisory Posted SignDouglas

Douglas County Permanent Recreational Use Advisory: South Umpqua River and mainstem Umpqua River

The advisory covers the South Umpqua River from Canyonville downstream to the confluence with the mainstem Umpqua River, and the mainstem Umpqua River downstream past Elkton to Lawson Bar. Pools in the bedrock along the rivers edge are known to develop cyanobacteria (blue-green algae) blooms that can be harmful to pets and people if accidental ingestion occurs. Signs have been posted at several access areas along the river.