Current Cyanobacteria Advisories

Current harmful algal bloom (HAB) recreational use health advisories are listed in the table below and displayed on the Oregon Harmful Algal Bloom Advisories map. Both the table and map are updated regularly with the latest information as advisories are issued and lifted throughout the season for monitored 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."

Click the buttons below to access the interactive Oregon Harmful Algal Bloom Advisories map:

Advisory Map (English) Mapa de Advertencia (Español) Advisory Map (Mobile) Mapa de Advertencia (Móvil)

Report a suspected harmful algal bloom (HAB) or related illness:

HAB Reporting Form Animal Illness Reporting Form Human Illness Reporting Form

Advisory Levels

= Advisory in effect = Precaution in effect = Advisory has been lifted

Advisory: Cyanotoxins have been confirmed through testing and are at unsafe levels, or a bloom has been sighted and water will be sampled within 1 business day.
Precaution: A bloom has been sighted and water sampling is unavailable within 1 business day due to limited resources.
Advisory Lifted: An 'Advisory' is lifted when water testing shows safe levels. If a site has previously tested at unsafe levels, regular testing continues until the bloom is visibly gone and cyanotoxins are at safe levels. A 'Precaution' is lifted when testing shows cyanotoxin levels are safe, or when the bloom is visibly gone.

Waterbody	Status	Date/Link	County	Toxin	Data
Emigrant Lake	Advisory Lifted	5/9/2025	Jackson
Wapato Marsh at Oaks Bottom Wildlife Refuge	Advisory	5/1/2025	Multnomah	Microcystins	191 ug/L
South Umpqua River and mainstream Umpqua River	Permanent Advisory	Posted Sign	Douglas

Note: This table only includes health advisories for HABs affecting water bodies in the state of Oregon. To find advisories for water bodies in bordering states, please refer to the following websites:

California: Harmful Algal Bloom Reports Map
Idaho: Harmful Algal Bloom Water Quality Testing Results
Nevada: Harmful Algal Bloom Dashboard
Washington: Harmful Algal Bloom Map

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 Sawyers Rapids. 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.