The 2026 HABs monitoring season began on May 4th. Current cyanobacteria harmful algal bloom (CyanoHAB) 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.
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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 cyanobacteria harmful algal bloom (CyanoHAB) or related illness:
HAB Reporting Form Animal Illness Reporting Form Human Illness Reporting Form
Advisory Levels
= Advisory in effect
= Precaution in effect
= Advisory/precaution has been lifted
- Advisory: Cyanotoxins have been confirmed through testing to be unsafe levels for swimming and boating at speeds that cause water to spray into your face, OR a combination of conditions indicate that cyanotoxins may be unsafe for swimming and boating at speeds that cause water to spray into your face. Toxin levels are unsafe for pets.
- Precaution: A bloom has been confirmed or cyanotoxins are present but at levels that are safe for human recreation. Toxins levels may still be unsafe for pets.
- Advisory downgraded to Precauation: An 'Advisory' is downgraded to a 'Precuation' when water testing shows safe levels for human recreation, but bloom or toxins are still present. Toxin levels may still be unsafe for pets.
- Precaution lifted: A 'Precaution' is lifted when testing shows cyanotoxins are not present, or when the bloom is visibly gone.