In the Klamath Basin blue-green algae blooms typically occur between June and October when temperatures rise and water conditions are favorable for algal growth. Blue-green algae monitoring typically occurs May - November. If river conditions exceed public health standards for toxic algae the area is posted with a health advisory sign.
View the Klamath BGA Tracker Interactive Map
For more information, please check California's HAB Incident Reports Map.
Updated Posting Status
8/3/22- Klamath River from Weitchpec to Klamath Glen (Roy Rook) has been posted at Caution Level 1 due to the presence of microcystin in samples collected on July 26th and 27th. Advisory signs have been posted at public access points and will remain in place until this reach has been de-posted.
7/28/22- Upper Klamath Lake has been issued a recreational use health advisory. This expands the advisory initially issued on 7/1/22 for Shoalwater Bay to include all areas of Upper Klamath Lake due to the presence of a cyanobacteria bloom and cyanotoxins above recreational use values for human exposure.
July 22nd, 2022- Copco Reservoir has been posted at the 'Danger' level based on microcystin samples collected on 7/12/22 that exceed recommended trigger levels. This supersedes the June 17th 'Caution' advisory. Advisory signs have been posted at public access points and will remain in place until this reach has been de-posted.
June 17th, 2022- Copco Reservoir has been posted at the 'Caution' trigger level based on microcystin samples collected on 6/7/22 that exceed recommended trigger levels. Advisory signs have been posted at public access points and will remain in place until this reach has been de-posted.
June 17th, 2022- All other reaches of the Klamath River are below posting threshold.
About the Tracker
The BGA Tracker Map was built to inform the public and research community regarding river conditions. The Tracker utilizes current information to track and map the blue-green algae blooms throughout the Klamath Basin. The Blue-Green Algae Tracker identifies blue-green algae public health threats (i.e. exceeds health thresholds identified in the appropriate guidance) by river reaches bounded by public health monitoring locations.
River reaches which exceed applicable criteria for public health are indicated by different colors on the map that vary depending on the number of tiers within each jurisdiction's advisory thresholds. Advisory colors within the map are:
Blue-green Algae Official Notifications