Current Posting Status:

Gerber Reservoir is De-Posted: January 31st, 2012

Environmental factors and field observations at Gerber Reservoir warrant de-posing based on the State of Oregons ’s Recommended Threshold for Recreational Waters for toxic species cell counts.

Klamath River Reservoirs are De-Posted: January 27th, 2012

Environmental factors and field observations at  Iron Gate and Copco Reservoirs warrant de-posing based on the State of California ’s Recommended Threshold for Recreational Waters for toxic species cell counts.

Klamath River above I5 Bridge De-Posted: November 28th, 2011

The sample results collected November 28th, 2011 from  above I 5 Bridge locations are below the State of California ’s Recommended Threshold for Recreational Waters for toxic species cell counts.

Klamath River at Brown Bear De-Posted: October 26th, 2011

Blue-Green Algae Tracker

How to use the Tracker

About the Tracker

The Tracker was built to better inform the public and research community regarding river conditions. The Tracker utilizes up-to-date multi-agency data to track the blue-green algae bloom throughout the Klamath Basin. 

Having trouble? The tracker doesn't work well on older versions of Explorer. Try this LINK.

Blue-Green Algae

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. In an effort to protect public health, 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. The Blue-Green Algae Tracker (below) identifies blue-green algae monitoring results by location: "green" balloon = below public health threshold; "red" balloon = above public health threshold.

*Posting Guidelines - Updated July 2010 - Report (pdf)

The California State Water Resources Control Board (SWRCB), California Department of Public Health (CDPH), California's Office of Environmental Health and Hazard Assessment (OEHHA), and Oregon Department of Health Services (ODHS) provide guidelines for posting advisories in recreation waters. These guidelines were developed using information provided in World Health Organization. Both SWRCB and ODHS recommend posting advisories in recreation waters under four circumstances: (1) if "scum is present associated with toxigenic species"; (2) if scum is not present, but the density of Microcystis or Planktothrix is 40,000 cells/ml or greater; (3) if scum is not present, but the density of all potentially toxigenic BGA is 100,000 cells/ml or greater; and (4) If the concentration of total microcystin is greater or equal to 8 ppb or if anatoxin-a is detected.

Posting Removal Guidelines - Updated July 2010

This general approach may be useful in determining when to lift warning advisories:

• If posting occurred due to visible scum – wait two weeks (there should be no visible scum recurrence during this time) before lifting the advisory.

• If posting occurred due to exceeding a cell count guideline – wait two weeks after cell count falls below the recommended guideline (there should be no visible scum recurrence during this time) before lifting the advisory.

• If posting occurred due to exceeding a toxin concentration guideline – wait 1 week after the toxin concentration falls below the recommended guideline (there should be no visible scum recurrence during this time) before lifting the advisory.