California Harmful Algal Blooms (HABs)

HAB events represented below are voluntarily reported to the State Water Board's Surface Water Ambient Monitoring Program. Data provided are for general information purposes only and may contain errors. The exact location, extent and toxicity of the reported bloom may not be accurate and may not be affecting the entire waterbody. The data are subject to change as new information is received. Please check back for updates.

Recreational water body closures & advisories due to harmful algal blooms
Click on a water body to get more information.