Is the lake safe?

California

Toxic algae in Marin County lakes

18 lakes and waterways in Marin County have harmful algal bloom reports in California's official data. The most recent entry is for Stafford Lake: A bloom was reported at Stafford Lake on 30 September 2026 at stafford lake park. Marin Civic Center Lagoon and Richardson Bay have had blooms in three or more years.

Lakes with bloom history

Newest report first. Each lake has its own page with the full history and what the results mean.

Other waterbodies with a report

These have one or two reports in a single year, which isn't enough history for a page of their own yet.

Source: California State Water Resources Control Board, official data, checked 24 October 2026. For today's conditions see the California HABs Portal map. No report doesn't mean a lake is safe: most water is only tested occasionally.