California
Toxic algae in Plumas County lakes
27 lakes and waterways in Plumas County have harmful algal bloom reports in California's official data. The most recent entry is for Lake Almanor: There are no bloom reports for Lake Almanor in the last 30 days of California's data. The most recent was a Caution advisory on 8 September 2026 at Cove near Lakeview Terrace. Lake Almanor and Rock Creek 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.
- Florentine Arm Jamison Creek 2022
- Frenchman Lake 2022
- Frenchman Reservoir 2020
- Grizzly Creek 2025
- Jamison Creek 2026
- Lake Kaweah 2020
- Lily Lake 2020
- Little Grizzly Creek 2022
- Little Last Chance Creek 2021
- Mill Creek 2026
- Nelson Creek 2022
- North Fork Willow Creek 2025
- Red Clover Creek 2021
- Round Valley Reservoir 2023
- Spanish Creek 2026
- Stony Creek 2026
- Yellow Creek 2021
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.