Toxic algae in Lake County, California
23 lakes and waterways have harmful algal bloom reports in California's official data.
Lakes with bloom history
| Lake | Years with reports | Most recent |
|---|---|---|
| Clear Lake | 11 | 2026 |
| Lake Pillsbury Hydrologic Subarea | 3 | 2021 |
| Lake Pillsbury | 4 | 2026 |
| Upper Blue Lake | 3 | 2024 |
| Lower Blue Lake | 3 | 2024 |
| Blue Lake | 2 | 2020 |
| Blue Slides Creek | 2 | 2022 |
| Forbes Creek | 2 | 2024 |
| Putah Creek | 2 | 2026 |
| Stanton Creek | 2 | 2022 |
Other waterbodies with a report
These have one or two reports in a single year, so there isn't enough history for a page of their own yet.
- Bear Creek (2024)
- Blue Lakes (2022)
- Borax Lake (2018)
- Copsey Creek (2024)
- Hidden Valley Lake (2025)
- Highland Creek (2023)
- Highland Springs Reservoir (2024)
- Kelsey Creek (2021)
- Manning Creek (2022)
- Middle Creek (2026)
- Seiger Canyon Creek (2022)
- St Helena Creek (2022)
- Welch Creek (2026)
Source: California State Water Resources Control Board, official data. For current conditions see the California HABs Portal map.