California
Toxic algae in Riverside County lakes
32 lakes and waterways in Riverside County have harmful algal bloom reports in California's official data. The most recent entry is for Harveston Lake: There are no bloom reports for Harveston Lake in the last 30 days of California's data. The most recent was a Caution advisory on 18 August 2026 at lake-wide. Harveston Lake, Canyon Lake and Lake Elsinore and 5 more 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.
- Harveston Lake Caution
- Diamond Valley Lake Caution
- Jenks Lake Bloom reported
- Havasu Lake Bloom reported
- Canyon Lake Bloom reported
- Lake Elsinore Bloom reported
- Lake Hemet Caution
- Lake Evans Caution
- Reflection Lake Caution
- Lake Perris Bloom reported
- Salton Sea Caution
- Mystic Lake Caution
- Santa Ana River Bloom reported
- Lake Skinner Bloom reported
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.
- Baker Pond 2022
- Barton Creek 2026
- Ben Williams River Wildlife Refuge 2022
- Cole Creek 2024
- Gunnerson Pond 2022
- Indian Creek 2026
- Lake Cahuilla 2024
- Murrieta Creek 2023
- North Fork San Jacinto Creek 2024
- Other Lake Or Reservoir 2018
- Plunge Creek 2019
- Private Pond 2026
- San Jacinto River 2024
- Stone Creek 2026
- Strawberry Creek 2024
- Temecula Creek 2023
- Temescal Creek 2024
- Vail Lake 2024
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.