Is the lake safe?
Toxic blue-green algae reports and bloom history for 963 lakes in New York, California and Florida, from official state data.
New York
352 lake pages · 247 with blooms in 3+ years
Latest entry 19 November 2025
Florida
293 lake pages · 77 with blooms in 3+ years
Latest entry 30 December 2025
California
318 lake pages · 168 with blooms in 3+ years
Latest entry 19 October 2026
Latest reports
- Trout Creek
California · Bloom reported - Eagle Lake
California · Bloom reported - Hume Lake
California · Bloom reported - Prosser Reservoir
California · Bloom reported - Spring Lake
California · Bloom reported - Carter Creek
California · Bloom reported - Stafford Lake
California · General awareness - Salton Sea
California · Bloom reported - New Bullards Bar Reservoir
California · Bloom reported - Santa Ana River
California · Algal mat general awareness sign - Lake Oroville
California · Bloom reported - Arnot Creek
California · Bloom reported
How to read this site
Each lake page shows the most recent entry in the state's published data, every year a bloom was recorded, and recent results. States test only some lakes, and only some of the time. No advisory doesn't mean the water is safe, so always check posted signs and avoid green, scummy or discoloured water.