Is the lake safe?

Florida

Toxic algae in Hillsborough County lakes

31 lakes and waterways in Hillsborough County have harmful algal bloom reports in Florida's official data. The most recent entry is for Lake Thonotosassa: Florida's most recent sample from Lake Thonotosassa, on 29 December 2025 at Lake Thonotosassa - South Shore, found a bloom and microcystin toxin measured 1.7 µg/L, below the US EPA swimming advisory level of 8 µg/L.

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: Florida Department of Environmental Protection (DEP), official data, checked 24 October 2026. For today's conditions see the DEP Algal Bloom Dashboard. No report doesn't mean a lake is safe: most water is only tested occasionally.