Kansas
Toxic algae in Johnson County lakes
19 lakes and waterways in Johnson County have harmful algal bloom reports in Kansas's official data. The most recent entry is for Amesbury Lake: Kansas has a public health watch in effect for Amesbury Lake, last updated on 23 October 2026. The latest published sample, on 5 October 2026, was at Watch level (microcystin 0.65 µg/L, 109,927 cyanobacteria cells/mL). Amesbury Lake, Kingston Lake and Roses Lake and 2 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.
- Amesbury Lake Public health watch
- Kingston Lake No current advisory
- Frisco Lake Public health warning
- Gardner Lake No current advisory
- Kill Creek Park Lake Public health warning
- Wilderness Lake No current advisory
- Edgerton City Lake No current advisory
- Roses Lake No current advisory
- South Park Lake No current advisory
- Summercrest Lake No current advisory
- Cedar Lake No current advisory
- Meadowbrook Park Lake No current advisory
- Tomahawk Park Lakes No current advisory
- Deanna Rose Farmstead Fishing Pond No current advisory
- Antioch Park Lakes No current advisory
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.
- Hidden Woods Park Pond 2023
- Lenexa City Lake 2022
- Mize Lake 2019
- Shawnee Mission Lake 2026
Source: Kansas Department of Health and Environment (KDHE), official data, checked 24 October 2026. For today's conditions see the KDHE algae bloom map. No report doesn't mean a lake is safe: most water is only tested occasionally.