Lake by lake, from official state data

Kansas algae blooms

17 Kansas lakes are under a KDHE public health watch or warning, based on KDHE's advisory list checked on 24 October 2026. KDHE has tested 184 lakes and ponds since 2010, usually after a bloom was reported, and 53 have reached advisory levels in three or more years.

Open the Kansas algae bloom map

184lakes and ponds tested, 2010 to 2026

145lakes with a full history page

53lakes at advisory levels in three or more years

Current advisories in Kansas

KDHE public health watches and warnings in effect, checked 24 October 2026. Official list: KDHE algae bloom map.

Lakes with the most bloom years

Lakes where toxic algae comes back year after year.

Lake	County	Years with blooms
Marion Reservoir	Marion	14
Melvern Outlet Pond	Osage	11
South Park Lake	Johnson	10
Milford Lake	Geary	9
Webster Lake	Rooks	8
Lake Afton	Sedgwick	8
Lake Shawnee	Shawnee	8
Marion County State Fishing Lake	Marion	8
Norton Lake	Norton	8
Lovewell Lake	Jewell	7
Gathering Pond	Geary	7
Harvey County East Lake	Harvey	7
Memorial Park Lake	Barton	7
Hiawatha City Lake	Brown	7
Overbrook City Lake	Osage	7

Kansas counties

Every county with at least one lake or river in the state's bloom records.

How Kansas tracks toxic algae

The Kansas Department of Health and Environment (KDHE) collects bloom reports from its own staff, local agencies and the public. Its data is updated as samples come in, with advisories reviewed through the April to October season. This site groups those reports by lake so you can see each lake's latest entry and its full history in one place.

Not every lake is tested, and lakes that are tested are usually checked only some of the time. A lake with no report may simply not have been looked at, so always follow posted signs and avoid green, scummy or discoloured water. View the source data.