The Kansas Department of Health and Environment issued the warnings Thursday for Memorial-Veterans Lake in Great Bend and Old Herington City Lake in Dickinson County.
The agency also issued health advisories for seven lakes where blue-green algae have been detected. Advisories mean boating and fishing may be safe, but direct contact with the water is discouraged for people, pets and livestock.
Those lakes are Cedar Bluff Reservoir, Lovewell Reservoir, Milford Lake, Overland Park South Lake, Logan City Lake, Marion Reservoir and Winfield City Lake.
Blue-green algae can cause allergic reactions, diarrhea, vomiting and death. Animals can die from drinking too much tainted water.