Swim beaches closed at Pomona Lake
POMONA LAKE, Kan. – Kansas Department of Health and Environment and Kansas Department of Wildlife and Parks have issued a public health advisory due to blue-green algae, today, June 18, 2026, for several Kansas lakes including Pomona Lake in Osage County.
In response to the algae bloom, on June 15, U.S. Army Corps of Engineers had closed the swimming beach at Michigan Valley Park at Pomona Lake until further notice, and Pomona State Park announced on social media that its swimming beach is closed effective June 15.
A social media post by USACE announced, “Recent testing found elevated levels of algal toxins in concentrated areas near the beach and other areas downwind of the dam, prompting all Pomona Lake beaches to be placed in warning status.
“Our staff is actively monitoring conditions and working closely with the Kansas Department of Health and Environment to protect visitors and provide timely updates.”
KDHE advises Kansans to remain vigilant while engaging in activities taking place in or on the water, such as swimming, boating, and fishing.
A harmful algae bloom can look like foam, scum or paint floating on the water and be colored blue, bright green, brown or red. Blooms can develop rapidly; if the water appears suspicious or there is decaying algae on the shore, avoid contact and keep dogs away. These toxins can be absorbed by ingestion, inhalation of aerosols and even skin contact. Symptoms vary depending upon the type of exposure, such as direct contact, ingestion or inhalation, but can include rash, vomiting, diarrhea, fever, sore throat, and headache.
If people or pets come into contact with algae, rinse the area with clean, fresh water. Suspected algae bloom-related health incidents, whether human or animal, regardless of season, should be reported as soon as possible at kdhe.ks.gov/1163.
These blooms can shift quickly with wind and changing weather conditions. Pet owners are advised to use extra caution. Dogs are especially vulnerable to algae toxins, and ingestion can cause serious illness or death.
The federal and state agencies remind visitors that campground drinking water and showers remain safe, and boating and fishing can continue. Visitors should simply avoid areas with concentrated algae or surface scum. Anglers are encouraged to rinse fish with clean water, consume only the fillet portion and wash their hands thoroughly after handling fish.
Current active warning advisories in Kansas lakes, including Pomona Lake, are at Gathering Pond, Geary County; King Lake, Lyon County; Marion Reservoir, Marion County; Pomona Lake, Osage County (added June 18); Lake Afton, Sedgwick County; Wellington Lake, Sumner County (elevated June 18).
Active watch advisories are in effect at Augusta Santa Fe Lake, Butler County (added June 18); Herington City Lake, Dickinson County; Clinton Lake, Douglas County (added June 18); Jewell State Fishing Lake, Jewell County (lowered June 18); Jeffrey Energy Center Make-up Lake, Pottawatomie County (added June 18); Chisholm Ridge Ponds (Clearwater), Sedgwick County.
A warning status indicates that a harmful algae bloom is expected or present, and the following precautions should be taken:
- Signage should be posted at all public access locations.
- Inhalation of spray or aerosols may be harmful.
- Lake water is not safe to drink for pets or livestock.
- Lake water, regardless of blue-green algae status, should never be consumed by humans.
- Water contact should be avoided.
- Fish may be eaten if they are rinsed with clean water and only the fillet portion is consumed, while all other parts are discarded.
- Do not allow pets to eat dried algae.
- If lake water contacts skin, wash with clean water as soon as possible.
- Avoid areas of visible algae accumulation.
A watch status means that a harmful algae bloom is possible and may be present the following precautions be taken:
- Signage should be posted at all public access locations.
- Water may be unsafe for humans or animals.
- Avoid areas of algae accumulation and do not let people or pets eat dried algae or drink contaminated water.
- Swimming, wading, skiing and jet skiing are discouraged near visible blooms.
- Boating and fishing are safe. However, inhalation of the spray may affect some individuals. Avoid direct contact with water and wash with clean water after any contact.
- Clean fish thoroughly with potable water and eat fillet portion only.
Advisories are lifted when cell densities and toxin concentrations dissipate to levels below the watch thresholds.
For information on blue-green algae and reporting potential harmful algal blooms, see kdhe.ks.gov/harmful algae bloom. For information about Pomona State Park, call 785-828-4933, or USACE Pomona Lake, call 785-453-2201.
USACE graphic.
