Pomona Lake -- Public health update concerning harmful algae blooms at Kansas City District’s Pomona Lake
KANSAS CITY, Mo. – June 18, 2026 – The Kansas City District, U.S. Army Corps of Engineers, is actively responding to a toxic blue-green algae bloom at Pomona Lake in Osage County, Kansas.
Effective immediately, Michigan Valley Park’s swim beach is closed to the public until further notice. The beach will remain closed until water conditions improve, with USACE staff actively inspecting the beaches and monitoring water conditions.
Recent laboratory results indicate that dense hazardous algae blooms at Michigan Valley Park’s swim beach specifically, and other areas across the lake such as Pomona State Park, which is managed by the Kansas Department of Wildlife and Parks. The algal toxin (microcystin) levels in these concentrated areas exceeded the Kansas Department of Health and Environment criteria for recreational contact, placing all Pomona Lake beaches in “Warning Status.”
Pomona Lake staff have posted public health advisory signs in coordination with recommendations from state health agencies.
Blue-green algae blooms are unpredictable, can develop rapidly and may float or drift around the lake. Visitors are urged to exercise their best judgment, but if the water has surface scum, a paint-like appearance or is bright green, visitors should avoid all water contact.
Dogs are highly susceptible to algae toxins when frequently ingested, so we highly suggest pet owners exercise extreme caution. Pets that encounter water affected by a harmful algal bloom or eat dried algae along the shore may become seriously ill or die.
Drinking water and showers at campgrounds are safe and remain unaffected by the algae bloom. Boating and fishing also remain safe under current conditions; however, areas with concentrated algae or surface scum should be avoided. Anglers should always rinse caught fish with clean water, consume only the fillet portion, and discard all other parts. Hands should be washed thoroughly with clean water after handling fish taken from the lake.
Pomona lake staff will continue monitoring the algae bloom and work closely with the Kansas Department of Health and Environment to determine toxicity levels. Updated public health notices will be posted at the lake and provided on the Kansas City District’s public web and social media pages as new information becomes available.
For media inquiries, please contact: CENWK-PA@usace.army.mil.