Pomona Lake harmful algae advisory: KDHE moves to LIFT on July 2

Kansas health officials have updated the blue-green algae public health advisory for Pomona Lake in Osage County. KDHE moved Pomona Lake to “LIFT” on July 2, but the U.S. Army Corps of Engineers previously ordered the swim beach at Michigan Valley Park closed “until further notice” and said it would remain closed until water conditions improve.

Pomona Lake advisory timeline: June 18 → June 26 → July 2

KDHE and the Kansas Department of Wildlife and Parks placed Pomona Lake on the public list as a “WARNING” on June 18. The archived list published June 26 still showed Pomona Lake under “WARNING.”

On July 2, KDHE updated the advisory status and moved Pomona Lake to “LIFT.”

What KDHE means by “WARNING” vs. “LIFT” (what residents should do)

KDHE says a Warning means a harmful algae bloom is expected or present. During a WARNING, KDHE’s precautions include:

• Post and follow signage at public access locations
• Avoid water contact (inhalation of spray/aerosols may be harmful)
• Lake water is not safe to drink for pets or livestock, and lake water should never be consumed by humans
• Do not allow pets to eat dried algae
• Keep pets away from visible algae accumulation
• If exposure happens, rinse with clean fresh water

KDHE explains that advisories are lifted when cell densities and toxin concentrations dissipate to levels below the Watch thresholds. Even with a LIFT status, KDHE says Kansas residents should remain vigilant: if water looks suspicious or there is decaying algae on shore, avoid contact and keep dogs away.

KDHE also directs residents to report suspected HAB-related health incidents involving humans or animals as soon as possible.

Why the June 18 Michigan Valley Park swim-beach closure still affects plans

Separate from KDHE’s advisory list update, USACE (Kansas City District) announced an immediate closure of Michigan Valley Park’s swim beach on June 18 “until further notice.” USACE said the beach would remain closed until water conditions improve while staff inspect and monitor conditions.

USACE tied the closure to toxic blue-green algae findings: it said algal toxin (microcystin) levels in concentrated areas exceeded KDHE criteria for recreational contact, and that this placed Pomona Lake beaches in a “Warning Status.”

USACE also provided practical guidance on what it considers generally okay vs. what to avoid:

• Drinking water and showers at campgrounds: safe and remain unaffected
• Boating and fishing: remain safe under current conditions, but avoid areas with concentrated algae or surface scum
• Fish handling: rinse caught fish with clean water, consume only the fillet portion, discard other parts, and wash hands thoroughly after handling fish
• Swim access: follow posted closure information at Michigan Valley Park

What to do today if you’re heading to Pomona Lake (especially with pets)

• Check before you go: look for the latest KDHE advisory list status and any posted signs at Pomona Lake access points.
• For swimming: treat the Michigan Valley Park swim beach as closed unless on-site postings indicate it has reopened; USACE’s closure was “until further notice” pending improving water conditions.
• For dog owners: keep pets out of the water and away from algae/scum along the shore; do not allow pets to eat dried algae.
• If contact happens: rinse the area with clean fresh water, and report any suspected HAB-related health incident involving a person or animal as soon as possible.
• If you see a bloom: avoid suspicious foam/scum/paint-like water and stay away from visible algae accumulation.

The key takeaway for Lyndon-area families is that KDHE’s advisory status changed to LIFT on July 2, but USACE’s June 18 swim-beach closure was issued separately based on ongoing water-condition testing and posted access rules.

Sources

• KDHE News Flash (June 18, 2026): Pomona Lake added to WARNING list for blue-green algae
• U.S. Army Corps of Engineers (Kansas City District) news release (June 18, 2026): Michigan Valley Park swim beach closure
• KCLY Radio (June 22, 2026): Local reporting on Pomona Lake algae advisory + beach closures