Harmful Algal Blooms

Harmful algal blooms (HABs) monitoring is concurrent with the water recreation season, April 1 through October 31. The public is encouraged to stay informed year-round because exposure through contact or ingestion can cause illness for animals and humans. Blooms are unpredictable. They can develop rapidly and may move across a water body due to wind or water current, so lake visitors must use their best judgment.

Current Advisories

The three advisory levels are Watch, Warning and Hazard. Current advisories are listed in the table or view the current lake advisories map. To hear current advisories, call the HAB hotline at 855-HAB-LAKE or 855-422-5253.

Lake County Level Notes
Marion Lake Marion Warning Added May 25
Norton Lake Norton Warning Added May 25
Big Eleven Lake Wyandotte None Lifted May 25
Melvern Lake Osage None LIfted May 25
Pomona Lake Osage None Lifted May 25


Click through the tabs to learn what to do during a Harmful Algal Bloom advisory.

  1. Watch
  2. Warning
  3. Hazard


A harmful algal bloom is possible and may be present

  • Signage should be posted at all public access locations.
  • Water may be unsafe for humans and animals.
  • Avoid areas of algae accumulation.
  • Do not let people/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 well with potable water and eat fillet portion only.
  1. Use Caution
  2. General Information

For Animals & Humans

Exposure to HABs, whether through contact or ingestion, can cause illness and even death in animals and humans. Do not allow livestock, pets, or working animals such as hunting dogs to drink from HAB-affected waters, eat dried scum on shorelines, or lick their fur after exposure.

Zoned Lakes

Some lakes have more than one management area, or "zone." Click the images to view or download and share the full-sized zone maps for the following lakes:

Milford Lake Zones (PDF)

Milford Lake Zones

Perry Lake Zones (PDF)

Perry Lake Zones

Tuttle Creek Zones (PDF)

Tuttle Creek Zones