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.

There are no current or active advisories.

Lake County Level

Updated: 1/18/2024


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

  1. Hazard
  2. Warning
  3. Watch


A harmful algal bloom is present, and extreme conditions exist

  • Signage should be posted at all public access locations
  • It is recommended that either a portion of the lake or the entire lake or zone, be closed to the public.
  • In some cases, the adjacent land should be closed as well. Actual setback distances will be determined on a site-specific basis, if necessary.
  • When partial closures (i.e., beach or cove) are issued, the remaining lake or zone area will carry a warning status.
  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