Keatons Lake Harmful Algae Bloom Advisory

Keatons Lake HAB Notice:

Status has been downgraded to

a SWIM ADVISORY due to

Harmful Algal Bloom (HAB) Conditions.

People may resume recreational activities such as boating or kayaking on Keatons Lake. All people and pets should use caution and avoid contact with water or any activity that could lead to ingesting water.

Residents choosing to use the lake during this period must do so at their own risk. Anyone who comes in contact with the water should promptly rinse with clean water. Anyone experiencing signs of illness after water contact should seek appropriate medical attention.

8/12/26 TREATMENT UPDATE:

Algaecide Treatment was applied successfully on Wednesday, August 12

• Pre-treatment samples were collected in the morning on 08/12/2026.
• Algae treatment was successfully applied on 08/12/2026
• Post-treatment samples were collected on 08/17/2026
• Pre-treatment 08/12/2026 sample results = PTOX average of 37,000 cells/ml
• Post-treatment 08/17/2026 sample results = PTOX average of less than 40 cells/ml
• Initial toxin samples indicated toxin concentration was well below the level of concern. 

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NEXT STEPS:

Water Quality Testing: Staff will take more follow-up samples. If consecutive sets of testing results are below concerning thresholds, the last warning level will be lifted, and the lake will return to normal status.

Continued Monitoring: Water sampling will continue throughout the response process until results indicate it is safe to lift the lake closure or any advisory conditions.

To learn more about our testing and what we are learning, go to the following link: Algae Science at Lake of the Woods

We will continue to keep the community informed as we monitor progress and await post-treatment results