Public Advisory: Blue-Green Algae Dissipated (Three Mile Lake) (Updated: December 4, 2025)

Muskoka Lakes, ON – August 14, 2025 — Updated December 4, 2025 — The Township of Muskoka Lakes is advising residents and visitors that the Simcoe Muskoka District Health Unit (SMDHU) has confirmed the presence of blue-green algae impacting the North Shore Road area of Three Mile Lake has dissipated.

Blue-green algae can produce toxins that may pose health risks to people and pets. Conditions on the water can change quickly; blooms may appear, move, or dissipate with wind and weather. The Township will continue to share updates from SMDHU as they become available.

When a bloom is confirmed:

• Avoid contact with water where algae is visible; keep children and pets away.
• Do not drink, cook with, or brush teeth with lake water from the affected area. Boiling does not remove toxins. Use an alternate safe water source (e.g., bottled water).
• Do not fill pools or spas with lake water.
• If you choose to eat fish from the lake, consume only properly cleaned fillets and avoid organs.
• If you develop symptoms after contact with affected water (e.g., skin, eye, throat irritation; stomach upset), contact your healthcare provider.

If you suspect a blue-green algae bloom, contact the Ministry of the Environment, Conservation and Parks (MECP). Incidents can be reported online or Toll-free: 1-866-MOE-TIPS (663-8477). 

For information on the potential health risks associated with blue-green algal blooms, please contact Health Connection at 705-721-7520 or toll-free at 1-877-721-7520 to speak with a public health inspector..

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Media Contact
Township of Muskoka Lakes – Communications
communications@muskokalakes.ca
705-765-3156