Map of Simcoe Muskoka


Contamination and availability of clean water

Key Messages
Number of Beach Advisories
Number of Confirmed Blue-Green Algae Events
Technical Notes

Key Messages

  • Climate change can impact water quality and water safety as a result of changing temperatures and weather patterns including drought and rainfall events.
  • Swimming advisories were posted at nearly half (46%) of public beaches that were sampled in Simcoe Muskoka in 2019.
  • An increasing number of blue-green algae blooms on bodies of water in Simcoe Muskoka are reported to the health unit each year

Number of beach advisories

  • There were 44 swimming advisories posted in 2019, at 24 out of 52 (46%) public beaches sampled across Simcoe Muskoka.
  • The number of beaches with posted swimming advisories varies each year, from 18 in 2016 to 27 in 2015.


Number of confirmed blue-green algae events per year

  • Eight blue-green algae blooms were reported in bodies of water across Simcoe Muskoka in 2019.
  • The number of blooms reported to the health unit has increased every year since 2014.
  • From 2009 to 2019, fourteen bodies of water (lakes and creeks) across Simcoe Muskoka experienced blue-green algae blooms, with between zero and eight blooms reported per year.


Technical Notes

The SMDHU and municipal and conservation authority partners monitor select public bathing beaches from June to August each year. A list of beaches included in the monitoring program and their current status is available through the health unit Inspection Connection webpage. Provincial park beaches, such as Wasaga Beach, are monitored by the Ministry of Environment, Conservation and Parks. Beach water quality results for these parks are available on their website.

When advisories are posted for a beach, they will remain in effect until follow-up testing of the water shows that the bacterial contamination is gone. Advisories may remain in effect after several samples.

SMDHU works in collaboration with the Ministry of Environment, Conservation and Parks to assess blue-green algae blooms.

Further Reading

For more about contamination and availability of safe water, see:

Page Last Updated: August 18, 2020.