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Update: Blue-green algae and GRCA reservoirs

The presence of blue-green algae has been observed at Conestogo Lake reservoir. While the beach area and boat launch are both closed for the season, the GRCA has notified the Ministry of the Environment, Conservation and Parks as well as the local health unit, and signage is being posted. The previously confirmed blue-green algae blooms at Belwood Lake and Woolwich reservoirs are still present. 

Conservation Area visitors, recreational users and cottagers should be aware that when blue-green algae is visible the precautions noted below should be taken:

  • Keep children and pets away from the algae.

  • Avoid contact with the algae.

  • Do not eat fish from the lake.

  • Do not use the water for drinking or any other purpose.

  • Boating is allowed, where permitted, but boaters and recreational users should avoid touching the algae.

  • Do not swim in areas where you see scum, or it is accumulating along the shoreline.

Blue-green algae thrive on nutrients from fields and lawns that find their way into local waterways and reservoirs during heavy rainfall and spring melts and cause their populations to grow rapidly, forming blooms or scum on the surface of the water. Some varieties of blue-green algae can produce toxins that are harmful to both people and pets.

When an algal bloom starts to grow, a noticeable green or brown scum will form on the surface of water bodies and the water look like green or bluish-green pea soup. Once blue-green algae are in full bloom, it may look like spilled ‘paint’ along the shoreline. A new blue-green algal bloom often smells like fresh cut grass, while an older bloom can smell like rotting garbage.

More information about blue-green algae

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Media Contacts:

Lisa Stocco, GRCA Manager, Strategic Communications and Environmental Education
Phone 519-621-2763 x2316  |  Email lstocco@grandriver.ca

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