RESOLVED: Blue-Green Algae Bloom at Prior Lake (Thetis Lake Regional Park)

Aug 29, 2019 (updated Oct 01, 2019, 10:07am)

As of Oct 1, the advisory has been lifted for Prior Lake. However, blue-green algae blooms are unpredictable and may occur at any time.

The CRD, in consultation with Island Health, has lifted a beach advisory for Prior Lake located at the north end of Thetis Lake Regional Park. Water samples collected indicated a “below detection limit” result for cyanotoxins. The extended absence of blue-green scum combined with test results are good indicators that the bloom is over. 

Park users are reminded to watch for the distinctive blue-green sheen, which can appear on the lake surface. Blue-green algae blooms are unpredictable and may occur at any time. These algae are known toxin producers. Ingesting water containing these cyanotoxins may cause a range of symptoms, including headaches and abdominal pain in humans, and can lead to lethal liver damage in dogs.

To learn more about blue-green algae visit these sites:

Healthlink BC

Health Canada

Thetis Lake Regional Park map (PDF)