The CRD has issued an advisory for Elk/Beaver Lake Regional Park.
Water samples from Elk Lake have tested positive for a type of blue-green algae that can produce cyanotoxins.
Authorities are advising visitors to avoid Elk Lake and to keep animals on a leash to prevent them from drinking or swimming in the water.
Algal blooms are known toxin producers and can be harmful to both humans and animals.
While unpredictable, blooms typically occur over the winter months from November to March.
The algae usually produce a visible blue-green sheen, which appears as surface scum. However, not all blooms are easy to see, and toxins can still be present in the water even if you cannot see them.
Ingesting water containing the algae may cause a range of symptoms, including headaches and abdominal pain in humans, and can lead to lethal liver damage in dogs.
An blue-green algae advisory remains in effect for Prior Lake and Lower Thetis Lake, located within Thetis Lake Regional Park.