A blue-green algae warning has been issued for Thetis Lake.
Warnings were already in place at Durrance, Beaver and Prior lakes.
The warnings were made by the Capital Regional District in consultation with Island Health.
Algae blooms can produce toxins that can lead to headaches and abdominal pain in people, and fatal liver damage in dogs.
The blooms often appear as a blue-green sheen on the water.
People are advised to avoid contact with the algae and keep dogs leashed while at the lakes to prevent them from swimming or drinking the water.
