With a heat wave descending on the region, officials are warning of a blue-green algae bloom at Elk Lake, a popular swimming spot.
A similar warning has been in effect at adjacent Beaver Lake since October.
The Elk Lake alert was posted Friday at 2 p.m. by the Capital Regional District, in consultation with Island Health.
Blue-green algae can produce cyanotoxins, according to the CRD. People are advised to avoid contact and to keep animals on a leash to prevent them from drinking or swimming in the lake until the advisory has been lifted.
The algae usually produce a visible blue-green sheen, which appears as surface scum on the water.
But the alert says not all blooms are easy to see and toxins can still be present in the water even if you can’t actually see a bloom.
“These algae are known toxin producers,” says the CRD alert. “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.”