The public is being advised to limit activities at Pyramid Lake — a popular swimming, boating, fishing and waterskiing destination — to avoid an algal bloom that has developed there.
The state Department of Water Resources issued the warning on Wednesday. It’s not clear when the bloom developed.
The lake, a man-made reservoir, is in northwest Los Angeles County off the 5 Freeway south of Gorman.
Contact with or ingestion of water affected by an algal bloom can expose people — and pets — to toxins, the department said. A high-concentration exposure can cause rashes, irritation, headache and gastrointestinal distress.
People are advised to avoid contact with the water, and to prevent dogs from going into or drinking the water.
Boaters should avoid going over mats of algae to prevent inhalation or ingestion of algae-infused water spray.
Consumption of fish caught in the lake is also not recommended.
Despite the warning, a handful of people were visiting the lake on Thursday. One mom said her family was warned about a "bacteria in the water" and was told they'd be swimming at their own risk.
She said they all planned to go home and shower.
More information on harmful algal blooms is on the State Water Resources Control Board’s website.