State water officials have detected a harmful algal bloom in Lake Hemet, where the water appears green and cloudy with visible scum and algae along the surface, according to LAist.
The presence of the bloom raises concerns about potential toxins that can cause illness in humans and animals, leading authorities to advise keeping both people and pets away from the water and any shoreline deposits.
Young children and dogs are considered particularly at risk because they tend to swallow water while playing near or in the lake, as highlighted by the State Water Resources Control Board.
The current advisory for Lake Hemet follows a comparable warning issued for Big Bear Lake about a week earlier and will stay in place until further notice from state officials.
Harmful algal blooms occur most frequently in California during the period from late May through October, though they remain possible throughout the year, and the public can review an official state map to identify any additional reports nearby.
This report is based on coverage by LAist: https://laist.com/news/climate-environment/harmful-algal-bloom-shuts-down-swimming-in-riverside-countys-lake-hemet