Toxic algae was found in Lake Del Valle near Livermore on Monday, prompting the park district to close the lake to swimming for people and dogs, according to the East Bay Regional Park District.
It's the latest lake in the district to have toxic blue-green algae blooms.
The algae has been found in Quarry Lakes in Fremont and Lake Chabot in Castro Valley. Earlier this year, the blooms were found in Lake Temescal in Oakland and Lake Anza in Berkeley. While the blooms have since
cleared in those lakes, they remain closed for the season until April.
Exposure can cause skin irritation, diarrhea, vomiting and headaches, according to the park district.
Lake Del Valle is the largest lake in the East Bay Regional Park District at five miles long. Boating and fishing are still allowed and the fish are edible so long as they are rinsed and their guts are removed,
according to the park district.
The park is also open for other activities, such as camping and picnicking.