Boaters launch from Castaic Lake Boat Launch Ramp at Castaic Lake, a reservoir formed by Castaic Dam on Castaic Creek, in the Sierra Pelona Mountains of northwestern Los Angeles County, California. Photo taken May 11, 2023.

Today, the Department of Water Resources urges people to avoid physical contact with water at Castaic Lake in Los Angeles County until further notice due to the presence of blue-green algae.