Catastrophic flooding could impact as many as 1 million people in the Los Angeles region, causing water infrastructure such as dams to fail, according to a Los Angeles Times report.
Called an ARkStorm, the mega flood event could last for weeks and cause damage up to $725 billion statewide.
Current analysis by the U.S. Army Corps of Engineers showed the Whittier Dam, which is 60 years old, could fail in the event of a massive rain event, the Times reported.
The corps is seeking $600 million in federal funding to update the earthen dam, which spans three miles.
Daniel Swain, a UCLA climate scientist, criticized the Army Corps’ forecast data, saying that it needs an update. A flood in California in 1861-1862 brought 36 inches of rain to Los Angeles.
It was previously thought that type of mega flood would occur only every 1,000 to 10,000 years. New research is challenging that, Swain said.
“A newer study suggests that chances of seeing another flood of that magnitude over the next 40 years are about 50-50,” Swain told the Times.
If the dam failed, the damage would extend over a broad swath of Los Angeles County from Pico Rivera to Long Beach.