A series of storms have inundated California over the past few weeks, and the latest deluge is currently swelling rivers and reservoirs that are already spilling over. Vast swathes of California continue to be at risk for flooding as the storm runoff makes its way through river systems, the National Weather Service warns. Across California, residents were evacuated when local rivers flooded, including a small Northern California town that experienced a levee breach Monday night.
“So it appears that California may be due for another episode soon.”
The severe flooding may feel like a whiplash development in a state that’s been locked in drought for five years — and in an “exceptional drought” for three of them. Still, California has seen worse: massive floods have swept through the state about every 200 years for the past 2,000 years or more, climate scientists Michael Dettinger and Lynn Ingram recount in a 2013 article.
The most recent was a series of storms that lasted for a near-biblical 43 days between 1861 and 1862, creating a vast lake where California’s Central Valley had been. Floodwaters drowned thousands of people, hundreds of thousands of cattle, and forced the state’s government to move from Sacramento to San Francisco.
More than 150 years have passed since California’s last, great flood — and a team of researchers with the US Geological Survey have predicted what kind of damage a similar flood would cause today. Their simulation, called the ARkStorm, anticipates that a stretch of the Central Valley 300 miles long by 20 miles wide would be underwater. Cities up and down the coast of California would flood. Winds would howl 60 to 125 miles per hour, and landslides would make roads impassable.