You know how Southern California’s supposed to fall into the ocean someday when “The Big One” breaks the Golden State in half along the San Andreas fault? Of course you do. The storyline’s so prominent it was turned into a film and a bunch of people in Hollywood watched almost half a billion dollars fly their way.
Apparently, scientists are now saying rain (of all things) may bring even more destruction to Southern California one day. They’re calling it the ARkStorm (for Atmospheric River 1,000), intentionally avoiding calling it the much cooler-sounding “900-Year Flood” or “900-Year Storm,” to avoid instilling a false sense of security. Or perhaps they didn’t want to sound more apocalyptic than Bodhi’s 50-year storm prediction? In reality, the 900-year storm distinction is important because while experts are saying the storm will happen, they’re also not really saying it will happen…or at least when.
It’s kind of a dubious notation. According to a story in the LA Times, it’s actually just a nod to the probability of the ARkStorm occurring in a given year, which is 1 in 900 or .1%. It could happen two years in a row or it could happen once in almost a thousand years. So to summarize before digging any deeper, this storm may not happen. But it also might happen. If you are looking for something closer to an actual forecast and time frame, one UCLA climate scientist told the Times that the odds of seeing a flood in California at the magnitude of the state’s 1861-1862 event within the next 40 years “are about 50-50.”
So why all the fuss over a storm that’s being forecast with the reliability of predicting an earthquake?
On one hand, experts are bringing awareness to ARkStorm because Southern California’s existing infrastructure would be devastated by it, causing an estimated $725 billion worth of damage and displacing 1.5 million people in the Central Valley and Mojave Desert, according to the U.S. Geological Survey. Experts are also pointing out that our awareness of climate change is leading the Average Joe to assume events like this are less likely in a region that just climbed out of a massive drought, when in fact, climate change is making it more likely. In a warming world, they say we’ll see more “whiplashing” shifts between extremely dry and extremely wet periods. This partly touches on why the state just endured more than five years of drought followed by an El Niño and back-to-back exceptionally wet winters.
Everybody from the U.S. Army Corps of Engineers to the U.S. Geological Survey, a survey by UC Irvine researchers, researchers from UCLA and USC, and plenty more were cited in the Times report, outlining how “rain of biblical proportions” will cause dam breakages and other infrastructure failures and floods. One government study used computer models to estimate how a 900-year, 7,500-year, and 18,000-year storm of this magnitude would impact the state. In each case, they said catastrophic flooding could occur from Pico Rivera to Long Beach, which more or less extends the width of the Los Angeles area from East to West.