ARkStorm: California's other, much bigger, 'Big One'

FRESNO, Calif.

As Californians we have long been told "The Big One" is coming. A reference to the massive earthquake expected somewhere along the San Andreas Fault. But a much bigger, "Big One" may also be brewing. It won't be an earthquake, but a flood. It's happened before and the experts assure us, it will happen again.

Hurricane Sandy is seen by many, as a warning of things to come across the country. While hurricanes aren't expected here, the Central Valley does get flooded.

Ken Austin heads Fresno County's Department of Emergency Services. He told Action News, "Here in Fresno County as you know the biggest issues are severe storms and flooding along our rivers."

Ken, and his counterparts around the state have also been warned to prepare for a massive flood. Two scientists from the US Geological Survey, Dale Cox, and Mike Dettinger are warning Californians to get ready for what they call the ARkStorm, after the biblical storm that floated Noah's big boat.

Mike Dettinger explained, "These things have happened before, there's no reason to believe they won't happen again, it's just a matter of time."

The last ARkStorm hit California back in 1862, as this video from the USGS explains.

Excerpt from the video: "California, 1862. It's been raining for almost 45 days. 300 miles of the Sacramento and San Joaquin Valley have been flooded."

Massive storms like this hit every one or two-hundred years, fed by atmospheric rivers of wet air.

Mike Dettinger added, "They extend in some cases clear across, almost to Japan."

Major flooding hits somewhere in California on a regular basis. Most are caused by these atmospheric rivers. The last really big storm that hit the Central Valley was in 1997. Lasting just five days, it caused widespread damage, and threatened to be much worse.

"If the rains had continued for a few more hours, we would have gotten into really serious problems on a number of our reservoirs," Mike Dettinger said. "We would have had overtopping of reservoirs."

The USGS is helping state and local governments to get ready for these big storms. Ventura County, no stranger to mudslides and floods is holding an ARkStorm simulation. County public works director Jeff Pratt knows what's at stake.

"If a storm like this occurs the damages are going to far exceed any earthquake along the San Andreas Fault," Jeff Pratt said. "If we're not prepared, something close to a trillion dollars in damage."

With heavy equipment outside for effect, inside, county workers get an idea of what kinds of communications and other problems they will encounter with the real thing.

Dale Cox explained, "How many houses are going to be flooded? What are the impacts to the roads to the pipelines and then what is the impact to the people in their homes what is the economic impact, so we're taking it all the way through. These are the most comprehensive scenarios ever created."

Fresno County and other Valley counties have held similar flood disaster scenarios.

"I won't say we have imagined the whole Valley flooding scenario for us," Ken Austin said. "Certainly things could occur that we are not anticipating. So, the better my family is prepared and your family is prepared the better able they will be to weather the storm."

We don't know if an ARkStorm will happen in the next month, or the next decade, fortunately any big storm in the pacific will be spotted days in advance, giving communities and individuals some time to prepare or evacuate.

The US Geological Survey is encouraging local governments and individuals to begin thinking about what they would do in the event of a big disaster. They say it's always a good idea to have something set aside, food, water, and batteries. Ready to deal with the unexpected.

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