Between earthquakes, wildfires, landslides, and flash flooding, it seems California's perils know no bounds. Still, up until now, residents weren’t preoccupied with fears of being washed off the face of the earth. Enter the ARkStorm scenario.

Despite its biblical-sounding moniker, ARkStorm is a scientific model of the economic, social, and environmental impacts from a mammoth winter storm hitting the West Coast. The hypothetical results are nightmarish—more than 6,000 square miles of flooding, 1.5 million people displaced, $725 billion in damages and clean up costs, and decades before the state reaches anything like recovery.

The U.S. Geological Survey’s Multi-Hazards Demonstration Project used past weather events and climate models to project the “scientifically realistic” storm scenario, released earlier this month. Using data from two relatively recent (1962 and 1986) storms placed back to back, the project conjures up a megastorm that could produce precipitation levels not seen in hundreds of years.

“The model is not an extremely extreme event,” stated Lucy Jones, the project’s chief scientist, in a USGS release. “We think this event happens once every 100 or 200 years or so, which puts it in the same category as our big San Andreas earthquakes.”

The most recent events paralleling the theoretical storm occurred during the winter of 1861-1862. According to New York Times, that deluge filled California’s Central Valley, covered one-third of the taxable land, and left the state bankrupt. With millions of more residents to be affected today, a similar event would wreak havoc nationwide.

"If we had a catastrophic disaster that takes down the California economy, that is a problem of national significance," USGS Director Marcia McNutt told the Times.

Flood threats, however, have a hard time capturing imaginations in a place where earthquakes loom ever present.

“For a lot of people in California, we don't think of ourselves as being this flood-prone,” ARkStorm co-author and disaster recovery expert Laurie Johnson told the Sacramento Bee. "It's just too difficult to comprehend."

Perhaps for the average Californian—but not for the scientists, emergency planners, disaster researchers, and policy makers who make up the Multi-Hazards Demonstration Project. The project is in the business of using scientifically supported dark imaginings to motivate people to prepare. Its ShakeOut Earthquake Scenario helped thousands conceptualize a 7.8 magnitude earthquake on the San Andreas Fault. The hope is that ARkStorm will similarly raise public awareness and preparedness.

“The time to begin taking action is now, before a devastating natural hazard event occurs,” McNutt stated in the USGS release. “This scenario demonstrates firsthand how science can be the foundation to help build safer communities.”