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Winter Storms in California that Could Cause $300 Billion in Damage

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Detailed Description

Beginning on Christmas Eve, 1861, and continuing into early 1862, an extreme series of storms lasting 45 days struck California. The storms caused severe flooding, turning the Sacramento Valley into an inland sea. The storms were caused by atmospheric rivers, a hurricane-like phenomenon that occurs on the west coast.  A storm comparable to that of 1861-1862 could occur again. To prepare for a storm of this magnitude and greater, a team of atmospheric scientists, U.S. Federal and State agencies and academic institutions have created a model scenario, called ARkStorm, for understanding the damage and impacts from a California winter storm. The scenario estimates that the State's flood protection system would be overwhelmed and more than $300 billion in damage would result. Kara Capelli spoke with Lucy Jones, chief scientist for the USGS Multi-Hazards Demonstration Project, about the results of this emergency-preparedness scenario.




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Kara Capelli: Welcome to USGS CoreCast. I'm your host, Kara Capelli.

And I'm here today with Lucy Jones, the chief scientist for the Multi-Hazards Demonstration Project. Lucy started this project about four years ago to demonstrate how hazard science can increase a community's resilience to natural hazards.

We're here today to talk about ARkStorm, the second full disaster scenario created by the Multi-Hazards Demonstration Project.

Lucy, thank you so much for being here today.

Lucy Jones: It's great to be with you. Thank you for having me.

Kara Capelli: So we're here today to talk about the ARkStorm scenario. What is a n ARkStorm?

Lucy Jones: ARkStorm stands for Atmospheric River 1000. Meteorologists have come to understand that the phenomena of atmospheric rivers bring in the largest amount of rain, especially to California. We get very hard hit here in California. If you look at the map of the United States, for the very highest rainfall events, you see the hurricane states and  California. The ARkStorms are different from hurricanes and that they're primarily winter phenomena and the wind and the rain are not as well coupled. So, they're primarily flooding events but they're capable of huge levels of damage, and that's what we wanted to look at in this project.

Kara Capelli: When was the last time an ARkStorm happened?

Lucy Jones: The biggest storm in the history of California happened in 1861-62. It rained for 45 days, created a 300-mile long lake though the Central River, changed the economy of California because so many cattle were killed that the ranching industry basically came apart, and lost one-third of the taxable land of California. So it was a huge economic event. Since that time, we've had somewhat smaller storms but still very devastating that were atmospheric river storms. The ones that people are most likely to remember were in  Northern California in 1986 and 1997 and in Southern California in 1969.



Kara Capelli: So tell us a little bit about this project then.

Lucy Jones: The ARkStorm scenario is a model from the physical sciences of just what can happen in this type of events. And then, a physical model with the engineers of what the physical consequences are from these events. And then, a social model of what happens to our society that we get with economists and social scientists. So it's a complete picture of what that storm will do to the social and economic systems of California.

Kara Capelli: So how likely is it that an ARkStorm of the size that you just described could happen to California?

Lucy Jones: OK, well, the last time we saw it was in 1861, so 150 years ago. We have geologic evidence through flood deposits that even bigger storms than 1861 happened about once every 300 years. We have six events in 1,800 years of geologic record. So we think this event happens, you know, once every hundred, 200 years or so, which puts it in the category as our big San Andreas earthquakes.

Kara Capelli: What have been the results of this project?

Lucy Jones: This atmospheric river that we modeled is similar to 1861-62, causes devastating losses to California. We see coastal erosion and wave damage along the coast can be a significant issue. The largest damages come from flooding and the modeling end up estimating that almost one quarter of the houses in California would have some flood damage from the storm. So it's an incredibly widespread flooding damage. Wind damage is very significant but more towards the eastern part of the state. It has less consequence on the flooding. The flooding damage, direct flooding damages, works out at almost $400 billion in damage. By comparison to wind damage, it's $5 billion. Landslides are extensive, about a billion dollars in damage.



And then, in addition, there would be business interruption that will be in the hundreds of billions of dollars. We also took a look at what the environmental consequences of the event could be and those aren't directly incorporated in the economic losses but they're also very significant. Large numbers are, for instances, animal feeding lots are located within the flood plains. And then we're talking about animal carcasses entering the water supply. There are petroleum refineries, lots of waste water processing facilities. So there's very wide spectrum of environmental damages that could also happen because of the event.

The bottom line ends up being because the storm is a statewide event where an earthquake in general, probably, is not going to be a few hundred miles long, we subject many more people to the impacts of the one event and the total losses were estimated to be about four times the economic losses of a big San Andreas earthquake. That means that for a storm of about the same probability of occurrence as the earthquake, we're seeing four times as much damage.

Californians are very aware that they face a risk from earthquakes. They are less aware of the risk they face from floods.

Kara Capelli:  So it sounds like Californians may have a pretty big problem on their hands here. How might this affect the rest of the country?

Lucy Jones: It is not just a Californian problem. For one thing, California's about 15% of the nation's population. But it's also one of our big economic engines and so as we disrupt the economic system of California, that's going to have impacts across the country. There's probably going to be disruption to ports and transportations systems. And much of the imports of the United States come through the California ports. So this won't just be a California problem. The economic impact will be felt across the country.

Kara Capelli: Well, Lucy. Keep up the good work. Thank you so much for being here today.

Lucy Jones: Thanks for having me.

Kara Capelli: For more information on this topic and project as well as historic images of past ARkStorms, you can visit

For USGS CoreCast, I'm Kara Capelli. CoreCast is a product of the US Geological Survey, Department of the Interior.

Thanks for listening.


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