California’s Biggest Risk is a Storm, Not Earthquakes

Hmm, how’s this for some uplifting news?

Could insurance companies be hit by a Californian super-storm on a Biblical scale? The US Geological Survey believes so, and has created a hypothetical scenario for emergency planners.

What kind of storm are we talking about? Up to 10 feet of rain and $300 billion of damage. Here’s more from Business Green:

Created by combining prehistoric flood history with climate change projections and recent flood maps, the super-storm scenario estimates flood damage to almost a quarter of the houses in California.

ARkStorm stands for ‘Atmospheric River 1000’. An atmospheric river is a super-storm that is different from a hurricane because the wind and the rain are decoupled, explained Lucy Jones, chief scientist for the USGS Multi-Hazards Demonstration Project. As a result, the bulk of the damage from super-storms tends to come from flooding.

“The biggest storm in the history of California happened in 1861-2,” Jones said. “It rained for 45 days, created a 300 mile-long lake through the central river, and changed the economy of California because so many cattle were killed that the ranching industry came apart.” One-third of taxable land was lost, she added.

Storms of this magnitude happen every 100-200 years, which puts it in the same category as large earthquakes from the San Andreas fault.

However, unlike an earthquake, the storm would be a statewide event, Jones said, which would create around four times as much damage.

“Californians are well aware of the risk from earthquake, but they are unaware of the risk from floods,” she concluded.

Sounds like trouble… let’s hope it doesn’t happen, but given the extreme weather we are seeing these days from climate change and USGS predictions, seems like something to be aware of.

Photo Credit: vgm8383