Hugh Pickens writes "The LA Times reports that California's "big one" may not be an earthquake at all, but a devastating megastorm that would inundate the Central Valley, trigger widespread landslides and cause flood damage to 1 in 4 homes costing more than $300 billion in property damage — four times that of a very large earthquake. A team of more than 100 scientists, engineers and emergency planners used flood mapping, climate change projections and geologic flood history to simulate a hypothetical storm so intense that it occurs only every 100 to 200 years with an "atmospheric river" of moisture from the tropical Pacific hitting California with up to 10 feet of rain and hurricane-force winds over several weeks. The simulation is based on a 45-day series of storms that started in December 1861 that turned the Sacramento Valley into an inland sea, pushing California into bankruptacy, forcing the state Capitol to be moved temporarily from Sacramento to San Francisco, and requiring Gov. Leland Stanford to take a rowboat to his inauguration. "We need to recognize that flooding here in California is as much of a risk as an earthquake," says Lucy Jones, chief scientist for the Geological Survey's Multi-Hazards Project. "These storms are like hurricanes in the amount of rain that they produce.""