SACRAMENTO  California faces the risk not just of devastating earthquakes but also of a catastrophic storm that could tear at the coasts, inundate the Central Valley and cause four to five times as much economic damage as a large quake, scientists and emergency planners warn.

The potential for such a storm was described at a conference of federal and California officials that ended Friday. Combining advanced flood mapping and atmospheric projections with data on California’s geologic flood history, over 100 scientists calculated the probable consequences of a “superstorm” carrying tropical moisture from the South Pacific and dropping up to 10 feet of rain across the state.

“Floods are as much a part of our lives in California as earthquakes are,” said Lucy Jones, the chief scientist for the United States Geological Survey’s multi-hazards initiative, adding, “We are probably not going to be able to handle the biggest ones.”

The geological survey estimates that such a storm could cause up to $300 billion in damage. The scientists’ models estimate that almost one-fourth of the houses in California could experience some flood damage from one.