California has experienced severe floods throughout the 20th Century, including in 1969, 1986, and 1997. But a flood from farther in the past – the Great Flood of 1862 – is being eyed by researchers as the threat to California grows by the day.
Though it occurred 160 years ago, the flood – deemed a "megastorm" for its historical rainfall covering huge swaths of the state – illustrates that the threat is not merely theoretical.
