… I live in Davis, California and sometimes wonder if we Davisites are too complacent in recognizing that a similar or even bigger flood event might happen to us.  At some point, we may experience a megaflood in the Central Valley … Indeed, the whole landscape of the Central Valley is shaped by major flood events. … Sediment cores show such floods have occurred once every 150 to 200 years … The last such flood, a small one by geologic standards, was in 1861-1862 when the Central Valley became an “Inland Sea” … Sacramento was underwater and the newly elected governor famously had to be rowed from his house to the building where he was sworn in, on the second floor.