Biggest Floods in History—Does Mississippi Make the List?
See how current flood compares with epic deluges of past two million years.
The most destructive river flood in U.S. history, the 1927 event moved about 2 million cubic feet (65,000 cubic meters) of water—enough to fill about 26 Olympic-size swimming pools—every second. (See pictures: "Mississippi River at Its Worst.")
"The numbers are still provisional, but [the current flood's peak water discharge] looks to be about the same" as the 1927 flood, said James O'Connor, a hydrologist with the U.S. Geological Survey (USGS).
Still, the 1927 and 2011 Mississippi River floods remain just drops in the bucket compared to other known freshwater "megafloods" around the world, according to O'Connor.
The scientist co-authored a 2004 USGS report that ranked all freshwater floods known