Artificial levees on Mississippi River dramatically increased extreme floods

A new study has revealed for the first time the last 500-year flood history of the Mississippi River. It shows a dramatic rise in the size and frequency of extreme floods in the past century—mostly due to projects to straighten, channelize, and bound the river with artificial levees. The new research also uncovered a clear pattern over the centuries linking flooding on the Mississippi with natural fluctuations of Pacific and Atlantic Ocean water temperatures.