As floodwaters surge along major rivers in the midwestern United States, a new study from Washington University in St. Louis suggests federal agencies are underestimating historic 100-year flood levels on these rivers by as much as five feet, a miscalculation that has serious implications for future flood risks, flood insurance, and business development in an expanding floodplain.
Washington University in St. Louis hydrogeologist Robert Criss, PhD, wasn’t particularly surprised by the spring floods on the Mississippi this year. Floods are becoming more frequent and more severe, he says. “We are increasingly constraining the river by building wing dikes and higher levees and then upping the ante by building in the river’s natural flood plains” Criss says. “There are far better ways to deal with this problem than have municipalities compete with one another to build the highest levee and fight over who has the right to be protected in times of distress.”