May 7, 2019

Record floods worsened by warming and levees. 'How idiotic'

Davenport, IA
Daniel Cusick
An aerial view of Davenport, Iowa, which remains flooded after a temporary levee broke. Credit: DRONE, Newscom
An aerial view of Davenport, Iowa, which remains flooded after a temporary levee broke. Credit: DRONE, Newscom

A snow-slogged and rainy springtime in the Midwest has helped drive the river to heights not seen since the Great Flood of 1993.

A growing body of scientific evidence, including last year's National Climate Assessment, made clear that "increasing precipitation, especially heavy rain events," across the Midwest "has increased the overall flood risk, causing disruption to transportation and damage to property and infrastructure."

And in large river basins like the Mississippi and Missouri rivers, the report found that floodwaters could inundate more populated areas, "resulting in drinking water contamination, evacuations, damage to buildings, injury, and death."

Olivia Dorothy, is the Associate Director of American River’s (a nonprofit) Upper Mississippi River Basin campaign, American Rivers

Dorothy attributed the high water to "predictable changes in weather patterns" forecast by climate experts, along with a very large snowpack in Minnesota, Wisconsin and northern Iowa that saturated soils in the Upper Midwest when it melted.

Robert Criss [an emeritus professor of earth and planetary sciences at Washington University in St. Louis] said the Mississippi has become "more flashy," essentially rising and falling more erratically, in recent decades, elevating flood risk…

Criss stopped short of placing too much emphasis on climate change. For him, people are causing a different set of problems: navigation and commercial development up and down the Mississippi.

"This is heavy rain, there's no question about it, and that's going to aggravate the problem," he said.

Criss places much of the responsibility for the more persistent Mississippi flooding at the feet of elected officials and river managers who have allowed the floodplain to be converted for farmland and residential and commercial development. They have done so on the promise that levees and other flood control structures will keep people and property safe, even as the Mississippi has shown time and again it respects no such boundaries. 

"Our problem isn't not enough river control. It's too much river control," said Criss, who has frequently clashed with the Army Corps of Engineers over river channelization and flood control measures. 

"We've messed with the rivers too much, and we've got to start going backwards and lower some of these levees to allow the river to spread out," Criss added. "A few old river cities, sure, they need their floodwalls. I get that. But trying to wall off both sides of the river for a thousand miles — how idiotic."