Most of us living in the Mississippi River valley did not look at Global Climate Change as a cause of all that rain that poured down on the Midwest and caused the Flood of 1993. It was not an issue for the folks who examined the causes of the flood when they issued Sharing the Challenge early in 1994.
That’s changing. Gerald E. Galloway, who headed the team that examined the 1993 flood, Jeffrey J. Opperman of The Nature Conservancy, and others published an article in Science last month title, “Sustainable Floodplains Through Large-Scale Reconnection to Rivers.” The writers expect the risk of flooding to increase in the coming years, listing climate change first and shifting land uses second, including the filling of wetlands and the construction of roads, parking lots, roof tops, creating more and more runoff to the rivers as we expand cities and suburbs.
Developers look at all that good, flat land on floodplains and see industrial parks and even housing developments. Too protect them from flooding they are building higher and stronger levees, withdrawing natural floodstorage capacity floodplains offer and creating higher and more dangerous floods, even as the maintenance of existing levees is underfunded.
The authors propose reconnecting rivers to their floodplains by either removing levees or at least setting them further back in floodplains, particularly in floodplains devoted to farming. Doing so would reduce the risk of flooding in populated areas and increase the goods and services floodplains offer.
For example: there is a section of floodplain at the end of the Jefferson Barracks Bridge in Monroe County, Illinois that has been flooded now for two years. It first flooded in the spring of 2008, reflooded in the fall of 2008 when Hurricane Ike blew through the Midwest, and reflooded again in the spring of 2009.
Fish washed in with the first flood and bred. As the flood receded the fish got trapped in very shallow water. Egrets and other fish-eating birds moved in to feed on the fish. When the egrets went south in the fall of 2008, gulls replaced them and fished the floodplain. So did quite a few humans.
The image above is of the American Bottom, the vast floodplain south of St. Louis. It taken a few days after the Flood of 1993 destroyed the levee a mile or two upstream of Fountain Creek, flooding the bottom. The levees that guide Fountain Creek, while the same height as the levee that broke, sit two feet below in a landscape, that slopes south. Therefore, the flood overtopped and broke through the Fountain Creek levees and flowed south to Prairie du Rocher, where the Corps of Engineers blew up a section of the mainline levee to release floodwaters back into the Mississippi. The floodwaters hung around in some parts of the floodplain until the following spring.
While setting back levees in places like the American Bottom would give the Mississippi room to spread out during major floods, tell that to the farmer who has seen his fields given over to fish and egrets for two years. I’m not sure he would agree. Farmers in the American Bottom still resent that the breaking of their levee, the flooding of their fields, and the destruction of the town of Valmeyer in the bottoms allowed the flood level upstream at St. Louis to be reduced by 1.6 feet.
The article in Science requires a $15 fee to access it. Resilience Science has quotations from the article on its website.
Go to TwoTankTours.com and download An Ecological Tour of Bluff Road and the American Bottom for $7 for a tour of the American Bottom that includes hikes to the Fults Prairie, the Fort Chartres Island Side Channel and Island, the Meissner Division of the Middle Mississippi NWR, the Kaskaskia River Wildlife Area.