While many levees on the major Midwestern rivers are in good shape, many others are old and in need of repairs.
“It’s pretty frustrating,” said Mike Klingner, chairman of the Upper Mississippi, Illinois & Missouri Rivers Association. “We’re dealing with levee elevations that were established on the Illinois in the 1940s and on the Mississippi with the 1950 Flood Control Act. Those were based on the record flood in 1947. Now we see water, on average, 7 feet higher.”
On the Mississippi River across from St. Louis, work has progressed. Levees from Alton to Columbia have been strengthened over the past few years. Five levee systems are included in the Southwestern Illinois Flood Prevention District Council.
“We’ve been building these projects since 2013. Everything functioned as designed. Everything worked well,” said Chuck Etwert, chief supervisor of construction for the district.
He has concerns, however, on meeting funding goals for remaining work due to the COVID-19 pandemic. While the U.S. Army Corps of Engineers provides 65% of the money, the remainder of the project load is financed by a quarter-cent sales tax, and with many businesses closed, that money is drying up.
“We’re about $25 million short,” Etwert said. “We were hoping to issue new money, but weren’t able to. With the coronavirus, we have no idea what kind of reduction we will have.”
The challenges are expected to increase with climate change. A report recently released by the Chicago-based Environmental Law & Policy Center raised concerns about 2019 floods and the levee systems designed to prevent them. According to the report, scientists have recorded a 9% increase in annual precipitation over the past few decades.
“The Corps needs to do a thorough engineering analysis of the levees they have identified as being at risk,” said Howard Learner, the center’s chief executive officer. “Some of the levees that had significant problems last year were not levees that were identified as especially at risk by the Corps. Were they weakened by the flooding last year, and what’s happening this year?”
Klingner pointed to levees that have not been repaired following breaks during flooding in 2019.
“In general, there are a lot of concerns out there,” he said. “They’re not where they need to be, even from prior recommendations.”
He said a lot of work remains on levees on the Upper Mississippi on the Illinois-Missouri border. Last spring, a breach in a levee in Washington Township, across from Quincy, Illinois, flooded much of the 4,000 acres it protects.
“That’s one area you don’t want flood damage,” he said. “We had a near failure there. The Marion County, Missouri, district still has repair work to do. We’re weakened and haven’t got the repair work done.”
Illinois levee districts aren’t in as much trouble.
“On the Illinois side we’re doing a little better, but those repair jobs haven’t all been executed yet,” Klingner said.
Some of the levees included in Etwert’s district have had extensive attention. In some, engineers dug deep cutoff walls that go down to bedrock — some as much as 150 feet — to control seepage.
“We also have pump stations and hundreds of relief wells to keep water from coming under the levee, and what does come under, we pump back over,” he said.
The process is expensive, costing as much as $7,000 per foot. The trenches made by the machine are replaced with a bentonite slurry.
Klingner is hoping for movement on a bill in the U.S. House of Representatives that would authorize additional dollars for flood protection.