Metro East levees are again certified to withstand a 100-year-level flood.
The Federal Emergency Management Agency made the final signoff last week on the 65-mile system of levees that stretches from Alton to Columbia.
It comes 15 years after FEMA considered revoking the levee’s accreditation when the Army Corps of Engineers determined the system might be compromised, said Chuck Etwart, supervisor of construction for the Southwestern Illinois Flood Prevention District Council.
“It was a threat,” he said. “That would have meant mandatory flood insurance in the Metro East area. Stricter codes requiring buildings to be built above the base flood elevation.”
That move would have put the 156,000 residents and 4,000 businesses the levees protect in the floodplain and cost those residents and businesses about $50 million a year in flood insurance, Etwart explained. The agency didn’t end up following through because Madison, St. Clair and Monroe counties established a flood prevention district council to bring the levees up to the 100-year standard, he said.
There wasn’t anything expressly wrong with the original levees, which had been built in the 1940s and '50s, Etwart said.
“The only thing that changed over the many years was engineering standards and the measurement of flood risk,” he said. “Everything that we’ve done is to control that seepage and stabilize the levees.”
Seepage is a perennial challenge for levees, which are designed to stop flood waters from passing through, Etwart said. The flood prevention district council used various methods, like making the levees wider from top to bottom and installing walls down to bedrock that prevent water from flowing underneath, he said.
The recertification of the Metro East levees to 100-year levels is an important milestone, especially for economic development, said Steve Zuber, a partner at commercial real estate brokerage Barber Murphy Group.
“Most companies are adverse to risk,” he said. “And if you have that potential for flooding, and it’s going to be a problem, people are going to go elsewhere.”
Zuber said it’s important that companies in the American Bottom floodplain not need flood insurance since it can be pricey. The reaccreditation has made it easier to move forward with some development projects, he added.
The next step for the local levee system is bringing it up to FEMA’s 500-year standard, which will be done by the Army Corps of Engineers, said Tracey Kelsey, program manager for the Metro East levee projects at the St. Louis district of the corps.
“We are hoping to complete the work within the next three years,” she said. “Not all of the funding has been received. We are still dependent on congressional funding for the rest of the costs.”
The Corps will be employing some of the same solutions the local flood prevention district council did to meet FEMA’s 500-year standard, like deep cutoff walls and seepage berms, Kelsey said.
“The levees will not become taller or larger, we’re not doing that,” she said. “The features that go into the construction are primarily to help prevent when water seeps through underneath the levee.”
The Corps and Flood Prevention District Council have already seen the benefits of this kind of investment. The Flood Prevention District Council’s projects to achieve the 100-year level were completed in 2018 just before massive flooding the next year.
“In 2019, that was the second highest ever on record,” Etwart said. “All the improvements that we built were tested and everything worked as it was supposed to.”
Eric Schmid covers the Metro East for St. Louis Public Radio as part of the journalism grant program: Report for America, an initiative of The GroundTruth Project.
