The levees holding back flood waters protect many communities in the metro east from costly flood damage and the U.S. Army Corps of Engineers wants the public to know what it is doing and what it plans to do to assure those levees hold when it counts.
The levee system in the metro east has been undergoing a massive repair and rehabilitation project to assure the levees are stable enough to withstand the pressures of flood water. So far, $134 million has been spent on metro east levee system. The rehabilitation of the entire metro east levee system is expected to be completed by 2018.
"It's not about how tall the levees are, they are tall enough. It's all about the foundation," said Army Corps. Col. Christopher Hall, commander of the St. Louis District. "All the above-ground work is done, now, we are looking at the below-ground issues."
Underseepage, not a lack of height, is the biggest problem facing the metro east levees, Hall explained. Flood water on the river side of the levee produce enough pressure to force water through soil and sand beneath the levee to bubble up on the other side and weaken the entire structure, leading to possible failure. Part of the project has been to install and repair relief wells and seepage berms to prevent underseepage and resulting sand boils, as well as build new pump stations and add more seepage berms where possible. The levee system has 618 relief wells, 99 gravity drains, 16,000 feet of floodwall, 40 pump stations and 35,085 linear feet of seepage berms. The seepage berms provide additional pressure on the soil on the land side of a levee to help prevent underseepage. Future plans for the levee system includes the construction of more seepage berms, additional relief wells, more pump stations, drainage ditches and cutoff walls.
The levee system in the metro east consists of 75.8 miles of levees that protect 111,700 acres and 280,000 people, which includes Alton, East St. Louis, Wood River, Granite City, Cahokia, and Columbia. The land, including infrastructure, property, business and industry infrastructure, has a value of $4.8 billion.
The Corps has a partnership with the Southwestern Illinois Flood Prevention District Council, the Metro East Sanitary District and the Wood River Drainage and Levy District and have been working to repair and reconstruct levees to assure they function as planned to hold back flood water.
"We have an ongoing commitment with our local partner and continue to reduce the risk to the local folks, the economy and the communities right here," Hall said. "It's about reducing the risk and that's our long term goal with the federal project. We, along with our partners, have been vigilant in reducing flood risks to the metro east."
People interested in learning more about the work done and the work planned for the levee system can visit am Army Corps of Engineers open house Thursday at the National Great Rivers Museum in Alton. The event is free and open to the public and will be held from 4 p.m. to 6 p.m. Technical experts will be on hand to answer questions about the federal levee projects, levee safety, levee structure and stability and the levee inspection and rehabilitation program.
Additional information can be found at www.mvs.usace.army.mil, at the Corps' You Tube channel at youtube.com/teamsaintlouis or its Facebook page by liking Teamsaintlouis.