It may have only a 1 in 500 chance of happening in a given year, but with Stantec on board, the Monarch-Chesterfield Levee District is better prepared for a major flood (0.2% annual exceedance probability, or 500-year, flood event). As the Levee District engineer firm, we work with the USACE and the Levee District Board on the planning and design for improved flood protection systems.
In the Chesterfield Valley area of the Missouri River, the existing 100-year levee protected approximately 4,700 acres of bottom land, located in the West St. Louis County metropolitan area. After the Great Flood of 1993, the decision was made to provide protection from the 500-year event. Our team coordinated with FEMA and the USACE to provide geotechnical explorations, analysis, and design for improvements (including slope stability, seepage, and interior drainage).
Now the area is a model for the successes of successful flood protection, with billions of dollars’ worth of development and hundreds of businesses. Overall, the area is better prepared for nature’s impact.