Flood Risk Management - Overview

Praire du Rocher LeveeThe St. Louis District's flood risk management system is comprised of three major components: urban levees or floodwalls, agricultural levees and multi-purpose reservoirs. When performance of a flood damage reduction system is evaluated, all components must be considered and evaluated as a whole system and not as separate features. As a Federal leader in Flood Risk Management, it is our vision to provide and sustain a comprehensive floodrisk reduction system within the St. Louis District watershed boundaries that reliably minimizes risk to lives and property damage.

Urban levees are built very high to protect cities and towns against floods of great magnitude. Agricultural levees are smaller levees that provide relatively lower levels of protection to millions of acres of cropland against more frequent, less severe floods. Multi-purpose reservoirs provide flood storage capacity and support other Corps missions, such as water supply, hydropower, environmental stewardship and recreation.

Mark Twain LakeLevees fall within three categories: Federal, non-federal and private. There are 89 levees in the St. Louis District that fall into two categories, with 47 Federal and 42 non-federal levees comprising more than 700 miles of structures. Together they protect some 578,365 acres. Since 1960 they have prevented more than $11 billion in damages within the St. Louis District.

Federal levees are built by the Corps and then turned over to the customer (city, county, levee district) for operation and maintenance. One exception in the St. Louis District is the Chain of Rocks Levee, which is operated and maintained by the Army Corps of Engineers.

Non-federal levees are built by public entities or are publicly sponsored. In order to qualify for federal assistance following a flood event, these privately-funded levees must be built to Corps standards and pass annual inspections. Private levees, built by private concerns, are typically built to a lower level of protection than Corps standards, although some private levees may meet or exceed Corps standards. If an eligibility inspection is requested and passed, private levees can be eligible for federal funding to help recover from damages.

STL Floodwall 1993The entire structural flood damage reduction system in existence in 1993 reduced potential flood damages by 50 percent. The system in this region cannot prevent all damages caused by all floods because it is not designed to do so. But the system has an impressive record. However, with aging infrastructure and underperformance issues noted during the 1993 flood, there are numerous systems in need of reconstruction and rehabilitation. The Army Corps of Engineers St. Louis District is working with Federal, state and local officials and with levee districts and sponsors to study, design and construct solutions for these issues.

In addition to building projects, the Corps of Engineers, through its Flood Plain Management Services, advises communities, industries, and property owners on protection measures they can take themselves, such as zoning regulations, warning systems and flood proofing. Last year this service responded to more than 44,000 requests for information. The value of property protected by this program is an estimated $6.2 billion.

The Corps was first called upon to address flood problems along the Mississippi river in the mid- 1800's. We began work on the Mississippi River and Tributaries Flood Control Project in 1928, and the Flood Control Act of 1936 gave the Corps the mission to provide flood protection to the entire country.