The Southwestern Division U.S. Army Corps of Engineers portfolio of levee systems is comprised of approximately 149 individual levee systems in Texas, Oklahoma, Arkansas and parts of Kansas and Missouri totaling more than 800 miles, range in age from 10 years to over 70 years. These levees are incredibly beneficial to communities (more than 2 million people live and work behind them) and they contribute to significant reduction in flood damages each year and are relied upon to be the quiet sentinel against unpredictable flooding.  Levees in the Southwestern Division include large urban levees that provide flood risk reduction to Dallas and Ft. Worth, Texas, Tulsa Oklahoma, Wichita Kansas, Little Rock Arkansas and Hurricane Protection Systems for Freeport, Texas City and Port Arthur Texas as well as smaller agricultural levees.  This flood defense infrastructure provides a return on investments many times over the cost of original construction. Keeping these levee systems in operating condition is largely the responsibility of local sponsors who work hard to ensure they are maintained in safe physical conditions. In addition to the physical condition of levee systems, risks are also influenced by the dynamic natural environment (changing flood frequency and increasing ground subsidence) and the intensification of development in and upstream of leveed communities.

Approach: The Southwestern Division Levee Safety Program’s mission is to work with others to assess, communicate and manage inundation risks to people, property and the environment resulting from breach or malfunction of components of levee systems.

Inventory of Levee Infrastructure: includes collecting and visualizing physical features, documents, and status about the levee systems via the National Levee Database (NLD). The public may access the NLD and find the inspection ratings for levees near them by zip code. While USACE administers the NLD, we have authority to address only about 10 percent of the total national portfolio of levees. Currently, the NLD contains levee systems within USACE authorities and is accessible to both official data users and partners such as federal, state, and local governments, and sponsors, and the general public. Southwestern Division is working closely with other federal agencies such as FEMA Region VI, states, and others to incorporate their data into the database on a voluntary basis. Additional information about levees and things anyone who lives behind a levee should know can be found at these links: SWD Levee Safety Brochure and ASCE “So You Live Behind a Levee”.

 General Condition of the Infrastructure: Under the USACE Levee Safety Program, Southwestern Division  conducts levee inspections (routine, periodic and special event), which have identified a wide array of deficiencies including unsatisfactory culverts, non-compliant vegetation, encroachments, and animal burrows. USACE uses inspection findings to “rate” the levee system to determine compliance with operation and maintenance requirements (including some measures of performance), understand the overall levee condition, and determine eligibility for federal rehabilitation assistance under P.L. 84-99. Currently, approximately 15 percent of Southwestern levee systems portfolio are “acceptable,” while about 55 percent are “minimally acceptable” and 30 percent are “unacceptable.” Many of these “unacceptable” levees are among the oldest that provide flood reduction to agricultural areas in Arkansas. 

 Assessing Risks Associated with Levees: USACE uses risk assessment to place the inventory, inspection, and flood performance findings in context to better understand the nature and degree of risk, as well as the priority and urgency of action. Seepage, which represents a small percentage of the deficiencies, and overtopping are the major drivers for performance concerns and life safety risk.