National Levee Database: Roles and Responsibilities of Army Corps of Engineers and FEMA
Fast Facts
After Hurricane Katrina, the Army Corps of Engineers created a national database on U.S. levees—structures that help prevent flooding. The Corps and the Federal Emergency Management Agency maintain the publicly available database, which includes levee conditions and information about the people and property at risk if levees fail. The Corps and FEMA regularly update the database after levee inspections.
This Q&A looks at how this information is shared and used.
While the data can help policy makers and communities understand flood risk, it's unlikely to have much effect on federal flood insurance premiums—which are based on many other factors.
Highlights
What GAO Found
Levees are man-made structures, such as earthen embankments or concrete floodwalls, that play a vital role in reducing the risk of flooding. The National Levee Database contains critical information for all known levees nationwide. Such information includes a levee’s location and condition as well as the population and number of vulnerable structures behind a levee should a levee fail or be overtopped with floodwaters. The U.S. Army Corps of Engineers(Corps) and the Federal Emergency Management Agency (FEMA) update data in the National Levee Database on an ongoing basis, typically in conjunction with scheduled levee inspections and efforts to map flood risks, respectively. The Corps and FEMA routinely share information from the database.
Corps Inspector Using a Mobile Device to Record Levee Information
According to FEMA officials, data updates regarding levee conditions may not substantially affect the cost of insurance premiums for those participating in the National Flood Insurance Program (NFIP), which FEMA administers. This is because the premiums are based on multiple factors, including geographical, structural, and policy variables, such as distance from the flooding source, type of structure impacted, and amount of insurance coverage requested by policyholders. Moreover, the premiums remain in effect until policies are due for renewal, and annual increases are generally limited by statute.
GAO found that the Corps does not typically rely on data in the National Levee Database for analyzing the benefits and costs associated with flood risk management activities, including levees. The Corps obtains the information it needs from other entities, such as state and local governments, that operate and maintain federally authorized levees.
Why GAO Did This Study
The Corps established the National Levee Database—the first centralized repository of information on the nation’s levees––in the aftermath of destructive levee failures during Hurricanes Katrina and Rita in 2005. The database was established under the National Levee Safety Act of 2007 and became publicly available in 2011. The database is intended to help decision-makers better understand the scope of the nation’s levees, including their location and condition. The database also provides other benefits, such as supporting community preparedness and quantifying the nation's flood exposure.
Corps and FEMA each have roles and responsibilities regarding the levee database. For example, the Corps hosts the database, which contains information on levees managed by the Corps as well as other entities. The Corps works in partnership with FEMA, which populates and maintains certain information in the database including data related to NFIP. This program makes flood insurance available to property and business owners located in communities that participate in the program by adopting minimum floodplain standards. This report provides information on how the Corps and FEMA enter, share, and use levee information in the database.
For more information, contact Cardell D. Johnson at JohnsonCD1@gao.gov.