Hurricane Katrina was one of the worst natural disasters in U.S. history, killing more than 1,000 people and destroying homes, historic buildings, and cultural landmarks. In the storm's aftermath, questions abounded on how the system of levees and floodwalls designed to protect New Orleans could have failed. To investigate those concerns and to provide advice on strengthening the system, the U.S. Army Corps of Engineers established the Interagency Performance Evaluation Task Force (IPET). Subsequently, the National Academy of Engineering and National Research Council conducted a series of assessments of IPET draft reports.
For more than three years, the study committee examined IPET's work, as well as held meetings in New Orleans to listen to concerned citizens. In April 2009, they released their final report, The New Orleans Hurricane Protection System: Assessing Pre-Katrina Vulnerability and Improving Mitigation and Preparedness. Levees and floodwalls surrounding New Orleans cannot provide absolute protection against over-topping or failure in future hurricanes — no matter how large or sturdy the structures are, the report said. For vulnerable cities such as New Orleans, the National Flood Insurance program standard of insuring properties for a 100-year event is inadequate. Furthermore, settlement in areas most susceptible to flooding should be discouraged.
Throughout the review process, IPET incorporated many of the NAE and Research Council’s recommendations into its own plans, strengthening levee rebuilding and storm preparation efforts. In addition, the Army Corps is in the early stages of considering construction of a system that would offer protection against a 500-year storm.