Michael Duncan, Ph.D.,
Figure 1. Flood protection structures in the New Orleans area.
n Monday, August 29, 2005, Hurricane Katrina
struck the U.S. Gulf Coast and the New Orleans
area during the early morning hours. The storm
produced a massive surge of water on the coastal regions.
The surge overtopped and eroded away levees and flood-
walls along the lower Mississippi River in Plaquemines
Parish, along the eastern side of St. Bernard Parish, along
the eastern side of New Orleans East, and in locations
along the Gulf Intracoastal Waterway and the Inner Harbor
Although much of the hurricane protection system was
overwhelmed by Hurricane Katrina with overtopped levees
and flood walls in the New Orleans area, the damage due
to flooding would have been one-third less if none of the
levees or floodwalls had failed and breached. In all, about
50 breaches of hurricane protection levees occurred due
to overtopping and erosion, or due to foundation failures.
Approximately two-thirds of the flood damage was due to
breaches that increased the volume and depth of flooding,
and made dewatering of the flooded areas more difficu It.
In response to Hurricane Katrina and issues associated
with the performance of the New Orleans area hurricane
protection system, the Chief of Engineers, U.S. Army Corps
of Engineers, established the Interagency Performance Eval-
uation Task Force (IPET) on October 10, 2005, to provide
credible and objective scientific and engineering answers
to fundamental questions about the performance of the
hurricane protection and flood damage reduction system
in the New Orleans metropolitan area. The key objective of
IPET is to understand the behavior of the New Orleans Hur-
ricane Protection System to Hurricane Katrina and assist in
the application of that knowledge to the reconstruction of a
more resilient and capable system for the future.
In all, the IPET team included about 150 engineers and
scientists covering a wide range ofspecialties from meteorology
to social science. The team investigating the performance ofthe
levees and floodwalls included about 30 geologists and geo-
technical engineers from government, industry and academia.
The authors ofthis article were the co-leaders ofthis team.
The draft final IPET report, nperformance Evaluation of
the New Orleans and Southeast Louisiana Hurricane Protec-
tion System," is available on the I PET web site, https:/IIPET.