A March 6 article about the repair of levees in New Orleans misstated the relationship between a panel of levee experts and the National Science Foundation. The panel received funding from the foundation but does not represent the organization in any advisory or oversight role. The article also misidentified a flood wall referred to in a discussion among Jefferson Parish officials. The correct name is the Parish Boundary Canal flood wall.
Levee Fixes Falling Short, Experts Warn
Monday, March 6, 2006
NEW ORLEANS -- The Army Corps of Engineers seems likely to fulfill a promise by President Bush to rebuild New Orleans's toppled flood walls to their original, pre-Katrina height by June 1, but two teams of independent experts monitoring the $1.6 billion reconstruction project say large sections of the rebuilt levee system will be substantially weaker than before the hurricane hit.
These experts say the Corps, racing to rebuild 169 miles of levees destroyed or damaged by Katrina, is taking shortcuts to compress what is usually a years-long construction process into a few weeks. They say that weak, substandard materials are being used in some levee walls, citing lab tests as evidence. And they say the Corps is deferring repairs to flood walls that survived Katrina but suffered structural damage that could cause them to topple in a future storm.
The Corps strongly disputes the assertion -- by engineers from a National Science Foundation-funded panel and a Louisiana team appointed to monitor the rebuilding -- that substandard materials are being used in construction. Agency officials maintain that the new levees are rigorously inspected at each step. But they acknowledge that much more work will be needed after June 1, the beginning of hurricane season, and that the finished system still will not be strong enough to withstand a storm the magnitude of Katrina.
"The people of New Orleans need to get back to at least the level of hurricane protection we had before Katrina," Corps spokesman Jim Taylor said. "We were authorized to do that, and do it quickly. It's up to Congress to decide to take it to a higher level."
But Ivor van Heerden, a Louisiana State University engineering professor and leader of a state-appointed team of experts investigating the failure of the levee system during Katrina, charged that "the government is trying to create a sense of security that doesn't exist."
"What we have today," he added, "is a compromised levee system that failed during a fast-moving Category 3 hurricane. Absolutely nowhere are the levees ready to stand up to the same kind of test."
The Corps said several steps that could help the levee system survive a major hurricane will have to wait until next year. For example, systematic testing for weak soils beneath the levees will not be completed until 2007. Two of the most devastating flood wall breaches during Katrina have been blamed in part on weak, peatlike soils beneath the walls' foundations.
In addition, a plan to line the bases of certain critical levees with a protective layer of rock or concrete -- a process known as "armoring" -- is not expected to begin until summer, and then only if Congress provides additional money. Levee armoring significantly lowers the risk that a levee will collapse when it is overtopped by floodwaters.
A recent report by a prestigious panel of the American Society of Civil Engineers described the lack of armoring in New Orleans's levees as a "fundamental flaw" that demands urgent attention. The same report also faulted the Corps for making predictions about the system's safety before the agency officially determined what caused the levees to fail in the first place.
"Overtopping during Katrina caused catastrophic flooding and destruction of the levees themselves," said David E. Daniel, president of the University of Texas at Dallas and a member of the engineers panel. "It is inevitable that the levees will again be overtopped -- the only question is when."
Katrina breached the region's 350-mile levee system in dozens of places, blasting out huge chunks of concrete flood walls in central New Orleans and obliterating miles of earthen levees south and east of downtown. The breaches put 75 percent of New Orleans under water and transformed Katrina from a destructive but ordinary storm to a monumental disaster that claimed more than 1,300 lives.
The Bush administration has requested about $3.1 billion for repairing and strengthening the region's hurricane defenses. In addition to the $1.6 billion approved by Congress for rapid repairs to broken levees, the administration is seeking additional money for armoring, new floodgates and more pumping stations.