Levees' Construction Faulted In New Orleans Flood Inquiry

"Failure of the 17th Street and London Avenue canals was due to a design that did not take into account the very weak nature of the soils," Ivor Van Heerden, an engineering professor and leader of the Louisiana team, said in prepared testimony. "The design criteria of these levees was not exceeded."

In the eastern part of New Orleans, which suffered the greatest impact, levees were overtoppedby the storm surge. Still, poor design may have made floodwalls more likely to fail, Van Heerden said.

"Much of the flooding of New Orleans was due to man's follies," he said. "Not to have giventhe residents the security of proper levees is inexcusable."

Nagin, in his testimony before the Senate Environmental and Public Works Committee, said: "We need to rebuild this great city. . . . Now is the time for this country to make a commitment to upgrade our levy systems and associated protection with that." Existing Corps plans, he said, "will provide little comfort in a city devastated by a storm and whose flood protection is not as strong as it should be."

Committee members expressed concern at the slow pace of federal decisions. "People need absolute assurance that the level of hurricane and flood protection will be much greater than before Hurricane Katrina," Sen. David Vitter (R-La.) said.

The testimony underscored the centrality of the city's shattered, 200-mile levee system to both the Aug. 29 Hurricane Katrina disaster and to the future of New Orleans. Louisiana Gov. Kathleen Babineaux Blanco and Nagin have said a prerequisite to any rebuilding plan is restoring business confidence that the levee system will protect the city in future storms.

The Corps has pledged to rebuild levees to Category 3 levels, or 17 feet high, by the start of the next hurricane season, in June. Existing levees were built to 15 feet, but sections had settled to 12 or 13 feet, Nagin said.

The White House on Friday redirected $1.6 billion in untapped Katrina relief funds to levee reconstruction, plus $250 million to restore coastal buffers and wetlands.

But state officials have pushed a $14 billion plan to shore up the coast and marshlands, which absorb storm surges. Rebuilding levees to Category 5 levels could cost $2.5 billion, the Corps has estimated, and the state has requested as much as $20 billion to expand defenses and to include storm barrier and drainage systems.

New Orleans is facing a "critical point" as businesses decide whether to return, Nagin said. He said 80 percent of electricity and 60 percent of gas service have been restored to certain areas. About 150,000 people work in the city and about 75,000 reside overnight, compared with a pre-storm population of 480,000.