Engineers Want Levees in New Orleans to Be Checked

The Army Corps of Engineers needs to immediately inspect all the levees in New Orleans and possibly across the nation, based on defects that investigators have uncovered, according to a letter issued Friday by the American Society of Civil Engineers.

The society, which is overseeing the corps’ investigation into levee failures during Hurricane Katrina, issued its warning in a letter to Lt. Gen. Carl Strock, chief of the corps.

The society’s letter said the “gravity and potential impact” of the problems require the corps’ immediate attention.

Army officials said they are discussing the letter but generally agree with its findings.

The warning was based on several factors, including what the society called defects in the levee designs and inadequate margins of safety.

This month, the corps issued a preliminary report saying that the 17th Street levee in New Orleans failed when the concrete storm wall tilted under water pressure and allowed water to pour into a gap along its foundation, essentially splitting the levee in half.

The corps said the problem was not anticipated, but the society found the corps had conducted extensive testing in the 1980s that identified the potential problem.

Nonetheless, those tests were not considered in designing the storm walls in New Orleans.

The corps also failed to consider the potential impact of weak soils, even though it knew that soft soils along the edges of the levee could be a problem.

And the society said the corps designed the levee with an inadequate margin of safety for a critical structure that protected the public.

The combination of issues “is inconsistent with a pattern of engineering conservatism appropriate for critical structures,” the letter said.

The society’s criticisms are similar to those issued by investigators at UC Berkeley, who are operating under a grant from the National Science Foundation.

The letter to Strock was released to the public a day after another corps official, Maj. Gen. Don Riley, visited New Orleans.

Riley said undamaged sections of levees had been inspected and should hold up against another Katrina-like storm.

Corps spokesman Lt. Col. Stan Heath, in Washington, said the letter was received Friday and that corps officials had been in discussions with the ASCE about its recommendations.

“In general, we agree with the ASCE’s concerns and, in fact, have already been implementing actions in line with their recommendations,” Heath said.

“Nobody wants to know more than we do about the performance of the hurricane protection system, as this information will help to guide our ongoing and future levee work around New Orleans.”