Scientists working on an independent study of a floodwall that collapsed during Hurricane Katrina said Monday that a government test 21 years ago predicted the wall could fail.
The U.S. Army Corps of Engineers' built a levee and floodwall system to test a design similar to the 17th Street Canal in 1985, which "indicated that failure was imminent," according to a statement from Raymond B. Seed and Robert G. Bea, in charge of the National Science Foundation's Independent Levee Investigation Team.
"Not only did they have that in their repertoire of information, they failed to use it, as best we can tell," Seed said in a telephone interview from the University of California, Berkeley.
Corps spokesman Wayne Stroupe said his agency knew about the 1985 test, and that he would forward the scientists' statement to a Corps official for a response.
Seed said that "sometimes there's separation between the engineers in the research center and the working Joes in some of the districts. It wasn't all that surprising. It was just disappointing."
On Friday, the Corps said the breach at the 17th Street Canal was the result of water working its way between the floodwall and the earthen levee into which it was set, and of soft subsurface clay.
Once the levee split, the force of the high water pushed the floodwall, and the half of the levee behind it, backward on the clay, the corps task force said.
The corps called it an unforeseen combination of events that split the earthen levee and toppled the floodwall.
Beyond the 1985 test, the Corps should also have known about the soft clay behind the levee, the independent scientists said, since the complex and challenging geology of the region had been noted in past studies.
"The Corps should not claim that the weak foundation soil strata at the 17th Street canal breach site were unexpected," the scientists' statement said.
Seed also said two other problems could have caused the floodwall to fail, which his team will study and then discuss in May.