"In the Gulf, Katrina was a Category 5 storm, and the surge was still Category 5 when it hit the ground... It's the surge -- the pressure of water against those levee walls -- that's the most important factor, not the winds."
As previously discussed, there are questions over whether ACE's design of the levees and floodwalls was faulty or not.
And, the downgrading also affects LA's government:
"That storm was the biggest storm ever to enter the Gulf of Mexico," [Edmond J. Preau Jr., Louisiana's assistant secretary for public works] said in testimony before the Senate's Homeland Security and Governmental Affairs Committee. "I think it would be a real disservice to everyone if Katrina goes down in the history books as a '4' because the wind speed dropped at the last minute."
To some local experts, the report was further evidence that human error was primarily to blame for New Orleans's drowning.
"This is a further indictment of the levee system," Ivor Van Heerden, an LSU professor and leader of a team of Louisiana investigators probing the cause of the levee breaches. "It indicates that most of the flooding of downtown New Orleans was a consequence of man's folly."
Other engineering experts agree: Considering Katrina's weakened state at the time it reached New Orleans, the failure of the city's 17th Street and London Avenue canal floodwalls can be explained only as a failure of design or construction, said Robert Bea, a civil engineering professor at the University of California at Berkeley.
"The water level in the canals wasn't that high when the floodwalls breached," said Bea, a member of an investigating team funded by the National Science Foundation. "We had a premature failure of the defense system."