The USACE has brought up the “overtop vs. breach” debate again. But here it is more than just semantics:
A top federal official ignited controversy Monday when he said overtopped rather than breached levees accounted for much of the water that engulfed New Orleans after Hurricane Katrina.Simply put, if overtopping caused most of the flooding, then nothing in the design could have been done to save New Orleans from Katrina, and the engineers who built the levees bear no blame. If levee breaches occurred before being overtopped, then the levees did not work, and the builders of the levees bear some blame.
A federal investigation due out in June will say just that, Dan Hitchings, director of Task Force Hope for the U.S. Army Corps of Engineers, told a House committee.
So, if the federal investigation to be released says overtopped levees caused much of the flooding, it absolves the federal government from much of the blame:
Hitchings told the committee that, once the federal investigation is over, it will show that even without the breaches a significant amount of water would have entered the city because of overtopped levees.The USACE has already called the breach of the 17th Street Canal floodwalls the result of a “design failure.” Therefore, the report to be released is probably focusing on flooding in the Lower 9th Ward and N.O. East, involving the Industrial Canal and MR-GO levees.
Much of the damage to homes in the Lower 9th Ward stemmed from breaches, he said. But lots of that flooding would have taken place anyway because of the overtopping, Hitchings added.
He said the breaches did play a big role in the speed of the destruction.
Our local experts disagree with the USACE on what happened with the Industrial Canal and the MR-GO levees:
“Eighty-seven percent of all water that got into New Orleans was because of levee breaches,” van Heerden told the House Committee on Transportation, Highways and Public Works.Previously, LSU researcher Dr. Hassan Mashriqui has proposed that these levees failed before they were overtopped:
He said homes were knocked off their foundations in the Lower 9th Ward by a 14-foot surge of water because of levee breaks. In St. Bernard Parish, 92 percent of the water got in through levee breaches, the official said.
Van Heerden said the levees ruptured “due to design,” including the failure to properly account for soil conditions.
LSU researchers said levees on the MRGO and the intracoastal waterway may have started to fail before they were overtopped by Katrina’s storm surge. They said that when that surge reached the Paris Road Bridge, the water was racing at a rate of eight to12 feet per second, and it may have been that rapid movement of water that was scouring and breaching the levees.Poor soils and lack of armoring combined with the erosive effects of fast moving water could have caused breaches before the levees were overtopped. This, too, would be a design failure.
Mashriqui said he believes the levee breach at the Bayou Bienvenue gate may have occurred before the water topped the levee.
No one will see the federal report until June. So, I can’t comment on what it says. After reading it, I might agree with it completely. Science doesn’t lie, and if the science says it wasn’t the USACE’s fault, it wasn’t their fault.
I'm just saying be prepared. The federal government, and especially this Executive branch, isn’t very good at admitting and taking responsibility for its mistakes.