...”LA would not have sustained such horrific damage had the levees been in good repair”....
The levees didn’t fail. Concrete floodwalls in two canals, one from the Mississippi River, the other from Lake Ponchartrain, were overtopped by storm surge and broke. There is a vast misconception that the levees failed.
Alas, levees, once there’s water behind them, work just fine ~ and become part of the problem. I think they’ve improved the AFTER THE STORM drainage capability there.
I would suggest that you seriously need to go and read in detail the reports by the American Society of Civil Engineers, Interagency Performance Evaluation Task Force (IPET) which was headed by the Army Corp of Engineers (who were obviously accused of lacking credibility), University of California at Berkeley, Louisiana Department of Transportation and others.
There was a total of 50 locations along the levees were problems occurred and of the just under 300 miles of levees, approximately 60% of it ended up being damaged. There was some overtopping but even in those cases, some levees continued to perform except where they were built on dirt or peat that was quick to erode. Like all major disasters, there wasnt just one thing that could be pointed to after the fact
there was a huge number of design flaws with respect to the poor reinforcement of the levees, the fact that much of it was built on substrata of incredibly low and unacceptable shear strength that had been grossly overestimated with regards to its strength, pilings that were not deep enough, levee sections that were not interlocked, lack of maintenance, a fundamental problem with the design of the I-walls (that had been clearly identified in 1984 as being a disaster waiting to happen) and on and on
The real problem was that there were four major levee breaks which occurred where the water level was still below its design elevation i.e. no overtopping required for failure. Some of those were located in neighbourhoods where the residents had been reporting the growing marshes in their backyards for several years. It is not possible to summarize fat reports into a couple of concise conclusions but suffice it to say that when the Army Corp of Engineers accepts the responsibility for the mess, what you are obviously dealing with is a massive engineering failure.
***There is a vast misconception that the levees failed.***
I have read that the levee failed because a barge broke loose and drifted into it.