Question for building/structure experts about NO levees?

[shireen]

I've been hearing in several places (NYT article yesterday, Chertoff at today's press conference) that no one could have anticipated the levee breaches.

We all know that New Orleans is sinking. This would have made the levee foundations weak. A weak foundation could have caused the breach, especially from the forces against them during the storm surges.

Anyone who has built a sandcastle on a beach and watched the high tide claim it knows that.

So why are the "experts" so shocked over the breached levees? If you're a building expert, or structural or civil engineer, please educate me.

[starmaker]

1. unconfirmed info i know

was told today that satellite infared photos
of levees showed hot spots or weak places
If this is true it's just one more example

[KerryOn]

2. The answer is simple....

The levees were not designed to withstand a storm with the power that Katrina had. This was a category V hurricane. The system of levees and flood walls were only designed to withstand a category III hurricane.

When Katrina hit, it created a great surge of water moving through the lake. The surge of water struck the levees breaking holes allowing the waters from the lake to flow into the city.

The eye of the hurricane hit just east of NO, and in that area they had 25 foot surges of water. If the hurricane would have hit NO more direct, NO would have seen these 25 foot surges. In this case even if the levees held the water would have toppled over the levees and into the city anyway. The levees were just not designed for such a large storm.

Money was appropriated to improve the levees, but Bush cut the funding to 20%, and diverted the money to the war in Iraq. Not that it matters anyway because the project would not have been completed in time for Katrina. But the fact still remains that our government had been warned that if a category V ever it NO it would be the worst disaster in our history.