Watch New Orleans flood (Times-Picayune)

Very interesting.

There was a long segment on NPR Friday afternoon looking at why the levees collapsed. The major conclusion among a number of engineers who looked at the event was that the Army Corp did a poor job of analysing the soil on which the levees sat. They were in many parts built on soggy clay and when saturated with rain and surge water the soils simply floated away.., taking the levees with them. The residents of New Orleans had been living with a false sense of security.

I don't know anything about the geology of New Orleans, but I do know that when about all you've got to build on is clay you are in trouble. It shrinks in the summer heat and swells up like a toad in a wet winter, meanwhile whatever you've rises and falls, bulges and cracks forming at every seam.

The levees were probably built on the good 'nuff good and the plen'ny good principles of the broader South. Good enough for government work and plenty good for us.

Joe(It's like watching an invading army)Nation

Wow, that was the best recounting I've seen yet.

What gets me is how fast things fell apart, go back and watch again and note that the time frame is very short between rising waters and breachs.

The storm arrives in full force at 6:10 and by 7:30 huge areas are flooded.


Katrina invades, step by step

Joe(No wonder they keep axes in the attic.)Nation

Yeah, I was keeping track of the timing..... scary.

The NPR segment was very interesting. One of the issues that has come out of the investigation is that the levee system was plan C for thee Army Corp at New Orleans. Plan A was a flood gate at the outlet of Lake Pontchartrain similar to the gates they have on the Thames River below London or below Providence RI on Narragansett Bay. This resulted in a huge court fight with environmentalists and a federal judge ruled against it in 1977. Plan B was to put flood gates at the head of the canals (such as the industrial canal). This also met with objections from environmentalists and a federal judge ruled against that. The result was plan C, levees built on clay.