The Acadian French, like the Dutch were experts in constructing dams, levys and drainage systems in claiming farmland from the sea. In Nova Scotia three hundred year old systems still hold back the tidal rivers that flow to the Bay Of Fundy. (The worlds highest tides). After the great deportation many of these people became the Cajins of Louisiana. I would suspect that they were some of the original levy builders on the Mississippi. No doubt the systems were greatly improved upon over the years but the purpose would have been to protect the floodplain for agriculture, not habitation. I can't understand the reason to build a large city in such a fragile location. Perhaps the destruction three years ago should have opened some eyes but I wonder if it really has? In any case I pray that the people will be spared this time around!