Our entire approach to flood control in this country is wrong.
It would be better to leave the river alone, and build the houses on landfills above the flood level.
Levees destroy the land (no soil replacement), cause periodic flooding when they fail, and damage the Gulf (because the soil that would have been deposited on the farms winds up in the Gulf, instead).
Around here you can’t so much as move a rock in a brook or even replace a culvert without getting algore’s permission and yet the Army Corps of Engineers has been playing God with, I believe, disastrous consequences for hundreds of years out west. Left to its own devices, I’m told the Mississippi River would not even flow through New Orleans any more but would divert to the west somewhere around Baton Rouge and go more due south rather than southeast. I say “LET IT!”