Standard double-wall space-frame dome with articulated self-repairing tile windows made of AlON, just like the Flying Castle. Only the NoLa Dome closes inward, where our windows operate the opposite way.
They want to keep the sea-water out; we want to keep the air in.
The top of the NoLa Dome has an inverted half-dome, with plants and greenery at its base. In the very center, a very wide aperture similar in function and purpose to the Oculus of the Parthenon.
It also is open to the atmosphere, and provides sufficient daylight for activities below.
Well, if you've been reading many of the New Orleans threads you might have seen some ideas.
For example, the one I advocate is turning New Orleans into a giant garbage tip.
Because of it's location at the mouth of the mighty Mississippi, it is ideally located to accept garbage from the entire Mississippi basin and Gulf Coast.
Fill in the entire Crescent City area with enough garbage, mine tailings, slag, and fly ash to build it up to 30 feet above sea level.
Cover it with 10 feet of dirt, incorporating underground utility grids, a few feet of topsoil, and rebuild on top of that.
Tel New Orleans would become the South's new 'Shining City on a Hill'.
Fund the entire project with fair market rate disposal fees.