How about we just don't rebuild it below sea level and avoid the whole problem entirely?
Galveston did it after 1900, NO should be able to do it today.
There are parts of the country where houses are built on stilts and that seems to offer pretty good protection against flooding. Won't help anything if a storm surge comes by that's 20' above floor level, or of the structures are hit by 200mph winds, but if a house in New Orleans were built on stilts up to the lake level it would probably still be habitable.