Here's an excellent
elevation map of the city, and here's a map of the
neighborhoods with neat, concise descriptions (click on links). It makes no sense to rebuild the slums, and much of what's below sea level was exactly that. Concentrate on restoring the high ground and do whatever with the rest. Raising it shouldn't be a huge problem in the grand scheme of things because most of it needs to be leveled now anyhow. Just do it!
Nice map. Prior, I used
this one. Scroll down to the pinkish one. The little high ground area along the lake, also has some chic neighborhoods (my brother has a friend that lives there; we checked it out last night; it went underwater too, because the water got to five feet above sea level, as the lake rose, but presumably not by more than about 3 or 4 feet or so). I don't think it is an accident that the money followed the elevations. Other than that island, the motto was to live between St. Charles Street and the river, and hope the river levees last as long as the Wall of China.
Which reminds us, that in a surge, the lake will rise, and if the winds are strong enough in a perfect storm, the surge will be another 5 or 10 feet, and nothing will be spared. Nothing. The motto is that if you live there, and the weather Gods get ugly, you need to leave. Period.
The house my mother grew up in is about seven streets west of the Industrial Canal and just three streets north of the Mississippi. If you look on the map AntiGuv posted, it is one street below the street (Burgundy) shown in the location I described. It looks to me like that area is from 1 to 3 feet above sea level. Do you know if that area was spared the heavy flooding? The cemetary where I've got family buried is several streets north of Burgundy, so we probably aren't as lucky there.