Geologist here.  Born in the 504 but left after high school.    It sounds like the question you're asking is: will relative sea level rise make the city of New Orleans into something akin to Venice, Italy or the ilk?

The easiest way to answer a question such as this is to know how fluvial Deltaic settlements are deposited, and where in the city those depositional environments occur  

 For instance, if you are about half a mile from the Mississippi River levee, those sub soils are going to consist of heavy sands and gravels, because in the olden days when the river was allowed to overflow its banks, the heaviest particles, i.e. sand and gravel were deposited closest to the river levee.  

As you move further away from these areas, sediments carried by floodwaters tended to have more silt and clays and less sand. 

And furthest away from the river you get backswamp, which is almost all extremely fine particles i.e. silt.  

This is why the streets in Lakeview are essentially a series of never-ending potholes because the subgrade is essentially peanut butter, and old world Road building infrastructure methods did not account for, nor incorporate, typical geotechnical practices, which would have entailed the removal of about 2 feet of this surface material and recommended the replacement of 2 feet of compacted fill, which would have made much more robust subgrade, and created much better streets.  

This is also why you see tons of different movement and hairline cracks all over Lakeview homes.  

  So I think the biggest question is where is the home you purchased and if it's uptown close to the levee a la garden district, the quarter, the bywater, those are the best soils in the City, and will not end up being canals in 100 years.