Apparently as long as we remains in the present warming cycle this is going to be a problem at near sea level elevations. The sea level is rising mainly because of the expansion of water volume with temperature. In some places the land is also sinking. Put these two together and there are big big problems for cities on low lying ground next to the sea: Miami, Houston, etc. Much of the grade in New Orleans is below sea level. A lot of work has been done recently on New Orleans' pumping system which goes back to the 19th Century and some new pump systems have just been put into service. They seem to be working fairly well so far, but apparently more pumping capacity and up grades are still needed. What I notice driving around the city are that the houses built before the river levy was built are all elevated to different heights depending on location. Each was built to put the lowest occupied floor level above sea level. In more recent years, long after the levy was built and pumping stations were installed, at lot of development was allowed to go in at grade level. This proved disastrous during Katrina, whereas those old houses built above sea level came through without serious damage when most of the city was flooded.
The history of the human race is bound up with the seemingly endless battle to get cause and effect right.