We know all about big blows, getting threats from several each year. Because we have a long coastline, only occasionally does a big city cop one, though both Townsville (big Yank base in WW2) and Darwin on the north coast of Australia were both flattened to varying degrees in separate cyclones. The floods associated with them tend to do more damage.
50% of the Netherlands is below sea level. From memory, I think parts are up to 23 feet below. While dykes have been built for centuries, the big push came in the 1900`s. A Dutch friend told me many of the levees are hundreds of yards across. Might be an idea for New Orleans to consider Dutch expertise when they recover.
Australia is about the same size as the U.S. We get a natural disaster almost on an annual basis--bushfires,floods, cyclones,drought. Sometimes more than one a year. So we are fairly well organised in coping with these events. Our PM has offered a number of disaster response coordinators if you think it will help. These events usually take more than a few weeks to solve as unforeseen side-effects start to surface. The long-term damage is to personal losses--all your photos, records, favourite items gone. I`ve been through it. You have to start almost from scratch.