If they really want to rebuild New Orleans and have it last into the future, should they just patch the old levees? Or maybe embark upon an incredibly expensive project such as The North Sea Protection Project? It is referred to as one of the "seven wonders of the modern world". Of course this is designed to hold back the North Sea so that they can reclaim land from the sea.
THE NORTH SEA PROTECTION PROJECT
http://wonderclub.com/WorldWonders/ProtectionHistory.html".........The movable barrier consists of 65 concrete piers weighing 18,000 tons apiece. The piers support 300- to 500-ton steel gates and their hydraulic machinery, as well as a roadway above and load-bearing beams below. Constructed on the work islands, the piers and their mechanisms had to be lifted into precise positions in the estuary. But the type of equipment needed for such gargantuan and specialized tasks did not exist anywhere in the world; it had to be invented.
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....As part of the measures taken to stabilize the sea floor, mattresses were laid under each pier to prevent erosion. They were not the hand-built weaving of trees and brush used to close the Zuider Zee, however. Instead, they were high-tech sandwiches of sand and gravel between space-age fabric covers."
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"In terms of magnitude," an American trade journal wrote, the North Sea project "approaches of the Great Wall of China. In terms of complexity and technical sophistication, it approaches the lunar shot. It is unique, expensive, and quite unlike any other civil engineering project to be found on this planet."
Source: The Wonders of the World, National Geographic Society