After years of political wrangling, a broad group pulled together by the Louisiana government in 1998 proposed a massive $14 billion plan to save the Louisiana coasts, called Coast 2050 (now modified into a plan called the Louisiana Coastal Area project). Wetland restoration was a key component. "It's one of the best and cheapest hurricane defenses," says Day, who chaired its scientific advisory committee.
Although the plan was never given more than token funding, a team led by Day has been conducting a pilot study since 2000, diverting part of the Mississippi into the wetlands downstream of the city. "The results are as good as we could have hoped," he says, with land levels rising at about 1 centimeter per year—enough to offset rising sea levels, says Day.
Even if the wetlands were restored and new levees were built, the combination of geologic subsidence and rising sea levels will likely sink New Orleans another meter by 2100. The problem might be solved by another ambitious plan, says Roel Boumans, a coastal scientist at the University of Vermont in Burlington who did his ph.D. at LSU: shoring up the lowest land with a slurry of sediment piped in from the river. The majority of the buildings in the flooded areas will have to be razed anyway, he says, "so why not take this opportunity to fix the root of the problem?" The river could deposit enough sediment to raise the bottom of the New Orleans bowl to sea level "in 50 to 60 years," he estimates. In the meantime, people could live in these areas Venice-style, with buildings built on stilts. Boumans even takes it a step further: "You would have to raise everything about 30 centimeters once every 30 years, so why not make the job easier by making houses that can float."
Whether that is technically or politically feasible—Day, for one, calls it "not likely" —remains to be seen, especially because until now, the poorest residents lived in the lowest parts of the city. Any decision on how best to protect the city in the future will be tied to how many people will live there, and where. "there may be a large contingent of residents and businesses who choose not to return," says Bill Good, an environmental scientist at LSU and manager of the Louisiana Geological Survey's Coastal Processes section. It is also not yet clear how decisions about the reconstruction will be made, says Good, "Since there is no precedent of comparable magnitude." Every level of government is sure to be involved, and "the process is likely to be ad hoc."
Even with the inevitable mingling of science and politics, we still have "a unique chance to back out of some bad decisions," says Good, who grew up in New Orleans. "I hope that we don't let this once-in-history opportunity slip through our fingers in the rush to rebuild the city:"
1. The passage gives a general description of the suggestions to reconstruct New Orleans after Hurricane Katrina.
2. Two examples to deal with water are Netherlands and Venice.
3. The canals have nothing to do with the flooding.
4. The levees will be shored up further with clear long-term fate.
5. The basic problem for New Orleans is the subsidence of Mississippi River delta.
6. The key component of Coast 2050 is wetland restoration.
7. The plan of Coast 2050 will get billions of federal funding.
8. New Orleans will likely sink ________________ by 2100.
