Many well-meaning advocates of Southern Louisiana push for massive levee projects expanding across Louisiana far out to protect small towns way down on the coast. I agree that we need some big levees, especially around already concentrated populations in lower risk areas. However, any discussions of levees should include considerations of their downfalls.
1) Levees are very expensive to build and also very expensive to maintain. A poorly built or maintained levee- as we saw in Katrina- is like not having levee at all! The larger the levee, the harder the fall if it is compromised at any one point.
2) Levees encourage development. The more "protection" we build in flood-prone areas, the more we actually encourage people to move there and to build their lives there on a sense of false security. This is probably not wise in extremely marshy, low-lying areas so close to the Gulf. Undeveloped coastal areas should probably stay that way, supporting only the existing population necessary to do the work of coastal industries.
3) Levees kill wetlands. The more levees you put down, the more cut off outside wetlands are from river water and sediment that builds them. As wetlands die, communities are closer and closer to open ocean and no protection other than the levee from storms.
4) Levees harm wetland ecology! Shrimp and other yummy seafood need to go from salty water nurseries to more freshwater areas in their lifespan. If you prevent this by building a levee across wetlands, you endanger all of that good seafood that keeps the people of coastal Louisiana enjoying life there in the first place.
You can't have it all-- you can't save the wetlands, build a huge levee system surrounding every small town, and live like you did before Katrina. Even if it could be done, Congress isn't going to fund it in the forseeable future; the American taxpayer won't tolerate it. You have to find a realistic balance.
If even conservative estimates are correct, the Cajun coast is most certainly going to suffer some loss in this coming century. The solution to preserving this culture is not to build a giant wall around every house that has been built. No, the solution is for strong-willed leaders to make the smart, tough decisions that achieve the most sustainability possible for the entire region.
Yesterday I asked an expert in land-use planning the following question: "Where will we get the political capital to make these tough choices? How can we grow the spine to tell tax-paying, hard-working people that their area is just too risky or that a huge levee is not the answer?"
That expert's answer? "Well, that's the big question."
My suspicion is that we if ever get that political capital, it will be through persistent education of our communities. So spread the word.