Rebuilding Louisiana Wetlands
ROBERT SIEGEL, host:
Billions of dollars are being earmarked to undo the damage from Hurricanes Katrina and Rita. Getting people and businesses back on their feet is the top priority. Somewhere down the list is restoring coastal wetlands. Wetlands have been disappearing as southern Louisiana has become more urbanized. Many scientists believe creating new wetlands is key to protecting the region from the next storm, but as NPR's Christopher Joyce reports, they're not sure how to do that yet.
CHRISTOPHER JOYCE reporting:
Turn a corner in southern Louisiana and you could find yourself in a wetland, like Cypress Lake in southern Lafayette. It's in the city so there's a helpful sign about the alligators.
Mr. ROBERT TWILLEY (Ecologist, Louisiana State University): Do not feed the alligators, but, you know, we slip every now and then in following authority around here. You know, it's easier to get forgiveness than permission.
JOYCE: Robert Twilley has spent a lot of time in alligator territory, the region's three and a half million acres of coastal wetlands. Twilley is an ecologist at Louisiana State University. He says clearing marshes for navigation channels and oil pipelines has nibbled away at the wetlands, which act like a giant sponge. A smaller sponge meant less protection from storm surge when Katrina hit.
Mr. TWILLEY: We're going to have to rethink our entire idea of exactly what kind of landscape is required and needed to actually protect New Orleans.
JOYCE: That means remaking a landscape. Some say that's even harder than rocket science. It took decades, after all, just to plan the restoration of Florida's Everglades. In southern Louisiana the job's even tougher. The wetlands are smack up against towns and cities and the nation's biggest oil patch and one of its biggest fisheries.
Mr. TWILLEY: There are very important inconveniences that some industry is going to have to put with related to the protection of public good.
JOYCE: The Louisiana Gulf Coast is a river delta made up mostly of sediments spit up by the flooding Mississippi. Levees have cut off that source of sediment, so New Orleans sinks while the wetland buffer shrinks. To protect the city, the levees can be built higher, but what about the sponge?
Mr. JERRY GALLOWAY (Civil Engineer, University of Maryland): Katrina should be a slap up the side of the head with a two-by-four telling us that we've got a real problem and that we need to deal with it.
JOYCE: Jerry Galloway is a civil engineer at the University of Maryland. He says there's a hopeful experiment already under way in Louisiana. At a place called Carnarvon, engineers cut several 15-foot-square culverts into a levee. These allow 18,000 cubic feet per second of fresh water to flow into wetlands and that's a lot of sediment, food for wetlands. But after 10 years, scientists can't be sure it's the best way to restore wetlands. Galloway says that's the way it is with ecological engineering. It's experimental.
Mr. GALLOWAY: Well, this makes people who are handing out money--the Office of Management and Budget of the Congress--very nervous because they see it as a blank check.
Representative WAYNE GILCHREST (Republican, Maryland): You folks are in a fishbowl right now. You're in the laboratory.
JOYCE: That's Maryland Representative Wayne Gilchrest at a recent hearing in Congress. He expressed a certain anxiety about how scientists might spend taxpayers' money in Louisiana.
Rep. GILCHREST: Our constituents want it done right and our constituents want that sediment to build up. They want the wetlands to protect the buffers. And I'm not just saying because I'm a green, radical moderate Republican. These are issues now that are in the forefront.
JOYCE: The trouble is scientists aren't sure what will work for Louisiana's wetlands. For example, geologist Mark Culp(ph) of the University of New Orleans thinks punching holes in levees might not work as well as simply building more land.
Mr. MARK CULP (Geologist, University of New Orleans): Sediment is dredged up with machinery that pushes it through pipelines. And those pipelines are directed by the coastal engineers to key locations where the sediment then accumulates at the other end of the pipeline. And then in many cases we actually go out and vegetate that newly created land.
JOYCE: The National Wildlife Federation, Environmental Defense and other groups are pushing Congress to approve a $5.5 billion restoration plan. Three billion would go for more diversions like Carnarvon and land building. Another billion would go for more study if Louisiana can wait. Christopher Joyce, NPR News.
MELISSA BLOCK (Host): You're listening to ALL THINGS CONSIDERED from NPR News.