Turning the Tide

There had been big changes in southern Louisiana since my last visit in January 2006. For one thing, there was about 1.5 billion square feet less of it.

The state’s coastal wetlands—wild, beautiful fish and wildlife sanctuaries that sustain ecosystems far inland and far into the Gulf—have been disappearing at the approximate rate of 83,000 square feet per hour since 1932. That was about 60 years after the Army Corps of Engineers set about “protecting” floodplain residents with large levees that constrict the Mississippi River, squirting marsh-building sediments out to sea, where they fall off the continental shelf. It’s like heating your house by burning the beams, floors, and siding.

The levees have reversed an ancient process by which the river eased over its floodplain, snowing sediments and creating flood-absorbing marsh at the rate of between 800,000 and a million acres per millennium. Now, as the Gulf of Mexico races inland, storm surges get higher and stronger, more hurricane levees fail, and more get built.

But in June 2008 I saw other big changes, too—encouraging changes. At least in state and federal government, most everyone had abandoned the notion that levees by themselves can protect people. Educated by Hurricanes Katrina and Rita, most agencies now agree that barrier islands have to be rebuilt, and wetlands restored by pumping or diverting sediment from the river into silt-starved marshes destroyed or degraded by wind, waves, and saltwater intrusion.

On June 5, 2008, a week before I arrived in Louisiana, Congress had authorized the U.S. Army Corps of Engineers to plug the Mississippi River Gulf Outlet (“Mr. Go”)—the 76-mile, little-used shipping shortcut between the Gulf and New Orleans that has destroyed or degraded at least 27,000 acres of wetlands by burying them with spoil and exposing them to waves from ships, and that funneled storm surges into New Orleans. At Parrain’s Seafood Restaurant in Baton Rouge, Natalie Snider and Steven Peyronnin of the Coalition to Restore Coastal Louisiana, Paul Kemp of Audubon’s Louisiana Gulf Coast Initiative, and I raised our beer mugs and toasted Mr. Go’s impending demise.

In 2006 ancient cypress swamps that had slowed and absorbed storm surges were being clear-cut for garden mulch. Last year Wal-Mart and Lowe’s, heeding the pleas of Audubon and other environmental groups, stopped marketing cypress mulch from southern Louisiana, shutting down most local suppliers.

A measure of enlightenment seems to have descended upon even the Corps’ New Orleans district office, which is embracing the idea of restoring and protecting wetlands as levee buffers. The Corps is backing away from the super levee it conceived before the hurricanes, when its strategy was to charge out in front of the wetlands, carve a line in the sand, and dare the sea to step across it. The 72-mile “Great Wall of Louisiana,” as the project is called by its many critics, would weave from Morganza to the Gulf, through the Terrebonne Basin between Larose and Houma, cutting 550,990 acres of wetlands off from the river and exposing them to development. According to the Corps’ own model, it would funnel storm surge, increasing the high-water mark by as much as 12 feet.

When the Great Wall was conditionally authorized as part of the 2000 Water Resources Development Act (WRDA), it was going to cost $680 million, but because the Corps was late filing paperwork, it had to be restudied and reauthorized in the 2007 WRDA, at which point it was going to cost $882 million. With that, the Corps announced that the real cost would be at least 20 percent higher than this last estimate, which meant the project would have to be re-restudied and re-reauthorized. Now there are federal requirements for better, non-local construction material that will have to be trucked or barged in, soaring fuel costs, and new specs for greater height and width. So the Great Wall’s expected cost has ballooned by least 1,000 percent. The latest (not final) estimate is between $10.7 billion and $11.2 billion.

“The Corps realizes the levee has to be bigger,” says Paul Harrison, the Environmental Defense Fund’s coastal Louisiana project manager. “And that can be a fatal flaw, because if you build something bigger out in the wetlands, it becomes exponentially more expensive and may become physically impossible. I think there are a lot of people in the Corps who realize this is a boondoggle. Frankly, it’s not going to work.”

Using wetlands and barrier islands as the first lines of defense against floods is central to the “multiple lines of defense strategy” being pushed by the state and the environmental community. You protect wetlands by nourishing them with flows of freshwater from the Mississippi that simulate natural, pre-levee flooding. This keeps out saltwater, which can destroy wetland vegetation. You restore wetlands by saturating them with silt pumped from the river or, where possible, cutting diversion channels in levees and letting the river deposit the silt itself.