Removing the levees, finally

Cornelia Dean has an article in The New York Times about changes in attitude and changes in altitude:

In the 1960s, a group of businessmen bought 16,000 acres of swampy bottomland along the Ouachita River in northern Louisiana and built miles of levee around it. They bulldozed its oak and cypress trees and, when the land dried out, turned it into a soybean farm. Now two brothers who grew up nearby are undoing all that work. In what experts are calling the biggest levee-busting operation ever in North America, the brothers plan to return the muddy river to its ancient floodplain, coaxing back plants and animals that flourished there when President Thomas Jefferson first had the land surveyed in 1804.
“I really did not know if I would ever see it,” said Kelby Ouchley, who retired last year as manager of the Upper Ouachita National Wildlife Refuge, which owns the land. He pursues the project as a volunteer consultant in coordination with his brother Keith, who heads Louisiana operations for the Nature Conservancy, which helped organize and finance the levee-busting effort.
The idea goes against the grain in Louisiana, where people have battled river flooding since colonial days. European settlers were often required to build levees to establish homesteading claims; in recent decades, landowners built levees to create farmland by the hundreds of thousands of acres. Hurricane Katrina brought a clamor for more and stronger levees to protect people and buildings farther south.
Yet at the same time, there is a growing awareness that Louisiana’s levees have exacted a huge environmental cost. Inland, cypress forests and wetlands crucial for migrating waterfowl have vanished; in southern Louisiana, coastal marshes deprived of regular infusions of sediment-rich river water have yielded by the mile to an encroaching Gulf of Mexico. Some scientists have suggested opening levees south of New Orleans so the Mississippi River can flow normally into the swamps.
The parcel that the Ouchley brothers plan to restore, known as Mollicy Farms, was added in the 1990s to the federal Fish and Wildlife Service’s Upper Ouachita holdings in a series of purchases assisted by the Nature Conservancy and totaling $6.6 million. The brothers and their organizations have since worked on several environmental projects there, including a 10,000-acre tree-planting operation, Kelby Ouchley said.
The workers replanted cypress and tupelo in low areas, then oaks and green ash, and then sweetgum and pecans— “life-sustaining, system-supporting diversity,” as Kelby Ouchley called it in an essay.
Eventually, he predicted, the restored landscape would be home to black bear cubs, largemouth bass, fireflies, crawfish and “gobbling wild turkeys and cottonmouths with attitudes.” Still, the brothers felt dissatisfied. A few years ago, Keith Ouchley said, “I was standing on the giant levees with my brother and I said, ‘Well, there is one thing missing here. The big challenge is restoring this floodplain.’ ”
Environmental scientists say the very notion of undoing levee construction may be the most important aspect of the Ouachita project. “The idea that we can take levees down— that’s a good thing,” said Denise Reed, a coastal scientist at the University of New Orleans. Dr. Reed is also among those advocating levee-opening on the Mississippi south of New Orleans, a proposal that she says is under review by state officials. The more rivers like the Ouachita are again permitted to flood, she said, “the more they function like rivers and the more we get what we need out of them in terms of habitat.”
The Nature Conservancy has already taken part in levee-busting projects on Klamath Lake in Oregon and the Emiquon Preserve on the Illinois River in Illinois to help restore wetlands. But the Ouachita project is far larger, people involved say, both in its size— roughly 25 square miles— and the effort required to remove each levee, roughly thirty feet high and 120 feet wide at the base.
The plan, designed by hydrology experts whose work was financed in part by $250,000 from the Nature Conservancy, was originally to use bulldozers to chew away at the levees in five places and then wait for spring floods to level them gradually, said George Chandler, the project leader for Fish and Wildlife Service projects in North Louisiana. The effort was to have begun last fall, he said, but heavy rains forced a delay until May, when unusual rains delayed it again. On 23 May, the swollen Ouachita seized the initiative, breaking the levee and flooding the Mollicy acreage. At first, Mr. Chandler said, people involved in the project feared that the flood would smother the newly planted trees with sediment from the river and dirt from the levee itself. But they emerged unscathed. The plan now, he said, is to start bulldozing in late July or early August. “We expect that next fall or winter, whenever the river comes back up, we will have normal flows of water that will return to these bottomlands out there,” Mr. Chandler said. “It will rise and fall with the rhythm of the river.”
The work is expected to cost more than $4 million.
Cristina Mestre, a spokesman for the conservancy, said her organization would monitor the site for four years. The conservancy hoped its work there would serve as a model for other restoration projects, Ms. Mestre said.
Project planners worry that the project could have unintended effects. For example, Kelby Ouchley said, it is theoretically possible that opening the levees could alter water flow enough to force the river into a new course. On the other hand, Keith Ouchley says, planners hope the project will reduce flood threats downstream “by providing more storage capacity in the river’s flood plain, like it normally would have.”
Mr. Chandler said recent events suggested that this hope was well founded. After the levee was breached in May, a flood threat to the downstream city of Monroe subsided.
In any event, Kelby Ouchley said: “If we make mistakes, other people will learn from them. It’s recognized here as a win-win thing.”