http://www.sciam.com/print_version.cfm?articleID=00060286-CB58-1315-8B5883414B7F0000
Excerpt from Scientific American Oct 2001
The Scare
Humankind can't stop the delta's subsidence, and it can't knock down the levees to allow natural river flooding and meandering, because the region is developed. The only realistic solutions, most scientists and engineers agree, are to rebuild the vast marshes so they can absorb high waters and reconnect the barrier islands to cut down surges and protect the renewed marshes from the sea.
Since the late 1980s Louisiana's senators have made various pleas to Congress to fund massive remedial work. But they were not backed by a unified voice. L.S.U. had its surge models, and the Corps had others. Despite agreement on general solutions, competition abounded as to whose specific projects would be most effective. The Corps sometimes painted academics' cries about disaster as veiled pitches for research money. Academia occasionally retorted that the Corps's solution to everything was to bulldoze more dirt and pour more concrete, without scientific rationale. Meanwhile oystermen and shrimpers complained that the proposals from both the scientists and the engineers would ruin their fishing grounds.
Len Bahr, head of the governor's Coastal Activities Office in Baton Rouge, tried to bring everyone together. Passionate about southern Louisiana, Bahr has survived three governors, each with different sympathies. "This is the realm in which science has to operate," Bahr says. "There are five federal agencies and six state agencies with jurisdiction over what happens in the wetlands." Throughout the 1990s, Bahr says with frustration, "we only received $40 million a year" from Congress, a drop compared with the bucket of need. Even with the small projects made possible by these dollars, Louisiana scientists predicted that by 2050 coastal Louisiana would lose another 1,000 square miles of marsh and swamp, an area the size of Rhode Island.
Then Hurricane Georges arrived in September 1998. Its fiercely circulating winds built a wall of water 17 feet high topped with driven waves, which threatened to surge into Lake Pontchartrain and wash into New Orleans. This was the very beast that L.S.U.'s early models had warned about, and it was headed right for the city. Luckily, just before Georges made landfall, it slowed and turned a scant two degrees to the east. The surge collapsed under suddenly chaotic winds.
A Grand Plan
The scientists, engineers and politicians who had been squabbling realized how close the entire delta had come to disaster, and Bahr says that it scared them into reaching a consensus. Late in 1998 the governor's office, the state's Department of Natural Resources, the U.S. Army Corps of Engineers, the Environmental Protection Agency, the Fish and Wildlife Service and all 20 of the state's coastal parishes published Coast 2050--a blueprint for restoring coastal Louisiana.
No group is bound by the plan, however, and if all the projects were pursued, the price tag would be $14 billion. "So," I ask in the ninth-floor conference room adjacent to the governor's office in Baton Rouge, "give me the short list" of Coast 2050 projects that would make the most difference. Before me are Joe Suhayda, director of L.S.U.'s Louisiana Water Resources Research Institute, who has modeled numerous storm tracks and knows the key scientists, Corps engineers, and city emergency planners; Vibhas Aravamuthan, who programs L.S.U.'s computer models; Len Bahr; and Bahr's second-in-command, Paul Kemp. All were involved in designing Coast 2050.
First and foremost, they decide, build a river diversion at several critical spots along the Mississippi, to restore disappearing marshland. At each location the Corps would cut a channel through the river levee on its south side and build control gates that would allow freshwater and suspended sediment to wash down through select marshes toward the gulf. The water could disrupt oyster beds, but if the sites were carefully selected, deals could be made with landowners.