Work continues Friday afternoon on a three-mile segment of the Morganza-to-the-Gulf levee near Pointe-aux-Chenes. The overall hurricane-protection project would be 72 miles.
HOUMA – The clock is ticking down for coastal Louisiana. We’re losing land, another hurricane season in nearing and a billion-dollar plan to restore the coast must be submitted for approval to the state by April 12.
Louisiana’s “great wall” of levees includes Morganza-to-the-Gulf, Terrebonne’s segment, whose proposed alignment curves along the natural bayou ridges and canals of the parish to encapsulate Houma, Dulac, Boudreaux, Chauvin and Montegut within its protective walls before hooking up with the Lafourche levee system at Larose.
For eight long years parish officials fought an uphill battle for authorization of Morganza-to-the-Gulf. Finally, in this congressional session, federal authorization seems imminent, according to officials.
The 72-mile system of “leaky” levees, culverts, floodgates and locks, estimated to cost $888 million, is touted as Terrebonne’s last hope for hurricane protection. And the parish and levee district have defied the project’s lack of federal funding by starting construction on Morganza with money raised by the state and a local sales tax. The first 3-mile stretch of Morganza, near Montegut, is nearing completion.
But is the parish resting its hopes on an unreliable levee system, as some critics claim?
“It’s easy for these people to sit in their universities and pontificate,” said Jerome Zeringue, executive director of the Terrebonne Levee and Conservation District. “But Morganza has been in engineering and design for over a decade. If we’re going to live down here and these communities are going to continue to exist, we have to build levees.”
SHOULD A LEVEE ‘LEAK’?
Morganza is the result of more than a decade of discussion between the community and conservationists, said Kerry St. Pé, director of the Barataria-Terrebonne National Estuary Program.
Though it does incorporate some of the “leaky levee” science into its design, the three-mile span that has been built so far is all made of traditional earthen levee, built higher and with a slope calculated to better handle storm surge.
In the meantime, said Cathy Gibbs, a spokeswoman for the U.S. Army Corps of Engineers, the design process for Morganza is ongoing.
“There are still questions about how many culverts we will use and where, but basically we want to allow for sediment to flow through systems that can be shut during a storm,” Gibbs said. “We’re concerned about restoration and protection, but we have to worry about the people at the same time.”
However, the “leaky levee” is a relatively new concept, and many question whether it will work, and if it’s even a good idea at all, said John Day, an Louisiana State University professor emeritus and a leading estuary researcher.
“It’s almost an oxymoron,” said Paul Kemp, an oceanographer who specialized in storm-surge modeling at the LSU Hurricane Center. “I understand the idea, but I think this was invented in another era. The leaky levee is a compromise that people shouldn’t be willing to make.”
Kemp worries that the “leaky” design will fail at both jobs. The hurricane protection it provides would be unreliable at best, he suggests – earthen levee height is difficult to maintain because of the constant sinking of land in Terrebonne Parish, and the idea that a healthy hydrology could be sustained through a series of doors in a wall is laughable to him.
Any system that restricts the natural hydrology of an area is going to have an effect, no matter how many culverts you put in a levee system, St. Pé said.
St. Pé admits that while levees don’t exactly help the situation for some of the area’s wetlands, if life is to go on nearly as usual in Terrebonne, there’s not much of a way around them, either. The best you can do is build them strategically – and away from sensitive wetland areas.
That’s where many conservationists are finding common ground in Morganza: The levee’s path looks schizophrenic until you note it is dictated by the curves of the bayou ridges and canal banks – it was designed to go out of its way to follow existing hydrological barriers so that it won’t disrupt the natural flow of water.
“Morganza could be a way in which we could balance our need for protection with our need for ecosystems,” said Denise Reed, a scientist with the University of New Orleans, and an adjunct faculty member at the Louisiana Universities Marine Consortium in Cocodrie.
AN ALTERNATE ENDING?
There is one little glitch on Morganza’s wetlands-friendly levee image. A short, dotted line on the state coastal-restoration plan’s levee map illustrates an alternate alignment that does not follow any natural ridges or barriers. Instead, it cuts a clear path across the middle of wetlands from Pointe-aux-Chenes to Larose, walling up a large chunk of wetlands inside the levee system.
The alternate alignment was proposed because the original Morganza system design makes a sharp northward turn in that area, and Lafourche residents believed it would funnel storm surge that came up through Pointe-aux-Chenes right into their parish.
The alternate alignment is still up for debate, but its presence on the map troubles estuary conservationists like Reed and St. Pé.
Windell Curole, general manager of the South Lafourche Levee District, said the wetlands in that area is so degraded anyway that enclosing them within a protective environment could help.
Salt water coming in from the Gulf is chiefly what is eating away at the area marsh, and with a levee in place, according to Curole, the hydrology of the area could be recreated to support a larger variety of wetland plants while providing extra of protection for the people of Lafourche Parish.
St. Pé disagrees with the idea that closing off a marsh could possibly be beneficial.
He would rather restore the natural hydrology than recreate it artificially.
“We don’t have the luxury of just looking at the environmental opinions,” Curole said. “There is nothing in south Louisiana right now that doesn’t cut both ways.”
ANY OTHER IDEAS?
Some have suggested alternatives to the great walls of levees in the state Coastal Protection and Restoration Authority’s plan, but with little time and money to go around, many local officials would just rather stick with what is known.
Day and Kemp suggest looking into ring levees that would encircle vulnerable communities as an alternative to miles-long levee walls.
Zeringue said that while he wasn’t sure how the costs would match up, a series of ring levees around communities would increase the cost and the length of levee systems, and because of the vulnerable areas they would be constructed in, the environmental impact would also increase.
The problem is, there is no time to wait for a radical new idea, Zeringue said. Criticisms are nothing without a realistic alternative option.
“I think we should look at all areas of protection,” said St. Pé, “But I also think a lot of people are not understanding the constraints and the magnitude of the need here. We have 10 years to get serious about all this in my opinion. All these discussions and debates are just delaying things”
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