News

Sediment Impediment

by Walter Pierce

Wednesday, May 25, 2011

Thanks to a myopic Army Corps of Engineers and stubborn coastal politics, Louisiana is squandering an opportunity with the Mississippi River flood. By Walter Pierc****e

At a forum last week in Belle Chasse hosted by America's Wetlands Foundation, virtually everyone - politicians, ecologists, hydrologists, constables, merchants, geologists, land owners and residents - agreed: Louisiana's coast is nearing a point of no return and desperate measures to restore it must be undertaken. Yesterday.

Wednesday, May 25, 2011

Thanks to a myopic Army Corps of Engineers and stubborn coastal politics, Louisiana is squandering an opportunity with the Mississippi River flood. By Walter Pierc****e

At a forum last week in Belle Chasse hosted by America's Wetlands Foundation, virtually everyone - politicians, ecologists, hydrologists, constables, merchants, geologists, land owners and residents - agreed: Louisiana's coast is nearing a point of no return and desperate measures to restore it must be undertaken. Yesterday.

But that meeting south of New Orleans also underscored how diverse the stakeholders are in coastal restoration, and how unanimity on the solution is nearly impossible. Many of the coastal politicians want massive federal projects to pipe sediment into the marshes to restore land, believing that their political livelihoods depend on keeping their constituents - people living in areas that, before the 1927 flood and the advent of Army Corps of Engineers levees and river-control structures, routinely flooded each spring - high and dry.

What gets almost no traction at these meetings is talk of restoring the river's natural processes, because while a flood may be good for the coast, it's bad for people.
In the backdrop of the meeting was a once-in-a-lifetime flood from a swollen Mississippi River, and efforts - heroic, praise-worthy and widely disseminated by the media - to mitigate it, to save homes, people and pets.

"This is a national disgrace," AWF Chair R. King Milling of New Orleans said at that meeting. "During this flood season, we are painfully reminded that actions of man have trapped these wetland-building waters and funneled them past some of our most deteriorating ecosystems in the world."

A few media outlets have reported on the plus side of the flood for crawfishermen and shrimpers - an influx of fresh water in the basin where crawfish breed and along the coast where shrimp spawn will likely be a boon for the those populations.

What hasn't been widely discussed, except among scientists, is both the benefit of millions of tons of sediment from the diverted Mississippi River replenishing our wetlands, and the idea - a politically sensitive one to be sure - of using river control structures like the one at Morganza - to do what Old Man River did for millions of years through annual spring floods: build land.

"Politically that's not a very popular opinion," says Dr. Len Bahr, a widely respected authority on coastal ecology and former LSU professor. "But after this flood, there's a great opportunity to make that case again. People can understand, I think."

Bahr spent almost two decades in the Governor's Office of Coastal Activities after his years at LSU and was an outspoken critic of Gov. Bobby Jindal's berm plan during the BP spill crisis last year. He, along with other scientists unencumbered by the political calculus of balancing constituents against a coast in peril, believes this historic flood event provided an opportunity - one that we are squandering.

"It's my feeling, and most of the scientists would agree, that the Corps of Engineers has long known that they should be preparing for unusual high flood events like this - this one is exceptional, but even every three or four years there's a pretty good flood, and right now we've had very little capacity to take advantage of that," Bahr says. "So, when the sediment comes down it gets either washed offshore into deep water or it fills up the [man-made navigation] channels and gets dredged and dumped off shore. And that's just a tremendous waste of a resource."

Paul Kemp of the National Audubon Society agrees, telling NPR's All Things Considered recently, "I would have loved to say, This was the event we were waiting for. We were prepared and we were able to do 50 years of restoration in one year.' I can't say that today."

"The tragedy of this opportunity is that there are tons of sediment moving past an area that's vitally starved for it," Val Marmillion, managing director of the AWF, told The Daily Comet in Thibodaux last week. "Our country can't plan ahead enough to realize that we can take that sediment suspended in the river and use it to build land."

The Corps, Bahr and others contend, is too focused on controlling the river and doesn't pay enough attention or devote enough resources to working with the river to ensure the vitality and long-term rebuilding of the coast, especially south of New Orleans, which is vanishing at a fleet clip.

"The Corps of Engineers has been given three missions but they only pay attention, in my judgment, to two of them - navigation and flood protection," Bahr says. "So, they've regulated the whole river system to the point where they're very proud of having devised ways of keeping it within the levees most years. And when something like this year's event happens, they're totally unprepared to be able to harvest any of that sediment."

Bahr cites two examples - little-known, smaller flood control structures on the east bank of the Mississippi River south of New Orleans known as Davis Pond and Caernarvon - that, although they've been opened in the past, were not unlocked by the Corps for this historic event. Opening those structures would have diverted tons of sediment into the marshes. But coastal politicians, oystermen and others have long fought such emergency measures, and the Corps kept them shuttered, blowing an opportunity to rebuild a lot of marshland quickly - at the expense, no doubt, of some homes, businesses and oyster beds.

"The third mission of the Corps is to restore the coast, but I never felt deep down like they took it seriously," Bahr laments. "Their engineers are not ecologists and they're not geologists, and they respond very much to public pressure and to political influence, and the politicians don't understand the science either. There's not been a lot of leadership shown by the governor's office where I used to be, and so we've got this once-in-a - take the number you want, the Corps will probably call this a one-in-a-1,000-year event, which I don't believe. But it's an exceptional event, and we should have seen it coming and tried to convince the Corps to be ready, to be able to open everything up and let her rip."

It's widely understood that the levee system built by the Army Corps of Engineers following the 1927 flood chimed a death knell for the complex ecosystem of the Louisiana coast. The sediment that annually replenished what wave and wind stole stopped flowing because the river was prevented from operating as it naturally had for millions of years - swelling with the spring runoff from Midwestern rains and snow melts and disbursing that silty beneficence over the coastal marshes.
Dr. Robert Twilley, a distinguished coastal scientist and UL Lafayette's vice president for research, says decades-old news articles indicate that engineers knew as the levees rose that it would have an effect on sediment distribution and the coast. "Trade-offs were made," Twilley told the AWF gathering in Belle Chase, "and now we have to deal with them for the next generations."

And as we've cut off low-lying areas traditionally subject to flooding by muscling the Mississippi into a levee system, habitation - homes, camps, businesses - have filled the void created by our control of the river.

"Levees are what I call a moral hazard," adds Bahr. "They lull the public into thinking they're protected, and they are to some extent."

Likewise, salt water-loving oyster leases crept northward as land gave way to sea. Yet, within that void now filled by thousands of homes, some of which by the time this article is published will be inundated thanks to the opening of the Morganza River Control Structure, few were prepared. A recent analysis by The Times-Picayune finds that of the 561 homes in Krotz Springs, only 51 have federal flood insurance. In Butte La Rose, 20 percent of homeowners carry the insurance.
Bahr still sees solutions in our predicament, thanks to an anticipated windfall for the state from last year's BP disaster.

"The smartest thing we could do with the BP money, some of which should be coming pretty soon, is not to build projects, but to use it to buy land, to buy real estate, to buy the surface rights at least, so that people would not be able to rebuild in flood-prone areas," he says. "Then you could build diversion projects that would flood the land without having to worry about lawsuits and people saying, You flooded me out.' That would be in the long term the cheapest way to spend money."

But don't hold your breath; save it, instead, for the next flood.