Rebuilding Louisiana’s Disappearing Delta

FRITCHIE MARSH, SLIDELL, LOUISIANA — “It all changed after Katrina,” Earl Jackson told me, shaking his head as he reeled in his bait. I found him fishing on the side of a two-lane highway here, 30 miles outside New Orleans, and he recounted how, more than a decade after the hurricane, the land here still hasn’t recovered. “That high water, whoa, it wreaked havoc through that area down there,” Jackson said, gesturing to the south. “I know down in Delacroix, the marsh has changed.”

Such is the sobering reality of the modern, storm-ravaged Mississippi River Delta, a lingering and expensive problem at which politicians and engineers continue to throw a whole lot of money — and sand.

Louisiana is in the midst of a $50 billion, 50-year plan to rebuild its disappearing marshland and reconstruct its delta’s protective shield of barrier islands. Last month, a federal-state task force approved more than $70 million of coastal protection and restoration work in wetlands like Fritchie Marsh and barrier islands like the Caminada Headlands on Grand Isle.

Many of these projects have been decades in the making. But now, after reprioritizing Louisiana’s extensive list of coastal reconstruction projects, several have been given the green light. (See map below.)

https://undark.cartodb.com/viz/66bce502-d03d-11e5-9965-0e3a376473ab/embed_map

Why is rebuilding this “green infrastructure” important? It’s not simply about restoring oyster beds and breeding grounds for piping plovers. By nourishing its defaced coast, the hope is that New Orleans and its surrounding parishes will be better protected from inundation, whether brought on rapidly through storm surges or gradually through sea level rise. It’s not a new problem: Louisiana has lost over a million acres of wetlands since the 1930s — in large part due to coastal development, but also as a result of devastating storms like Katrina.

Fritchie Marsh is beautiful and eerie. While there, I saw huge tufts of marsh grass and soaring pelicans. I saw the skeletons of houses torn down by Katrina, teetering on their stilts at awkward angles, as if still reeling from the waves. I also saw lots of open water — one of the symptoms of an unhealthy marsh choked off from freshwater and nutrients. A healthy marsh will soften storm surges, buffering wave energy by reducing their height.

That’s what the recently approved $3 million Fritchie Marsh restoration project aims to achieve. The plan calls for dredging up between 2 and 5 million cubic yards of sand and sediment from nearby Lake Pontchartrain, piping it into Fritchie, and creating several hundred acres of new marsh, in addition to nourishing existing marsh. The plan also calls for adding several miles of terraces: 3-foot-tall ridges built into the open water that encourage new marsh to form. The whole project, if fully funded with $30 million, would benefit more than 1,000 acres of Fritchie Marsh.

Some Fritchie Marsh residents aren’t too optimistic about the reconstruction plans. Roy Darby, a crab fisherman living in a newly-built elevated house here, thinks it’s futile to pour money and sand into Fritchie, and that it would be better spent on more vulnerable parts of the Louisiana coast.  “To me, that would be asinine,” he says of the plan to relocate all that sand and sediment to Fritchie. “I don’t even see the purpose of it. It don’t make any sense to me.”

That’s the complicated thing about Louisiana’s disappearing delta. There are hundreds of marshes like Fritchie and a long string of barrier islands that could all be improved. So how do you decide which is worth the effort, especially in the face of increasingly tenacious storms?

I put the question to Ioannis Georgiou and Mark Kulp, two geologists at the Pontchartrain Institute for Environmental Sciences at the University of New Orleans. The coastal restoration projects that are most successful, they explain, will be sites that, when nourished, will in turn dole out benefits to the overall system. Establishing marshland that protects residential real estate while sheltering young fish, for example, or reinforcing a barrier island with sediment that, when eroded, feeds two other adjacent islands.

“It’s not just about building new land or minimizing our land loss,” says Georgiou. “What if the mineral sediment you’re adding makes your present footprint more resilient to other events, helps those marshes build more organic sediment, and keeps pace with sea level rise?”

That, scientists, politicians and fisherman can all agree, would definitely be more bang for your $50 billion buck.