Fading Away: Louisiana's Battle Against Coastal Erosion

THE VANISHING COAST

It’s long been the goal to tame the Mississippi River. Engineers have spent decades corralling it and containing one of the world’s mightiest rivers. In doing so it has allowed Louisiana to prosper, the river acting as the main artery for the economic heartbeat of the state. It has allowed Louisiana to control one of the largest ports in the country, with goods flowing through in and out of the Gulf of Mexico. As levees have reigned in the powerful floods the river brings, neighborhoods have been allowed to grow up in areas that used to be flood plains. Yet for all the economic success the Mississippi has provided the state, it pales in comparison to its most important contribution of all, the very land itself. 

Every year, as spring begins to melt the snows to the north and rains roll across the country the Mississippi River rises. It picks up sediment as it moves ever quicker down to the Gulf of Mexico where all that sediment is deposited. Naturally this cycle would occur every year with sediment continuously being delivered to the delta, this sediment in turn would build up and rise out of the ocean. Once built up the sediment begins to compact and sink back down, but in a natural cycle as it sank more sediment would be added. It’s on this sediment that Louisiana lies, a constantly sinking plot of land that no longer has access to the sediments that once kept it afloat.

In the quest to tame the river levees were built up along the river to protect areas from flooding, a massive campaign to control the Mississippi began after the flood of 1927. The river was contained and prevented from bursting its banks. Instead of spreading out it’s sediment that same land-building material was dumped by the river offshore, no longer replenishing land that was being lost due to subsidence. Louisiana has been sinking ever since, and the amount of land lost in that time is estimated to be roughly 19 hundred square miles. That’s the equivalent of losing Iberia, St. Martin, and St. Mary Parishes, and experts estimate that without intervention the coast could lose another 4 thousand square miles. Thomas Hymel of Sea Grant put it bluntly: “In the end the coast is disappearing and it’s disappearing fast.” 

It hasn’t solely been subsidence that has caused the Louisiana coast to disappear at astonishing rates, though it has been a significant contributor. Sea levels continue to rise as the climate warms and saltwater intrusion remains a major problem. It’s in the loss of sediments though that engineers see a potential solution to a growing existential crisis for the state.  

RE-ROUTING A RIVER

The headquarters for the Coastal Restoration Protection Authority sits alongside the very river it’s trying to use. Along the Mississippi River in Baton Rouge the building houses a team of engineers working to try and rebuild Louisiana’s vanishing coast. It’s in that building that you can find a replica model of the Mississippi, mapping out all its twists and turns as engineers try and simulate sediment disposal.  In that model there are two cuts, two areas where engineers hope to divert parts of the river as well as capturing those important sediments.  

The concept of a sediment diversion isn’t new, they’ve been done in other river delta’s that are suffering from the same problem. What CRPA is proposing though is the same process but on a different scale. “The difference with this project is the scope and magnitude of restoring a natural process” said Brad Barth, the director of the Mid-Basin Sediment Project. The plan calls for two cuts down river from New Orleans, one that would redirect part of the river to into Mid-Breton Sound and another into Barataria Bay.  

A redirection of the river would help spread the sediments needed for marsh creation out into areas that are losing ground to the Gulf of Mexico and start replenishing the land Louisiana is losing. Edwin Theriot the director for the Institute for Coastal and Water Research says that this is a vital tool in the battle against coastal restoration. “If you’re going to attempt to protect and restore some of this coastline you have to restore a natural system, that’s what a diversion is” says Theriot. While he believes the diversion is vital, he also warns that “we should not expect this to solve our problem, the plan is large but it's not large enough to compensate the damage that was done previously and what we see now with sea level rise and changing weather patterns.” Diversions aren’t perfect, but almost every expert believes you can’t fight coastal erosion without them, even if they’re not the only method deployed. CRPA has been trying to build up barrier islands along the coast to add a buffer to the intrusion of saltwater, but without those sediments sustaining those islands is impossible.

Those who may be skeptical of a river’s ability to build land need to look no further than the eastern side of Vermilion Bay. Over the last few decades, the Atchafalaya River has been creating marsh and building land, one of the few areas Louisiana is seeing natural restoration. Thomas Hymel of Sea Grant believes that this area could be used as an example for the benefits of the proposed Mississippi diversions: "You look at a major example of what diversions are already operating you look at the Wax Lake outlet along the Atchafalaya Delta, that's the exact same water that's coming off the Mississippi. It's a robust ecological system, there's tremendous fisheries in it and around it." 

WORRIED ABOUT FRESH WATER

While shrimpers, fisherman, and crabbers will all be impacted perhaps none will be as affected as oysterman. “It affects oysters a whole lot because oysters don’t move,” said Ralph Pausina the President of the Oyster Growers and Dealers Association. Traditionally the Barataria Bay has been a prime location for oysters, due in part to the perfectly balanced salinity that the bay has to offer. The oyster industry has already suffered through changes in salinity, the oil spill and countless hurricanes and Pausina worries that this is just going to be another hurdle they’ll have to face.  

“As soon as that diversion thing was approved that was one of the reasons why I retired too because right where that's going to flow out that's right where our business was. Right there at the Wilkerson Canal. There's a 500-acre lease right there, and it's just going to be destroyed,” said Pausina. When asked if he knew people who still had leases in the Barataria he responded that they did and that “they're just waiting, you know sooner or later something terrible is going to happen.” 

Oystermen may see the biggest impacts from an increase in fresh water, but they’re far from the only ones. Shrimpers worry that by diverting the rivers into these bays they’ll lose the ability to catch Brown Shrimp, a particular species of shrimp that rely on these areas. Shrimpers say that you can’t find Brown Shrimp anywhere else in Louisiana because the salinity is already too low in other spots along the coast.  

“The folks that are the fisherman, have these concerns. They have these real concerns on what it's going to do to their livelihood, the social fabric, the economic fabric of these coastal communities," said Hymel. There have been meetings between seafood industry representatives and CRPA to discuss these issues, and an environmental impact study is currently underway to study the consequences of the diversions. The results from the study of the Barataria cut should be available for the public by the end of 2020, and studies will be available public comment for Breton Sound by next year.  

THE COST OF DOING NOTHING: PARADISE LOST

The road that runs to the Isle de Jean Charles is surrounded by water, it’s more a bridge then it is a road and even that feels like a generous description. Pieces of the road are crumbling and falling into the Gulf of Mexico, and with a strong enough wind the water will come up over it, isolating the Isle de Jean Charles. At its peak Isle de Jean Charles was home to about 600 residents, predominantly of tribal ancestry, but that number is down to about a dozen families. Chantel Comardelle who used to call the island home but has since moved described the encroaching salt water as a cancer. “It’s slowly eating it away and you can see it every time you go,” she said. 

The loss of the Isle de Jean Charles is the cost of doing nothing. It’s an example of ignoring a problem and hoping that it goes away. Comardelle said her grandfather started trying to ring the alarm bells about what was happening 60 years ago: “He was very outspoken about it; he clearly could tell. He said it's beyond the point of being able to fix it. Either something desperately has to be done to try and reverse it, or we just have to live with it and adapt to it."

As more and more of the coastline is lost other communities will be threatened, and more people will have to be relocated as the sea slowly swallows their home. Theriot estimates that roughly 2 million people who live coastal Louisiana are threatened by storm surge and coastal loss. "We'd have to move people back from the existing coast, we have to do that now," says Theriot when asked about the consequences of not seriously addressing the issue, adding that if we did nothing the coastline would be around I-10 in 40 years.  

Comardelle now lives in Houma, further inland and away from the expanding Gulf of Mexico but even then, still says she can see the affects from a loss of coastline. “It's really scary, even 30 miles from the coast every time we have a storm no matter how little or how big it is you see the water line get a little bit higher every time.” The diversion isn’t a perfect solution, unfortunately, when it comes to restoring the coast a perfect solution doesn’t exist and sitting around looking for one isn’t an option either. "You've got to do something. Doing nothing you can see what's happening," said Hymel.

THE FUTURE OF THE COAST

"In the end the coast, we're not ever going to recover our coast to the degree that you might imagine," was the assessment offered by Hymel. The damage done to the coast is extensive, decades of land loss that likely can’t be undone, but the hope is that it can at least be slowed. "I think it is a major daunting task that we're in a fight against,” said Barth. Almost everyone who spoke about this project has a personal story about seeing fishing spots vanish in their lifetime. The fight to save the coast though must go on, too much depends on it. As Louisiana saw in 2020 the value the coastal marsh offers in buffering storm surge is unmeasurable, it’s our last line of defense against the Gulf’s most powerful storms. "That marsh loss is backing up to our line of protection. And as you lose that then it jeopardizes that line of protection. It jeopardizes the levee systems and the flood reduction systems we have in place to protect the communities that live behind them, said Barth.

Our economy, culture, and heritage are all tied up in the activity along the coast and parts of that are threatened by the encroachment of salt water. CRPA is already putting together the 2023 Coastal Master Plan and diversions, dredging and other land building tactics will certainly continue. Among those tactics the diversion of the Mississippi River will be one of the biggest and most important tools in that battle. Engineers in reigning in the river allowed for the Mississippi to provide for Louisiana’s past, now engineers hope they can get the river to provide for Louisiana’s future.