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Wetlands – Our Hope, their future

Wetlands – Our Hope, their future

The Mid-Barataria Sediment Diversion Project

Blog by Al DuVernay III, Paleontologist, CRCL Volunteer

November 3, 2023

After thousands of years on the planet, a conspicuous conclusion is that modern humanity is rarely accused of being an attentive and productive steward of our environment. Our natural resources are truly abundant and may seem limitless. Alas, they are not. Take the Mississippi River, which is indeed a formidable powerhouse of nature. Over eons, she has patiently, doggedly drained and crafted most of the land within its basin down to and into the Gulf of Mexico. She is a sediment delivery machine second to none.

Millisecond by millisecond, day by day, eon by eon, she has drained much of the continent and simultaneously deposited land-building sediment and nutrients. The older upstream portion of the valley is mature hard ground suitable for roads, buildings, agriculture and a variety of human activities and enterprises. By contrast, the lower, youngest portion of this essential landscape is quite squishy and very fragile.

The river’s modus operandi is that it is continuously changing. Grain by grain, slurry of mud by slurry, she provides a substrate for a vast assemblage of flora and fauna to claim and thrive. A natural event like a storm or flood regularly occurs and destroys acres or perhaps millions of acres of this new terra (sub) firma. No matter. She instantaneously gets busy ruthlessly building toward the sea. Always toward the sea, nourishing wetlands and building land. These are our nation’s wetlands, and they are the cradle of life.

There is a new river diversion project proposal for the Barataria Basin in southeast Louisiana. The basin includes all of the land and wetlands on the west bank of the Mississippi River from Luling to Grand Isle. We have lost a tremendous amount of land in the basin over the decades, and we are continuing to lose it at an alarming rate. I have personal and intimate experience with the demise of our ecosystems — and equally with the tools and techniques used for restoration. The Environmental Impact Statement for the Mid-Barataria Sediment Diversion is a public document and is available on the Army Corps of Engineers’ website. Please read and understand it. Do it for our progeny. For our legacy.

A verity of our local environment and way of life is that we are losing our coastal lands and countless resources at a disturbing rate. This is demonstrable and not in dispute. What to do about it, however, is up for debate and is indeed quite controversial. Some of this land loss is due to the natural phenomena of subsidence. Sediment deposited by water quite simply dewaters and compacts over time. Most of our land loss, however, is anthropogenic. Yep, we did it with laser focus and resolve. We did it over decades and indeed, even centuries. We did it, of course, with the best of intentions, i.e., for the betterment of our existence in this environment; for our safety and security and to enhance our access to vital resources.

Land Loss in Louisiana

These maps, from the United States Geological Service, show wetlands around Buras in 1960 and open water in the same spot in 2020.

Since Europeans first settled here hundreds of years ago, they built levees to protect their properties. They were small-scale and private structures at first, then massive communitywide, government-sanctioned projects. These levees prevented the river from delivering the sediment necessary for building and sustaining the wetlands.

We also dug channels through the wetlands to improve conveyance of people and resources. Unfortunately, these canals accelerated saltwater intrusion and erosion. I will opine that early on, we mostly did all of this with honorable intent and innocent ignorance of the long-term effects.

Including me – guilty as charged. I am a geoscientist (paleontologist). As such, I’ve spent my entire professional life studying, understanding and working with the mechanics and processes that created our coastal lands and the biota they support. I know why, when and how our land was created. Equally, I know the same about its demise. Not so much when I was a young human playing in this sportsman’s paradise. In the 60s, I fished and hunted in the south Louisiana marsh and offshore nearly every weekend with my dad or friends. We reveled in the abundance of wildlife. Year round, we harvested fish, shrimp, crabs and oysters. In winter, we hunted ducks, rabbit and snipe all from a seemingly unlimited resource. We would revel whenever a new canal was being dug. I’ll repeat that: We reveled in canal digging. We’d reckon with enthusiasm, “Great, a new shortcut to our favorite redfish hole,” or “a new mud spoil bank to walk and hunt rabbit and snipe.”

In many ways, these landscape alterations enhanced our outdoor excursions in the short term. Where we used to catch bass and bream and catfish in St. Bernard Parish within the dead or dying cypress swamps, we now caught boxes full of speckled trout that we brought back to the launch.

We know now, of course, that those short-term gains were just that. Short term. In addition to natural subsidence and compaction, turning off the sediment machine of the river with levees and digging channels through the marsh has obliterated a once healthy and thriving deltaic ecosystem beyond recognition. In the early 60s, with a good pair of shrimp boots, a well-planned route and an occasional knee-deep wade, a person could step off of the road in Buras and walk to the Gulf of Mexico. To get to the Gulf today from that same waypoint, you’ll be needing a good bay boat. Furthermore, you’ll not encounter a single blade of marsh grass in your 8-mile or so tour (see photos).

Coastal restoration. You may ask: What is that, and is it even possible? Can we restore a system as complex as coastal wetlands to its original condition? We cannot, because there is no “original” condition of the geology and ecology of a deltaic system. By definition, it is a dynamic system that changes continuously with infinite variables. What we can do, however, is stop destroying it. Furthermore, we must engage in activities and projects that will reverse sediment starvation, mitigate against more land loss and build new land.

We have many tools at our disposal for restoring and mitigating and rebuilding. We’ve been employing some of these tools for a long time, so we know what works and what doesn’t. We’ve dredged sand from offshore shoals to rebuild barrier islands and ridges. We’ve dredged and transported bay sediment to recharge dying marshlands and land bridges. We’ve reconnected the river to the wetlands in order to semi-replicate the natural land building and nourishment processes. We’ve done native grass and tree plantings, dune building and living reef construction. All of these tools are valid, effective and essential. Know, however, that each tool is effective for specific objectives, and no one tool is well suited for all of our needs.

The dredging and digging and pumping-type operations are effective and relatively quick. They work, and we’ve many successful examples. We also know that the process will have to be repeated from time to time to sustain the features created, because, unfortunately, the moment that the dredge pulls anchor and motors off location, the restored feature succumbs to the natural forces of nature such as erosion and subsidence. It’s not a problem. It’s simply what’s so. Still, it’s a great and necessary tool if you need to build a beach or replenish a land bridge or a localized area.

The diversion-type tool endeavors to replicate the river’s natural land-building processes by continuously introducing her water and sediment into the surrounding area. Clearly, it’s not a one-to-one replication of an unrestricted natural river system. To do that, we’d have to remove all the levees, and for good reason, that will not happen. It is instead a point source of fresh water and sediment that nourishes the marshes, ponds, bays and basins within its area of influence. On a much smaller scale, it’s the same processes that we terminated with levees and subsequently exacerbated by carving up the wetlands for enhanced access. We’ve many successful examples of this tool as well.

In 1972 I built a camp with my best friend in the upper Barataria Basin near Lake Salvador, just south of the current Davis Pond diversion. The 1970s were my college and early professional life years during which I learned my trade as a sedimentary geologist and paleontologist. It was then that I became aware of and intimate with the mechanics of our ecosystems. It was then that I learned of the methodical and unrelenting demise of our coastal environment; of the merciless disappearance of marshlands and islands; of the steady encroachment of salt water. Over the years, I observed the relentless mutation at our camp on Bayou des Allemands from a near pristine freshwater environment to one of more saltwater influence and less marshland. Where we used to exclusively catch freshwater species (bass, bream and freshwater cats), we started catching more saltwater species (specs, reds, hardhead cats). The ecologic and environmental transfiguration was stark. Even the bugs changed. For the worse.

Then, in the early 2000s, the Davis Pond Freshwater Diversion started operating. I’d followed its progress from design through implementation. I’d studied the models and was very hopeful yet not optimistic that I would ever live to see any significant positive impact. I was wrong. Less than two decades later, the environment, including the fauna and flora, are as I remember when I first explored and played in the area as a teenager. In my lifetime, bream and bass and catfishing has never been better.

I recently toured the Davis Pond area. I walked on flotant marsh and hard-ground willow tree forest that just a few years ago was open water. It’s working beyond my wildest dreams.

The proposed Mid-Barataria diversion is a similar initiative planned for a lower part of the basin and at a much larger scale than Davis. In fact, when implemented it will be the largest project of its kind. Like Davis Pond, it shall work as well. It will replenish and rejuvenate existing wetlands and build new ones.

Will it displace and/or kill some saltwater dependent species such as oysters, dolphins, shrimp and specs? It shall. We must remind ourselves, however, that those species are currently there only because of the ongoing and persistent destruction of the natural environment that used to exist there. We must also intuit that over the decades we have adapted and relocated our own fishing and harvesting practices in order to comply with these destructive forces as the saltwater habitat has steadily moved landward. If we do nothing, we will run out of land to encroach. We will run out of habitat for those species to thrive. Those species will continue to adapt and move to their appropriate environs, and likewise we will have to adapt our harvesting of that area to that of a near offshore environment. The biggest losers will be our children and grandchildren. They shall be forced to live with the consequences of our inaction.

I’ve had discussions with commercial and recreational outdoorsmen, and a common dialogue is that “my daddy fished here, and his daddy fished here and his … .” Actually, that’s not completely accurate. I’m as old as their grandad. I couldn’t drag my shrimp net, nor collect oysters on that reef nor pop a fishing cork there, because that was not open water. It was marsh land and splendid tidal channels and ponds and bays. Your grandad and I had fished/worked south of there, where the habitats were suitable and productive.

Will there be losers? Absolutely. I’m one of them. Among other things, I’ll no longer be able to chase specs and reds in my favorite spots in Barataria Bay. I’ll have to adapt and move to the appropriate environment that supports and sustains the species that I’m targeting. Pretty much like we all have been doing for decades as the habitats have continuously changed and disappeared.

It is our own actions that have caused the fabric of the life we love to unravel like a nickel mop in a rainstorm. By our own actions, we can repair and rebuild it. My vision for the future of our coast looks much like the coast that I grew up in. That’s a legacy I will be proud of.

The Barataria Basin is vast and vital as a storm buffer; for human and wildlife habitat; to our culture and economy; but, through our actions and neglect, it has steadily disappeared. Both the demise and successful restorations of wetlands are apparent and abundant as are the challenges. I have lived through many of these changes and faced their difficulties, yet my hope endures. Restoration will require great effort, determination and yes, sacrifice, but we must make the hard choices for our progeny, for our legacy. Or not and lose it completely.

THANK YOU, AL DUVERNAY III, PALEONTOLOGIST, CRCL VOLUNTEER AND COASTAL ADVISORY COUNCIL MEMBER.