Opposing opinions on river diversions show contentious nature of coastal master plan

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Coalition to Restore Coastal Louisiana

While not designed originally to build land, the Caernarvon Freshwater Diversion had built 1000 acres

Editor’s note: When a group representing the interests of sport fishers and the fishing industry submitted the following op-ed against plans to diver part of the Mississippi River to wetlands, we knew there was strong sentiment on the other side of the debate. So we asked a pro-diversion coalition to respond. Both columns appear below.

Polluted river shouldn’t be flowing into marshes; dredging also can build land

By Kerri Callais
Secretary/treasurer of the Save Louisiana Coalition

Reconnect the river to the marsh. We’ve all heard it, and it seems to make sense; it’s even kind of romantic. Who wouldn’t want to go back to the natural way? But there is a huge problem. Our beloved Big Muddy has created “the most tainted coastal ecosystem in the world.” Not even China, where some waterways are so foul they’re flammable, ranks as high in pollution as the Mississippi. Nonetheless, large-scale river diversions pumping hundreds of thousands of cubic feet of river water into our marshes every second remain the cornerstone of the state’s Comprehensive Master Plan for a Sustainable Coast.

There is a proven alternative: pipeline dredging, along with armoring and smart maintenance. It’s an approach that can rebuild land now, land you can drive bulldozers on in four days, land that won’t be rendered useless by storm surge or force coastal communities to beat a retreat that devastates our unique culture.

In 2010 alone, 12.7 million pounds of toxic chemicals were dumped into the river. This creates several problems, first and foremost, the dead zone. There are over 550 dead zones in the world, and the one formed in the Gulf by the Mississippi is the second largest, over 5,000 square miles — about the size of Connecticut. A dead zone is an area of water that is depleted of oxygen. It is caused by the excess of nutrients in the river mostly from wastewater and the fertilizers washed into the river from the corn belt. No marine life survives in it. Crabs, shrimp, oysters, fish — all forms of marine life die in a watery, Connecticut-sized graveyard. Considering that Louisiana is the nation’s No. 1 source of shrimp, crab, and oysters, you would think fixing the dead zone would be a priority. Unfortunately not much has been done to stop it.

And the dead zone is just the beginning of our coastal pollution problems. Several scientific studies show that while high nitrogen and phosphorous levels may feed the marsh, they also weaken it. The marsh gets inundated with the fertilizers from the nation’s mid-section and the vegetation doesn’t have to work as hard to grow. This causes the vegetation’s once hardy root systems to shorten, and a void is created in the soils they held together.

Now, when a storm comes through, the marsh is rolled up like a carpet. This was clearly shown during Hurricane Katrina. By far the greatest land loss was in the area affected by the Caernarvon diversion. Forty-two square miles of land was lost and 37 of those miles were the marsh closest to the diversion. Geologist Chris McLindon put this into perspective: “The biggest cause of land area change over the last two decades is coastal restoration. It is causing land loss in south Louisiana.”

In other words, the Caernarvon diversion has caused more land loss in the last 20 years than subsidence, sea level rise, or sediment deprivation. Garret Graves, then head of the state’s Coastal Protection and Restoration Authority, told a town hall meeting in St. Bernard  Parish that Caernarvon was a failure and no future diversion would ever be modeled after it.

It is a failure, and on this very day it is still pouring polluted, nitrate-rich river water into our estuary. When we speak of land gained in diversion projects, it is in acres, not square miles. Even if sediment diversions lived up to their fullest potential, they would never build enough land to compensate for the land loss that they have already caused and will continue to cause. It does not matter if they are sediment diversions or freshwater diversions, they still have the same delivery system, the Mississippi River.

It’s not just marsh that is affected. The same problem is seen on Wax Lake Delta, the poster child for successful diversions. Satellite images show lush green vegetation, the acres and acres of “land” that the diversion has created. The problem with this is the fertilizers cause hyacinths and other aquatic plants to flourish on the surface giving the appearance of land, but there is no sustainability. If you look at the Wax Lake Delta following Hurricanes Rita and Ike, you can see the skeletal remains of the lush, full pictures we are shown. Furthermore, a map of land loss clearly reveals that the places with the most severe land loss are the ones most affected by the river.

No one denies the river is polluted, or that there is a dead zone, or that the river is the cause of it. These are undisputed facts. So why would anyone even consider taking this river that is killing our Gulf and dumping it into our estuaries?! The precept that governs medical interventions should apply here: First, do no harm.

The initial argument in favor of diversions was that dead zones couldn’t form in shallow water. But last year two dead zones popped up in Breton Sound as a result of current diversions, killing over 10,000 redfish and drum. Another argument was that the marsh would absorb the nutrients and maybe even help the dead zone in deeper water.

Wrong again.

First of all, the pollutant levels are much too high for the marsh to be able to sequester the toxins, and even if they could, it is at the expense of the marsh. The purpose of large-scale diversions is to build land. But what is the point of building land if the method you’re using renders that same land useless?

Instead of reminiscing about a river that built our delta 7,000 years ago, we need to take a realistic look at our current situation. There were no towns and cities on the delta 7,000 years ago. In recent decades,  we have dammed it, changed its course, and dumped every pollutant known to man into the Mississippi. Unless we want to abandon New Orleans, give up our flood protection, and let the river run free, there is no point invoking something that happened 7,000 years ago as an argument for current strategies. Until something changes and The Big Toxic is cured, all talk of dumping it into our precious estuaries needs to be diverted.

 

The muddy Mississippi: Our strongest weapon against coastal land loss

 

By Kimberly Davis Reyher
Executive Director, Coalition to Restore Coastal Louisiana

We can all agree on one thing: Louisiana is sinking. We’re already seeing the effects as we lose our rich, productive wetlands and the protection they provide.

With no action, we will lose land equivalent to the size of about 850,000 football fields – or 287 Grand Isles – in the next 50 years. Unless we develop and implement long-term, sustainable solutions for building land and impeding coastal land loss, our descendants will never know the places that have been our homes and that of our ancestors for centuries.

With so much at stake, the people of Louisiana deserve factual solutions. Although we empathize with the Save Louisiana Coalition, we respectfully disagree with its attempt to demonize our strongest weapon in the fight to actually save Louisiana: sediment diversions. Reconnecting the river to the marsh is more than a romantic idea. It is a science-based, critical and necessary course of action.

On this let me be clear: While we believe a comprehensive approach – including significant use of dredged material – is key to achieving success in combating our land loss, sediment diversions are the most effective tool. There is a reason why sediment diversions anchor Louisiana’s Comprehensive Master Plan for a Sustainable Coast, put together by leading scientists and experts: Because they are understood to be a powerful vehicle for building land effectively and continuously — solid land that you can walk on that supports complex natural habitats essential for a healthy ecosystem.

The Muddy Mississippi built our coast by depositing sediment to build this delta. Now that the river is constrained by a system of levees, much of the mud flows out into the Gulf of Mexico, and coastal wetlands are starving, sinking, receding and dying. Sediment diversions create controlled pathways for the river to again deliver sediments and nutrients into marshes.

Diversions vary from freshwater to sediment, based on what is targeted for capture. Freshwater diversions are designed to capture  water from the surface of the river but little sediment. Sediment diversions are designed to tap into the sand and mud moving in the deeper waters of the river. Both freshwater and sediment diversions deliver fresh water, in varying degrees, which also can combat saltwater intrusion and create an improved fresh-to-salt water balance needed for healthy estuaries.

Across the coast, we have already seen positive effects of diversions:

  • The Caernarvon Freshwater Diversion was opened in 1992 to improve fishery conditions, not to build land. Yet, built land it has, more than 1,000 acres in a short amount of time. That has led scientists to conclude that sediment diversions will be far more effective.
  • The Wax Lake Outlet recently received significant national media attention for its success as one of the only places in Louisiana where we are gaining land. It was dredged in 1941 to divert some water from the Atchafalaya River to reduce water levels and the risk of flooding for Morgan City. New land rose above the water after the flood of 1973. To date, the outlet has built 25 square miles of new, sturdy land. Some might point to images showing the land around Wax Lake Delta has been damaged by recent hurricanes. As a peninsula, it’s more susceptible to damage from storm surges. But with its supply of sediment, the Wax Lake Delta continues to bounce back and build more land without costly intervention.
  • The uncontrolled West Bay Diversion was constructed in 2004. Down at the Bird’s Foot Delta where land is quickly sinking, the location of this simple cut through the levee was too far downriver to be ideal. Still, with the help of small islands constructed at the end of 2008, new land emerged after the 2011 floodwaters receded. Land is continuing to be built in West Bay today, and this diversion is being used to understand how features such as the islands can help build land faster.

Even though these are not controlled sediment diversions, we have evidence that the Muddy Mississippi is an extremely effective tool to rebuild our coast. And yet, we don’t believe sediment diversions are the only answer nor should they be implemented in isolation.

Sediment diversions should be used in concert with marsh creation through pipeline dredging, barrier-island and oyster-reef restoration, ridge restoration and more. Our coast is incredibly diverse, and no one-size-fits-all project can protect and rebuild it. We do know that without continuous delivery of sediments through diversions, other projects — including dredging — will fail. Without the power of the Mississippi to regularly deposit land-building and sustaining sediment in our marshes, dredged land that is pumped through pipelines will sink and erode.

Some argue that the Mississippi is too polluted to be used for restoration. We share the concern about the health of our river, especially elevated nutrient levels from nitrate and phosphate used to fertilize farms upriver. But we note that it meets state drinking standards and that regulation and improved practices have led to progress, in particular for the decades-old legacy of DDT and other industrial contaminants.

We dispute the assertion that using the river for sediment diversions would do more harm than good.Recent reviews of studies of nutrients and thedelta cycle suggest that the level of nutrients from the existing freshwater diversions are not high enough to cause harm to wetlands. The few studies that have warned of such damage were problematic because they used nutrient concentrations nearly 10 times higher than what has been introduced by freshwater diversions.

Diverting river water to wetlands will help filter out the fertilizer, decreasing what reaches the gulf, thereby helping to reduce the size of the dead zones offshore.

The bottom line is this: Sediment diversions are our most powerful tool for coastal restoration. Without sediment diversions, our wetlands will be lost. As we approach the 10th anniversary of Hurricanes Katrina and Rita, when so many of us witnessed the devastating results of a withered coastline, it’s time to come together and get to work implementing solutions that can achieve longterm protection for coastal communities.

For more facts about sediment diversions and other priority restoration projects, we encourage you to read our answers to these10 fundamental questions about the Mississippi River Delta.

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