Izaak Walton League Publications

Damaged Delta

Man-made Changes to the Mississippi River Are Sinking Louisiana's Coastal Wetlands
By Dawn Merritt, IWLA Communications Director

The Mississippi River might be the most “managed” river in the country. Along its length you’ll find levees to prevent flooding, locks and dams for river navigation, and dredging operations for commerce. These changes may have been made with good intentions, but they drastically damaged the natural functions of the river.

Sediment that used to flow down the Mississippi River is now locked up behind dams and levees. The sediment that does make it down river is channeled into the depths of the Gulf of Mexico rather than spreading through the wetlands that surround the river’s end. With no river sediment to sustain them, coastal wetlands are sinking into the sea. And the thousands of miles of canals dredged for oil and gas drilling have turned coastal areas into a patchwork quilt of wetlands that are isolated from the freshwater they need to survive or are enveloped by encroaching saltwater. Fish and wildlife that depend on these wetlands – for nurseries, nesting areas, food sources, or a rest stop during migration – are losing them at a frightening pace.

There’s a broader human impact too. The wetlands of the Mississippi delta not only support local livelihoods, they also produce much of the fish and shellfish we eat, support waterfowl populations hunted across the country, and protect the lives and property of millions of Americans. 

Delta by Design
The phrase “Mississippi delta” might conjure up scenes of moss-draped oak trees, a fishing line dangling from a dock, or nights under a bayou moon, but the word “delta” is more practical than romantic. It describes how a coastline is built and sustained.

For thousands of years, as the Mississippi River neared the Gulf of Mexico, its water slowed and spread out, depositing sediment that had washed downstream. This sediment combined with ocean deposits to build five million acres of land along the Gulf Coast, much of it wetlands. This area built by the river is called a delta. The wetlands of the Mississippi delta support a wide variety of fish and wildlife and provide services that are critical to life along the coast.

At least 60 percent of North America’s birds and 40 percent of our waterfowl migrate along the Mississippi River corridor. Wetlands in the Mississippi delta provide essential nesting, migratory, and wintering habitat for these birds and support insects and plants that sustain bird populations – from endangered species like the brown pelican to waterfowl hunted across the United States.

Coastal wetlands are also important nurseries for young fish and shellfish. Louisiana’s coastal fisheries produced more than $289 million in dockside landings in 2007 – 26 percent of the seafood in the lower 48 states. The Gulf of Mexico is also the top shellfish-producing region in the nation.

The abundance of fish and wildlife in Louisiana draws hunters, anglers, and wildlife enthusiasts from across the country. According to the U.S. Fish and Wildlife Service, hunters spent $525 million in Louisiana in 2006, anglers more than $1 billion (including trips and equipment), and wildlife watchers about $312 million. Not only do these outdoor activities support jobs and local economies, the taxes hunters and anglers pay support state fish and wildlife agencies and conservation projects nationwide.

Coastal wetlands do more than support fish and wildlife; they absorb the force of winds and waves, holding water that would otherwise flood residential and agricultural areas. For example, studies show that the levees along the Mississippi River with wetlands in front of them survived Hurricane Katrina in 2005; those without wetlands were more likely to crumble. Louisiana’s wetlands also protect important international ports, support energy development (oil and natural gas), and help sustain drinking water supplies.

However, many of these wetland values have declined and others are at risk because coastal Louisiana is disappearing into the Gulf of Mexico.

Losing Louisiana
Louisiana’s wetlands are disappearing at the rate of about one football field every 38 minutes. This is not land that has been dug up to build houses or shopping malls – these wetlands are being swallowed by the sea.

Soft sediments like those found in the Mississippi delta naturally sink. For thousands of years, sinking wetlands were replenished by the same river sediment that built them – a natural process that kept some of the land above water. Today, however, locks and dams keep some of that sediment from moving down river. Levees built along the sides of the river to prevent flooding also prevent sediment from entering the river after a flood and increase the speed of floodwaters.

“Sediment and flooding built the Mississippi River delta,” says Cyn Sarthou, executive director of the Gulf Restoration Network. “Once we straight jacketed the river, we started the death of the wetlands.” Additional wetlands damage came in the form of dredging. More than 9,300 miles of canals have been dredged through coastal wetlands for oil and gas development, Sarthou explains. Dredge materials piled up along the sides of these canals further block the exchange of sediment between the Mississippi River and surrounding wetlands. In addition, the canals allow saltwater to seep into the wetlands, where it destroys vegetation needed to prevent wetland erosion. Intruding saltwater can also infiltrate groundwater and surface water supplies and even convert a wetland into open water.

Our alterations to the Mississippi River began centuries ago in New Orleans; the first levees were built to protect the city in 1720. By the 1840s, levees lined much of the river from New Orleans to St. Louis. But these makeshift levees frequently failed, so Congress created the Mississippi River Commission in 1879. The commission worked with the Army Corps of Engineers to build levees and channelize the river to prevent flooding along the lower Mississippi. The levees gave residents a sense of security in building homes and farms along the banks of the river. However, a series of heavy rains in late 1926 and early 1927 caused levees in Arkansas, Louisiana, Mississippi, and Missouri to break. More than 26,000 square miles of land in seven states were flooded, and more than $100 million in crops and farm animals were destroyed ($1 billion in today’s dollars). Following the Great Flood of 1927, as it was called, the Corps of Engineers was again charged with taming the Mississippi. Under the Flood Control Act of 1928, the Corps built 1,000 miles of levees along the river and hundreds of runoff channels to divert water.

Up-river construction projects cut the amount of sediment carried down the Mississippi River by as much as 60 percent, says David Muth, Louisiana state director for the National Wildlife Federation, who spent 30 years working for the National Park Service in Louisiana. The sediment that does manage the journey down to the delta does not replenish the wetlands – it’s lost at sea. The Mississippi River Commission and the Corps built jetties at the mouth of the river to keep a deep channel open for ocean- going ships. However, the jetties confine the river sediment. The Corps of Engineers also dredges the river bottom to ensure the river is deep enough for these ocean-going vessels. “About 90 percent of what the Corps spends on dredging in United States is spent on the lower Mississippi River,” says Muth. The deep river bottom at the mouth of the Mississippi sends sediment out into the Gulf of Mexico, where it falls hundreds of feet down into the water and drifts away.

All of these man-made changes to the Mississippi River and the resulting loss of coastal wetlands have made Louisiana more vulnerable to storm damage.

Hazardous Hurricanes
In August 2005, Hurricane Katrina – with winds of nearly 175 miles per hour while at sea – barreled into New Orleans and the Gulf Coast, followed one month later by Hurricane Rita. Katrina left 80 percent of New Orleans under water and close to 2.3 million people across the region without power. The Kaiser Family Foundation estimates that 400,000 jobs – affecting family income and health insurance coverage – were lost due to Katrina. The death toll from Katrina is still a subject of debate due to missing persons and indirect deaths, but numbers reach into the thousands. Loss of life from Hurricane Rita was significantly less due to aggressive evacuations.

The impact of these hurricanes reached beyond Louisiana’s coast. Louisiana contains 5 of the 12 largest U.S. ports, including the first largest (South Louisiana) and fifth largest (New Orleans). When Hurricane Katrina struck the Gulf Coast, it brought a halt to the flow of agricultural trade in and out of the United States through the Mississippi River system. The storm destroyed about one-third of the Port of New Orleans – one of the largest U.S. ports for foreign trade of products including grain, rubber, steel, plywood, and coffee – causing significant interruptions in national and international trade.

It’s impossible to quantify exactly how much of this damage could have been prevented if coastal barrier islands and wetlands were intact, but those lands would have slowed storm surges and helped absorb wave energy and water. Surging waters from both hurricanes – particularly Rita – also killed vegetation in freshwater wetlands, causing further wetlands loss. Although these storms did bring in some new layers of sediment, researchers with the U.S. Geological Survey estimate that Hurricanes Katrina and Rita combined caused about 18 years’ worth of wetland loss in Louisiana.

Disaster on the Horizon
Further damage to Louisiana’s wetlands came in the form of oil. On April 20, 2010, the Deepwater Horizon oil rig exploded while drilling a well one mile down in the Gulf of Mexico. Eleven crew members died and others were injured as fire engulfed and destroyed the drill rig – and more than four million barrels of oil began gushing into the Gulf of Mexico, just 49 miles off the Louisiana coast.

More than 1,000 miles of the Gulf Coast were affected by the oil spill, and the full impact may not be known for years. “It’s in the sand, it’s in the dunes, it’s beneath the water out there, and it is being picked up by all the creatures that depend on the ecosystem here,” says Muth of the oil and associated chemicals. “It’s actually becoming a part of the whole ecosystem and could cause problems in the food chain for years to come.” This oil could have a major impact on wildlife already struggling with the disappearance of the habitat they need to survive.

Road to Recovery
Slowing and even reversing wetland loss – and the associated problems this causes for wildlife and people – all comes back to sediment. Denise Reed, PhD, a professor in the Department of Earth and Environmental Sciences at The University of New Orleans, estimates that 120 million tons of sediment is being dropped into the Gulf of Mexico every year. “We have to do something bold here and stop wasting the very resource that can rebuild the coast,” says Reed. “To survive, marshes need a supply of sediment and healthy plants to help build up soil. Soil building will also allow coastal wetlands to keep their heads above water in the face of sea level rise. The river built the coast, and management of the river is impairing our ability to get it back.”

It will take billions of dollars to undo the decades of damage to the Mississippi River delta. Fortunately, there are several funding sources in place after the Deepwater Horizon spill that could be used to accomplish this task.

Damage Assessment, Remediation, and Restoration Program (DARRP): Administered by the National Oceanic and Atmospheric Administration (NOAA ), this program was spill. DARR P’s scientists, economists, and attorneys work with response agencies, including the Environmental Protection Agency and U.S. Coast Guard, to assess and restore natural resources damaged by the release of oil and other hazardous substances. Through this program, NOAA recovers funds from responsible parties for the protection and restoration of coastal resources, including fish, marine mammals, wetlands, reefs, and other coastal habitats. DARR P uses a process called Natural Resource Damage Assessment to identify the extent of resource injuries, the best methods for restoring those resources, and the type and amount of restoration required.

One year after the Horizon oil spill, this assessment has not reached a conclusion – and may not for quite some time. On April 21, NOAA announced an agreement through which British Petroleum (BP) will make a $1 billion down payment on the costs of restoring ecosystems damaged by the oil spill. Under the agreement, Alabama, Florida, Louisiana, Mississippi, and Texas will each receive $100 million, as will NOAA and the Department of the Interior. The remaining $300 million will be spent on projects proposed by the states and selected by the federal agencies.

Clean Water Act: As you might expect, spilling millions of barrels of oil into America’s coastal waters is a violation of the Clean Water Act. The parties responsible for the 2010 Gulf oil spill could be fined up to $21 billion. However, this money might not go toward Gulf Coast restoration at all. Without Congressional action, the fines will be deposited into the Oil Spill Liability Trust Fund (to be used for future cleanups) and the federal Treasury rather than directed toward restoration efforts that are urgently needed now. Legislation was introduced in the U.S. House of Representatives in January 2011 to direct 80 percent of Clean Water Act fines to restoration of the Gulf Coast, but that legislation has not moved forward. Senators Mary Landrieu and David Vitter (both from Louisiana) introduced a similar bill in the U.S. Senate in April 2011.

President Obama formed The National Commission on the Deepwater Horizon Oil Spill and Offshore Drilling to investigate the oil spill and recommend ways to prevent future such events. The commission presented its findings in January 2011, stating that, “The Gulf ecosystem, a unique American asset, is likely to continue silently washing away unless decisive action is taken to start the work of creating a sustainably healthy and productive landscape.” The commission also recommended that Congress dedicate 80 percent of Clean Water Act penalties to long-term Gulf restoration. (You can read more of the commission’s findings online at http://www.oilspillcommission.gov/).

A Sustainable Future
As we work to find the middle ground between energy development, conservation, and our ability to live our lives, the keys to progress are sediment and sustainability, says Reed. “I try not to talk about ‘restoration’ – I try to talk about a sustainable future and using sediment to rebuild the coast. I don’t mean putting the Gulf Coast back the way it was. A lot of this change is irreversible. It’s about having something in the future,” Reed explains. “It will be smaller in terms of wetlands. But if we use the sediment, we stand a good chance of having a high-quality, productive wetland ecosystem through the 21st century.”

How exactly that should be done is still under discussion. “There are many plans on the books – too many,” says Muth. “Part of our job over the next year or two is to winnow that down to a workable number that have the best science and best chance to succeed. Once you re-engineer the river, we’re talking a decades-long process to rebuild the marsh.”

Rather than dumping dredged sediment off the continental shelf, the Corps of Engineers could use that sediment to rebuild coastal wetlands. In fact, while visiting New Orleans in February 2011, IWLA Board members toured a site where this exact approach was used successfully to rebuild 493 acres of marsh. (See sidebar on the previous page for more details.)

The New Orleans District of the Army Corps of Engineers has the largest annual channel operations and maintenance program in the entire Corps. A 2004 Corps report estimates that the New Orleans District dredges approximately 70 million cubic yards of material from the Mississippi River every year and puts only 14.5 million cubic yards of that to “beneficial use.” The report states that there is “reasonable potential” to use an additional 30 million cubic yards of dredge material from the New Orleans District for beneficial use each year if funding were available. The additional cost is approximately $1.00 per cubic yard for beneficial placement of sediment, which creates approximately 0.00025 acres of land. “Four thousand dollars per acre – a trivial cost considering the economic and ecosystem services an acre of wetlands provides,” says Muth.

Other proposed strategies to protect and rebuild coastal wetlands include additional dredging to increase the amount of material available to restore, create, or enhance coastal wetlands; diverting waters to specific wetland areas to restore fresh water and sediment flows and rebuild wetlands; preventing sediment loss into the Gulf of Mexico by trapping and pumping sediment to create marsh land; and refilling unused oil and gas canals to restore the flow of water and nutrients to wetlands and prevent additional salt water intrusion.

These are not inexpensive propositions. Some estimates of the cost to restore coastal Louisiana are as high as $14 billion. The best chance for these efforts to succeed is to use fines from the Deepwater Horizon oil spill. The question now is: Are we going to use the funding from this natural resource disaster to jump start comprehensive restoration of resources affected by the spill – or will we miss this opportunity to make a difference in the Gulf and for citizens across the country?

We can’t afford to wait. The natural resources continue to decline and we (hopefully) will not have fines of this magnitude available again to fund restoration. Members of Congress need to hear from people around the country that the Gulf Coast benefits our communities – regardless of where we live – and that we support efforts to spend Deepwater Horizon oil spill fines on long-term solutions to this coastal crisis. Visit www.iwla.org/advocacy to take action. Working together, we can keep the Mississippi delta productive for fish, wildlife, and ourselves.
– Dawn Merritt is Director of Communications for the Izaak Walton League. 

Wandering Through Wetlands
Take twenty-four League leaders and national office staff, one small bus in desperate need of new shocks, an unseasonable dose of bitter cold temperatures – and drop them all in coastal Louisiana. That’s exactly what happened during the 2011 mid-winter Board of Directors meeting. The group got a firsthand look at Louisiana’s disappearing wetlands and learned how the entire country is affected.

At a breakfast briefing, Aaron Viles, deputy director of the Gulf Restoration Network, and David Muth, Louisiana state director for the National Wildlife Federation, gave an overview of the damaged Mississippi delta.

“The Mississippi River has been fundamentally altered from its natural state,” said Viles. “We’ve done things with an eye to the economic output, not the environmental effects.” Viles pointed to the 2010 BP oil spill as another layer of damage to these ecosystems. “One thousand miles of coastal area was affected by the crude oil. Oil was coming ashore in the most productive areas of the marsh. The fundamental building blocks of life in the Gulf have been compromised. As we affect the ability of these areas to be productive, we’ll see cascading effects.”

Then Muth, who spent 30 years with the National Park Service in Louisiana, led the group on a tour of the Barataria Preserve at Jean Lafitte National Historical Park and Preserve. The preserve offered a close-up view of the diversity of wetland ecosystems and the challenges we face in restoring these areas.

A boardwalk built over top of an old oil company road offered a path deep into the woods. We walked past air ferns and Spanish moss draped over live oaks. As we moved to the back slope of a natural levee, built by old river sediment deposits, we were surrounded by palmettos. Muth pointed out that this area had as many dead oak trees as live ones due to natural subsidence. After walking downhill just eight inches, we were in a classic bottom-land swamp. This area has standing water most of the year, and tupelos and bald cypress thrive. However, Muth pointed out, the swamp trees are not reproducing because they need periods of drought for seeds to sprout. With the wetlands sinking and no new river sediment coming in to raise the ground back up above the water level, there are no dry periods.

Our next stop was a wetland restoration site. Brad Miller and Peter Hopkins from the Louisiana Office of Coastal Protection and Restoration gave the group a tour of a 493-acre marsh restoration project jointly sponsored by the U.S. Environmental Protection Agency and the Louisiana Department of Natural Resources. The goal of the project was to use the renewable resource of Mississippi River sediment to create marsh in a rapidly eroding and subsiding section of the Barataria Landbridge. This landbridge protects the Barataria Basin – more than 1.5 million acres of swamp forests and marshes that provide nursery and breeding grounds for migratory birds, waterfowl, fish, and shellfish – from excess saltwater intrusion and erosion.

To restore the marsh area (which had become open water due to subsidence and erosion), project managers dredged approximately 2.7 million cubic yards of sandy material from the Mississippi River and pumped it through more than five miles of pipes. It took four months of pumping to move all the sediment. Bulldozers and excavators spread the sediment. Dikes were built to contain the sand, but gaps in the walls promote water exchange. As we walked across the new sandy soil, it was astounding to imagine that it had been open water just a year earlier. Miller told the group that this land would eventually subside to become a productive marsh. The area should be self-sustaining, although the project partners will monitor it over the 20-year project design life. “We hope that the sustenance of the site will come not from more pipeline delivery of sediment but from sediment diversion just downstream at Myrtle Grove, which will allow the river to sustain the area naturally,” said Muth.

At the end of the day, Captain Ryan Lambert hosted our group for a dinner of redfish and other local specialties. Lambert, a native of Louisiana, runs Cajun Fishing Adventures, which offers an array of fishing and duck hunting experiences. His lively stories ranged from the wilds of coastal Louisiana to the destruction caused by Hurricane Katrina and the lost lives and livelihoods. When asked about the current state of Louisiana’s wetlands, he said simply, “The river built Louisiana. Put it back.”

Lambert has witnessed wetland loss first-hand. “When I put the boat in the water to go fishing, I used to have to navigate through the marshlands, dodging here and there according to the GPS. Now you can just point the boat and go.”


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