- The country’s levee system is showing signs of severe strain, but development is still occurring on floodplains.
- In Louisiana, the Conservancy is preparing to breach a leaking levee at Mollicy Farms to restore a critical floodplain.
- Learn how Mollicy Farms has become a laboratory in the field and a model for policy experts working with the Army Corps of Engineers.
“Overreliance on hard engineering infrastructure … has not only decimated our ecosystems, but it has given a false sense of security to people living behind these structures.”
Andy Warner, freshwater policy expert for The Nature Conservancy
Kelby Ouchley cut the engine on his four-wheel drive. Then he and his brother stepped down onto the massive levee in northeast Louisiana and gazed out at The Hole in the World.
That was the term Kelby and Keith Ouchley had been using for the scene that stretched before them — a 25-square-mile expanse of low, flat land dotted with muddy sloughs and lakes. For centuries, a bottomland hardwood forest had sprung from this place, but beginning in 1969, local farmers and businessmen had cleared just about all of it, building a 17-mile-long, C-shaped levee and a system of ditches, pumps and pipes in an effort to keep the Ouachita River and its floodwaters off what became known as Mollicy Farms.
But the plan hadn’t worked. The levee squeezed the Ouachita (pronounced WAH-shu-taw), raising the water level. River water and rainwater would often get trapped behind the levee, keeping fields too wet for too long. The soggy ground mucked up combines and made access to the fields nearly impossible. More than one farmer went broke trying to work the land.
The levee frustrated conservationists, too. It disconnected the river from a huge expanse of prime floodplain forest. Left to its own devices, the floodplain served as a kidney, purifying water, and as a percolator, holding water just long enough for it to seep into aquifers below. The levee destroyed those functions, draining the bottomland forest and decimating habitat for hundreds of species.
Then, during the 1990s, the U.S. Fish and Wildlife Service began buying up pieces of the failed Mollicy Farms and turning the area into a refuge. Kelby Ouchley, who managed wetlands projects for the agency, had been instrumental in making those purchases, with the ultimate goal of restoring the tract to the rich floodplain forest it once was. Kelby and his colleagues had set out to replant no fewer than 3 million native trees, including oak, ash and cypress, on the huge tract. For his part, Keith, then a postdoctoral researcher, conducted a historical analysis of the vanished forest for the U.S. Fish and Wildlife Service in order to determine which species to bring back. Later he rode the planter himself, placing one seedling after another into the ground.
Now it was 2007, and on that fall evening, Kelby had headed up to the levee on the ATV to scope out the waterfowl population. Keith, who by then led The Nature Conservancy’s work in Louisiana, came along to see how the reforestation was going. From where they stood on the 30-foot-tall, vegetation-covered embankment, they could look at their reforestation project — miles of trees, each not much taller than a man — and see a budding bottomland forest. They’d done a fine job, they agreed.
Looking west past the winding Ouachita, the brothers saw the original intact bottomland forest that still stretched for miles beyond the river’s unleveed bank. The Ouchleys had grown up in the 1960s and ’70s downstream near Monroe — hunting, fishing and roaming the swampy forests. They knew firsthand how the waters of the Ouachita could feed and draw sustenance from the surrounding bottomland forest. They knew the natural richness of that forest — the rafts of ducks and wading birds, the cottonmouths and ’gaters, the wild turkeys, deer and black bears.
And deep down they knew something else, too — something that had been gnawing at them both for years. Keith turned to his brother: “We got to get this levee out of the way.”
It stood to reason, of course: To bring back a true floodplain, you have to allow for floods. But Kelby was then less than two years from retirement from the U.S. Fish and Wildlife Service and just catching his breath from a decade of land acquisition negotiations and reforestation projects. Getting this levee out of the way would be an undertaking to rival any of his career — it was almost inconceivable. Nonetheless, that evening on the levee he listened to his brother, and the wheels started turning.
The Ouchley brothers had no way of knowing that day that they were considering what could be the largest levee breach and one of the largest floodplain-restoration projects in the nation. They had no idea that their project might serve as a model for new ways of managing levees across the country. Nor did they realize that national policy changes on levee management were on the horizon or that the Conservancy was positioned to weigh in. The brothers did know, however, that opening the levee, reconnecting the river to its floodplain, would ultimately benefit their Louisiana hardwood forest and all of its species. And it would benefit the people who lived downstream: The restored floodplain would take in water, lessening the flood risk, and it would absorb agricultural runoff, improving water quality all the way to the Gulf of Mexico.
Kelby looked out at The Hole in the World and considered the plan they’d just hatched. “Let’s do it,” he said. “Let’s get on with it.” And from that point on, Kelby says, “we started scheming.”
What does it take to breach a levee? Watch a video to find out.
A Lousy Report Card for Levees
From European settlement on, farmers in the United States cleared floodplain forests and tossed up crude earthen embankments to claim the rich soil for crops along rivers such as the Illinois and the Iowa, the Sacramento and the San Joaquin, the Wabash and the Ouachita. Small towns popped up along the rivers, and local officials threw together levees to protect them.
Then came the devastating Mississippi River floods of 1927, drowning farm fields and river towns from southern Illinois to the Gulf of Mexico. In response, Congress empowered the Army Corps of Engineers to protect people by building sturdier, reinforced levees along the Mississippi and its major tributaries. At the time, little was known about how floodplains functioned and how they would be affected.
Today, the Army Corps oversees 2,000 levee systems representing 14,000 miles of levees. Yet these account for just a fraction of the thousands of miles of concrete and earthen embankments that hold back water across the country. In fact, no one knows how many miles of levees actually exist in the United States — the standard estimate is 100,000 on top of those in the Army Corps program. Nor does anyone know where all those levees are located, much less what condition they’re in.
That confusion stems partly from the fact that no comprehensive national policy exists to oversee levee safety, and the range of authorities spans federal agencies and local officials. Standards and criteria for levee design, construction and inspection vary widely. And some levees have existed for decades without any agency oversight or maintenance whatsoever.
Since the 1960s, an odd confluence of policies enforced by the Army Corps of Engineers and the Federal Emergency Management Agency (FEMA) has inadvertently encouraged people to build and live in floodplains behind minimally protective levees. One policy required local governments that wanted levees to share the cost of building and maintaining those embankments with the Army Corps. Many of those governments compromised between cost and protection, building levees that met federal flood-protection standards, but just barely. Another policy exempted homeowners with federally insured mortgages from mandatory purchase of FEMA flood insurance if their homes sat behind levees that had less than a 1 percent chance of being overtopped in a given year. At first blush, that sounds like pretty good protection, except when you consider that buildings behind such levees still have up to a one-in-four chance of being flooded during the 30-year lifetime of a typical mortgage.
Levees built under these policies joined the even less protective levees that had been built not by engineers but by farmers 50 to 100 years before. Originally intended to protect farmlands, those levees later shielded subdivisions.
Today, the country’s levee system is showing signs of severe strain. More than 6 million buildings nationwide sit in areas that have more than a 1 percent chance of flooding each year, according to a 2002 study by the University of North Carolina. Development is still occurring in floodplains, and flood damages have doubled (in constant dollars) since the early 20th century. As damages have climbed in recent decades, the National Flood Insurance Program has racked up a massive $19.2 billion debt. “For a number of levees, it’s questionable whether they would function adequately if called into service,” says Larry Roth, deputy director of the American Society of Civil Engineers, a group that conducts periodic evaluations of the nation’s infrastructure. In 2009, that group gave the country’s levees, as a whole, a grade of D-.
Levee failures have been routine and dramatic in recent decades. The catastrophic floods along the Mississippi River and its tributaries in 1993 topped or breached 1,083 levees, killed 48 people, and cost the nation $21 billion in damages. In 1997, 30 levees burst in California, killing nine people, and the Red River breached its levees in North Dakota and Minnesota, causing economically devastating floods. Committees were formed and reports were written, recommending an overhaul of the national levee safety system, but little changed.
Then came Hurricane Katrina. After New Orleans’ levees failed catastrophically, inundating most of the city, the structurally unsound state of many of the nation’s flood-control systems drew the national spotlight. That attention dovetailed with a burgeoning awareness — by engineers and environmentalists — that protecting the country’s remaining floodplains could provide better protection for humans. “Overreliance on hard engineering infrastructure … has not only decimated our ecosystems,” says Andy Warner, a freshwater policy expert for the Conservancy, “but it has given a false sense of security to people living behind these structures.” It’s time, he says, to rethink the whole enterprise.
A Grand Experiment
Like so many levees across the United States, the one ringing Mollicy Farms has had its share of problems. In the decade and a half since the U.S. Fish and Wildlife Service (FWS) began acquiring the farmland, the levee has not been maintained and has sprung leaks. But no one has really paid much attention to those problems. After all, the area vulnerable to flooding is now wildlife refuge, not soybean fields. That and the fact that FWS owns it made this particular levee ideal for the Ouchleys’ experiment.
Ideal but not easy. The brothers still had to come up with a way to get rid of a 30-foot-high, 17-mile-long mound of earth. One method seemed especially tempting. “Just get some dynamite and take care of the thing,” says Keith Ouchley, recalling the brothers’ thinking at the time. “But all our science and construction people said you’d blow out all the windows from Jackson to Shreveport.” Besides that, they learned, they could screw up the river itself, changing the entire course and flooding neighboring properties. “That would really upset the Army Corps,” says Keith. The brothers quickly scratched the explosives plan and agreed to round up some top hydrologists who could figure out the right way to replumb the floodplain.
Stephen Haase, a hydrologist for the Conservancy, used computer modeling, topographic profile data and aerial survey maps to help determine the best places to breach the levee.
The idea was to work when the river was low, using bulldozers to carve out five separate 1,000-foot-long gaps in the levee, thus reconnecting the tract’s bayous to the Ouachita. Later, the scientists would try to restore Mollicy’s original internal drainage patterns and varied floodplain habitat as best they could.
The project had secured financial support from FWS and the Conservancy, as well as the U.S. Environmental Protection Agency, the Louisiana Department of Environmental Quality and Caterpillar Inc. The Army Corps of Engineers lent political and PR support. And the brothers had persuaded some Conservancy donors to give money for the project, expected to cost $4.5 million.
The breach was planned for June 2009. FWS and the Conservancy would jointly hold a big groundbreaking event atop the levee, with a stage for speeches and a tent for VIPs. They’d have a ceremonial shovel to dig up the first shovelful of dirt — or maybe a politician on an excavator could scrape up some soil.
But Mother Nature had other ideas.
For much of April and into May, it rained heavily in the region, then it rained some more. By May 14, the Ouachita had climbed a full 32 feet above its typical level and was lapping at the top of the earthen levee. On May 19, FWS closed the entire Mollicy tract to the public; the ceremony was canceled. The Ouachita began flowing across the top of the 41-year-old levee in three spots, then four, then five. At one such spot, Joe McGowan, who manages the Upper Ouachita National Wildlife Refuge that includes Mollicy Farms, waded in, up to his knees in fast-flowing water. He turned back quickly. “It was like Niagara Falls,” he says. “I got scared. I was afraid it was going to sweep me down.”
On May 24, the Ouachita River exploded through the levee in two locations — only not the right locations, not the ones the scientists had carefully selected for their breach. Within hours, the water had scoured a new lake 60 feet deep. The force of the blowout uprooted mature trees and blasted big clumps of dirt and river sand for miles over the floodplain. Within hours, the 25 square miles of Mollicy Farms had filled up like a bathtub.
Weeks after Hurricane Katrina’s high waters blew through New Orleans’ levees in 2005, with the city still under water, Congress set in motion a flurry of changes to the nation’s levee policies.
Job one was to figure out where all the nation’s levees were located and identify those that were at risk. The Army Corps began its first-ever national levee inventory, focusing initially on the 2,000 levee systems overseen by the agency. As of February 2009, the agency had identified 177 that are likely to fail in a flood. The Army Corps is now developing a way to inventory levees beyond its purview, based on surveys conducted by other agencies and by states.
Meanwhile, FEMA was tasked with ensuring levees and flood-prone areas were properly mapped for insurance purposes. It turns out that many had either never been accredited by FEMA or had had their accreditation lapse. Since residents living behind unaccredited levees must pay hundreds of dollars a year for flood insurance, that news got people’s attention.
As the feds take stock of the country’s aging levee system, the Conservancy is not only paying attention but also looking for ways to assist the agencies. By invitation, the Conservancy has worked closely with the Army Corps since 1998 to change the management of dams to benefit biodiversity — for example, by adjusting the timing and amount of water released from reservoirs to mimic seasonal patterns such as snowmelt. As a result of that relationship, the Conservancy is now well-positioned to help the Army Corps think through possible changes to levee management.
Warner, the Conservancy’s expert on water management policies, believes that strengthening and rebuilding levees probably will be necessary in some urban areas to protect lives and livelihoods. But if building bigger, stronger infrastructure is all the country does, it will be making a big mistake, he says: As levees age and climate change brings heavier rainfall and rising waters, we’ll be playing a “high-stakes game” and will face the same crises all over again. But “if we can reconnect rivers and floodplains,” he says, “we’re reducing the risk of catastrophic failure.” Indeed, now’s the time to “look more holistically at our river-floodplain ecosystems,” Warner says. That might mean removing levees, as the Conservancy is doing in Louisiana. But levees could also be pushed farther off rivers to make room for at least a little floodplain. Or at periods of extreme flooding, levees could be altered, allowing farm fields to fill, with farmers being reimbursed for lost crops.
In an article in the December 11 issue of the journal Science, the lead authors, Conservancy scientist Jeffrey Opperman, and retired Brig. Gen. Gerald Galloway, describe and advocate for the benefits of large-scale river floodplain reconnection, using these strategies and others. Galloway, a former Army Corps official appointed by the White House in 1993 to study the Mississippi River flood that year, is an expert on floodplain management. He believes that compensating farmers will allow for more and bigger levee-alteration projects. And he’s convinced that many farmers would participate in such a program because they know their farmland is marginal. To support his theory, Galloway points to the experience of the U.S. Department of Agriculture after it made available $145 million of the 2009 economic stimulus money to buy floodplain easements on frequently flooded land. Galloway says the department received applications for 474,000 acres, 10 times the acreage that it had money for.
“This is a worldwide issue,” says Galloway, “this ability to make good use of the floodplain without disrupting the economic and social life of people that live there.” Speaking for his co-authors, he adds, “We believe it can be done.”
Army Corps officials say they’re amenable to the idea and to working with partners to do it. Asked if the Army Corps would favor setting back and opening some levees, Tammy Conforti, manager of the Army Corps’ national levee safety program, says: “We’re key supporters of that, and we would seek opportunities where they arise.” In fact, Army Corps officials for the Vicksburg, Mississippi, district, which includes northern Louisiana, were close observers and advisors to the breach at the former Mollicy Farms. At a press conference discussing the planned breach, Gary L. Young, chief of the Environmental and Economic Analysis Branch for the Army Corps in Vicksburg, said: “The agency has a mandate to balance flood risk management, navigation and ecosystem restoration. This serves as a good model to help us achieve it.”
Amid the national scrutiny of the country’s aging levee system, Warner sees an opportunity for the Conservancy. The organization understands the need to protect people from flooding, says Warner. “But we can do that in a way that also restores critically imperiled floodplains, replicating Mollicy Farms a thousandfold.”
A Matter of Inches
The Ouchleys hadn’t counted on the Ouachita River tearing holes through the Mollicy Farms levee in May 2009 and filling the old fields to the rim. Those natural events spoiled their best-laid plans. Still, the events provided supporting evidence for the claims the brothers had been making. The levee was not up to snuff; it hadn’t protected anything. Had crops been planted behind it, some farmer would have lost everything in the deluge. Instead, all that empty land had done the job of a floodplain, and the people who lived downstream could measure the effects in sandbags.
As Mollicy Farms started filling with water, the flood-waters some 40 miles downstream in Monroe began dropping. They dropped 6 inches by evening. “That meant I didn’t have to pull my dogs and chickens into the house,” says Harris Brown, president of the local levee district. “Inches are precious around here,” he says.
The floodwaters gradually receded, but then summer and autumn rains came, further delaying the Ouchleys’ plans to open the levee properly — scientifically — with backhoes and bulldozers. Nonetheless, more than half a dozen scientists from universities and federal and state agencies have begun collecting baseline data and setting up extensive monitoring work to determine the effects the engineered breach will have on the ecosystem. Geologists from the U.S. Geological Survey (USGS) are looking at changes to sand and silt. Biologists with Louisiana State University and the University of Louisiana at Monroe are looking at changes in plants and animals. And Conservancy scientists are gathering data on water levels across the floodplain when the river overflows its banks, which will help reveal the tract’s complex patterns of water flow and help scientists sculpt the land to restore its original plumbing.
“We’ve got a laboratory in the field,” says Steve Faulkner of the USGS National Wetlands Research Center in Baton Rouge, who is conducting tests at the site. “[It] allows us to look at the process of reconnecting floodplains to a river system that we can’t do anywhere else — or very few places.”
One outcome of the Ouchley brothers’ Mollicy Farms experiment is already clear: “We’re going to do more of these [levee breaches],” says Keith, speaking of his plans for the Conservancy in Louisiana. “There’s no doubt about it.”
Another thing he is certain of: “We can buy all the land we want and protect existing forest and reforest land,” Ouchley says. “But if we don’t get that [floodplain] restored back to like it was, we’re coming up short of the mark.”