Inside the race to save Louisiana’s first line of storm defense

Published 3:51 pm Saturday, July 21, 2018


NEW ORLEANS (AP) — Ten miles from Louisiana’s receding shore, on an island that was on the verge of sinking away, new land is growing at a rate of 200 feet per day.

A slurry of sand blasts from a 30-inch-wide pipe with the force of a firehose. In foaming sheets, it spreads across the beach of Whiskey Island, making it thicker and wider by the minute. Backhoes and bulldozers finish the job, sculpting the sand into something resembling the island’s younger self, before storms, oil spills and erosion took a heavy toll.

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The project’s manager, John Huit, suppresses a prideful grin as he watches a landscape quite literally taking shape before his eyes.

“Where we’re standing was nothing but water – 12 feet deep – when we started this,” he said, standing in rubber boots next to the gushing pipe.

The $118 million restoration of Whiskey Island on the edge of Terrebonne Bay is one of the world’s biggest land building projects. More than 15.8 million cubic yards of sand – enough to fill the Superdome three times – has been dredged and spread across the island, creating nearly 2,000 acres of new beach and marsh. More sand was moved than the state’s previous record, the Caminada Headland restoration, which spread 8.8 million cubic yards across 13 miles of coast, from Port Fourchon to Elmer’s Island.

Whiskey Island’s restoration, which is set to wrap up in early fall, amounts to only a fraction of the money and sand Louisiana is pouring into the rescue of its chain of barrier islands. And for good reason. Growing smaller and fewer in number by the year, the more than two dozen barrier islands are Louisiana’s “first line of defense against hurricanes and storm surges,” Gov. John Bel Edwards said.

“Louisiana’s barrier islands are some of the most important features of our coastal landscape – a true source of protection for our communities,” he said.

The slim, sandy islands act as speed bumps, absorbing wind and wave power that would otherwise travel unimpeded through fragile wetlands and into towns and cities, including metro New Orleans.

Slide divider right and left to see islands before and after restoration.

Behind barrier islands, watery worlds meet and blend into something more complex. The sea, calmed by protected bays, mixes with river water rich in sediment and nutrients, giving rise to a third kind of ecosystem – one that teems with fish, shrimp and oysters. Suspended river sediment is slowed long enough to sink, eventually stacking into new land or building back what erosion had taken away.

Barrier islands themselves are much less dynamic, except during nesting season. The islands draw raucous crowds of gulls and terns every spring. Some bird species nest nowhere else, including the state’s icon, the brown pelican. Seven barrier islands host 90 percent of the state’s population of nesting pelicans.

“Some of these islands have a tiny footprint of land,” said Erik Johnson, Audubon Louisiana’s director of bird conservation. “They might seem to have very little value, but from a bird perspective they’re irreplaceable.”

Over the past 20 years, nearly $817 million has been spent restoring Louisiana’s barrier islands, bulking up 75 miles of beach and back-island marsh, according to a recent assessment by the state Coastal Protection and Restoration Authority (CPRA). The state plans to invest another $1.5 billion over the next 50 years as part of the Coastal Master Plan, an ambitious restoration and storm protection initiative estimated to cost $50 billion.

Despite the barrier islands’ importance, and the vast sums of public money going into their repair and upkeep, they are out of sight, out of mind for most Louisianans. That’s not the case in many coastal states, where barrier islands are prime real estate dominated by beach homes, hotels and crowded beaches. Louisiana’s islands are remote, low-lying and often bare. Only Grand Isle, population: 1,400, has a year-round human presence.

“Not many people think about them, but the barrier islands are critical for our coast,” said Windell Curole, manager of the South Lafourche Levee District. “Restoring them offers us a better chance of survival.”

On a warm August night in 1856, a raging hurricane made a direct hit on Isle Derniere, a 24-mile-long barrier island that guarded Terrebonne Parish’s soft, marshy middle. French for “last island,” Isle Derniere boasted a sprawling resort popular with New Orleans’ wealthiest families. Gale winds and towering waves broke the island in two and tore away the hotel, casinos, summer homes and all the island’s trees.

“The wind blew a perfect hurricane; every building upon the island giving way, one after another, until nothing remained…,” an eyewitness told The Daily Picayune on Aug. 14, 1856. “The sea waved over the whole island. Those who were fortunate to find some object to cling to were seen floating in all directions.”

More than 200 people drowned or were crushed by wreckage. The island, cut through, began to splinter further, eventually giving shape to Whiskey and three other islands – East, Trinity and Raccoon.

Had Derniere not been in the hurricane’s path, the destruction would have been far worse on the mainland, where several fishing communities dotted the bayous northward to Houma. The hurricane made abundantly clear that barrier islands were a treacherous place to live, but it wasn’t understood for another century the protective role they play. By then, nearly all of the state’s barrier islands were in danger of slipping away.

Louisiana State University oceanographer Joe Suhayda sounded the alarm in the early 1990s. With the help of computer scientist Vibhas Aravamuthan, Suhayda produced models that altered or erased the barrier islands under several storm scenarios. Even small changes to the island’s shapes and heights had big implications, they found. Shrink an island a bit and hypothetical storms strike the mainland harder, faster and with taller waves.

A Category 3 hurricane thrown at the more robust Louisiana coastline of 1930 would have left Houma high and dry, according to their model. The same hurricane let loose in 2020, when much of the barrier chain would have eroded away, put the city under three feet of water.

Remove Whiskey and its neighbors, and 1992’s Hurricane Andrew swamps Cocodrie with an extra foot of water, the modeling showed. But bulk the islands up a bit, giving them a touch more height and width, and Andrew’s flooding would have been cut by as much as five feet.

“Thinking about these islands as though they were gone – that put a lot of emphasis on them and the projects to save them,” Suhayda, now retired, said in April.

Just as the islands’ importance was becoming clear, so was their rate of loss.

In 1992, the U.S. Geological Survey, undertaking the first comprehensive assessment of Louisiana’s barrier islands, estimated that the islands had decreased in area by an average of 40 percent over the past century.

“A few islands are expected to disappear within the next three decades,” the USGS study warned.

Disappear they did. Grand Gosier and Curlew – both part of the Chandeleur Islands on the state’s east edge – were a combined 600 acres in 1996. Less than a decade later, they’d been dwindled to just 75 acres. After Hurricane Katrina, they were gone.

In 2005, the coast-wide scope of loss became clear: since the 1880s, nearly 24,000 acres – about 76 percent of the total area of barrier islands – had disappeared, according to the CPRA. That averages out to 200 acres per year.

Change is a constant for barrier islands. They begin life not as islands but as the outer edges of river deltas, dynamic landscapes that naturally shift and retreat and build anew. Louisiana’s barrier islands took shape some 6,000 years ago as the Mississippi River altered course and abandoned parts of its much wider delta. The delta’s sandy edges turned into islands as the marshes behind them eroded, becoming what are today Terrebonne and Barataria bays on the delta’s west side and Breton and Chandeleur sounds to the east.

The Gulf of Mexico has never been gentle with barrier islands. Waves and wind are constantly scraping at their sides, and storms occasionally break them into bits. But what the gulf took away the river always restored. Silt and sand suspended in freshwater flowed into the gulf and eventually washed up on island’s shores. That changed after humans began to alter the Mississippi, hardening its banks and damming up the sediment-rich rivers that flowed into it. What sediment remained was channeled by levees to flow straight off the continental shelf at the river’s mouth.

Meanwhile, climate change is fueling stronger and more frequent hurricanes that pummel the islands. Rising global temperatures have also contributed to the slow upward creep of sea levels – a problem expected to worsen in decades to come.

Subsidence, the gradual sinking of soft delta land, is also at play. Grand Isle, Whiskey and other large barrier islands are dropping by a half inch each year, according to the CPRA.

Then there’s the oil industry, which has cut some barrier islands into pieces in the search for untapped reserves. Once torn apart, the islands tend to erode faster. Oil companies have tried quick fixes to shore up islands that support wells and pipelines, but their preferred solution – rock embankments – has only sped up erosion, said Darin Lee, a coastal resource scientist who manages CPRA’s barrier island projects. Wave energy bounces off the rock and scours out sand under the water line, making the bank steeper.

“Eventually the rocks collapse, and they sit there, preventing recovery because no new sand can get back to the island,” Lee said.

Oil spills also take a toll. The BP Deepwater Horizon disaster in 2010 saturated several barrier islands. Cat Island on the edge of Barataria Bay had been one of Louisiana’s four largest nesting sites, hosting dense concentrations of pelicans and other birds. The island’s soil soaked up BP oil like a sponge, killing the roots of grasses and mangrove trees. As the plants died, the soil more easily washed away. Before the disaster, Cat Island was about six acres. Two years later, less than one lifeless acre remained. Now the island is a 10-foot-wide strip of sand that will likely wash away with the next big storm.

The effort to save the barrier islands began not with big-budget projects by the federal government or state but by Terrebonne Parish.

“Look at us on a map – Terrebonne’s sticking way out there,” said Mart Black, the parish’s coastal restoration director. “We’re more vulnerable. When there’s a storm, we get hit before the others.”

In the 1980s, the parish pushed for bigger and better structural protections, eventually getting federal support for Morganza to the Gulf, a network of levees, locks and floodgates under construction across nearly 100 miles of Terrebonne and Lafourche Parish. Terrebonne’s leaders also lobbied for help rebuilding their crumbling barrier islands but got little traction with the U.S. Army Corps of Engineers, the federal agency that issues permits for big coastal projects.

“The Army Corps wanted to study it and study it,” Black said. “We said ‘no, no, we need something now.’”

Terrebonne Parish engineer Robert Jones dove in, establishing Louisiana’s first barrier restoration project in March 1985. It was a low-budget, low-tech affair using dredged near-shore sediment to build protective dikes along the edges of East Island. Atop the island, Jones strung cheap plastic mesh from posts to catch drifting sand. He hired teenagers to plant the new dunes with beach grass. They dragged sticks to make furrows and plopped in seeds from a Coke bottle.

The project rebuilt more than 3,000 feet of 8-foot-high dune, all for about $750,000. The island withstood three hurricanes during its first year and a pounding from Hurricane Gilbert in 1989.

“Terrebonne was the first to show it could be done,” Lee said. “The parish gave us our first big push.”

The project inspired similar local efforts and served as a blueprint for some of the state’s earliest coastal restoration efforts. But Jones, who died in 2002, knew his shoestring approach needed to be scaled up.

“If the U.S. was losing this kind of territory to a foreign aggressor, there’d be no expense spared,” Jones told The Times-Picayune in 1992.

But by the late ‘90s, CWPPRA was pouring millions of dollars into barrier island build-ups. Then came the multiple settlements from BP and its drilling partners over the Deepwater Horizon disaster. The billions of dollars in those settlements gave a huge boost to Louisiana’s coastal restoration efforts, paving the way for epic projects like the ones on Whiskey and Caminada. Before the 2010 disaster, barrier island projects averaged less than 3.3 million cubic yards. After 2010, projects had jumped to 5.2 million cubic yards on average, according to coastal engineering consultant Steve Dartez.

More than 20 state-managed barrier island restoration projects have been undertaken over the past two decades, re-creating 9,300 acres of sandy, sea-facing beach and back-island marsh on the Louisiana coast.

The projects have gotten a lot bigger than in Jones’ day. “But we’re using the same principles,” Lee said.

First step: find a sand source. Early restoration projects would use the dredge-and-barge method, which can be time consuming and expensive, depending on the distance between the island and the sand source. Sand is an abundant material but finding the right type in vast quantities isn’t easy.

In 2012, the CPRA turned to the Mississippi for the first time. Sand was dredged from the river and sent through a pipeline from Buras to Scofield Island, a fast-dissolving barrier island near the river’s mouth. The 22-mile-long pipeline had to duck under and jump over several hurdles, including two hurricane levees, two highways and a busy shipping canal. A headache for engineers and builders, the project’s total cost was nearly $57 million for 510 acres of restored beach and dune. The restoration of neighboring Pelican Island was, in contrast, accomplished with sand dredged from the Gulf. It ended up costing about $10 million less than Scofield and restored 76 more acres.

Offshore sand is now the primary source of material for rebuilding barrier islands, but it, too, has challenges. The first one is locating good Gulf sand under all that Mississippi mud.

“Finding sand for our uses takes a lot of searching,” Lee said. The CPRA reviews geologic data collected over the past century to find large sand deposits under heaps of mucky river sediment. They zero in on their quarry with a combination of sonar readings and sediment sampling.

The richest sand sources are ancient barrier islands – ones that sank under the waves after the river retreated or changed course. Ship Shoal, the main sand supplier for the Whiskey and Caminada restorations, was a barrier island 7,000 years ago, around the time humans invented the wheel.

Then comes the second challenge: getting through all of the oil and gas pipeline that lay in a tangle across the seafloor.

“There’s a ton of oil and gas infrastructure on Ship Shoal,” Lee said. “Even if we wanted to, we couldn’t dig up the whole shoal. We have to find blocks that are useable.”

Pipeline maps aren’t always reliable, so avoid breaking through a pipe with a dredge, the CPRA and its contractors must use high-powered metal detectors to get the exact locations of undersea obstacles.

Once a sandy sweet spot is found, a dredge digs in, vacuums up the sand and pumps it through a pipe to the restoration site.

Oil and gas infrastructure can also make offloading the sand difficult. The restoration of East Timbalier Island in Lafourche Parish was mired by an extensive network of active and abandoned oil wells and pipelines, much of it buried and poorly mapped. Already expensive, the project’s budget swelled by over $2 million dollars as workers navigated what project manager Kenneth Bahlinger called “a spiderweb of lines.”

At a dredging summit last year, Dartez classified the Whiskey Island project as Louisiana’s “biggest,” Scofield as the “baddest” and Caminada Headland as the “bestest.”

While not strictly a barrier island, Caminada serves the same protective role on the coast. Its restoration wasn’t as big as Whiskey in the sheer volume of sand, but it was the first to tap into Ship Shoal, located nearly 35 miles from the headland. It tops Whiskey in money spent, totaling more than $216 million, and it covers more ground, some of which is easily visible to the public. Elmer’s Island, on the project’s east edge, is a popular state wildlife refuge – even more popular now that it’s covered in a thick coating of fine sand. It shields not just 13 miles of marsh, but Port Fourchon, a hub of oil shipping in the northern Gulf, and Highway 1, the only hurricane evacuation route for Grand Isle and other communities.

The Caminada project had another surprise benefit – becoming one of the nation’s biggest nesting colonies for least terns, a shore bird threatened by habitat loss. The birds swarmed in just after the project was completed last year, dropping thousands of eggs across the new beach.

“Build it and they’ll come,” said Johnson, the Audubon bird conservationist.

The big barrier island buildup has come to a close, at least for now. Only 3 percent of the state’s $50 billion Coastal Master Plan is earmarked for barrier islands. Four projects are on the docket – the restoration of Rabbit Island in Cameron Parish and West Grand Terre and Queen Bess islands in Jefferson Parish. The largest project, likely to cost $150 million, is a series of island upgrades in the Terrebonne Basin.

The state’s focus is now largely on upkeep. With the natural forces that built and restored barrier islands crippled by dams and levees, the state will need to keep the islands alive by artificial means. That will require regular dredging and sand pumping to replace material chewed away by waves and storms and swallowed by subsidence and rising seas.

Mississippi River sediment diversions – a major element of the master plan – could give barrier islands a boost. The Mid-Barataria and Mid-Breton diversions, totaling $2 billion in cost, would funnel some sediment toward the island’s backsides, but there’s concern the diversions could backfire, according to Suhayda. The complex water chemistry in protected bays makes them effective marsh builders. Their balanced mix of saltwater and freshwater has the effect of binding passing river sediment together. These larger sediment clumps sink rather than float away. Allow too much freshwater, Suhayda warns, and the saltwater is pushed out, and the sediment with it.

Another concern: maintaining the supply of sand. Ship Shoal can’t keep giving forever, and many nearshore sand sources have been exhausted. “The availability of beach-compatible sand has become increasingly scare,” Dartez said. Coastal managers may have to seek out distant reserves or rely more heavily on sediment dredged from the Mississippi.

Money is also a constraint. The BP settlement was a one-time deal. Barring another big disaster-induced windfall, the state will need to find reliable sources of money for expensive repairs and rebuilds. This isn’t a far-future concern. The lifespan of each of the multi-million-dollar restoration projects is a touch more than a house cat’s – 20 years, maybe less. That means Caminada may need another 13-mile, 8.8 million cubic yard coating of sand by 2037.

“In 20 years, we’ll be back where we were,” Lee said. “But if we have a stormy decade, we might not get 20 years.”