Few Sites Suffer Damage
Breaux Act Projects Stand Up to Hurricanes’ Punishment

Hurricane Rita made landfall near the west Louisiana town of Holly Beach on September 24, 2005.

The storm’s 120 mph winds and 15-foot storm surge wiped out subdivisions and camps along the shore, leaving behind only streets and the concrete slabs of buildings.

But nearby, a Breaux Act beach restoration project sustained only minor damage despite taking an even more direct hit from storm winds and waves.

Similar results were found across coastal Louisiana: Breaux Act wetland restoration and protection projects emerged from hurricanes Katrina and Rita largely unscathed.

“Out of 107 projects, only four or five experienced serious damage from Katrina and Rita — about $15 million in damage to $475 million worth of projects,” says Garrett Broussard, senior operation and maintenance engineer with the Louisiana Department of Natural Resources (DNR). The storms swept sediment off barrier islands and uprooted vegetation, but in most instances, Broussard notes, the materials used to create earthen terraces, rebuild beaches and shield shorelines remained in place.

“That’s an excellent outcome given the size and intensity of these storms,” he says. “It shows how well the science behind coastal restoration plays out on the ground.”

Shoreline Project Survives Amid Devastation

The Holly Beach Sand Management project was designed to protect 8,000 acres of marsh. Sand was deposited along the shoreline behind existing rock breakwaters, then held in place using vegetative plantings and two or three rows of sand fencing.

“Rita destroyed the fencing and swept some sand across the highway and into the marsh,” says David Burkholder, an engineer manager with the Louisiana Department of Natural Resources. But the fencing, installed in 2003 during the project’s construction, had created high, stable dunes, so altogether the beach lost little sand.

With the beach intact, the marsh is still protected from the long-term effects of salinity, and the project is still doing what it was designed to do. “The fences were a big factor in preventing more extensive damage and marsh loss,” Burkholder says. “We’ll take that lesson with us to future projects.”

Floodwaters a Boon to Land-Building Terraces

The 2005 hurricane season may have caused as much as 10 years’ worth of land loss in less than a month as it flooded marshes and eroded barrier islands. But at Little Vermilion Bay, located in southern Louisiana’s Vermilion Parish, hurricane flooding actually created new land. Completed in 1999, the Little Vermilion Bay Sediment Trapping project built 19,700 feet of earthen terraces to reduce wave energy and trap sediment. “We designed this project to mimic the functioning of a river delta — to collect sediment between thin fingers of land,” says project manager John Foret of the National Marine Fisheries Service.

Following Hurricane Lili in 2002, scientists discovered that as the storm surge receded from the bay, it left behind a thick layer of sediment on the bay bottom between the terraces. This experience was repeated with Hurricane Rita, says Foret, who visited the site by boat a month after Rita made landfall.

“Under normal circumstances this project traps sediment very well,” Foret says. “The additional sediment accretion during storms accelerates the marsh building process.”

That increases the restoration value of the project over time, Foret says. “This project has now survived three winters and two major hurricanes, and it has not only endured but has exceeded expectations for building a foundation for marsh plants to colonize. That confirms the validity of the science behind its design. We can build these kinds of projects with confidence that they’ll perform well.”

Island Losses Supply Valuable Information

As the coast’s first line of defense against hurricanes, barrier islands like East Island endure the full force of these storms, suffering severe erosion as they absorb wind, waves and storm surge.

Funded through the Breaux Act, the Isles Dernieres Restoration East Island project restored the island in 1999. But as hurricanes Katrina and Rita tore through its east end, East Island lost almost a third of its land mass.

“About 2,000 feet of the island is gone,” says Darin Lee of the Louisiana Department of Natural Resources. But the destruction offers important information to scientists who design barrier island restoration projects.

“The ends of these islands typically take more of a beating than other areas as water rises and scours around them,” Lee says. “With each storm, we gather more data regarding the optimal combination of elevation, sand placement, fencing, plantings and other elements.”

“Coastal engineering isn’t an exact science,” explains Burkholder. “But surveys of project sites after major storms give us an opportunity to fine-tune the science behind building wetlands. We call that process ‘adaptive management’ — evaluating projects and incorporating new information into our designs. We’re constantly learning how to make these projects perform better.”