Heavy equipment, dredge rebuild Louisiana barrier island

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This article was published 01/08/2021 (1612 days ago), so information in it may no longer be current.

WEST GRAND TERRE ISLAND, La. (AP) — Excavators, bulldozers and a dredge miles away from them are working on a $100 million project to raise and reshape a Louisiana barrier island.

West Grand Terre Island helps protect communities from New Orleans’ west bank to Bayou Lafourche from hurricanes and storm surge, depending on the storm’s direction, said Greg Grandy, deputy executive director of Louisiana’s Coastal Protection and Restoration Authority.

But, like East Grand Terre Island, where some of the BP oil spill’s iconic images were made, West Grand Terre was heavily oiled during the 2010 spill and was severely eroded before that. The two islands were one when Jean Lafitte and his Baratarian pirates made Grand Terre and nearby Grand Isle their headquarters, but now are more than a mile (1.6 kilometers) apart.

About $100 million in spill restoration money is being used to restore and create about 256 acres (104 hectares) of beach and dune and 143 acres (58 hectares) of marsh on West Grand Terre. About $2 million from various other sources was used to remove a fisheries lab destroyed by Hurricane Katrina in 2005.

“It is one of the most historically and ecologically important barrier islands in Louisiana,” Gov. John Bel Edwards said when funding for this and two other projects was announced in May.

The U.S. government evicted Lafitte and his crew to build Fort Livingston, one of a chain of coastal forts created after the War of 1812. Fort Livingston was never completed and is now a ruin on West Grand Terre.

It wasn’t the island’s last eviction — in 1999, state and federal crews removed about 20 feral goats and 70 feral cattle as part of work to rebuild the eastern half of West Grand Terre.

The island it stands on is getting 2.5 million cubic yards (1.9 million cubic meters) of sand — nearly enough to fill the Empire State Building twice.

The island’s outline won’t change greatly, because much of the sand will go on top of it. That will raise an island that averages 1 foot above sea level, with a maximum of 4 feet, to as much as 8 feet above sea level, said Brett Borne, project engineer for Coastal Engineering Consultants, Inc.

It’s being armored with a mile of huge rocks, starting at the end of similar construction added in the early 2000s as part of work to preserve what remains of Fort Livingston.

“A corner of the fort actually protruded into the water” before that earlier project, Grandy said.

The rocks being moved from barges on Wednesday weigh from 2.5 tons to 6 tons (2.3 metric tons to 5.4 metric tons). Below them is a core of smaller rocks about 2 feet (0.6 meters) long, with geotextile fabric lining the bottom beneath those, said Brian Champagne, project manager for Deep South Construction and Salvage, one of several companies on the project.

A half-dozen excavators were at work Wednesday. Four were moving rocks. The crews that run them named the biggest two King Kong and Godzilla, Champagne said.

King Kong’s four-clawed bucket alone weighs 2 tons (1.8 metric tons), he said.

Others were creating low lines of sand and dirt to guide the placement of dredged sand between the rocks and the current shore, adding to the beach and creating marshes.

The sand and water fountain up in a huge gray semicircle about 15 feet (4.5 meters) high. It has traveled through about 5 miles (8 kilometers) of pipe, most of it along the floor of the Gulf of Mexico.

On the island, sections of pipe are fitted together to direct its flow. At the far end, the rigid pipe at the bottom of the Gulf is attached to flexible pipe so the dredge R.S. Weeks can move around the area from which sand is being pumped.

The dredge’s crew lives on board, working 12-hour shifts so dredging continues 24 hours a day.

Weather permitting — Louisiana was hit by three hurricanes and two tropical storms last year and the season that began in June is also active — the work will be done in November.