GRAND ISLE, La., - The Louisiana National Guard’s 527th Engineer Battalion, 225th Engineer Brigade, completes reinforcement work on a land bridge on Elmer’s Island, La., in support of the Deepwater Horizon oil spill coastal protection efforts, July 20.
The Soldiers built up the existing land bridge along Thunder Bayou, a gap west of Grand Isle, La. It’s armored with large rocks, known as rip rap, on each side, which will help stop oil from seeping into the wetlands and gives the Soldiers better access for moving equipment.
“The purpose of the bridge was to keep water from overflowing into the protected marsh and as a bridge over the gap,” explained 2nd Lt. Christopher Hardy, project manager. “We raised the elevation of the bridge, and armored the gulf and bay sides with rock, geotextile fabric liner and sand.
Hardy, a Shreveport, La., resident, said that the existing bridge was originally built one foot above high tide. Using roughly 2,400 tons of rock and 1,800 cubic yards of loose sand, the engineers were able to raise the bridge from its previous height.
“We improved the bridge and it now stands at approximately four-feet above high tide level,” he said.
The land bridge was built by laying down rock, then compacting sand on top of the rock. A geotextile fabric, which is used to increase soil stability and provide erosion control was laid and then topped with more rocks and sand.
Hardy said the benefits were already proving themselves for the fragile wildlife that nested in the marshlands.
“The Soldiers believe we are protecting the marsh area,” he mentioned. “We took U.S. Wildlife and Fisheries out the other day, and they were thrilled we were improving the (land bridge) structure because of the threat to herons, pelicans and especially terns.”