ROCKEFELLER WILDLIFE REFUGE, La. (AP) - Louisiana is adding three miles of breakwaters to protect a state wildlife refuge where the shoreline is rapidly eroding and the bottom is extremely soft.
The new work is in addition to four miles of breakwaters already built along the Rockefeller Wildlife Refuge in southwest Louisiana. Like the earlier one, the new breakwater will put big rocks over a core of 10-foot-long (3-meter-long) geotextile "pillows" filled with very light clay baked at extremely high temperatures.
Such breakwaters can be built higher than all-rock construction, making them much better at slowing waves and preventing erosion, a study in 2011 found. It said that land behind the lighter, higher breakwater was worn back about 3 feet during a 14-month test, compared to nearly 18 feet (5.5 meters) behind the less expensive all-rock breakwater and more than 45 feet (13.7 meters) along an unprotected area.
"Our federal, state and local partners took a big problem - coastal erosion and difficult soil conditions - and came up with an innovative solution through good science and engineering," Gov. John Bel Edwards said in a news release Tuesday.
Officials hope eventually to add another two miles of breakwaters.
The new breakwater's $18 million cost includes $5 million of the state surplus, provided through the Coastal Protection and Restoration Authority, and $4.3 million from disaster grants to Cameron Parish. The rest will be matching funds from BP oil spill penalties, under a program aimed at state-parish partnerships.
"We consider this an investment in protection for an important portion of our parish," said Joe Dupont, president of the Cameron Parish Police Jury.
The parish plans to pay for a total of six miles of all-rock breakwaters at three areas west of the refuge, where the bottom is more solid, state Sen. Blade Morrish said.
"The construction techniques pioneered here in Cameron Parish could have far-ranging applications in the fight to slow down and reverse the erosion in coastal Louisiana," he said.