Louisiana levee to use stabilizing fabric
The 1,600-foot earthen levee, which runs south from the Old Estelle Pump Station, has failed twice, once in the early 1990s and again in 2007 when two sections totaling 600 feet long slumped badly; Army Corps of Engineers will use geotextile fabric to stabilize known trouble spots before raising the levee from 10 feet to 14.5 feet
The West Bank levee board has reached an agreement with the Army Corps of Engineers to shore up a troublesome levee south of Marrero that one board member has likened to “a cake that keeps falling flat.” The 1,600-foot earthen levee, which runs south from the Old Estelle Pump Station, has failed twice, once in the early 1990s and again in 2007 when two sections totaling 600 feet long slumped badly.
The Times-Picayune’s Paul Rioux writes that, prodded by the levee board, the corps has agreed to use costly geotextile fabric to stabilize known trouble spots before raising the levee from 10 feet to 14.5 feet to guard against a 100-year storm, which has a 1 percent chance of occurring each year.
The corps also agreed to use various monitoring devices during construction to detect any instabilities in the levee, said board member Mark Morgan, president of a Baton Rouge engineering firm. “The monitors will detect any slides or failures so we can correct the problems now, rather than waiting until the work is done,” he said Friday afternoon. “We don’t want to be mowing the grass six months later and notice, ‘Hey, the levee failed again.’ ”
As part of the agreement, the corps will cover the costs of repairing any failures for five years after the levee has been raised, Morgan said.
Soil borings have linked the past failures to high concentrations of woody material and shells in the ground beneath the levee.
The chronic problems came to a head early this year when levee officials noticed apparent seepage along the levee as a contractor wrapped up an intermediate project to raise the levee from about 8 feet to 10 feet.
Levee board members were adamant about fixing the problems before raising the levee to its final height. At the time, board member Michael Merritt, a Baton Rouge geologist, said he was wary of “putting another layer of icing on a cake that keeps falling flat.”
The deal announced Friday culminated about eight months of negotiations with the corps. “The agreement may not have everything we wanted, but it gives us a level of comfort that they’re going to do things right,” Morgan said.
