Sand berms to be built to hold off oil from Louisiana coast

Crews on ships work on skimming and collecting oil
Crews on ships work on skimming and collecting oil near the source site of the Deepwater Horizon disaster in the Gulf of Mexico near Venice, Louisiana. US officials were poised Saturday to begin building massive sand barriers in the Mississippi Delta in a last-ditch bid to keep oil from BP's gushing Deepwater Horizon well from reaching Louisiana's fragile wetlands.

US officials were poised Saturday to begin building massive sand barriers in the Mississippi Delta in a last-ditch bid to keep oil from BP's gushing Deepwater Horizon well from reaching Louisiana's fragile wetlands.

Coast Guard Admiral Thad Allen on Thursday approved plans to build a six-foot (1.82 meters) high sand berm at Scofield Island, around 10 miles (16 kilometers) southwest of the port of Venice.

The berm will be paid for by British Petroleum or by a federal fund set up in 1986 to help states hit by an oil spill, and will be a test-run to see if a plan of officials to build a string of sand barriers along the coastline to keep the oil away will actually work.

Local officials, including Governor Bobby Jindal, have been almost begging for permission to start building the berms by dredging sediment from designated areas in the Mississippi Delta and dumping it to make man-made barrier islands.

Billy Nungesser, president of Plaquemines Parish, which juts into the marshlands south of New Orleans, said this week he would build his own berms starting Saturday if the federal government did not approve the permits.

Louisiana Senator Mary Landrieu hailed the berm plan as "a significant and achievable first step toward minimizing damage to Louisiana's coast" from the oil.

But environmentalists have issues with berms, fearing the solution officials are proposing to hold back the oil from Louisiana's unique marshlands, if not done right, could do more harm than good to the Mississippi Delta, and might not do the job at all.

"Berms are being seen as a kind of silver bullet, a magic fix to prevent oil from coming in," Lake Pontchartrain Basin Foundation scientist John Lopez told AFP.

"But the more they've been studied, the more it's been realized that they're really only a partial fix, and not a very good one; but then nothing else is either," he said.

The original berm-building plans submitted by Louisiana officials in early May would have involved taking sand from a mile out in the Gulf of Mexico and pumping it closer in to shore to build manmade barrier islands.

That plan was "being pushed by the dredging companies with no science involved," said coastal scientist Angelina Freeman, one of the experts who told AFP that taking sand so close to the shore would promote coastal erosion, already a huge problem in Louisiana.

According to Lopez, the plan approved this week would take sediment from a distributary near Pass a Loutre in the Mississippi Delta that has silted up.

But the problem with taking sediment from the Mississippi Delta to make berms is that the bed of the delta is mainly mud.

"Mud is not good for making berms because it's very fine, and fine material won't stack," said Lopez.

"When you hydraulically pump sediment that's fine, it just bleeds out and flows away."

Even if it were possible to build a berm with mud, "any kind of tidal action would make it disperse," said Freeman.

Oil could easily become trapped in and absorbed by the mud, which would prevent it from weathering and breaking down, the scientists said.

Berms have to be built in such as way as to not block off tidal inlets, because narrower inlets would increase the velocity at which water is channelled into the delta area, which could mean that the oil is driven even further into the fragile marshlands than without the berms.

Berms can also alter water salinity which would affect the fragile marshlands.

The scientists said the plan approved by the Coast Guard was not perfect but better than the original plan which would have had an extensive network of berms running across the mouth of the Mississippi River.

The original plan put forward by Jindal would have "fixed only a part of the system instead of looking at it as a whole," said Freeman.

The plan approved Thursday would work with the natural system of the delta region by putting berms in places where barrier islands have been broken down naturally, and was "an option we can live with," the experts said.

Explore further

Experts debate diverting Mississippi to fight oil spill

(c) 2010 AFP

Citation: Sand berms to be built to hold off oil from Louisiana coast (2010, May 30) retrieved 24 May 2019 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

May 31, 2010
Since Katrina, there has been much heightened awareness of the dangers to the delta, and BEFORE the oil spill, restoration of the barrier islands was a BIG priority among local environmentalists.

I think much of the objection is political prejudice coupled with a sick desire to see as much damage as possible to the oil industry.

Why were berms and/or barrier islands important BEFORE the oil spill?

The causes of the loss of marsh are multiple and ALL addressed by the restoration of barrier islands. The following comment summarizes the reasons the delta has long been declining.

Take away: the protection of the marsh is not just from oil, but from a long list of threats that have been impacting us for a century. Let's use the oil spill to cure these longer term problems with the nation's most important marsh.

May 31, 2010
Causes in the decline of Lousianna's swamp land:
- natural subsidence of the organic rich soil, now no longer restored by silt from yearly flooding of the Mississippi river (the result of over 150 years of levee building);
- salt water infiltration due to levees blocking fresh water flows coupled with dranage canals, navigation canals and construction canals introducing greater quantities of salt water into the swamps (necessary effect of population growth);
- huricanes and shipping/fishing and oil industry boat traffic eroding the barrier islands;

... and many more examples for which I have no space.

Point: we cannot relocate millions, block ship traffic & international trade, destroy New Orleans and blow up the levees to restore the marshes.

We can and should restore the natural barrier islands to reduce erosion, salinity and pollution. We SHOULD have DECADES ago!

Don't let misplaced environmental politics destroy this natural resource.

May 31, 2010
Look at maps of the Gulf... barrier islands form a natural wave break from Key West, Fla to South Padre Island, Tx. Many of the nation's best beach vacation communities ride these islands.

But many of La's natural barrier islands have sunk or been washed away over the last 150 years for reasons listed above, but Katrina especially did major damage.

Study the history of the river levee system and the ship canals at the mouth of the river. To allow in ships (and protect warfs and other shipping industry infrastructure, e.g. RR's), silt has been flushed out ever deeper into the gulf rather than allowed to flow across the swamps.

The result is a saltier marsh, less rich in organic material. The later was partially compensated for the 1900s by fertilizer run off, now regulated/reduced.

We don't want/need levee style berms... that is what got us here. What we do need is restoration of the barrier islands in compensation for 150+ years of man-made damage to this ecosystem.

May 31, 2010
Final vent:
It is disappointing that so many "scientists", supposedly open minded and fact driven, choose to pontificate on what is good for an environment they don't live in. They discount the locals as "yokels" and uneducated riff-raff, without bothering to understand the history or the area, the biology of the delta or the realities of life.

Katrina taught us survivors that we are our own best protectors... we know our situation best and know how to cure it. Trust us, stay out of our way, let us make the rules and protect our shores and you will see our region bloom. Keep us down by taking away our oil revenues, fishing rights, shipping industry... all in the name of "protecting" us... and the entire nation will be diminished.

May 31, 2010
If they don't close the fissure in the earths crust that the greedy psychopaths have created by drilling too deep then the damage from oil is the least of our worries. We are looking at a global catastrophe as the pressure being released from the mhorovicic discontinuity layer is forced to find it way out of the earths crust. We are already seeing it in Iceland, Guatemala and now Vanuatu. The San Andreas faultline is experiencing a massive increase in activity too.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more