• The Mississippi: A Visual Biography by Quinta Scott

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Bobby Jindal’s Ersatz Barrier Islands: Where will he find the sand?

When a fast moving stream meets a still or slowing moving body of water, it almost comes to a halt and deposits the sediment it is carrying in the still body of water. This is how the Mississippi built the Louisiana Coast over the last 7,000 years. When the river ceases to push the delta front further and further into the Gulf of Mexico, the delta front, the headland, begins to deteriorate and transform itself into barrier islands. In time the barrier islands themselves are reduced to sandy shoals under the gulf. Such is the case with Ship Shoal, Trinity Shoal, and the St. Bernard Shoals.

From The Mississippi: A Visual Biography:

“Louisiana’s barrier islands buffer storm surges, reduce flooding in the bays and erosion in the marshes behind them, and preserve estuarine systems by maintaining the gradient between saltwater and freshwater in the basins they protect. The processes that build barrier islands–waves, tides, and the circulation of coastal waters–also erode and fragment them.”

Caminada Headland at Fourchon Beach

When the Corps of Engineers and the Louisiana Department of Natural Resources published the Louisiana Coastal Area Ecosystem Restoration Program in 2004 and Congress approved it in the 2007 Water Resources Development Act, one “near-term critical feature” of the plan was the restorationof the Caminada Headland, the delta front of the Mississippi that flowed along Bayou Lafourche,  which would protect oil and gas infrastructure at Port Fourchon, located on the headland. It also might prevent more land loss in the Barataria Basin, which has already suffered quite a lot of land loss.

Port Fouchon on the Caminada Headland

Gov. Bobby Jindal wants to build ersatz barrier islands (a project that looked intriguing a month ago, but on second thought not) out front of the Caminada Headland and Barataria Bay, which is already seeing BP oil spoiling Queen Bess Island, a pelican nesting colony the state established in 1968, when it looked as though the Brown Pelican was going to go extinct in the state of Louisiana. But where is he going to get the sand?

According the LCA program the state already has dibs on the sand at Ship Shoal, the sandy, underwater remnant of an ancient Louisiana delta that was active 7,000 years ago.

With permission from the Minerals Management Service the Corps and the DNR would mine between 9 and 10 million cubic yards of well-graded quartz sand from Ship Shoal to beef up thirteen miles of shoreline.  In essence they would build 529 acres of dune to the existing 430 acres of dune on the headland to bring it to a total of 959 acres of dune.

A similar beach reconstruction project  started on East Grand Terre Island in 2009, where sand dredged from the floor of the gulf is being pumped to the island,  spewed onto the beach, and spread by bulldozers. Perhaps, this is the model for Gov. Bobby Jindal’s ersatz barrier islands. The project will restore 2.8 miles of barrier shoreline with a 6-foot dune, build a 450 acre marsh platform behind it, install sand fencing, and anchor it with vegetative plantings, all at a cost of $36,705,731, which gives you an idea how far the $360 million Jindal hopes to get from BP for his barriers will go.

So suppose Gov. Jindal takes his sand from Ship Shoal and builds his barrier islands. What will happen to them? Again, look to the projected fate of the  reconstruction of dunes on the Caminada Headland as outlined in the LCA Study:

The LCA study points out that  49 acres of carefully designed and constructed sand dunes would be lost to erosion and sea level rise within the first year.  The 959 acres of dune would be down to 750 acres in ten years, and the state would have to cart in 2 million additional cubic yards of sand to bring the dunes back to 910 acres. In short restoring beefing up the Caminada Headland would be an endless process and much would still be lost to erosion and sea level rise.

The U.S. Geological Survey has a lengthy description about where the sand could come from and what will happen to Gov. Jindal’s poorly designed and hastily  constructed ersatz barrier islands to stop BP oil from invading and destroying coastal marshes. They would begin to erode away in the first big storm and a really big storm would simply carry the oil over them.

Mining the sand for Jindal’s berm gulfward of the Caminada Headland and other barrier island would create a pit into which nearshore sand would fall, hastening the erosion of the barrier island behind the berm, because wave wash does deliver sand to the barrier islands, especially in the summer when the gulf is fairly calm–hurricanes excepted.

The berms out front of Barataria Bay would required 36 million cubic yards of sand that would be washed away, useless for restoring the Caminada Headland.

Louisiana is in a pickle. A year ago two Louisiana State University scientists published a paper that stated there is not enough sediment remaining in the water column when the Mississippi flows pass the Louisiana marshes to rebuilt the marshes. It is all trapped behind headwater dams, built to retain floodwater in the uplands until a flooded Mississippi can handle it.  Louisiana cannot waste a single cubic yard of sediment–sand or silt. It’s too hard to come by.  LaCoastPost had a discussion of this issue at the beginning of the week.

What to do about the BP oil? It’s a mystery.

Update, July 12, 2010: Well, that didn’t work. Len Bahr at LaCoastPost has images of Bobby Jindal’s sand berms, built to protect the Chandeleur Islands from oil. They washed away in the rough seas of the last several weeks.

© 2010, Quinta Scott, All Rights Reserved.


6 Responses

  1. A blogger friend from Houma with roots generations-deep in Louisiana and a lifetime of experience with the wetlands has been critical of Governor Jindal’s proposal from the beginning.

    On its face, Jindal’s proposal makes sense and it certainly is appealing emotionally. The urge everywhere is to put up a barrier to the oil.

    But, as my friend has said and as you have explained, things are not so simple. Not only can nature render such barriers ineffective, the very process of creating them can become counter-productive.

    I’m quite curious about the so-called Wetlands Restoration Act I heard about on the news last night.
    Whether it is a truly useful move toward the sorts of action that has been urged for years by groups like BTNEP I can’t say. It may be nothing more than a political ploy, and a way for President Obama to appear, at last to be “doing something”.

    I’ve been desperately hoping for them to stop the oil. Now, I’m also hoping the politicians don’t try to persuade us that they’re the ones to restore Louisiana.
    I suspect the folks who have been working toward that goal for the past years could do quite well on their own, if only the government would get out of their way.

    • My first posting on Jindal’s islands was positive, because it did seem to make sense. But smarter and more knowledgeable people than I pointed out the error of my ways. I used the post to point out the years-long bureaucratic hoops any coastal project has to go through to get approval. Jindal is very good at putting Obama and the Federal government on the spot. But, they are both helpless in the face of this oil gusher that is destroying whole ecosystems.

  2. This is one of the most critical areas that exist in louisiana due to what lies behind it. Yes it will wash away and have to be redone over time. But this has to be done. Now or shortly in the future. Do it now.

    Hopefully longer term solutions that will slow the erosion can be developed. But that is just a hope.

    This small area must be preserved or the economic ramifications for the entire counrty will be felt in much higher gas prices which will even further damage our faltering economy.

    • Like everything that is happening in the gulf there days, Jindal’s islands are an expensive experiment.

  3. […] into letting him build his sand berms, thus bypassing the above process. I followed up with a discussion about where the sand could come from and how hard it is to come by. Len Bahr at LaCoastPost has a […]

  4. […] the construction of Bobby Jindal’s ersatz barrier islands to stop the oil from seeping into the marshes, I came to the conclusion that Bobby Jindal and […]

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