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Like sand through the hour glass, so are the dunes of our lies.

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by Len Bahr, PhD*

My apologies to NBC-TV for 'modifying' the logo for their popular soap opera

My apologies to NBC-TV for 'modifying' the logo for their popular 45 year old soap opera

Bobby Jindal’s coastal barrier project resembles a love letter to south Louisiana – written in the sand.Len2.21.10

This is my fourth (but probably not final) post on an obsessive push by Governor Jindal to force the feds to rubber stamp and BP to squander $360 building fragile sand berms parallel to the deltaic coastline of southeast Louisiana. This pipe dream would presumably repel surging oil from BP’s out-of-control Macombo well. IMHO this project is as likely to keep BP oil out of Louisiana marshes as the Maginot line kept the German army out of France during WWI.

I seem to have become as obsessively opposed to this project as the governor is determined to build it. Nevertheless, I harbor no unrealistic expectations as to the winner of this one-sided contest. The national media are treating the emergency sand berms as a fait accompli. For example see this otherwise excellent account of the causes and responses to the BP Blowout from June 5 in The New York Times, which discusses federal delays in permitting the Jindal sand berms without mentioning any scientific controversy.

The emergency sand barrier concept seems to have been broached initially by Plaquemines Parish President Billy Nungesser and I believe that Mr. Nungesser’s support is sincere and motivated by righteous desperation. On the other hand I believe that Governor Jindal’s support is motivated more by national ambitions than belief in the project.

Is this where long term coastal planning is headed in Louisiana?

Is this where long term coastal planning is headed in Louisiana?

As I have reported in previous posts, no coastal scientist of note supports the sandy Band-aids. I have cussed and discussed the sand berm concept with a number of technical authorities, not one of whom has been invited to proffer recommendations on the state’s ambitious plan.

These experts include, among many others, Dr. A, a petroleum geologist with extensive experience on the Mississippi River delta; and Dr. B, a senior coastal engineer and modeler. They relayed their respective opinions on the concept, after reviewing various official state planning documents. Some of their thoughts are as follow:

A: As I watch helpless like everyone else, and silent because of my current position, I cannot help but despair about the governor’s plan to build the sand band-aids. There are many unintended consequences that project advocates are almost certainly hearing about but either overlooking or ignoring because of a belief in an alternate universe of knowledge.

I made some calculations on sand requirements for this concept that your readers might find interesting.

Assume 130 km (80 miles) of barrier, 2 m (6 ft) high. Achieving this would require filling in low spots and creating a strip wide enough to be stable at 2 m above the surrounding landscape. Assume a berm 10 m wide at its base, tapering from a peak thickness of 3 m to account for filling in all the holes, to zero at the edges, for a mean thickness of 1.5 m. This yields a cross-sectional area of 1.5 x 10 = 15 m. Now multiply by 130 km, and you would need an absolute minimum of almost 2 million cubic meters of sand.

Remember that the Mississippi River delta suffers from a serious sediment deficit. Although we cannot know for sure, two million cubic meters of sand might be roughly equivalent to 2 years’ worth of total sand (see Editor’s note, below) delivered to the mouth of the river.** Considering that beaches in the Mississippi delta consist of of a very narrow range and specific size of sand grains, this could equal 5 years or more of total sand supplied by the river. Sediments outside of the size range ‘preferred’ by the beach and its wave climate will wash away almost immediately.

To illustrate the serious sediment deficit of the Mississippi River delta, I’ve adopted your proposed Superdome Equivalent (SDE) unit of measure, 5 million cubic yards, or about 4 million cubic meters of sediment. If massive river water diversions are not built soon to rebuild the delta, every year of delay will increase the deficiency by 15-20 SDEs.

According to the above assumptions, the proposed sandy band-aids would require about 0.5 SDE. This is not a trivial amount, especially when compared with the total amount of actual sand in the river’s sediment load (>90% is silt and clay). It also adds to the long-term sand deficit….which will be further exacerbated if these guys are allowed to do this!!

To get the 50 million cubic yards called for in the documents I’ve seen*** you would need a strip of sand 86 miles long by an average of 2 yards high by 165 yards wide. That would be a more stable Band-aid than the one I used for calculations. However, it also means a lot more sand. This is about 38 million cubic meters, about 9.5 SDE’s, or an equivalent of 20-50 years of the optimum size sand arriving at the river mouth.

I’m not saying that all the sand can or should be mined from the river; I’m only using the river load as a base for comparison. The big question is the possible sources of sand. It’s not as though unlimited sand exists out there on the shelf in readily accessible locations.

In short, I think the ‘Sandy Band-aid’ concept is a terrible idea that would have a marginal short-term gain, with a huge long-term cost. The gain, if any, would benefit marshes that will be submerged in 25 years anyway, sad to say.

B: I have seen nothing in state presentations and proposals that address my four primary concerns:

1) the availability of sufficient sand resources (and the possible waste of what little resources there are if the plan is not properly conceived);

2) the time that it would take – it is closing the barn door after the horses have escaped – the oil is already in the marsh; and

3) even if there were sufficient sand and time – the berms would no keep the oil out of the estuary, as the tidal passes would bring the oil that is in the Gulf into the interior;

4) even if the passes were successfully boomed off – that would only last until storm waves pushed the oil over the booms or, more likely, washed them away.

What is needed is a massive effort to soak up and collect the oil (and to stop the gusher!).

A: I agree with B’s 4 issues. I reviewed the presentation (by Garret Graves, Governor Jindal’s coastal advisor), which I feel is worthless, as well as the application to build the berms. On the surface, the berms look like a reasonable idea if there were a lot of sand laying around on the inner shelf – as off the coasts of Alabama and Florida. They would take a long time to build and would do little but put a decoration on the barriers with the opportunity cost of consuming much of the sand resources availability for longer-term restoration.

B’s point about tidal passes is absolutely crucial, as any changes to tidal prisms will result in unintended consequences as the shoreline adjusts to accommodate the prism elsewhere. And all bets are off if there is a significant storm later this season. As I understand it, the total length of berm segments now being proposed is much greater than the 85 miles that we discussed last week…according to the current permit request, the design includes 128 miles of berm, and 102 million cubic yards of sand, or ~20.4 Superdome Equivalents!

If they actually pursue the plan of taking sand from the nearshore system, with the intent to replace it at a later date, I don’t see how they can predict what will happen without serious modeling over periods of months to years – and it won’t be good. I don’t think there is much sand there anyway, except for near the modern river mouth and the older mouth bar sands the modern channel now cuts through south of Boothville.

Sand thickness off of the Chandelier Islands and the Isle Dernieres-Grand Isle chain is pretty minimal. I saw a recent report by the US Geological Survey (USGS) on sand near the Chandeleurs, which was deposited by a variety of processes (from old distributary channels and through longshore and offshore drift from the islands themselves). Restoration of the Chandeleurs must use the natural sand transport trends to make efficient use of sand. Spreading sand out evenly, as proposed by the state, will mean much of it will just go to waste.

B: There is also the issue of the ‘spaghetti’ of oil and gas pipelines on the shelf, where even the owners don’t know exactly where their pipes are! In other words, without a detailed (and time consuming) magnetometer-based survey of all the borrow areas mining sand for barrier berms would risk nearshore pipeline ruptures.

*Founding editor (leonardbahr@gmail.com)

**Dr. A’s first comments on sand volume requirements were sent before the original permit proposal submitted to the Corps of Engineers was modified from 80 to 86 miles of berm segments. Current proposals call for up to 128 miles!

Editor’s note 1: Since posting this article around 9:00 AM CDT a sharp-eyed reader spotted what appeared to be a major discrepancy re the average annual sediment load of the Mississippi River. He cited a 2009 paper by Bob Meade, retired from USGS and the acknowledged ‘dean’ of historical changes in Mississippi River sediment loads, who uses the figure of 145 million tons of sediment/year. This strongly contrasts with Dr. A’s number of about 2 million cu meters (roughly tons) of sand/year. The apparent discrepancy is explained by the fact that Meade’s figure includes the total river sediment load, including roughly 30% of the load that flows into the Atchafalaya River and the total suspended fraction (silts and clays) not just sand.

Editor’s note2: an alert reader just forwarded this link to a new report on the sand berm project by scientists with the US Geological Survey.

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  1. A convenient chart is given below to locate the reasons of dyapnoea.

  2. Yes more details on what is being built and what they want to build would be helpful. We get it you are against the project. But we need more information on what the project actually is. Where is it being built, were do they want to build it. Need some details!

  3. hweather I heard the same.

    The mayor of Grand Isle was on WWL with Tommy Tucker as I drove home from the State of the Coast conference in BR today. He was talking about sinking barges and rocks in Caminada Pass, as well as four others, to block the oil. His stated goal was to “reduce the passes by about 70%.”

    I called and called, but could not get on the air.

  4. hweather says:

    I, like many of you I presume, share the concerns brought about by B’s points 3&4, regarding how to deal with the inlets. Even if the berm is magically in place to specs overnight. As has been discussed, the tidal prism is pretty unwilling to broker a compromise. However, it appears that the ante has been upped, and the particle size of the berm will increase around inlets to inhibit entrainment by tidal currents. From what I have been told (by a scientist in a similar pickle as A and B), the D50 is in the range of rip-rap to sunken barges. He/she made me aware that the pilot area for this project is at Pass Abel/Quatre Bayou.,br> I had heard of this plan posited by Mayor Carmadelle. I have seen nothing of this actually happening in the news yet, have you?

    • hweather-
      Your comments, the observations of others and photographs of military dozers and dump trucks, e.g., on Elmer’s Island and who knows where else, suggest frenetic and unsupervised efforts by folks with little understanding of coastal geology, sediment transport, etc. I’m particularly struck by the impulse to incorporate non-native materials – rocks.

      Some of these folks may be motivated more by opportunism than by sincere efforts to mitigate oil. The chance to build levees that wouldn’t normally qualify for 404 permits or coastal use permits comes to mind.

  5. carolcrom says:

    It seems a flawed line of reasoning to suggest that in the absence of a “better” plan, one which would not work (according to basic scientific understanding of coastal/deltaic systems) and one which could cause irrevocable harm (in an area already experiencing a devastating calamity) is a “good” plan.

  6. Great post Len and guests. My concerns about this Band-aid proposal have always been along the lines of Scientist B’s four points. The “simple” calculations Scientist A presented should be placed front and center in all media coverage of this “solution” to the oil disaster in the gulf. I would hope that when people started to grasp the magnitude of the volume of sand required to build these berms, and the temporary nature of them, they would understand how ludicrous this proposal is.

  7. No one in the navigation industry has been contacted to discuss the possible impact either. A permit condition is no impact on navigation, not sure how they can be done without engaging the navigation industry?

    Seems like Garret is behind trying to make the oil spill a way to promote a coastal restoration effort without focusing on the spill first.

  8. HeidiHoe says:

    bet them OIL fellers wish they’d spent the bucks earlier in the game; fer doin the well cappin right and perhaps havin relief wells on the ready beforehand……

    the sand jobs will no doubt keep people employed fer years to come…. and come…. and come….

    as the newly placed sand goes….. and goes….. and goes……

    with the tides and waves……

  9. Charlie Viosca says:

    What a waste of time and money for something that will be washed away.

  10. riverrat says:

    Ezra has missed the point again – what help is a “plan” when the “plan” is deeply flawed and unrealistic? What the feds have approved (and developed) is a responsible revision of an irresponsible proposal. The state’s “plan” was never feasible in terms of keeping much oil out of the marshes. It could have compromised the Chandeleur Islands, however, right at the beginning of hurricane season.

  11. Anonymous says:

    Aside–with massive diversions will come massive navigational dredging–if the dredging industry really wants to help–that’s where we can use them the most.

  12. Wow… four posts…. and not a single paragraph on alternative plans to protect our coastal wetlands from BP’s Toxic Gumbo. Without any supporting evidence, all four posts insinuate corrupt motivations regarding the only good plan out there. Let’s see, assumed guilt in the absence of any evidence of a crime, and no alternative plan to protect our coast. What are you hoping to achieve Len?

    • Ezra-
      You apparently infer a sinister motive on my part. Do you actually think I’ve spent 37 years in south Louisiana because of a passion for oil production rather for the coastal ecosystem?

      I believe in the Hippocratic oath: “First, do no harm.”

      As a number of credible authorities are saying, the ‘cure’ for oiled wetlands can be far worse than the disease. Oil is toxic but biodegradable. Chemical dispersants contain ‘secret’ compounds not found in nature and are far less so.

      Physical damage to a subsiding delta in the guise of building sand berms is a bigger threat, in my humble opinion that is based on lots more study than you have under your belt so far. Sand box experiments with the limited substrate that’s out there is unconscionable.

  13. Anonymous says:

    Three other flaws: 1. Since the berms will be built in front of the existing toe, i.e. in “open water” the loss of material during placement will be very high–I’d guess up to 50%!! 2. If the net cross -section of embayment inlet opening is substantially restricted, the tidal prism/propagation will be affected–and will change circulation, oxygen, salinity and other aspects of embayment water quality. 3. In actuality, reducing overall inlet sizes will be difficult–w/o substantial amounts of rock–so tidal prism may not be changed and thus flux of water (and oil) between Gulf and embayments will not be controlled.

    We need to focus our $$ and other resources towards an “end-game” and some “optimal” fix 3- 5 YEARS down the road. Rather than engaging MMS, COE, USEPA, NOAA, USF&WS on a big decision to build the sand booms, we should be gearing up for a massive effort to use hundredes of thousands of cfs from the Mississippi River for the next several years to speed rehabilitation of the deltaic ecosystem!

  14. Willie Fontenot says:

    Dear Len, Where are these artificial berms supposed to be built?
    Sincerely yours, This sounds like an attempt to extend the life of Plaquemine Parish and to get BP and the federal government to pay for this questionable project.
    Willie Fontenot

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  1. Bobby’s berms and BP’s oil | Rubber Donkey.org - [...] Bahr, who a month ago was calling Louisiana Gov. Bobby Jindal’s pet sand berm project a “Maginot line” [...]
  2. Bobby Jindal’s Ersatz Barrier Islands: Where will he find the sand? « Quinta Scott’s Weblog - [...] it.  Louisiana cannot waste a single cubic yard of sediment. It’s too hard to come by.  LaCoastPost had a …

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