Berms: a sobering lesson from Dauphin Island

 

The more I poke around at the continuing and controversial (to some) issue of berm-building, the more mind-boggling and stupefying it becomes.

For example, they're building berms right now on Dauphin Island, a barrier system off the coast of Alabama. Now Dauphin Island happens to be the dramatic example of barrier island dynamics that I used in my book for the chapter on coasts; here's an illustration from the USGS that I adapted as showing the relentless redistribution of sand, the shape-shifting nature of barrier islands:

 

Three images over a very short period of time. The arrows locate the same points in each image and the period covers the ravages of Hurricanes Ivan (2004) and, of course, Katrina in 2005 - not to mention the more normal processes of tides, waves, and the regular lesser storms. At the lower left of the bottom image is an oil platform. In an earlier post, I referenced imagery that illustrates the effects of " normal, natural, wear and tear of wave and weather" - the emphasis in commentary on the current plans for "The Great Wall of Louisiana" may be on the likelihood of berms disappearing completely with the first tropical storm, but the fact is that everyday wear and tear will demolish them without the need for major weather events. And the history of berm-building on Dauphin Island is a case study - one that, should anyone be interested, is a sobering lesson. This is documented in a 2007 paper in the Journal of Coastal Research by Carl Froede of the Environmental Protection Agency. The paper is titled "Elevated Waves Erode the Western End of the Recently Completed Sand Berm on Dauphin Island, Alabama," and here's an extract (edited slightly in the interest of simplicity - references removed - and the emphasis is mine):

Dauphin Island is a microtidal barrier island in the northern Gulf of Mexico located approximately 8.0 km offshore from southwestern Alabama (U.S.A.). Passing hurricanes have historically brought about changes to the island since European settlement began in 1699. Hurricane Katrina struck the island on August 29, 2005, as a Category 2 hurricane and produced considerable geomorphic changes across the island. The low-lying residential western portion of Dauphin Island East was completely overwashed during the course of the storm. As a result, a significant portion of the Gulf-facing beach was removed and numerous island-cutting channels were formed . The damage to this portion of Dauphin Island required immediate action. Following the infilling of the numerous island-cutting channels and the restoration of the road, steps were then undertaken to create a 2.5 m high sand berm along the western 6.4 km of Gulf shoreline to protect this section of the island from future washover events.

Construction on the island’s largest sand berm project (to date) began on January 29, 2007, and was completed within four months.The berm was initiated on the western end of the island and proceeded toward the east. Sand was collected from the washover fans on the Mississippi Sound side of the island and pumped across the island, where it was reworked into a sand berm along the existing shoreline. No effort was made to create any beach zone in front of the sand berm. The berm serves as a temporary measure intended to provide time to determine a possible long-term solution for this portion of the island.

Erosion problems developed along the sand berm even before it was completed. Elevated waves in middle to late March began to erode sections along the western end, and corrective actions were undertaken to adjust the grade of the berm experiencing the excessive erosion. These actions proved futile, and several breaches to the berm developed in April. Waves continue to erode many sections of the sand berm along its western end.

The images at the head of this post are from this paper, and the captions are (left) "Elevated waves eroded away the former berm across this portion of the island. This is the largest of the breaches in the sand berm, extending approximately 92 m in length" and (right) "Significant erosion continues to occur along the western portion of the sand berm." The Images were taken July 27, 2007.

This was an interim report. By the time Hurricane Gustav had passed through in August 2008, the 10 foot high berm, built at a cost of $3.6 million of Federal Funds, had vanished. This was the third time since Hurricane Georges in 1998 that Dauphin Island's manmade "protective berms" had been wiped out by hurricanes - never mind the daily wear and tear. The erosional and depositional effects of Gustav are dramatically illustrated in a USGS report showing pre- and post-storm topography:

 

 Dauphin Island, AL, 2008. Three-dimensional view of changes in island elevation between June 2007 and September 8, 2008. Red indicates areas of elevation loss (erosion) and green indicates areas of elevation gain (accretion). The view is looking west along the island with the Gulf of Mexico to left. The emergency berm built after Hurricane Katrina was completely eroded, and sand was deposited inland. Overwash along the road was cleared prior to the lidar flight. Piles of cleared sand are seen in green along the north side of the road. The patches of red and green on the houses are an artifact of data processing. Large green rectangles on the ground are locations of houses built since Hurricane Katrina.

These berms were not, of course, "restoration projects" by any stretch of the imagination - they were built to attempt to protect property. Approximately 300 homes were destroyed by Ivan and Katrina and many of the lots are now in the ocean. The population of Dauphin Island? 1300 permanent residents - although that's stretching the definition of "permanent." Even back in 2006, the protective berms were controversial:

“Everybody is waiting on the berm,” said Jan Blackmon of Richmond, TX, whose vacation home was swept away by Katrina.

For others, such a project is a foolish waste of money, most of it from taxpayers, in a futile attempt to resist the wrath of nature. Even more, Dauphin Island is for them a symbol of the excessive financial aid that benefits mostly privileged folks whose vulnerable coastal property has been hit repeatedly by storms.

Opponents said such spending won’t outsmart Mother Nature. Steve Jones, a coastal geologist of the Geological Survey of Alabama, wouldn’t build a home there.

While the eastern end of the island is stable because of dunes, trees and other natural protections, the slender western end is little more than a big sand bar cut into plots for residential development.

“It’s almost like a dog wagging its tail it moves so much,” said Jones. Approximately all the homes that were destroyed or severely damaged were on that active, constantly moving western end.

In the face of all this, and presumably under a completely different regulatory system from that in Louisiana  (where there have been loud complaints about delays - or perhaps it's simply that it's not being paid for by BP), they're building berms on Dauphin Island again, and have been for several weeks (photo AFP):

 

But the story doesn't end here. Since Katrina, Dauphin Island has in fact been two islands, separated by a wide channel scoured out by the hurricane and maintained by normal coastal processes ever since. Note Google Earth images from 2000 and 2008 - and note the current and wave dynamics in the channel:

 

There is now a plan to block this entire channel. And what a plan! Here it is:

 

No, I'm not kidding. As reported on the Science Insider webpage published by the American Association for the Advancement of Science (I would have thought a reliable source), under the title "Emergency Oil Spill Response—How Sketchy Is It?":

It could be one of the sloppiest engineering plans the U.S. Army Corps of Engineers (USACE) has ever seen—a hand-drawn plan illustrating how engineers would fill in a channel in Dauphin Island to prevent oil from reaching sensitive wetlands. The corps posted the permit application and asked for comment from agencies and public in just a few hours.

The project could be a good idea, scientists say, but it's hard to tell given the rough plans, and it's equally hard to have confidence in such a quick evaluation. "It's very symptomatic of this whole episode," says George Crozier of the Dauphin Island Sea Lab, referring to the Deepwater Horizon leak. "There is a lot of panic and uncertainty."

I've quoted the informed views of coastal geologist Robert Young on the berms issue in previous posts. Here's what he had to say about this:

Coastal geologist Robert Young of Western Carolina University in Cullowhee, North Carolina, says he was stunned by the short deadline. Young, who says he often comments on permit applications for coastal engineering projects, only came across the proposal later that evening. "This makes me wonder how many of these emergency permits are out there that I haven't seen."

Young and other experts were also flabbergasted by the rough plans. "They're done by hand on a piece of notebook paper. I've never seen anything like this in my life." Young says it's difficult to tell from the drawings exactly what the consequences of filling the channel might be. And then there's the vague note on the map indicating "various buried pipelines."

There's a lot more in the Science Insider piece in terms of where the sketch came from and who is involved - I can't bring myself to repeat it here, but please, feel free.

What I still can't see are any signs of joined up thinking - not just on the berms issue, but on the response to dealing with the spill and mitigating this disaster (and I'm not talking about attempts to cap the well, but the management of the consequences). Back to Rob Young again:

The BP oil spill will be with us for years, not days. In order to move forward in a sensible way, the administration should set up a scientific review panel to vet all proposals for large-scale coastal engineering in response to the spill. The panel should include experts from science agencies like the U.S. Geological Survey and the National Oceanic and Atmospheric Administration, as well as leading academics. The review panel should still be charged with responding very quickly to permit applications, but the public needs to have a higher level of confidence that the best science is being brought to bear on this problem. At the moment, that is simply not the case.

There's no sign of such a panel, an emergency task force of scientists. I go on the website of the Federal Office of Science and Technology Policy, the sicentific advisory group for the Whitehouse and Congress, and I read their mission statement:

OSTP's Mission

The mission of the Office of Science and Technology Policy is threefold; first, to provide the President and his senior staff with accurate, relevant, and timely scientific and technical advice on all matters of consequence; second, to ensure that the policies of the Executive Branch are informed by sound science; and third, to ensure that the scientific and technical work of the Executive Branch is properly coordinated so as to provide the greatest benefit to society.

"All matters of consequence" - if this isn't one of those, then I don't know what is, yet look at the website and you'd never know that there is a catastrophe in the Gulf of Mexico and that actions being taken run the clearly defined risk of precipitating a whole series of further "matters of consequence" for the wellbeing of the entire Gulf Coast.

I have to admit that I'm on the verge of giving up on this series of posts. It's not that I expect this blog to make any difference, but there is the continuing invisibility of the people who know what they're talking about but to whom nobody is listening; people whose efforts and expertise should be making a difference.

There's an escalating sense of despair and pointlessness - and my supply of blood pressure pills is limited.

[For further interest, there's a video report, "Dredge, baby, dredge" on the Time Magazine site; for more comprehensive coastal studies see "Continued redevelopment of the west end of Dauphin Island, Alabama—A policy review," a Special Paper from the Geological Society of America, and "National Assessment Of Shoreline Change: Part 1 Historical Shoreline Changes And Associated Coastal Land Loss Along The U.S. Gulf Of Mexico" by the USGS]

Comments

[David]

Your argument against a berm as an erosion control method doesn't really apply to this situation, a berm constructed to prevent oil from coming ashore. They are two different needs, completely.

As you pointed out, the western part of the Island experiences overwash conditions during even minor, non-tropical storm events (this is when the Gulf of Mexico flows across the Island, and into the "Sound").

It is far cheaper to pile up a wall of sand on the shoreline to catch the oil than it is to try to clean up an Island that is coated with oil from an overwash, not to mention the damage to the 10,000 acres of coastal marsh and estuaries to the north of the Island, damage that can't really be "cleaned".

But back to your information about the "Katrina Berm" that went up in Feb/March 2007 . . . are you aware that the original berm plans called for a long "bench", with a sloping, drop-off into the water? Well, at the last minute, FEMA changed the berm planform, eliminating (I'm guessing here) at least a third of the berm's cubic yardage, and left it with a flawed design that neither had a sloping, energy-absorbing drop-off, nor the 100-foot plus "bench", and was instead just a pile of sand.

Dauphin Island has some severe issues to deal with after 30 years of neglect. If you don't like the berm, what do you think we should do about our multiple problems- oil and man-made erosion?

[Sandglass]

David - many thanks for your thoughtful response. I will admit right now that I can't answer your last question in any way that would be definitive or satisfactory - but then I'm not sure who can, and that is the cause of so much inefficiency and understandable frustration. As an article on the BBC remarked when all this started: "Oil extraction technology has improved a great deal over recent years, driven in part by the need to get it from these more difficult places. There have also been big improvements in operational procedures and standards, not least regarding the health and safety of oil workers. But technology and operational procedures to minimise the risk of environmental damage, and to cope with and clean up after environmental catastrophes, do not appear to have kept pace with extraction technology."

Yes, the two different purposes of berms reflect two different needs - but natural processes of erosion and sediment budgets, the effects on water circulation along a complex coast such as the Gulf, and the kinds of environmental concerns that have been raised, apply to any kind of berm to a greater or lesser extent. Yes, I was aware that the "Katrina berm" was poorly designed, but what designs have proved effective and long-lasting? At the end of the day any berm is simply a more or less sophisticated pile of sand, not a replica of a natural island.

Barrier islands migrate naturally, often quite rapidly. By "man-made erosion", I assume you mean the massive re-engineering of the coast through dredging and construction - this, as Katrina revealed, is a regional-scale problem: the sediment budgets of the entire coast have been changed.

I wish that I had a solution for the oil - its removal before it ever reaches the coast. It seems extraordinary that in this day and age, the technological capacity and the planning simply weren't in place. But it also seems to me that the focus, at least in the media and local government, has been entirely on berms as a solution, apparently at the expense of other approaches. I've posted about possibilities of bioremediation - again not perfect, but nothing is. There are all kinds of possibilities out there (in addition to Kevin Costner's) for effective skimming. In fact, as a number of news items describe (linked below), there are all kinds of ideas - the majority inpractical, but, amongst the others some real possibilities. I guess that part of my frustration originating perhaps from only being able to read Government Agency and media reports, is that urgent tests of such ideas are not apparent. I'm a scientist - I'd just like to see more science. But I do also appreciate that my perspective is not from the front-line of this catastrophe.

Thanks again, and here are some links (not in any way an exhaustive list, and I'm not quailifed to evaluate them) that at least refer to other possible approaches:

http://www.nytimes.com/gwire/2010/06/10/10greenwire-booms-berms-offer-imperfect-solutions-to-oil-s-79023.html?pagewanted=2

http://news.discovery.com/tech/the-4-feasible-oil-spill-ideas-from-the-public.html

http://www.bradenton.com/2010/06/11/2353495/oil-spill-solutions-coming-from.html

http://www.blackengineer.com/artman/publish/article_1165.shtml