Saturday, April 17, 2010

Notes on the 2010 Tulane Engineering Forum

Got a chance to attend the 2010 Tulane Engineering Forum yesterday. It's been evolving into the most interesting engineering conference in the city. There's a good chunk of the city's P.E.'s that attend it every year, including lots of business owners. There's also always at least one presentation every year on the state levees. Partly because of the technical proficiency of the audience, you get some extremely in depth and thorough debate.

Last year's introductory session {PDF} was given by the Corps and I'm told they spent the whole time praising all the things that are being fixed up and all the good things the Corps has done. I'm told that there was some interesting back and forth at the end of their presentation, but I don't know the details, so that's all I'm going to say about that for now.

This year's presentation was by Dr. Dalrymple, Dr. Bolard (PE), Dr. Christian (PE), and Dr. Reed. They were a part of the National Research Council's team that worked for the Corps on LACPR, basically the task force that Congress appointed to design "Category 5 Levees."

As we all know, to date, there is no solid plan for Category 5 Levees. The most up to date thing the Corps came up with was a "menu of options" (111 in total) that was slammed when it came out. The Corps, despite billing themselves as the premier coastal engineers in the country, left it up to Congress to make the ultimate determination of what would get done. While there are some political implications (see Oyster's post), the panel went through some of the scientific and engineering challenges that also pose problems.

First to present was Dr. Dalrymple. His main points were the lack of a "sediment budget" for the lower Mississippi River. The loss of sediment load and sedimentation action is the #1 coastal loss issue, according to him. This was one of his slides:
Sediment Load
Source

As a side note, if you were to poll the top 100 coastal Louisiana experts on what the biggest problem is, probably 95 would say either canals, primarily for oil and gas exploration, or sediment loss, primarily due to levees confining the Mississippi River. When you have someone from the Corps speak, they tend to play up the canals and when someone from the oil industry speaks, they tend to play up the sediment loss. All four presenters, while nominally affiliated with the Corps, were heavily into the sedimentation camp.

Dr. Dalryrmple went on to comment about to designing a "Category 5 Levee" system. It would be more accurate to describe what New Orleans needs as a 400-1,000 year level of storm protection. No matter what is built, some local cooperation is needed for non-structural mitigation strategies, such as zoning, building codes, and buyouts.

In the end, Dr. Dalrymple held a fairly pessimistic view of the future. When asked what was the NRC's influence on the Corps' plans, Dr. Dalrymple described it as "subtle." The audience of engineers nervously laughed.

Dr. Bolard was the next to present. He once again railed against the failure to take advantage of sediment, both with beneficial use of dredged materials and how we're still directing the majority of the sediment load that comes past the city off the continental shelf into hundreds of feet of water. 125 Million Tons per year of sediment are wasted in this way. Dr. Bolard pointed out that all of the plans from the Corps assume that we'll have basically the same coastline as we do now in 50 years, despite the fact that we lose 24 square miles of coastline per year and that trend has been more or less unchanged for 80+ years! The bulk of Dr. Bolard's remaining presentation was a complicated discussion of the Corps' attempt at using MCDA to whittle down the 111 plans into one or a few actionable items. He described the multiple attempts as failures, for a variety of reasons.

Dr. Christian was next to present and he had by far the best presentation of the group. I'll actually skip over most of his presentation because I want to come back to it in a later post. He mostly talked about the "600-lbs. gorilla in the room: the Corps' performance before during and after Katrina." He started off by listing things that Corps has done into 3 categories: things that have been blamed on the Corps, but aren't really their fault, things the Corps has done well, and thing the Corps has done "not so well."

On the things the Corps gets blamed for, but isn't really their fault, he claimed: split responsibility, Louisiana politics, and a few other minor things. He gave one example of a specific floodgate that has 5 different entities "controlling" it (railroads, roadways, the local levee board, and the Corps). He said that they looked up the operation procedures of each of the organizations and each one assumed that someone else would close the gate in the event of an approaching storm! Also, Louisiana's political scene doesn't do us any favors nationally when hunting for funds to build the levees.

Dr. Christian's list of things the Corps does well were Task Force Guardian, IPET, and the Corps' hydraulics and hydrology understanding. He particularly singled out the Vicksburg office for their understanding of hydrology.

Dr. Chrisian's list of things the Corps does "not-good" was pretty scary. First, he says that all too often you'll have a representative from the Corps, say that the Corps has never had a failure. He says that if you put enough modifiers and adjectives in there, you can get a strictly factual statement, but, in the end, THE LEVEES FAILED!
490px-NOAA_Katrina_NOLA_17th_Street_breach_Aug_31_2005
NOAA via Wikipedia

It's sad to say, but the Corps failed, the Corps failed, the Corps failed. He said it needs to be drilled in that the Corps' levees failed from Katrina's glancing blow under stresses far below their design capacity. The Corps-built levees resulted in the worst civil engineering disaster in American history. Dr. Christian was adamant that that fact not be overlooked in any way.

Dr. Christians other two serious criticisms was the Corps' geotechnical and soils analysis, especially with the New Orleans office is fundamentally flawed. He said that was his professional opinion and that he knew there were lots of people with the Corps that would take strenuous objection to the statement. Note that the debate safe water level in the outfall canals has been extremely contention because of just this issue.

Dr. Christian's last "not so good" Corps procedure was that peer review, while successfully implemented under TF Guardian and IPET, has become a "box-check" and not a real concerted effort. Getting any information out of the Corps is like pulling teeth and there's outright hostility to "outsiders" looking over the Corps' design process.

Dr. Christian made a lot of bold statements, but between the slides and his response to engineers' questions, he seemed to back them up, IMHO.

Dr. Reed was the last one to present. She spoke of the need to manage flood protection, navigation (remember, the reason New Orleans exists), and coastal restoration. We managing the lower delta (where to chop it off) is the big issue for the next 50 years. We don't have the sediment load to preserve everything that exists today, so we need to do some triage. She also mentioned that Mississippi is extremely concerned with any effort to gate the mouth of Lake Pontchartrain because of its effects on Mississippi Gulf Coast storm surges (probably increasing them).

Where does all this leave us? One attendee who saw both plenary sessions (2009 Corps and 2010 NRC/LACPR) described them as presenting "quite a different picture." Currently, we have no plan for Category 5 Levees. The Corps says they'll come out with a plan 'this summer,' but we'll see if/when it comes out and if it's just another "menu" of options. The full presentation will also eventually be uploaded to this page.


NOTE- Minor edits. Also, Dr. Christian praised the Times-Picayune coverage of the situation. He says they've done a better job of informing the locals of the challenges facing the city than anyone has ever given them credit for (and it's not like they've been ignored).

UPDATE- Looks like Mike Schleifstein made it. His article looks along the same lines as mine, but I've got a few more details and he's got a few more links. Also, he caught that the new due date for "Category 5 Levees" is July. I just caught summer.

UPDATE 2 - Presentations Online

UPDATE 3 - The Corps' summer plan is out and it's yet another "Menu of Options"

10 comments:

Editilla~New Orleans Ladder said...

Clay, a couple of things...
1) I gotta give you an award or something for this post. How about a pair of Brass Balls?
2) I've been reading back over Ashley's posts about Tulane crucifying their Engineering dept and will refer to them for the Punk Irony of this entire Forum.
You have presented it extremely well so we can see the balls (or ova) on the table regarding that 500lb pile of Gorilla Shit in the room.
3) I am really hoping that you will blog on this article from Big Schleif last night:
http://www.nola.com/hurricane/index.ssf/2010/04/hurricane_protection_plan_dema.html
Indeed I dropped by figuring on you having a word or two on it.
Couple that article's Engineering Take Down of the Corps ("Fool's Errand")with this forum, and I feel the weight of Very Big Worms Turning.
Looking forward to your views.
4) I won't even get into how vehemently I disagree with Christian's appraisal of the Times-Picyune coverage. Over the long road haul they have backed themselves into a corner of PR.
I'm saying over the Long Haul. Yes they Earned their Pulitzer. But after canning Jon Donley the whole thing dove down the Rabbit Hole. Even Big Schleif went over to mostly wetlands.
Yes they are the paper of record on the Corps, but not on their continued Engineering Malfeasance on the Bad Outfall Canal Pumps.
Kitten Mittens.
But now... even Sheila Grissett added a salient detail or two in her last article, rather than simply reprinting the Corps Press Release.
But as for doing a better job than anyone else? Hell the Fuck No.
You for one.
Matt McBride
Ashley
Oyster
Jeffery
levees.org
(ahem)Me
Hell, this is silly to list because the entire Nola Blog'o'sphere has been rolling this story. That is why I think it is the Fulcrum of the Plot on Treme, the event upon which the entire story is balanced like stacks of rocks and fine china.
But I learned so much stuff from your Blog that never happened in the T-P and Should Have.
I mean really... I just think they sold out to Velvetta.

But you really set my clock with this post.
Damn Fine Bloggin.
Thanks youz.

PS-I don't know if you are into this particular fetish, but your Word Thingy Formecator? WTFr for comments?
For this comment the word is:
"imirsup"
IMIRSUP
Get Down! Get Back Up Again!

Clay said...

1- Thanks. I haven't even gotten to the best part of Dr. Christian's presentation. Check back for more later.

2- Cowen's cuts were pretty painful. Trust me, I was there. It hurt, but you know what, Tulane engineering will be back eventually, be it weeks, months, years, or decades.

3- Looks like Mike S. made the conference. I'll go over his article in detail later, but it looks like most of his observations mesh with mine.

4- I agree with Dr. Christian that, on the whole, the Times-Pic has done a hell of a job, especially Mike Schliefenstein. They haven't written a single article that I can't find some sort of fault with, bu they've been on the scene time after time and over the long haul, a newspaper subscriber will get the full story.

Bloggers have done a fantastic job lasering in on specific things. We have expertise in areas the paper simply can't match, however we aren't there for everything. We have our own jobs and commitments. You saw it when Matt McBride got burned out. The paper has been there time after time. They deserve some credit for that.

Tim said...

Clay,

The Corps failed. As admitted by LTG Strock. As detailed in the volumes of IPET. As replayed in the Decision Chronology Report.

As engineers, however, that's not enough information. We need to find what failed and why, how and when.

I was not at the forum you attended so I can only comment on your account of what was said.

On the topic of levees, which are earthen structures constructed to hold back hydraulic design loads, there were no failures.

What failed: Walls, which fell flat under different scenarios. First, utter design failures, as we saw on the 17th and London Canals. Specifically, I-walls failed. Second, lack of resiliency, such as the IHNC walls and gates that gave out after overtopping flows eroded their foundations.

What else failed: Selection of the design loads used to build the entire system, coordination with local government and citizens in the design and communication of risk, notifying Congress of the danger when funding was short, delayed or non-existent.

These are the key failures in my mind; there are more that fall on the Corps, Congress, Presidents, local government and levee boards.

This is not simply a mind-game or a feeble attempt to defend the work of the Corps. The Corps failed. But some things worked. Some things were done right, and it is absolutely vital that we know the difference so we can focus on what needs to be worked on.

In the case of levees, there were no design failures. Let me say that again, no design failures. Levees that were designed to hold back loads up to a design elevation and received loads up to that design elevation did NOT fail.

During Katrina, some levees were overtopped by storm surge exceeding the design elevations. In some locations, damage to the levees was minimal. At other locations, damage was severe. Most tragicly levees in St. Bernard facing Lake Borgne were completed washed away.

Yes, they were not designed or built to correct elevations. So the hydraulic modeling and the vertical control system has been improved and continues to be examined.

Yes, levees that were overtopped were subject to erosion. So while the system is being constructed to halt the 1% storm surge and associated waves, levees and walls alike are checked to assure they will not be overtopped by the 0.2% storm surge. Additionally, weak points and the backs of all floodwalls are now armored to prevent erosion if overtopping occurs.

Again, I was not there but I gather from your blogging that the speaker is utterly dismayed that there is denial of failure from the Corps. From my personal experience, there is no denial of failure where failure occurred.

Thanks for blogging about this. The account in the TP was of course light on details, so I'm glad to hear your perspective.

Peace,

Tim

Tim said...

Also, I'm more than a little surprised given your vocal displeasure with Tulane that you participated in this for-profit forum. Did your employer pay your way? I hope so, because I know it would have been torture if you were forced to write that check for hundreds of dollars to Tulane University yourself.

Peace,

Tim

Clay said...

Tim,

Much of the presentations were commentary on the behind the scenes behavior of the Corps as told by the audience. Take it for what you will. The Corps did some things well and they weren't the only ones that screwed up, as pointed out by even their most vehement critic (Dr. Christian). But, at the end of the day, the Army Corps of Engineers is responsible for the worst engineering disaster in American history.

I got to attend at no cost to myself. This is the second time I've gotten to attend. I also went to the May 2006 TEF.

Sandy Rosenthal said...

These impartial experts are with the NRC which receives their funding directly from the Dept of Defense. The USACE is removed from the relationship. Further the NRC was set up to provide a neutral point of view and provide a (hopefully incorruptible) interface between government agencies and non-government agencies. And according to Dr. Ray Seed, U of Cal Berkeley, the ASCE has recently "adopted" this business and has only recently entered the business of "investigating whoever will pay them."

Editilla~New Orleans Ladder said...
This comment has been removed by a blog administrator.
Clay said...

Sandy,

The NRC committee, while under the auspices of the Corps, wasn't paid by them other than, in Dr. Bolard's words "some very nice meals at New Orleans restaurants."

The best way for an engineer to be objective is to throw the numbers out there and let the chips fall where they may.

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Note: comments deleted for spam and for ad hominem attacks on an individual

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Tim,

I'm a 4th generation Tulanian and I've always supported the University, if not the administration. Support the troops, not the war... That sort of thing.

The worst failure, IMHO, was the soils analysis at the outfall canals. The shear strength of the various stratas was averaged instead of basing design strength off the weakest strata. That's an error that every single undergraduate student in their first geotechn course learns.

At the presentations, there were lots of very specific examples given. You weren't there and I couldn't catch all the nuances in my notes, but one specific example is the St. Bernard levees you site.

During the investigation, they uncovered some emails where two senior engineers were debating whether or not to build a very tall, but flimsy levee, or a bit shorter levee that would be much more resilient to overtopping. The first design was a sand-cored levee with a relatively thin cap of clay. The clay will protect the levee from some scour, but when the clay is gone, the sand has no resistance whatsoever to scour and will just wash away.

Another engineer proposed lowering the height by 2' or so and using the substantial savings from material hauling to add some riprap at vulnerable areas and add a thicker clay cap.

The taller, less resilient design was chosen and the levee was completely obliterated in Katrina. The other design would have been overtopped first, but would have stood a much better chance at surviving the ravages of the storm. The NRC could find precious little information on how that decision between the two designs was chosen in their investigation.

There were a lot more details, but I'm limited by my memory, my notes, and what I can get down on paper (well, computer actually). A word-for-word transcript, neglecting discussion of the ideas discussed, could total up to 100 pages or more.

K. said...

"The best way for an engineer to be objective is to throw the numbers out there and let the chips fall where they may."

This gets at the broader problem of people denying the numbers. This day and age, it may be incumbent on your profession to defend data more than ever.

Tim said...

Clay,

I also wanted to comment on the sediment load of the Mississippi River. That's an important point. You hear a lot of people saying that we need to let the river rebuild the coast. They make it sound so simple, but most of them do not understand that the river today is not the same as the river that built south Louisiana. The river does not carry the sediment it used to as is so brilliantly communicated on that illustration you posted. I blogged about the sediment problem almost two years ago: http://timsnamelessblog.blogspot.com/2008/07/heres-mud-in-your-eye.html
The fact is the river carries just a fraction of what is needed to rebuild Louisiana's coast. So the problem is not simply that the river is not allowed to flood outside its banks; the significant decrease in available sediment means that even if we breached all the river levees it still would not be enough to rebuild faster than what is being lost each year. Glad Dr. Dalrymple and you understand the significance of that.

Peace,

Tim