Hurricane Katrina, Coastal Protection and Reconstruction Efforts

MODERATOR:  This afternoon we have a briefing from three people who will be talking about Hurricane Katrina and the Army Corps of Engineers and what the Corps has done since Katrina and some of the lessons learned from that event. 

With us we have Don Basham, who is Chief of Engineering at the Corps, we have Ed Link of the University of Maryland, and who is also Director of the Interagency Performance Evaluation Task Force which looked at Katrina, and Robert Traver of Villanova University and the American of Society of Civil Engineers.

They will be -- we’ll start off with a few comments from each of them about the hurricane, about the system along the Gulf Coast, what we’ve learned and what we’re doing going forward and then open it up for your questions.  So thank you for coming, and I think I’m going to turn it over to Don first off.

MR. BASHAM:  Thank you.  Thank you for allowing us to join this afternoon.  First of all, let me tell you briefly the U.S. Army Corps of Engineers has been given the task to do things here basically in New Orleans.  One is after the hurricane of last August is to reconstitute and rebuild the levee system of New Orleans as authorized by Congress.

Second, and concurrent with that at the same time the Chief of Engineers commissioned an investigation for -- I kind of term it a forensic analysis group, whose job it was is to look and see what actually happened in New Orleans.  Look at the facts.  Where were the failures?  What were the causes of those failures?  What can we do to prevent those failures in the future?  And some of that was real and live because as this group looking into the investigation and found what was wrong and came up with solutions of that, we were literally out there moving dirt within days of the hurricane.  You could watch it on national TV and see that.  We literally had to crank in solutions to that, help them solve those problems so we weren’t out there reengineering the same solutions we had before.  And so this was almost a spiraling effect.  But we learned from what went on, we’d come up with new solutions and then apply that out on the ground as we did the actual design and construction. 

So the Corps of Engineers’ role in that has been actually to do the design and reconstruction.  We’ve been authorized by Congress to restore the hurricane protection system back to a hundred year protection.  We had a strategy and plan that scheduled out and laid out over the next three years to have that completely done by the year 2010.

We’re talking about over 350-some odd miles of levee system in the New Orleans area, so it’s an extensive levee system.  While about 160 miles of that levee was damaged during the hurricane, parts and portions of the levee were stressed considerably.

What folks need to remember and understand out of this event, while there is a lot of discussion about when the hurricane came to landfall it was a Category Three, just 12 hours before then, the hurricane was a Category Five and had up to almost 180 mile-an-hour winds.  At the essence that that occurred, the wave and surge in the ocean had already been generated and was going to come ashore irrespective of what the hurricane downgraded to after that.  And so that’s much of what New Orleans saw.  And so you have to be careful about when people talk about, well, it was just a Category Three.  It was at landfall that a lot of the destruction that was created by the wave and surge essentially just overwhelmed the system had already been created 12 hours out in the ocean.

Dr. Link will talk about some of the findings we had, that we can validate that in terms of what they call wave period, as the waves come ashore, as compared to deep water waves versus shallow water waves, that gave us some indication that literally we had at the peak of the storm had waves -- storm surge that ranged from 28 to 30 feet along the Mississippi coast.  In most cases, in the New Orleans area that overwhelmed the system 5 to 6 to 7 feet over the top of the levees.

You’ve heard a lot about the breaches or failures of levees in the New Orleans area.  We’ve identified 50 what we call breaches in the levee system throughout the 169 miles.  Forty-six of those 50 breaches were attributed to actually water going over the top of the levee, as I said, to the tune in some cases as much as 5 or 6 feet, washing out behind the back side of the levee, and then essentially causing the levee to erode and collapse.

The one significant thing you need to take away from that is that we found no incidence where a levee failed as some would allege.  As the water came up on the front face of the levee, that there was erosion on the front face that caused the levee to fail.  We found no instance where a levee failed as a result of that.  In every case it was because the water went over the top. 

We had four instances where we had design failures in the system.  We had four I-walls, what we call essentially is a concrete wall that’s buried in the top of the levee, that actually failed before it reached its designed height.  And Dr. Link will talk a bit more about the specifics of that failure mechanism and what we’ve done to prevent that from happening as we go back fixing the levees because there are still a number of I-walls down in the New Orleans area.  We've isolated some of them and cut them off to where they won't be subject to future storm surges as an immediate stop-gap measure as we go back in and raise and reconstitute others. 

As I said, the Chief of Engineers was very concerned and wanted to get out to make sure what defined the causes of the problem in New Orleans.  And so he initially commissioned the Interagency Performance Evaluation Task Force that we asked Dr. Link to chair. 

At the same time, we asked American Society of Civil Engineers pull a team together to do an external peer review of the work that was being done by the IPET.  That was concurrent.  Again, just like we were coming up with solutions to apply back into the real work out in the field, we asked ASCE to join and do an independent peer review but not wait until we were completely done with our analysis and then review that, but again kind of in a sprawling method that we would find solutions, even the modeling, where decisions are made about which models to use to try to validate and recreate the events, we asked the ASCE peer review to review those models:  Do we have the right models, do we have the best models.  And so they were interactive throughout that process. 

In addition to that the Secretary of the Army commissioned the National Academy of Science to do another independent review of both the Interagency Performance Evaluation Task Force and the American Society of Civil Engineers’ work.  And so we literally had two independent reviews of the work that was being performed here.  We're talking about having over 150 of what I consider some of the best and brightest engineers, scientists in this country -- in some cases in the world -- that contributed to this, either working directly on the IPET, working on the ASCE external review or working for the National Academy during their oversight of the review as well.  And so we think we've brought some of the best and brightest minds to focus on this to make sure we come up with good solutions not only to what we can apply in New Orleans but elsewhere where we might apply in the United States and other levee systems and other infrastructure systems we have throughout this country. 

So with that, I think I'll stop right now and let Dr. Link talk to you a little bit more about the specific investigation we have with IPET and how we conducted that and some of the findings we had out of that. 

DR. LINK:  Thank you.  I'm Ed Link from the University of Maryland.  It was my pleasure to chair or direct the task force.  I really appreciate your interest in this because I think there are lessons learned here that need to be told, need to be communicated not just within the U.S. but around the world.  And there's certainly a lot of knowledge and lessons learned around the world that would be very valuable to the United States in dealing with these types of issues. 

I'd like to make a couple -- just a few points and then we can dive into details through your questions.  First, the IPET or the Interagency Performance Evaluation Task Force was formed to do two things: one, the forensic analysis and; secondly, a system-wide analysis, a system-wide assessment.  The forensic analysis was focused on what went wrong.  The system-wide analysis was focused on how to take that knowledge and apply it for the future, not just in the repairs. 

As Don mentioned, the -- basically, the results of our analysis are in the ground now because of the good work of the ASCE Review Panel, because they basically were giving us real-time review.  So as we learned something new, we were -- we had the confidence through their review to recommend it to the Corps of Engineers teams who were rebuilding and repairing the levees.  We had the confidence that they could apply that knowledge immediately and not wait until 1 June when ironically both our analysis and the repair of the levees were both due to be done on that same day.  So I think that was a unique aspect of this forensic analysis.  It wasn't just focused on the events of Katrina; it was focused on the rebuilding at the same time. 

Secondly, there were a lot of lessons learned here that are being applied and need to be applied though on more of a national scope, not just in New Orleans.  First of all, as Don mentioned, Katrina was a monster storm.  If you look at a satellite image of it, it covers the entire Gulf of Mexico.  If you go back on the web and you look at similar images of, for example, Hurricane Betsy in 1965, which was the storm that spawned the interest in creating these levees and flood walls, it was a much smaller -- even though it was equal in maximum winds, it was a much smaller storm in size.  So it did not have the opportunity to create the damage and losses of Katrina, but it was the first billion-dollar storm.  It was the first storm that ever created a billion dollars in damage.  And if you translate that up to today, those costs would have been in the neighborhood of $10 to $12 billion, about half of the direct property damages that we measured in New Orleans. 

Part of the -- part of what we learned in this was that the system that we use in the United States does not deal with change very well.  The original storm, design storm if you will, called the standard project hurricane, was developed in 1965 with the best available knowledge concerning hurricanes and meteorology and that became the criteria for how high to build levees and how high to build flood walls.

We know that storm intensities have changed.  We know that hurricanes have become more intense and more frequent.  And in 1979, in fact, the National Weather Service upgraded or updated the standard project hurricane because it has -- because it was obvious that the storms that New Orleans could potentially experience were getting stronger and stronger.

Today we know with Katrina that that trend has continued, but the levees and flood walls that were in New Orleans were still fundamentally designed to withstand that original 1965 storm.  They were not built to deal with a storm the size of Katrina.  So there was no accommodation of that change in the hazard that New Orleans faced, and there is no really -- no real quantification of the risk that was present in New Orleans because of that change in the hurricane hazard.

Secondly, the system changed.  There’s massive subsidence in New Orleans.  New Orleans is sitting on 30,000 feet of river sediment and those sediments are slowly compressing and consolidating.  And in some areas the flood walls, for example, were 2.5 feet lower now when Katrina hit than when they were originally built 35 years or so ago.  So that's subsidence fundamentally caused a loss of the level of protection and increased the amount of overtopping that occurred during Katrina.  So the system changed and, again, there was no major response to that change by this nation or by -- either federally or locally.

The other thing that changed was the -- more and more people were being placed into harm's way, if you will, by the increased population within the city of New Orleans.  So many, many areas there are very vulnerable because they're minus 15 or minus 20 feet below sea level, and those were the areas where predominantly residential areas were located and 78 percent of the losses from Katrina were in residential areas.  So those areas happened to be in the lowest -- in the areas of lowest elevation and they also experienced the greatest losses.

So that's another change.  So we've talked about hazard changing and we've talked about the system changing and we've talked about the demographics or the consequences of flooding changing, and none of those changes were accommodated with a change in the overall level of protection to be provided.  There's a separate study that's being done that will look into the why of those decisions, so I really can't get into the why because that study has not been released yet. 

But some of it was basically that the system started out as a very noble effort to protect New Orleans against something in the neighborhood of a 1 in 300 frequency event, if you will, a 300-year event.  And then there were a lot of compromises that occurred.  A lot of incremental decisions were made, competing priorities between locals and federal entities, cost considerations, and a lot of those incremental decisions radically changed the nature of the protection from its original scope as it was originally planned. 

There was no methodology in place at that time to understand the cumulative effects of those decisions to understand how much risk was being accumulated by those decisions that compromised not only the original intent of the project but the level of protection that ended up being available in 2005. 

So that was another major finding in our study.  We have to be able to deal with change and we have to be able to understand the amount of risk that is resident in a hurricane protection system.  And it's important both for the public to know that and also for the decision makers to understand just what level of protection is there and what that means in the overall assemblance of an emergency response plan. 

And the third item that I'll go back to is just risk itself.  One of the major products that we will generate is a complete risk assessment of the New Orleans area.  This will be the first time that this type of assessment has been made in the United States for hurricane protection.  And it will allow us to understand what the risks were prior to Katrina and what the risks are now after the repairs and will even project into the future when the repairs and rebuilding back to higher levels of protection are completed to understand what the risk levels are then.  The importance of the risk is both the policy makers, the decision makers and the public understanding one information set on what the situation is with regard to protection; and secondly, the risk assessment allows you to understand what the source of the risk is so you can focus in on the highest priority areas where you need to pay attention where you can make investments to reduce that risk.

I'm going to stop with that and pass it on to my peer review. 

DR. TRAVER:  I'm going to have to rewrite all this.  You took all my ammunition.  This is not my usual audience.  I won't try to give you a quiz or anything at the end of this.

My name is Rob Traver.  I'm a Professor of Civil Engineering at Villanova University and for the past nine months I've been a member of the external review panel that was part of -- from the American Society of Civil Engineers that basically was formed at the request of the chief of the United States Army Corps of Engineers to basically review and comment on the IPET process as directed by Ed Link.

The ERP basically has 14 different private consultants, academicians, public agency officials from multiple areas of civil engineering.  We have a social scientist and one member from the Netherlands. 

First of all, we did want to say we do want to applaud the Corps' and the IPET's professionalism and openness in the whole process, including basically opening their analysis to our external review all throughout the process, and the ongoing interaction I think made it very effective.

We feel that the IPET, that their work has been comprehensive and definitive and so far we have not identified any major flaws or any major problems with any of their data or analysis. 

Throughout the assessment process we have, as part of the ERP, identified findings that go well beyond the IPET scope of work, many of which you already mentioned so I'll try to breeze through some of those.  But a lot of it just applies to engineering practice and policy issues both in the United States and abroad and are incredibly essential to achieving an effective hurricane protection system for New Orleans and the surrounding region.

The first of these issues we feel there is really no single agency or official in charge of the whole system and there is no overarching structure to manage the responsibility for the components of the system between the local, state and federal agencies.  A designer cannot consider the pump station performance or land use in their levee designs if they cannot be guaranteed that the structure is going to operate or the decisions are going to be consistent over the life of the project.

Organizational and engineering effectiveness we feel must really go hand in hand to achieve optimal results.  We also believe, as it stated, that the lack of a system-wide approach to the design and the lack of design integration, with evacuation and recovery plans for an example, is really a major issue.  Pump stations, land use decisions, evacuation planning are all really components of a hurricane protection system and must be interrelated. 

The American Society of Civil Engineering Canon of Ethics states that engineers should hold paramount the safety, health and welfare of the public.  And the ERP believes this statement should serve as the core of a hurricane protection system rebuilding.  When we design for large dams and nuclear power plants, this process has taught us how effective external peer review of safety -- I'm sorry, external peer review can be in establishing appropriate margins of safety in ensuring quality design, and as such we really believe that all critical life-safety structures should receive comprehensive external peer review.

We have identified several other issues that have been of interest.  For an example, as Ed said, several of the canals, the levees and flood walls did breach well below the design height, and basically we feel that some of the targets, the target factors of safety were too low in that design process. 

With the benefit of hindsight, which is always easy, we feel the margin of safety was not large enough to account for a lot of the unknowns and we strongly encourage the Corps to reevaluate their levee designs, methods and practices and (inaudible) conditions to ensure that we do have an adequate margin of safety.

The standard project hurricane used the basis of the levee design height is representative as of only past events.  Every time you have a new hurricane, you learn more.  We actually can lower the height or raise the height depending upon this history.  The standard project hurricane does not include consequences of larger, more extreme hurricanes.  An example for life-safety structures would be the use of maximum possible floods in assuring the survivability of the dam.  The ERP feels that the selection of an appropriate level for protection, including levee height and survivability really should be based on a risk-base approach, which was also referred to by Dr. Link.  We also -- Dr. Link has already addressed the subsidence of the levees and so I'll kind of skip that particular portion of it.

We really feel that overtopping on these types of the designs is not a question of "if" but "when."  As such, the levee must be designed to survive and to prevent catastrophic failures.  The risk-based approach we feel facilitates this process and ERP is pleased to see a task force start in as -- already started to incorporate remedies consistent with these type of recommendations.

And finally, as really the first step in applying a systems approach, the role of the pump station system must be rethought, making it an integrated part of the hurricane protection system.  The pumps must be able to survive flooding and continue to be operable during and immediately following a hurricane.  It is important to note that during the course of this assessment, we have discussed these findings with IPET and the Corps and has been assured that our concerns are taken seriously and we believe that.

And I think I -- we basically, having identified these issues, we must now ask ourselves what should New Orleanians and the nation do next.  In our opinion we must first decide what level of risk is acceptable for the hurricane protection system, and as a nation need to determine our commitment to providing that level of protection.  While the residual risk to residents must still be determined, we really firmly believe that the commitment of the nation, the people of southeast Louisiana can effectively protect New Orleans, but only with a broad-based, risk-informed system-oriented approach to the design, the operation, the land use and emergency responses.

We do feel that IPET’s findings are really impressive.  They've done a magnificent body of work and they should have a profound impact on the future of New Orleans and also anywhere else that is subject to flooding or hurricane-type systems.  But really for it to be maximum effectiveness, the people and the local agencies must be informed of the meeting and the implications of these results and become stakeholders as the process moves forward.  The ERP encouraged this local engagement for the future success of the New Orlean's area and on behalf of ERP, appreciate your time.

MODERATOR:  We have some questions.  If you have a question, raise your hand and somebody will give you the mike.  Please state your name and publication.

QUESTION:  Hi, I'm Lara Jordan.  I'm with the AP.  I think you had said something about the four breaches that did occur through, I believe, I-walls.  Could you talk a little bit more about that for those of us who might not be as, you know, inclined to some of these terms as you are?  Well, what exactly does that mean?  I understand overtopping over the walls, but when we're talking about breaching, what are you talking about?

MR. BASHAM:  First all, let's don't make a distinction because some people have out there.  You know, a breach to us in the engineering profession and when you're talking about levees, any time that the levees is there to prevent water from going from one side or the other, when water moves from one side or the other, that's a breach.  When it's overtopping and no erosion, could be overtopping with erosion, or in a case of the four instances you're talking about where the I-wall just failed completely without overtopping, each and every one of those in our estimation is a breach.  Obviously each one of those brings a different outcome as a result to that.

An example, and I'll get to -- an example down the lower portion of Plaquemines Parish and St. Bernard's Parish, if we had not had any earthen levees fail, you would have had a period of time there, probably four to six hours, give or take a little bit, where we would have had five or six foot of water that would have gone over the top of the levees.  You still had a tremendous amount of inundation in those reaches of the parishes, but eventually the water would have subsided and you just had residual water to clean up inside versus what you saw literally on TV is for days because the levees failed either water from Lake Pontchartrain or water from Lake Borgne was actually draining in to the lower ninth ward or up in the New Orleans area.  And so there where you have actually breaches and where the levees failed themselves, and in many cases as Dr. Link said, a big portion of New Orleans is below sea level.  And so any levee that fails was very quickly going to put the whole water level system below sea level to where water's draining inside of it.

So there's different causes for a breach and they have each a different outcome of that.  And in the case of the four breaches that we had, three on the canals up on Lake Pontchartrain and the one over on IHNC were what we call concrete I-walls.  It's essentially a concrete wall that sticks somewhere between 6 to 12 feet in the air.  It generally will have a sheet pile wall buried in the ground underneath of it and it sits on top of that.  And then there's an earthen mound levee brought up on either side of that, but still you can see the concrete I-wall sticking up on top of it.

In the case of the four breaches, what happened is the water came up to somewhere generally about two to three feet on average below the top of the wall.  The wall tilted.  And of course anytime that you have -- if you took a toothpick or took a fingernail file and you just held one end of it, imagine that to be a concrete I-wall.  And what's in your hand is the earthen levee piece and the piece of the toothpick or the nail is sticking above that.  If you push on that it's going to deflect.  The thicker you make that piece of wood the less it's going to deflect.  Obviously the engineer designs that wall with the intention that it's always going to deflect because it's cantilever.  But you make some assumptions in designing that that it becomes rigid enough that it won't cause enough deflection to cause movement in the wall.

In this case here it did not happen.  In all four cases the wall moves sufficiently.  But if you have this as your wall and you have water up here, then when the wall moves sufficiently the water literally went down the front face of that wall and then went underneath the wall and failed.  And once the water went down the front face of the wall it separates the front half of the levee from the back half of the levee.  The total levee itself is what gives you your stability or your resistance to the water pressure.  And so now that you’ve lost the front half and you've only got the back half of the levee for resistance, then it was just a matter of time that the four -- those four areas were going to fail.  Does that help?

QUESTION - Follow up by Lara Jordan:  I think so.  I mean, when we were covering this a year ago -- almost a year ago -- we defined the breaches as water going -- breaking the wall, for example, for lack of a better term.  Is that not really the case then?

MR. BASHAM:  No, I would not say it broke the wall.  It -- eventually the wall breaks, but the idea is if it tilts over enough that when water goes down the front face of it and builds up sufficient pressure, then it moves out entire sections of the wall.  And so what you have is a wall that eventually just kind of leans over and then bulges out like this.  And then once it completely separated from the one end and in a couple of areas it moved out as much as 30 to 40 feet lateral, it did collapse and move out.  But our investigation, when we ultimately did some testing in the centrifuge and did some other analysis, you can actually now discover and see the failure plane as a result of the water going down the front face of the wall.  We actually were able to go out there and dig up with a backhoe and find that failure plane and then replicate that in a real test in a centrifuge.

DR. TRAVER:  The big difference in this case, though, was that at these four locations, the water never got to the where the designers expected them -- the walls are okay.  And the failure occurred at water levels below the design.  And the wall collapsed because of forces that were occurring underneath not from over top it.  Very, very different from the others.

MR. BASHAM:  And there were I-walls in other places that water did go over the top, eroded out back behind the backside of the I-wall.  It took away the stability of the wall, and then allowed it to move and it failed.

DR. LINK:  There were pictures of all the structures and some of these failure mechanisms in the IPET report.  I recommend you read all 6,113 pages.  But if you -- he has.  But if you aren’t that much of a masochist, volume 1, the executive summary, is about 50 pages and it has a lot of illustrations, and you can get that on our website, and we can provide you that website.  You can download the whole report if you like, or I recommend you get volume 1.  There are a lot of good graphics.

MODERATOR:  We have a question from New York.  State your name and publication.

QUESTION:  This is actually a multiple question if I’m allowed.  My name is Mercedes Gallego from the Spanish newspaper El Correo.  First of all, it’s -- what is the state of the levees right now?  I believe that it has been reconstructed to the previous levels of safety they have before Katrina.  So what is going to happen now with that?  If there’s another hurricane like Katrina, will that stand or will that go back to the same level?

The second question is about the pump system.  It’s been mentioned here that it should be reviewed.  Is that regarding the places that they are located or what exactly what it means to be reviewed?

And I'm sorry, the third and last question is about the canals that have been built in the city.  There is some fear that the surge of the hurricane came to these canals and put the pressure on the levees, while if these canals hadn’t been built that they are artificially the city had been much more safe.  Is that accurate -- correct assumption or not?  Thank you very much.

MR. BASHAM:  Let me try that and let me see if I can get them right; the first, to start on the top, the levees.  Yes, one GNR commitment was to restore the integrity of the levee system back to pre-Katrina conditions, and we’ve done that.  In some cases, we’ve had to do that not with a permanent fix but with a temporary fix.  An example of that, and I’ll come back to that in a minute, but your example of that is the canals.  We chose, instead of being able to replace all the I-walls that were on the three major canals that front Lake Pontchartrain, instead of trying to replace all of those which we physically could not get done by 1 June, we’ve gone up and built gated structures at the end of those three canals to where if we were to have another hurricane event, we could go up and close those gates off and prevent any water from coming up into the canals.  As long as you didn't have a hurricane and just a normal rainfall event or even a storm, you know, the gates would stay open and you use the normal pump plants to pump water through the canals.  But we still would have to monitor that because right now we've estimated that you would not want to have an elevation in the canals, what we call a plus-four which is plus-four feet above sea level against the existing walls because we're still concerned about the integrity.  So we've taken a temporary measure to install gated closures at the end of that to protect that. 

In addition to that, Congress has authorized us to -- in two subsequent appropriations to first to restore the levees back to their authorized level of protection, which as Dr. Link mentioned, some of that is in cases where the levees had subsided a couple of feet, this is to go back and put the additional two foot of lift to get it back to that authorized level. 

In other cases in the receptions of the system, I don't think we mentioned we mentioned here that when we talk about it being a complete system that hadn't actually been constructed yet or hadn't actually been completed yet.  And so they were in phases of construction already, in ongoing construction.  And so this authorizes us to take what we haven't even built yet and bring it up to the authorized level. 

The third increment of appropriation was to not only take it to the authorized level, but to take it to the 100-year level of protection which then is consistent with the Federal Emergency Management flood rate insurance that you can build behind a level of protection, 100 year, and get flood insurance for that.  So that's the second increment we're building to that.

 Understanding that each one of those levels of protection provides you more than what you had before Katrina.  The American people and the people in New Orleans would surely understand because they live behind them and work behind them every day, that that's still a huge amount of risk in that part of the country for a levee system and you still have to have emergency evacuation plans and arrangements to evacuate that area should you have another Katrina event.  Even if you had another Katrina event today, we do not believe we'd have any levees fail as far as collapsing, but you're definitely still going to have water that's going to go over the top of the levees and people are going to be inundated and it needs to evacuate and get out of the area. 

The second was on the pumps.  New Orleans is designed understanding that a big piece of the New Orleans is below sea level.  And so even without any levee system, New Orleans had to have a pump system to be able to pump water out just to get it above sea level.  Over the years with a combination of building the levee system and building the interior pumps, the interior pumping system has only ever been designed and run and operated to affect interior drainage water that falls within the footprint inside the levees.  It never was contemplated or built with the notion that you'd have overtopping of that and have to consider water that came in from over the top of the levees, whether the levees failed or didn’t fail or just the results of overtopping.  And so that was part of the issue that overwhelmed the pumping system to start with.

 And again, in one case we're talking about water, a big part of what shut down some of the pumping plants was the wind, as far as knocking out power lines and actually you have to evacuate the buildings to protect peoples lives because some of the buildings was concern about people's lives not being able to withstand a storm event.  Part of the authorization that Congress has given us is to go back in and -- what we call "harden" some of those pumping plants to make them stronger, raise the generators, raise some of the fuel supply up high enough to get them out of flooding areas and actually to where some of them you got -- people could stay in those facilities and weather a hurricane type event. 

So the issue here is not looking at as a system is a complete system would have assumed that there is a good chance that you're going to have an overtopping and that any pumping system ought to be contemplated on handling that overtopping and also the rainwater that came inside. 

The canals -- I believe I'm correct in saying that we found no evidence that the canals -- that excessive surge was generated as a result of the canals and the primary dampening effect to that was that each one of the canals has a major road, interstate that goes across -- up towards Lake Pontchartrain side that essentially when the hurricane started, if the bridge structures that went across the canals and the results in the debris that was piled up against the bridges dampened the effect of the surge that came in from Lake Pontchartrain.  And I'll ask one of these two gentlemen if they want to comment further.  But we didn't find any evidence that were like -- if you had a -- say, like normally coming off Lake Pontchartrain because you have such a large fetch and a large area there where you might have had a five-foot wave that came up the canal.  And because it got constricted in the canal, it would jump up to some higher value.  And we found no evidence of that at all. 

DR. TRAVER:  The big controversy concerning water surges being generated through canals was focused on the Mississippi River Gulf Outlet.  The -- this is a navigation channel that runs along the eastern side of New Orleans and there is the main hurricane protection levee is adjacent to it.  And it was a -- one of the urban legends or urban myths of New Orleans that -- and a number of people were calling this a hurricane highway.  That the -- if a hurricane came to the east side of New Orleans that the surge would run up this canal and create very high levels of the city up in the interior of the city.  We modeled that very, very carefully with the most advanced models available --  very high resolution -- and we found that the Mississippi River Gulf outlet had very impact on the surge levels in the interior of New Orleans.  The canal was just too small to carry enough water to have an impact.  When you have a channel like that and low levels of water, like normal tidal range, it certainly has an impact on water levels and saltwater intrusion and so on.  But for a large storm, it had almost no impact, in inches as opposed to feet.  So that was an urban legend in New Orleans that I think we were able to demonstrate was not a factor.  There were a lot of other factors but that was not one of the factors leading to the high surge levels in the city. 

I'm just going to say one other thing about pumping stations.  One of the examples we've been bringing up a lot is who is in control of what.  The Corps is not in control of the pump stations.  If the pump stations would be designed for the hurricane protection system, they may be very different in configuration.  So, for an example, when the Corps finishes the risk analysis, that also may give us information to look at changes to the system to make it more effective. 

QUESTION:  My name is Lotte Boot with the Netherlands Press Association.  You just mentioned an engineer from the Netherlands taking part in the review.  I was wondering if you can tell me something more about the role of the Dutch engineers in this whole investigation.

DR. TRAVER:  Well, in the review, with your country all under sea level, he was very helpful giving us perspective, giving us another look at it from an outside person who's not familiar with our system.  And his first name is Jurjen; last name I'm not sure I'm gonna -- I don't want to butcher it and pronounce it wrong.  I'm sure we can give it to you afterwards.  Very helpful from the experience from your flooding, I believe in the '50s, to your whole sequence of events and your structure.  The risk factor -- like I believe your risk factor is like 1 in 10,000 is what you use in your design.  And the fact that even with a 1 in 10,000 design you still emphasize hurricane evacuation.  And I think all that was very helpful in framing our thoughts and understanding.

QUESTION – Follow up by Lotte Boot:  Can you tell me something practical, give me more about Dr. Jurjen Battjes?

DR. TRAVER:  I think those are all practical.  (Laughter.)  If you're looking -- I mean, Dr. Battjes was part of the process every step of the way and a very key advisor and he's not afraid to open his mouth like the rest of us.  I think Ed will agree with that one.

It's hard to say practical because this is more of the systems approach.  I would say he was very helpful in looking at the systems approach, if you want a specific, of looking at everything as integrated, from land use decisions to evacuations to levees and pump stations and sump holders and we can go on and on and on.

DR. LINK:  I think the Netherlands had -- you had your Katrina in 1953 and you went through a process of reexamining how as a nation you were going to deal with this problem, and I think his experience in having been a part of that and as a member of the faculty at the Delft was extremely important, extremely valuable so that we could consider that knowledge right away and not have to learn it ourselves and so on.  It was very valuable. 

QUESTION:  Thank you.  Hi, I'm Stephanie Ho with Voice of America.  I just wondered, I think, Mr. Basham, you had mentioned that there were some permanent and some temporary fixes right now that were for the current hurricane season.  I just wondered if there was any move to make the improvements permanent and was there any discussion of possibly making the improvements so that everything would be better than before Katrina.  Thank you.

MR. BASHAM:  Yes, let me take the first one.  The temporary measures we've taken, will we make them permanent, yes.  And the example I would give you is example I gave awhile ago, where we put temporary gated structures at the end of the three canals of the front Lake Pontchartrain.  Congress has now authorized us to not only put permanent gates there, but also move the three major pumping stations that are at the end of those canals up to the front of Lake Pontchartrain.  And so the current pumping stations that are anywhere from a mile and a half to two miles in from Lake Pontchartrain, those pumping stations will now be rebuilt and reconstructed at the head of the canal.  That will prevent the surge from going up the canal and also take away the opportunity for a future surge going into the canal and actually will pump water out of New Orleans from that point.  So that's an example where we got a temporary gated structure and we'll go and put permanent structures in. 

Another example would be -- is on the two -- on what we call the inner harbor coastal canal, we also have been authorized to put two large navigation gated structures there for surge protection -- one along the GIWW that comes out of the canal and goes east and south of it that Dr. Link talked about a while ago.  And the other one that would come out of the Inner Harbor Canal that would go into Lake Pontchartrain. There we're replacing some of the I-walls and T-walls and levees along those canals today, but the addition of those two gated structures will essentially take some of those systems out of harm's way in the future from surge.  But we think that's a redundancy that we think's appropriate. 

MODERATOR:  We have a question from New York.  If you could state your name and publication. 

QUESTION:  Okay.  My name is Tomo Sonoo from NHK Japan [audio gap] a surge from hurricane and there is a lot of talk about the wetlands role of how it would -- protects the inland from the hurricanes.  So is there any plan to incorporate or to enhance the role of wetland of hurricane protection?  These two questions, please. 

DR. TRAVER:  One thing I just want to mention as a non-Corps employee, it might be easier.  When the Corps talks about temporary, it's not plywood and two by fours hammered it.  These things are pretty massive and oppressive.  So I mean, the term "temporary" I think is very misleading. 

MR. BASHAM:  Your first question, I think, really also ties in with the second question that the lady asked back here that I didn't answer is what is -- today as we rebuild what we have there, are we building to stronger -- and part of the question is:  What is stronger?  What do you mean by stronger?  And I would characterize that in two ways.  Stronger in the terms of pre-Katrina is building back a levee system that we've -- are pretty confident in that we will not have a failure from overtopping or breaching or a design failure like we had on the canals. 

How are we doing that?  In many cases, in the lower reaches of St. Bernard's in some of the areas we're putting back earthen levees.  We're actually importing clay on barges to the site and mixing that clay with some of the (inaudible) material to build a more resistant levee system so that even though you will have overtopping and you're probably still going to have some erosion on the backside of that levee, it shouldn't be sufficient at least in a Katrina event right now we think should not be insufficient.  It would cause a failure of the levee and you're still going to have overtopping. 

Other reaches of the system where we're actually rebuilding I-walls or have existing I-walls there and have done something to protect those, we've actually gone in there and built behind those I-walls what we call a scar pad (ph) and it's a concrete pad behind that I-wall so if you did have another overtopping it would not scar that I-wall out again and then cause it to fail. And in some cases where we're building T-walls, we're also installing pads behind those, so that their overtopping it will prevent scar.  And so those are what we're -- those are some of the things we're taking that -- what I call strengthening the existing system and building it back to the hundred year or the authorized level of protection. 

Understanding that in some cases, no matter how much money you throw at this and how much resources you throw at this, even though you talking about 350 miles of levee, there's only so much physically you can get accomplished on an annual basis to accomplish that.  And so we've had to take this in pieces.  And the first commitment by the President was to get folks at least back to restore to what they had before the storm event and then set about a strategy to try to give them better level of protection over the next two or three years back to the hundred year. 

The second piece of that was is there some effort in looking at some higher level protection and that's why I guess what I call -- you say or you got a stronger system.  The second piece of that stronger might be interpreted is a -- have I got a higher level protection to prevent me from -- protect me against even higher wave wash (ph) or a Category Five storm or Category Four storm. 

The Congress has authorized us to do a study, a two-year study that we just completed a six month report and submitted to Congress to look up to and including a Category Five level protection and come up with some plans and options that would help protect the community from an event like that.  Obviously you got to take in the social and economic, political -- the risks to that.  And we're hoping to do it in a systematic and a systems approach where at the end of the day, no matter what level of protection you have, just like it was mentioned about in The Netherlands, part of that systems approach you still got to have some type of an evacuation plan to get out of there.  Because one of the things you got to remember when somebody says it's a Category Five, while that's the upper limit on the scale right now, it's an unlimited category.  I mean, it's 170-mile, 179-mile-an-hour event for Katrina as a Category Five. 

But you -- you know, you can have 185 mile, you can have 195 mile or have a 200-mile-an-hour wind, it still would be a Category Five, because that's just the maximum it is.  Each one of those, the diameter of that storm event and the wind speed of that storm event and the movement of that event, each one is going to have its own unique profile of the amount of wave and surge it generates.  The question about part of that study will be looking at restoration of the marshes and the wetlands off the coast of Louisiana because it is a proven fact that I think for every mile -- every mile there's a foot of reduction or something like or --

MR. TRAVER:  It depends on where you are.  Several miles per -- 

MR. BASHAM:  It's a pretty significant reduction and so we're looking at how we can restore some of the wetlands area.  But we also need to remember that the whole frontal of New Orleans and the Louisiana and the Mississippi coast area is not protected by those wetlands.  And so there is a storm event that can come through that would never touch a wetlands area, but you still got to make sure that you'd have a level of protection or whatever that storm event is you can tell people what is the wind and surge that you're going to have coming ashore that's creating that wave and surge effects on the levee.  So yes, we are looking at the impacts of wetlands.  There is a whole other study out there to look to restoring wetlands in the coastal area. 

MODERATOR:  We have time for one last question. 

QUESTION:  Thank you.  Olga Bakova, Slovak Radio.  I would like to ask you first, you said that there is something in Congress and you are thinking how to strengthen levees up to a Category Five or something like that.  Do you have some kind of deadline when it should be, you know, some kind of conclusion -- yes, we will do it and it will be done by, I don’t know, 2000-something?  And then last -- second and probably last question, if something like Hurricane Katrina or maybe stronger hit New Orleans right now, what will happen? 

MR. BASHAM:  The first one, yes, Congress has directed that December of 2007, we have to submit this report and give a recommendation of what next level -- if there is some other level protection and then the decision to go invest in that level protection to do that.  And so the suspense date is December 2007.

The second part of your question; I wish I could say, as a big-time engineer, I had a crystal ball and can speculate.  I think I feel pretty comfortable with the great work that IPET's done and the American Society of Civil Engineers has done in looking at that and the great work of the men and women of the Corps, but also a lot of the folks in the private sector that have spent the last nine months working on restoring the levees.  We feel pretty comfortable that if we had another event like Katrina, as I said before, if you had the identical same event, you're still going to have two to three to four feet of water that's going to go over the top of those levees in many places. 

So the folks in New Orleans are still going to be inundated and still going to have water.  You're not going to have a pumping system that's up and running that's going to be able to handle both -- probably what would be a Katrina event; I think it was 14 to 15 inches of rain that occurred during that.  So it couldn't keep up the rain event, much less another two or three foot of water over top in that.  What we don't think it should have is the devastation caused by breaches, actually failing levees.  We think the levee system -- that either the combination of the measures I explained earlier that we've taken -- that we would not have a levee breach if you had another event today.

DR. LINK:  I think it's very important to realize that another Katrina, exactly the same storm moving along a different path, could create a much, much different result and the -- looking at Category Three versus Category Five types of designations is not very meaningful to a levee.  A levee cares about the level of water, wind, and surge level and wave levels that it experiences.  And the path of the hurricane is extremely important.

The path that Katrina took was one of the worst paths it could have taken to affect the east side of New Orleans.  It had almost no impact, just rainfall on the west side of New Orleans.  So a different path could not have impacted the east side very much, but could, in fact, impact the west side a lot.  So it is very critical how that storm moves to what the results are.  But largely, Katrina took one of the worst paths that it could take and it -- and the portions of the system that were most vulnerable to these very high surges and waves, in fact, were attacked.  And the system just had not been built to deal with the overtopping.  And we can look back on that now and say we should have built it stronger and better, but the fact is it didn't happen through history.

But right now, we -- the levees have been rebuilt so that if overtopping occurs in those areas that are most vulnerable, they will be much stronger.  A big conclusion we found was the system lacked resilience.  It lacked the ability to deal with the overtopping, the unknown, the very -- the water levels above design.  And that resilience now has been built back into the repairs and so those systems will be much less likely to fail.

QUESTION – Follow up by Christoph von Marschall, Der Tagesspiegel:  Just one clarification.  When you mean there might be a core overtopping by three to four feet, that doesn't mean automatically water will sit everywhere in New Orleans three to four feet higher, but what will happen with those three to four feet overtopping water?

DR. LINK:  The -- we have modeled that.  We know what area -- we can predict exactly which areas would be flooded and to what depth they will be flooded.  That's part of the risk analysis.  Go ahead.

MR. TRAVER:  And I was just going to elaborate on that a little bit.  I don't think the question is whether a 5 comes or a 4 comes or a 3 comes.  It's really the risk assessment.  It is different in different areas.  I mean, if you live near a nuclear power plant or a dam or in coastal Carolina or in the Netherlands or anywhere else, you're assuming a certain amount of risk.  What has concerned us, in some ways, is this risk was not communicated and it was not part of the decision-making process from the -- all levels of government.

MR. BASHAM:  If I could, I think one of the great pieces that will come out of this tragedy of our investigation and analysis is, there really has not been in this country -- at least in the water resource arena, there's been portions of it you can see in the Department of Transportation in analyzing risk associated with death and fatalities, seatbelts in your cars and airbags, but in the industry, in the dam safety arena and the levee arena there really has not been a good risk-based methodology out there that we can find, I think, anyone has used. 

Part of the work that the IPET and the American Society has worked jointly on is actually to hopefully develop a risk-based methodology that can be applied first in New Orleans so we can test it and make sure that it validates what we want it to validate.  But then second is to be able to take that tool and use it in California and use in other levee systems throughout the country.  The Congress has directed that we do a national levee inventory for the levees in this country and not just federal, but non-federal, and also to look at doing an assessment of those levees.  The question is -- of today is, what are you going to assess them against.  And there is no national policy or practice out there that tells you what to assess your levees. 

We believe the piece of work that comes out of the New Orleans effort will help give this country, now, an assessment tool to do that assessment.  The question's going to be, though -- it is just a tool.  It will help you order rank and give you some relative ranking of the risk associated with different levee systems in this country.  This nation is going to have to make its decision, what is it willing to invest to reduce that risk to what level in different places of the country.  And that's the question, I think, is out there for the American people to address.

MODERATOR:  Okay.  On that note, I think we'll conclude the formal portion of our program.  Thank you all for coming (inaudible) and to the Corps for coming over.