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Storm That Drowned a City homepage

After the Flood

Interviews conducted September 10 and October 5, 2005
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The storm approaches

NOVA: Bring me back: Katrina comes through Florida and starts making its way across the Gulf. Here at the Hurricane Center at LSU [Louisiana State University], what do you do?

VAN HEERDEN: Early Saturday morning, we assembled at LSU and started doing the [storm surge] model runs. We did about three that day. And the last one we did we released in the evening, and that was the one that showed that New Orleans was actually going to flood. I then sent an e-mail to a lot of different federal agencies, state agencies, the media, letting them know what was happening.

The Weather Channel and then The Times Picayune contacted us, and they wanted to use it for an article for Sunday morning. So we worked with them to get that together, because we felt that The Times Picayune could have a good image that might hasten the number of people who left. And obviously, we were doing whatever media interviews we could to get the message out: "Leave, leave, leave, leave now."

NOVA: What did your model tell you about Katrina?

VAN HEERDEN: It showed that most of eastern New Orleans was going to be underwater, with 11 feet of standing water in many places. And it showed there also would be significant flooding just west of the Industrial Canal.

NOVA: Did you think the model would be accurate?

VAN HEERDEN: Yes. We have a lot of faith in our models; we've been working on these models since 2001. We've done a lot of ground-truthing, with storms such as Ivan and Dennis, comparing the actual surge to what we produce.

NOVA: So you knew that there would be widespread flooding?

VAN HEERDEN: We knew that, and we also did some runs where we moved the track west of New Orleans, because that is the absolute worst-case scenario. And so, we knew that if the storm had come west of New Orleans, we were going to flood the whole city.

“We had a number of officials who basically scoffed at us.”

Obviously, we communicated our findings to everybody we could. Our e-mails go out to a lot of different agencies, but most importantly all the information is sent to the Louisiana Emergency Operations Center, and then everybody who is there is briefed, and that includes senior state officials, Corps of Engineers, military, and so on. By about 10 or 11 p.m. on Saturday night, everybody over there had been briefed.

NOVA: Was it a case of your warnings falling on deaf ears?

VAN HEERDEN: Well, let me start with the positives. Saturday evening, as soon as we put out our model, the Centers for Disease Control in Atlanta contacted us and asked if we could do a conference call with them the next morning. So Sunday morning at about 11 a.m., we went over all the different potential scenarios with them in terms of flooding, how many people are going to be rescued, what diseases we expect, and so on.

And certainly, we believe the state was aware of what the consequences were going to be. The state has quite a lot of confidence in our modelling, because it's proved accurate in the past. So I think they really recognized that this was going to be serious.

But in terms of the response, it doesn't seem that that urgency—the direness of the situation—got to those in command of, say, FEMA.

Broken promises

NOVA: Do you think FEMA officials and others were reluctant to believe the science, believe the models?

VAN HEERDEN: I think that there is a real lack of appreciation for the science. I know from the exercises we've been involved in, certainly with FEMA officials, not all of them have been very responsive. You know, I think a lot of them are ex-military folk, and to them we may be geeks.

NOVA: So at the Hurricane Pam exercise you did with FEMA in July of 2004, to play out a scenario of a major disaster, not all of the officials took what you had to say seriously?

VAN HEERDEN: At the Hurricane Pam exercise we had a number of officials who basically scoffed at us when we were talking about the potential of levees going and the very real threat to New Orleans of a major hurricane. I think they just believed it wouldn't happen.

There were other officials who did. Certainly at Jefferson Parish, they really paid heed to what we had to say, and we did a lot of work with them in helping them to understand.

The other important thing about the Pam exercise is that a lot of local officials came away from it understanding that FEMA, the Federal Emergency Management Agency, had to act within 48 hours—that FEMA would arrive with all the troops, all the food, all the water, and all the rescuers that we needed.

“All of us had been lulled into a sense of security by the continual assurance by the Corps of Engineers that the levees were never going to fail.”

NOVA: You've been warning about New Orleans' vulnerability to a big storm for years. If more government officials had heeded such warnings earlier on, could things have played out differently?

VAN HEERDEN: Yes. There were so many different areas where we could have seen a much better response from the government. Number one, we could have had the evacuation of the 57,000 families in New Orleans who don't own motor vehicles completed before the storm arrived. That's the first thing.

The second thing is, we could have had military transport aircraft flying into the New Orleans Airport—it was serviceable early on Tuesday [August 30]—bringing food and water, the necessary amphibious vehicles if needed. There was a promise that in 48 hours, FEMA would start delivering all those things. You know, we look at the Iraq War, and one of the first things our military did was to try and secure the Baghdad Airport, to use it as a staging base. The federal government could have done that in New Orleans. It didn't. So that's why we had this absolutely agonizing situation of the evacuation taking until almost five days later.

Also, desperate people do desperate things. We had violence developing in the city, and the feds again didn't move fast enough to bring in the resources to back up the [people and agencies here] who were trying to keep control. So that's another failure.

But the failing that is the absolute most damning of all was the Corps [of Engineers] should have been monitoring the levees, and they should have warned everybody when they let go. People went to bed on Monday evening—houses dry—and woke up in the middle of the night with water up to their waists. Those are the people that were forced up into their attics, many of them old and frail, because those are the ones who couldn't evacuate. And they didn't have the power to kick out their roofs, or couldn't get an axe or a chainsaw to do so.

The biggest failing in all of this was we should have warned everybody. We could have told the media on Monday night. The levees apparently broke Monday afternoon—the ones that really flooded the main city of New Orleans. We could have got to the media. We could have had vehicles driving on the interstates with bullhorns, telling people. We even could have used helicopters with bullhorns. We could have warned the people, "A big flood's coming, take evasive action." We didn't.

Catastrophic failure

NOVA: Did you expect the levee failures?

VAN HEERDEN: You know, I think all of us had been lulled into a sense of security by the continual assurance by the Corps of Engineers that the levees were never going to fail. Obviously, this was not the case.

Before Katrina arrived I had looked at just about every single levee in the Greater New Orleans area, and I definitely had some concerns about some of the designs. The Louisiana soils, when they get waterlogged, get very, very soft, and I was worried that some of the earthen levees might not stand the pressure.

“What is now very obvious is that these walls were underengineered.”

NOVA: How many breaches were there in the various levees?

VAN HEERDEN: There were 28 different breaches.

NOVA: Can you just describe the two main ones?

VAN HEERDEN: The 17th Street canal breach was over 600 feet long. The London Avenue canal had two breaches, both about 300-400 feet long. The field evidence shows that there was catastrophic structural failure of these levees. Basically, the whole levee system, including part of the dyke, slid sideways, in some cases almost 30 feet due to the pressure of the water.

NOVA: Why did the levees collapse?

VAN HEERDEN: Well, a lot of that's still under investigation, but the preliminary suggestions are that a) the foundations weren't deep enough and b) there might have been some design and construction problems and that [the levees] were weaker than they should have been.

NOVA: The Corps of Engineers says that the levees were designed to withstand a Category 3 storm. Wasn't Katrina just too strong for them?

VAN HEERDEN: Hurricane Katrina was a weak 4 and it may have only been a Category 3. But the London Avenue and 17th Street canals did not experience Category 3 conditions. They experienced conditions of a Category 1 or Category 2 storm, because they were on the left-hand side of the eye—the side that gets the least surge and the least wind.

So the design criteria weren't exceeded. What is now very obvious is that these walls were underengineered. And as a consequence, there was a catastrophic structural failure.

NOVA: Whose fault is it?

VAN HEERDEN: Those levees were designed and owned and maintained by the U.S. Army Corps of Engineers. They chose and supervised and inspected the contractors who built them, so the failure is the responsibility of the U.S. Army Corps of Engineers.

NOVA: Could floodgates have helped prevent the collapse?

VAN HEERDEN: Floodgates could certainly have stopped the surge from moving up those canals. The weak link on those two particular canals, the 17th Street and London Avenue, was the fact that they were open to the lake. We could have put barriers across the mouths of these canals. They would have been very easy to design and construct, and that is part of the catastrophe of New Orleans, that they weren't there.

[For a chronology of the levee failures, see How New Orleans Flooded. And for more on the history and construction of the levees, see A 300-Year Struggle.]

Aiding the rescue and preparing for the future

NOVA: As the city flooded, what were you and your team doing?

VAN HEERDEN: As soon as Katrina had passed through I contacted our funding agency and asked if I could divert our research funds to operational support. So we immediately got a mapping group organized at the Emergency Operations Center. They started producing maps for search and rescue, mapping the 911 emergency calls, producing other flood-related maps. We had other crews immediately going out to assess the level of damage so that rescuers could understand which areas they needed to concentrate on. And obviously we had a role with the state in advising them of what the next aspect of this disaster was going to be.

NOVA: And what now?

VAN HEERDEN: We're trying to characterize what happened in Katrina. What worked, what didn't work? How good were our models, and how can we modify our models for the future? We want to make all this available so that others will be able to use that information to better understand what the impacts could be if a major hurricane hit their area. This can help a lot of different governmental agencies both here and overseas in designing the structures and infrastructure for coastal cities, so that these governmental agencies, no matter where they are in the world, will be better prepared.

You know, we would hate to see the tragedy of Katrina repeated anywhere else in the world. Here, literally, government didn't come to the aid of the people. Now that we've seen it, now that we know the real outcomes, now that we've got the science to back it up, hopefully others will learn from the mistakes that were committed during Katrina.

“Every home has a story. Every home had a life. Every home had a family.”

NOVA: How should New Orleans be rebuilt? And do you think that New Orleans will ever be the same again?

VAN HEERDEN: Hopefully the federal government gets one thing right, and that is to rebuild Louisiana the way it should be done. We need to come up with a very secure hurricane protection system. We need to rebuild those coastal wetlands so we can get the full benefits in terms of surge reduction. We need to run all of those activities through the city of New Orleans so we regenerate the New Orleans economy.

And hopefully New Orleans will recover. It's never going to be the same again. One hundred thousand people lost everything: they lost their homes. Many, many of those families didn't have any flood insurance, so they're penniless, without a job. And they are spread all over the United States.

Unless the federal government admits its blame in that the levees that it built weren't up to the task and compensates all those people, those folk are never going to come back, and the longer it takes to get them compensation and to get the city cleaned up, the less chance there is of any of those residents ever returning.

Disgust and heartache

NOVA: It's clear you are upset about how the federal government responded to Katrina.

VAN HEERDEN: The federal government's involvement in Katrina was disgustingly slow. It was unbelievable, especially because we'd done the Hurricane Pam exercise and I had even briefed White House officials.

And, you know, for me, I grew up in apartheid South Africa, and what I saw in a lot of the images was mostly white policemen and military officials ordering mostly black Americans around. And I flashed back on the apartheid scenes that I saw back in the 1980s. It was totally disgusting, and the federal government really needs to apologize to every one of those people.

NOVA: It's been five weeks since Katrina. How does it make you feel to see the city now—with vast amounts of it still unoccupied, and some areas looking like they won't ever be occupied again?

VAN HEERDEN: I was in New Orleans again yesterday all day, and I went into some areas I hadn't been before where the devastation was even worse than I had seen previously. You know, I'm really, really heartsore for those people. Every home has a story. Every home had a life. Every home had a family.

And you walk past some of these homes—only half of them are standing, because they've been destroyed by the floods—and you see on the mantelpiece photographs, family photographs. You walk down the road and you see little trophies that kids got for playing soccer, you know.

They've lost so much, so, so much. And I think that's the really hard part for me to take—as I knew it was coming. And to go and see it day after day is really distressing, and I really hope the federal government admits its wrongs and compensates those people, because they deserve it.

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Van Heerden's team began issuing advisories like this one—showing how Katrina's storm surge would drown the city—the evening of Saturday, August 27. Katrina made landfall around 6 a.m. on Monday, August 29.

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Katrina would flood 85 percent of the city, and tens of thousands of survivors, like this couple, would need to be transported to higher ground.

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Breaches like this one (middle distance, beyond the bridge) on the 17th Street Canal caused the extensive flooding. It was not simply a matter of Katrina's storm surge overtopping the levees.

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A typical scene outside the Superdome. Raised in South Africa during apartheid, van Heerden was troubled by how black Americans fared during the crisis.

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Many of the survivors waiting for shelter in New Orleans just after the storm are now dispersed throughout the country. Katrina left roughly 100,000 people homeless.

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Storm That Drowned a City
The Man Who Knew

The Man Who Knew
Hurricane expert Ivor van Heerden saw Katrina coming for years.

A 300-Year Struggle

A 300-Year Struggle
Follow the Big Easy's ever-bigger battles with water.

Flood Proofing Cities

Flood Proofing Cities
What can New Orleans learn from other flood-prone places?

Anatomy of Katrina

Anatomy of Katrina
Track her from her birth off Africa to her clash with the Gulf Coast.

How New Orleans Flooded

How New Orleans Flooded
Annotated before-and-after satellite imagery shows where and how.

Map the Flood

Map the Flood
See how much of your area would have been submerged.

Interviews conducted by NOVA producer Joe McMaster (October 29, 2004), NOVA scienceNOW correspondent Peter Standring (September 10, 2005), and NOVA producer Tom Stubberfield (October 5, 2005). All were edited by Susan K. Lewis, editor of NOVA online.

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NOVA Home Find out what's coming up on air Listing of previous NOVA Web sites NOVA's history Subscribe to the NOVA bulletin Lesson plans and more for teachers NOVA RSS feeds Tell us what you think Program transcripts Buy NOVA videos or DVDs Watch NOVA programs online Answers to frequently asked questions