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The Man Who Predicted Katrina

For years, Ivor van Heerden, a hurricane expert at Louisiana State University, saw a tragedy coming. Since 2001, he and colleagues had been generating computer models of how a major storm could inundate New Orleans. He and his team sought tenaciously—at times desperately—to have their warnings heeded by government officials. In these interviews, conducted both 10 months before and then soon after Katrina hit, van Heerden expresses some of his worst fears, frustrations, and regrets.


Before the Flood

Interview conducted October 29, 2004

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NOVA: If this region—New Orleans, the wetlands, and all—were a patient in the hospital, how would you describe them? At what stage are they?

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IVOR VAN HEERDEN: Close to death.

Really? Don't hold back.

(laughter) Thank you. Louisiana is a terminally ill patient requiring major surgery, a patient that if it was given a new heart and new lungs and a new liver would live. If it isn't, it's going to die. That's the equivalent.

Ivor van Heerden
Ivor van Heerden was haunted by the knowledge that a major hurricane would devastate New Orleans. He is deputy director of the Louisiana State University Hurricane Center, and since 2001, he has led a team studying the public health impacts of hurricanes on the city.
© WGBH Educational Foundation

An ominous scenario

Walk me through the worst-case scenario—if a hurricane hits New Orleans.

If we look at the case of a slow-moving Category 3 passing west of the city, the floodwaters push into Lake Pontchartrain, and then they push through some highly industrialized areas. As they pass through these areas, they pick up a lot of chemicals. Remember, the flooding is occurring at the same time as a lot of wind damage, a lot of things breaking and coming apart. So these highly contaminated waters then flow into the city.

Within the city you have about 300,000 people who haven't left. There are about 57,000 families in New Orleans that don't own a motor vehicle. They can't get out. There are numerous homeless folk who can't get out. And then there's the disabled or bedridden. And those are the folk who have the least resources, the least ability to cope with what's going to happen.

While the flooding starts, these people are dealing with the winds pulling buildings apart, trees coming down, whatever. For the first five hours the water rises very slowly. But then it rises very, very rapidly. It rises higher than the average home's roof. So those 300,000 people, most of them, are going to have to leave their homes. They're going to end up hanging on to light poles, trees, trying to swim to high-rise buildings.

"We're in essence going to have a refugee camp."

There is the potential for extremely high casualties—people not only killed by flying debris, drowning in the soup, but also just imagine, how do we rescue the survivors? Unlike a river flood, it doesn't come up and go down. The water stays. And it stays for months and months and months. How do you rescue all of these people? If there's 200,000 survivors, you get 20,000 out a day, that's 10 days. So how are they going to hang on? You know, this is one of the big nightmares: how do you rescue those survivors? What are they going to need?

They're going to need to be detoxified. And this is Louisiana—it's 100 degrees Fahrenheit, 100 percent humidity. Putrefaction and fermentation go on very, very rapidly. So those folk are going to be surrounded by the proverbial witches' brew of toxins.

Superdome with Katrina refugees
New Orleans' Superdome served as a makeshift refugee camp. While van Heerden's nightmare scenario didn't play out in full, his vision of destitute survivors was all too prescient.
Courtesy FEMA

In addition to the folk that have to be rescued, we've got about 700,000 residents who can't come home. They're going to have to be housed in tent cities. When you start pulling groups of people like this into close confinement, the potential of very serious diseases goes up dramatically.

So just imagine, you've got this super, super crowding—highly, highly stressed folk. They don't have a home. They don't have a job. They don't see any future. They're living in tents. It's hot, humid Louisiana. And now you have the potential of disease.

These are some of the worst-case scenarios. We will have almost a million displaced persons that are going to be totally dependent on the state. We're in essence going to have a refugee camp. And it's going to require a massive operation to try and bring some normality into these people's lives.

Preparing for disaster

Is this something that a state can handle? The State of Louisiana?

No, this is definitely something that requires the full resources of the U.S. government. We are fortunate that the federal government is starting to recognize that this is a serious problem. In July of this year [2004] we had an exercise called the Hurricane Pam exercise, where all the federal agencies got together with state agencies. We did a simulation of what would happen, and then these agencies got together and tried to decide how they would deal with a flooded New Orleans. So there is some recognition now, especially by the Federal Emergency Management Agency, that this is a catastrophe that's right on the horizon.

PAM Hurricane simulation graphic
At the Hurricane Pam exercise, van Heerden showed FEMA officials a computer model of how a slow-moving Category 3 storm passing west of New Orleans would flood the city. In some areas, storm surge would cause more than 20 feet of standing water.
Courtesy Center for the Study of Public Health Impacts of Hurricanes, Louisiana State University

How great is the risk of this happening?

If we look in the last eight years, we have had two near misses of New Orleans [Hurricane Georges in 1998 and Hurricane Ivan in 2004]. And as the wetlands fall apart, the potential of these hurricanes to do major destruction through storm surges rises and rises and rises. So every year that goes by, the probability of this killer storm occurring increases. Statistics right now would suggest maybe once every seven to eight years we're going to have a near miss.

So if there's a chance of a big hurricane and this scenario playing out every seven or eight years, what's the solution? What could be done?

There are two very important mitigation activities that the federal government has to pursue today. Number one is our wetlands protect us from a surge. Our wetlands and barrier islands are our outer line of defense. We need to restore them. Now, that's in the longer term.

In the shorter term, we can start thinking about how can we reduce the amount of water that flows into Lake Pontchartrain and then floods the city? We need to be really innovative, think outside the box, and in addition we've got to change the way federal government does business. You can't give these sort of projects to the Corps of Engineers and have them mull over it for 20 years before it gets built. We need a group that's independent of the political system, that's well funded, has the right experts advising it, and then gets in and does it.

"Every year that goes by, the probability of this killer storm occurring increases."

This is the United States of America. This is the most powerful country in the world. It has unbelievable resources. At, literally, the snap of the President's finger, we can spend $40 billion in Iraq. If we can start rebuilding their infrastructure immediately, we can do the same thing back home. At the snap of the President's finger, perhaps, we could spend the $16-20 billion that's needed to save New Orleans. All it takes is the will to do it.

What do you think it takes to create that will? Does it take a catastrophe?

The unfortunate thing is, it does look like it's going to need a catastrophe in order to mobilize it.

After the Flood

Interviews conducted September 10 and October 5, 2005

The storm approaches

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?

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."

van Heerden's team began issuing advisories like this—showing how Katrina's storm surge would drown the city—on Saturday, August 27. Katrina made landfall around 6 a.m. on Monday, August 29.
Courtesy Center for the Study of Public Health Impacts of Hurricanes and Center for Computation & Technology, Louisiana State University

What did your model tell you about Katrina?

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.

Did you think the model would be accurate?

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.

So you knew that there would be widespread flooding?

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.

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

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.

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.
Courtesy FEMA

Broken promises

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

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.

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?

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."

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?

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.

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.
Courtesy U.S. Army Corps of Engineers, New Orleans District

Catastrophic failure

Did you expect the levee failures?

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."

How many breaches were there in the various levees?

There were 28 different breaches.

Can you just describe the two main ones?

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.

Why did the levees collapse?

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.

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

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.

Whose fault is it?

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.

Could floodgates have helped prevent the collapse?

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. For more on the history and construction of the levees, see A 300-Year Struggle.]

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

Aiding the rescue and preparing for the future

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

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.

And what now?

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."

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

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.

line of survivors
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.
Courtesy FEMA

Disgust and heartache

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

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.

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?

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.