Wednesday, April 29, 2009

Change the odds

A new report from the National Academy of Sciences generated sensational headlines recently. Unfortunately those attention-grabbing headlines and the ill-informed commenters that responded all seem to have missed the major point.

The report, The New Orleans Hurricane Protection System: Assessing Pre-Katrina Vulnerability and Improving Mitigation and Preparedness, was most widely quoted as declaring that New Orleans can never be made safe. The most popular quote appears to be this one: “Levees and floodwalls surrounding New Orleans -- no matter how large or sturdy -- cannot provide absolute protection against overtopping or failure in extreme events.”

Many seemed to have stopped reading right there and joined one of two opposing camps: those who say it’s hopeless and we should quit wasting time and money trying to do the impossible in New Orleans, and, those who say scientists, engineers and politicians who would surrender the city to nature are either idiots or cowards.

They're both wrong.

A more careful reading of the report, available online, reveals that the true intent of the engineer and scientist authors is to fully alert the public to the stark reality of residual risks. That is to say, no matter what science concocts or what government provides, it is neither possible nor realistic to expect all danger to be removed.

Is this surrender to the whims of nature? No. It is a plainly stated view of reality. The world is dangerous. We can do many things to reduce danger, but there’s always a risk. There’s always a risk.

Is this a cry of hopelessness? Again, no. Scientists and engineers accept the challenge head-on. Humans are naturally proud, stubborn and intelligent enough to figure things out. Some may crumble and compare the struggle for survival to the punishment of Sisyphus, but most of us are stout-hearted and bold with resolve.

And here’s what the NAS report recommends: don’t rely entirely on levees and floodwalls. Build smart. Choose wisely. Be proactive.

A levee is no guarantee. New Orleanians have had water in their homes many times when there was not a hurricane in sight. One example is May 3, 1978, a date many of us remember. Torrential rain filled the streets and flooded cars and houses in Orleans, Jefferson and St. Bernard Parishes.

A floodwall is no guarantee. Even if the new floodwalls are rock solid and bulletproof, there is always the possibility of a storm surge taller than the wall. The current goal is to build a system to stop a 1% per year chance exceedence flood. But as I've blogged before and as the NAS report points out, that so-called 100-year level of protection is really pretty small when you think about it.

The odds might be 1 in 100 if you live here for 1 year, but each successive year the odds get worse and worse. If you live a full 72 years in New Orleans, there’s a 52% chance you will experience that big flood that will overtop the floodwalls.

The major point the NAS wanted to make is that levees and floodwalls are just part of the answer. The rest is up to us.

So what can we do?

First, understand that the levees and floodwalls form the perimeter defense. Once water overtops or falls as rain inside the system, water is going to pool in the lowest parts of the city. Even when the pumps are going full bore—and we have the best pumping system in the world—we know we can still be flooded. If at all possible, we should build on naturally high ground.

After Katrina, I lived for a while in the “Sliver by the River.” That part of the city remained dry not because of better floodwalls or pumps—it was purely natural elevation that spared the homes and businesses there.

Secondly, we have to elevate our homes. Slab-on-grade houses are modern, less expensive and dangerous. I speak from experience here. My Gentilly home was just too darn low. Houses like that are just tempting fate. Every foot above the ground adds safety from flooding.

Thirdly, we have to build above the inadequate and dangerous 100-year level of protection. Not just levees and floodwalls—I’m talking about houses here. When the city issues a building permit, they will give the 100-year elevation required to qualify for the National Flood Insurance Program. That’s the MINIMUM elevation for construction. Why stop there? Add a foot. Add two or three.

Remember that the 1% per year exceedence flood will occur sooner or later. There’s a 26% chance it will happen in 30 years, and a 39% chance in 50 years. Those are not good odds.

We can change the odds by building higher.

Finally, buy insurance. All of the things I discuss above can and will reduce your exposure to the risk of flooding, but nothing is going to totally eliminate the danger. If all else fails, your final safety net is flood insurance to lessen the financial blow.

Just as seatbelts, airbags, and all the safety systems of a modern highway will not guarantee survival in the event of a car accident, the NAS wants everyone to understand that levees and floodwalls, no matter how high or sturdy, cannot guarantee safety from flooding. There is always some residual risk. And just as safe driving habits will bring us safely home, smart building and planning will go a long way to keeping our homes safe.

Sunday, April 26, 2009

Waiting for evidence

An engineer dies in a car accident and finds himself in Heaven where he is greeted by the full host of angels and a heavenly chorus. “This is fabulous,” the engineer says to Saint Peter. “Do you greet all new arrivals this way?” “Oh, no!” St. Peter says. “This is all to welcome you--the longest living human since the days of Adam.” Confused, the engineer tells the venerable gatekeeper that he was only 35 years old at the time of his death. St. Peter looks through a huge stack of papers and several books resembling accounting ledgers. “Well, according to all of these hours on your time sheets,” St. Peter says, “We figured you were at least 169!”

Unlike lawyer and doctor jokes, engineer jokes are few and far between. This one is an often-told joke that both honors engineers for our long hours of work and skewers us for the sometimes incredible amount of work for which we bill our clients.

I recalled this silly tale today as I read the news account of the ongoing trial against the government regarding the influence of the Mississippi River-Gulf Outlet on Hurricane Katrina’s storm surge. According to the Associated Press, witness for plaintiffs Bob Bea said he had spent “about 10,000 hours studying the levee failures during Katrina.”

Ten thousand hours? Really?

Katrina struck on Monday, August 29, 2005, and the subject testimony was given Friday, April 24, 2009. That’s a span of 1,334 days. And 10,000 hours divided by 1, 334 days gives us an average of almost 7.5 hours per day. That’s every day—seven days as week, 52 weeks a year. If the plaintiff’s witness had dedicated his full and undivided attention to the subject—40 hours a week with no holidays—the total hours would add up to less than 7,700 hours. And even that’s a stretch.

Not quite as ridiculous as the engineer in the joke, but still a tally that raises an eyebrow.

This same witness against the government compared levee building in Louisiana to the task of Sisyphus, the hopeless soul from Greek mythology. In this, California professor Bea joined a chorus of critics who have said rebuilding New Orleans would be a waste of money and effort. They say New Orleans is doomed and that nature will wash away our city no matter what we do.

It's unfortunate that an engineer, a person supposedly dedicated to using science and technology for the public good, takes such a defeatist view of our city. New Orleans has been here almost 300 years and it seems fickle and cowardly to declare the battle lost now when the resources to protect and preserve the city are more abundant than ever before.

But I suppose his testimony is no worse than the testimony of litigant Norman Robinson. According to news reports, Mr. Robinson took the stand earlier in the trial to detail the pain and suffering he experienced following Katrina. Depression, alcoholism, anger and thoughts of suicide all took their toll on the television newsman.

It certainly must have been gripping testimony. I’m just not sure what any of it has to do with the alleged malfeasance and errors of engineering. Mr. Robinson is neither a scientist nor an engineer and it would appear all he had to offer was his sad story and dramatic telling of it. If plaintiffs are relying so heavily on emotional appeal, it betrays their lack of confidence in proving their case based on science and factual evidence.

Of course, all we have is news accounts, which we know leave most of what is going on in the courtroom untold. It just seems to me that if there was some compelling science, some “smoking gun” evidence, we’d be reading about that rather than the emotional state of plaintiffs and the incredible number of hours their witness spent working on the case.

Perhaps they do have scientific and factual evidence which they will reveal before the trial ends.

Or, perhaps the next witness will tell us the story of the lawyer and the engineer who meet on a fishing trip in the Caribbean. The lawyer tells the engineer, “I'm here because my house burned down. The insurance company paid off well enough for me to take this vacation.”

“That's quite a coincidence,” says the engineer. “I’m also using insurance money for this trip. Except in my case, my house was flooded.”

“Amazing,” says the lawyer. A few moments later, the lawyer says, “So tell me, how do you start a flood?”