No Fair Blaming Lewisville Dam Problems on the Bible. It's You and Me, Babe.

North Texas journalism professor George Getschow’s piece in The Dallas Morning News on dangers in the Lewisville Dam managed to put urban flooding in Texas in what I have always believed is the most useful framework — the Bible. 

The U.S. Army Corps of Engineers, responsible for safety of this 6-mile earthen dam in the midst of vast suburban sprawl, was quick to assemble a press event after the Getschow story broke to assure the public that nothing biblical was about to ensue. I guess that was fair enough for their part, even if their assurances did seem kind of heavily cross-hatched with caveats about our luck holding out and the creek not rising.

But those assurances did nothing to allay the true core impact of the Getschow piece, which was to wake people up to the full dimension of the danger. Even if we trust the Corps to manage that danger, it’s healthy for us to understand the size of the urban flooding risk where we live. That’s where biblical comes in.


We think of bodies of water like Lake Lewisville as reservoirs — huge containers of drinking and lawn-watering water. But the Corps builds them as flood safety measures, to hold the runoff created by suburban sprawl during wet months until that water can be safely released during the dry months. The urban flooding we are beginning to see more frequently, as well as worn-out infrastructure like Lewisville Dam, are indications that our flood control measures are beginning to be overwhelmed.

If the Corps can’t stay ahead of that game — if Lewisville Dam were undermined by invisible seepage and broke loose without warning one night — then we could be talking about the potential for thousands of deaths in Dallas and an amount of property damage almost exceeding our ability to count.

So maybe while we’re on the topic anyway, we might actually devote a little bit of thought to how this risk has been created — how did these enormous risks pile up against us and what might we be able to do about reducing them?

There is a pretty general consensus among people who study 21st-century flooding in the built environment that the number one driver of flooding now is suburban sprawl and the sealing of formerly permeable land — land nature designed to soak up rain — with a stubborn hardscape of concrete and rooftops. The only meaningful way to address that risk is by reforming building codes and land-use policies.

And, in fact, efforts to do just that are underway at the federal level. Congress is considering raising the amount of elevation above a floodplain considered safe for residential development. The proposed change, from a so-called 100-year flood level to a 500-year level (just think higher) matches what major reinsurance companies are calling for in the private sector. 

But especially here in Texas, that kind of talk butts up against ferocious opposition from the real estate development interests and the town promoters. Nicholas Pinter, professor and chair of applied geosciences at the University of California-Davis, talked to me about the proposed new standard, still on the drawing board in Washington: “You know what, if that had been implemented last May when all the Central Texas flooding occurred south of Austin, a lot of the damages that happened then would have been avoided.

“Just weeks before that flooding,” he said, “a letter authored and co-signed by a number of (state and federal Texas legislators) was submitted to the president vocally opposing the new flood-risk standards. It’s ironic that the legislators whose own constituents were so heavily damaged, whose own constituents would have been safe had that standard been in place earlier, were among those most vocally arguing against a more robust safety margin in U.S. floodplains.”

In the letter Pinter refers to, Congressman Pete Olson, Republican of suburban Houston, told the president the proposed new standard would “likely dry up economic investment in these areas.”

That’s not a response to stricter flood control that should surprise anybody, at least not in Texas, according to Kevin Simmons. He’s an economics professor at Austin College who studies the economic relationship between damages from natural disasters and efforts to mitigate those damages with regulation.

Simmons says the anti-regulatory climate in Texas needs to be understood in terms of spirited competition for local growth dollars:

“Let’s say you’re a city on the edge of the metroplex. You’re just in northern Collin County or in Denton County, something like that, which probably is going to be a part of the metroplex in the next 10 years.

“You want developers to come and build in your city as opposed to a neighboring city,” Simmons says. “You want to be the next Frisco." 

“Do you want to give these developers stringent guidelines that would inhibit development in some areas of your city, or do you want to do things that would encourage them to build in your city?”

But the absence of meaningful land-use controls to control flooding — turning developers loose to build what they want, where they want — is exactly what piles up those huge risks and huge potential costs that somebody is going to have to pay some day when some dam or levee breaks in a densely developed area.

Somebody is you. The taxpayer. Pinter at UC-Davis points out that the costs for massive flood damage fell back on the taxpayers even when the taxpayers tried to protect themselves by setting up a national flood insurance program. (And remind us again: Who was it who thought an insurance company run by congressmen was a good idea?)

“The flood insurance program has been overgenerous with the result that we taxpayers are now $24 billion dollars in debt to the U.S. treasury,” Pinter said, “because pervasively across the country we have yielded the floodplains, inch by inch, acre by acre to these pressures to develop them.”

Maybe the most interesting thing to think about in all of this is not the doom and gloom, however. Simmons at Austin College co-authored a study in Moore, Oklahoma, published this year, not about flooding but tornadoes, the more frequent bane of that long-suffering community. Simmons looked at a tougher building code adopted by Moore officials after a tornado in 2013 killed seven children in an elementary school, the third catastrophic tornado to hit Moore in 14 years.

What they found was that if all the homes in Oklahoma had been built to the new Moore standards, the extra cost would have been about $3.3 billion, adding an average of $2,000 to each new house. But the savings in wind damages that Oklahoma could expect in the next 25 years would be about $11 billion. Not a bad trade-off.

I asked Simmons about the cost of running off developers by imposing stricter standards versus the benefit of attracting more people to Oklahoma because they’re less afraid of getting blown away with their little dog, Toto. He said it’s too early to tell. I think what he really meant was, “Only reporters ask things like that,” but he was too nice to say it.

There’s maybe one more strand of this puzzle that I hear from people — a very tangled version of the climate change debate. Some people say to me — and I could swear they’re the same ones who deny climate change at other times — that the increased flooding we are seeing in urban/suburban areas is not the result of development but of changes in rain patterns.

I don’t know what that means in terms of policy. Go ahead and develop where you want, because we’re all doomed anyway? But I did find one person with both academic and official standing to address it, John W. Nielsen-Gammon, a professor in the department of atmospheric sciences at Texas A&M University and the state climatologist of Texas. His studies of weather in Texas over the last half-century have found evidence of robust aggregate increases in the intensityof downpours but not in stream flows.

Nielson-Gammon says the evidence confirms climate change but not enough to make it a primary driver of the increased flooding we are seeing in urban areas.

“It is not obvious and probably I would say unlikely that changes in rainfall are the biggest driver in changes in flooding over the historical period,” Nielsen-Gammon told me. “I think land-use changes are probably the biggest driver of increases of flooding in urban areas.”

Why is that important? Well, going back to Getschow’s piece and the biblical catastrophe we face if that dam ever breaks loose, maybe it’s time to stop blaming it on the Bible. We created this mess. We continue to make it worse every day, when each new acre of permeable land falls beneath a shroud of rooftops, swimming pools, tennis courts and shopping malls.

The fascinating point in the work of Simmons at Austin College is the indication that tougher regulation is not necessarily an economy-killer. There is money to be saved and profit to be gained in common sense measures. Every little hick cow-patch town competing to become the next going-and-blowing big suburb may well be an economy-killer ultimately, not to mention loss of human life.

None of us is surprised when another dude in a heavily starched shirt and cowboy boots runs out on stage to promote his own cow patch as the next great suburban Nirvana. Any one of us might be tempted to do the same thing if the same size bag of gold were sitting on our own table just beyond our own grasping fingertips.

But for a society to be basically sane, some people have to be the grownups. That’s what I like best about the Getschow story. I read it, and I see Noah standing on his boat with his hands on his hips, telling us, “Hey, enough is enough, OK?”