Texas: a history of flooding is compounded by development and warming impacts

From the New York Times

The holiday and the type of hazard have changed, but once again fast-growing Texas is seeing outsize (and tragic) impacts from extreme weather events. On Labor Day weekend in 2011, the disaster was heat- and drought-fueled fires that whipped through the exurbs east of Austin, most of which didn’t exist just a few decades earlier. Now, Houston is flooded and Hays County, west of Austin, is still in search and rescue mode after Memorial Day weekend flash flooding swelled rivers to record heights, inundating fast-growing riverbank towns and sweeping away a home packed with vacationers. (A Mexican border town and parts of Oklahoma are also reeling.)

What connects wildfire and raging waters?

Somewhere, deep in the statistical noise, there is a contribution from the global buildup of heat-trapping gases changing the climate system.

Among the clearest outcomes of global warming are hotter heat waves and having more of a season’s rain come in heavy downpours. But the picture gets murky, indeed nearly insoluble, at the scale of states or smaller regions. There’s more on this below from the Texas state climatologist and others. The bottom line is there’s no trend in Texas gullywashers.

What’s vividly clear is the extreme vulnerability created by the continuing development pulse in some of the state’s most hazardous places — including Hays County, in the heart of an area that weather and water agencies long ago dubbed “Flash Flood Alley.” (Here’s a great interactive explainer.)

The region’s population and building booms are far outpacing efforts to reduce exposure to flood dangers, resulting in long-predicted scenarios playing out at high cost in lives and money.

“The main challenge to rational planning for flood risk in the country is that private property rights trump even modest limitations on floodplain development,” said Nicholas Pinter, an expert on floods, people and politics at Southern Illinois University, in an email today. “And that sentiment runs deep in Texas. The result is unchecked construction on flood-prone land, up to the present day and in some places even accelerating.”

It’s worth noting that a similar pattern, although with a different mix of drivers, can be seen far from the strip malls and condos around Austin. In some of the world’s poorest places, rapid population growth and flimsy housing in zones of profound “natural” hazard have created huge vulnerability (the latest case in point is, of course, Nepal).

In Texas, there’s a “too little, too late” feel to the steps that have gotten under way — including a variety of United States Army Corps of Engineers studies of flood risk. 

One such flood analysis, for the northern part of Hays County, begun in 2011 and is just now entering final review. The risk was laid out four years ago in an announcement of the study:

Hays County’s population has been increasing dramatically – the county’s population grew from 97,589 in 2000 to 157,107 in 2010, a 61% increase. Development has subsequently increased as well. This growth has the potential to place residents at a greater risk for human and economic losses from floods.

In a telephone interview, Randy Cephus, a public affairs official in the Corps’s Fort Worth district office, said this was a fast pace. “The Corps has gone through a transformation,” he said. “In the past, studies have taken 8 to 10 years to complete. We’re trying to undergo those within 3 years.”

It’s important to get these studies done, but I doubt they’ll have much impact as long as politicians and communities in the region stick with the go-go development mentality that has been so vividly on display.

Read the full story (much more) at the NYT’s

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