Texas Floods Highlight Urban Vulnerability

Hilary Tuttle


August 3, 2015

texas flooding

Between May 23 and 30, record rainfall and severe thunderstorms caused significant damage across Texas and Oklahoma, with overflowing rivers and flash floods killing at least 32 people and inundating more than 5,000 homes in Texas alone, including the metro regions of Houston, Austin and Dallas. In the wettest month recorded in Texas history, more than 37 trillion gallons of water fell on the state, the National Weather Service reported— enough to cover the entire state in ankle-deep water. The wettest region, near Dallas-Fort Worth, got more than 20 inches, and the drought-ravaged state saw rivers and reservoirs go from 20% to more than 100% capacity in what forecasters estimated as a 150- to 200-year flood.

Total economic losses from the storms are expected to exceed $1 billion, with insured losses at least in the hundreds of millions, although they could have been higher as flood insurance penetration is lower in Oklahoma and the drier parts of Texas. Overall, “because of the high risk of flood, Texas has the second-highest number of National Flood Insurance Program (NFIP) policies in effect nationally, trailing only Florida,” said Lynne McChristian, catastrophe response coordinator for the Insurance Information Institute (III). The federal government’s most recent figures show these policies cover property valued at $157 billion. Of these policies, 41% are in Harris County, which includes Houston, with $32 billion of property covered in the city itself.

While homeowners should largely find relief, damage to infrastructure and other state resources could rack up a large tab and take months to fully repair. The storms caused at least $27 million in infrastructure damage, Veronica Beyer, a spokeswoman for the Texas Department of Transportation, told the Associated Press. Roadways in more than 65% of counties suffered storm damage. Preliminary damage estimates in the Houston area total at least $45 million, with more than $25 million in damage to public utilities and infrastructure, according to Francisco Sanchez, public information officer for the Harris County office of Homeland Security and Emergency Management. Simply removing storm debris from the city’s flooded bayous, neighborhoods and streets had already cost $15 million, not to mention the costs to repair buildings and equipment.

The state’s agriculture industry is likely to suffer as well. Crop losses will reach “many millions of dollars,” Gene Hall, director of public relations for the Texas Farm Bureau, told CNN. A small but significant number of farmers will lose entire crops, and the question for the rest will not be whether they take a hit, but how much. “To some degree, virtually all farmers in the state have been affected,” he said.

But the damage could have been worse. In 2001, Tropical Storm Allison caused $1.1 billion in insured flood losses, worth about $1.5 billion today, the III reported. Officials remembered Allison’s valuable lessons this year: Authorities were able to warn residents by phone and in person to seek shelter, and after the torrential downpour, firefighters and other first responders carried out hundreds of water rescues, many involving stranded motorists.

Many of the areas most impacted, however, have a sizable tourist population, with many vacation homes located near the coast and thriving vineyards outside of Austin. Notifying these individuals proved challenging, officials said, since the emergency messaging systems are still awaiting improvements. In Houston, for example, the Office of Emergency Management is working with FEMA on a system to alert residents with more targeted warnings, but it has not yet been installed.

Such shortcomings are a small facet of the region’s flooding challenges. The real issues are far more systemic, and illustrate a broader trend. Over the past two years, thunderstorms and heavy rainfall events have been an increasingly prominent driver of loss. Indeed, according to Aon Benfield’s 2014 Annual Global Climate and Catastrophe Report, two of the top three perils for the year were flooding and severe weather, accounting for a majority of economic losses, and causing four of the year’s 10 costliest overall loss events and seven of the top 10 insured loss events. While more severe natural catastrophes mean more severe destruction in a single event, the sum of these theoretically “normal” events takes a greater toll on residents, businesses and insurers.

The weather may be getting worse, but urbanization and land development play a significant role in making any event more destructive. For example, a booming energy industry and rapid expansion have turned Houston into the fourth-largest city in America. Concrete and construction in already vulnerable areas put greater amounts of property at risk and decrease geographical resilience.

“Houston is the number-one city in America to be injured and die in a flood,” Sam Brody, director of Texas A&M University’s Center for Beaches and Shores, told Time. “Houston is so vulnerable. There’s very little topography. They’ve added hundreds of miles of pavement and can’t keep up with all the positive initiatives. …So we get these floods.”

The city has invested hundreds of millions of dollars to battle the effects of urbanization. On Buffalo Bayou alone, for example, flood control efforts totaling half a billion dollars in the past decade have included bridge replacements, the addition of detention ponds for runoff, and creation of green spaces that serve as parks in normal weather while offering more land surface that can absorb water in foul weather.

But the investments are not enough. “Houston may be doing things to try to improve…but there’s a long history of pre-existing stuff that is still there,” Walter Peacock, an urban planning professor at Texas A&M and director of the school’s Hazard Reduction and Recovery Center, told Time. “Think about every time you put in a road or a mall and you add concrete—you’ve lost the ability of rain to get into the soil and you’ve lost that permeability. It’s now impermeable, and therefore you get more runoff.”

Rivers, bayous and other receptacles for runoff might take months to return to normal levels, officials said, forestalling complete recovery while also leaving the region especially vulnerable to further weather events as the Atlantic hurricane season ramps up. Indeed, about two weeks after the storms, Tropical Storm Bill formed over the Gulf of Mexico, making landfall in Texas and bringing almost a foot of rain. While weaker than initially predicted, Bill still caused further flooding, road closures, and flight cancellations as areas that had flooded before—and not yet recovered—flooded again.

Hilary Tuttle is managing editor of Risk Management.