Did Houston Flood Because Of A Lack Of Zoning?

Mother nature seems indifferent to the zoning codes in various cities.
By Scott Beyer | Aug 30, 2017 |
By Scott Beyer | Aug 30, 2017 |
Texas National Guardsmen rescue a resident during Hurricane Harvey. / Department of Defense

To advocates and skeptics alike, Houston is a symbolic urban model. For those who dislike government control, its rapid population growth and minimal regulations help explain its economic success. For those who embrace urban planning, such deregulation has made Houston a chaotic, even ugly, city.

This partisan debate is resurfacing now that Houston sits underwater. Over the past 5 days, the metro area suffered a U.S-record 52 inches of contiguous rainfall from Hurricane Harvey. The flood has killed 14 people and caused an estimated $35 billion in damage. This has caused a mini-war within the media–mainstream and social–about why the city has experienced such flooding, not only this week but in recent years. And a predictable culprit has come up—the city’s lack of zoning, and its general embrace of fast, unfettered growth.

The strongest connection between Houston’s liberalized policy and its flood problems was actually made in late 2016, when Pro Publica documented its flooding during Hurricane Rita. It argued that rapid sprawl development has reduced water-soaking prairie land across the metro, and instead covered the region with impervious surface, creating runoff problems. Just a few weeks later, the Houston Chronicle published a piece claiming that in the last 40 years, rainfall in the Brays Bayou watershed had increased by 26%, but runoff by 204%.

Amid this most recent flood, other media outlets—including The Atlantic, Slate, and Newsweek—have piled on with their “floodsplaining”, screaming out headlines like “Houston Is Drowning–In Its Freedom From Regulations.” As Slate columnist Henry Grabar wrote:

The flood-absorbent grasslands of the Katy Prairie have been cut by three-quarters over the past few decades as Houston sprawled west. The state played along, funding expansion of I-10, “the Katy Freeway,” and another road, the Grand Parkway, which further opened that land up for development. To make matters worse, money-hungry officials also encouraged development in low-lying, flood-prone areas without regard to future risk. There have been more than 7,000 units built in the hundred-year floodplain since 2010.

Questions remain, though, about just how much impact such development actually has in worsening floods–and whether added regulations would change anything. After citing several scientists in their article, Pro Publica interviewed Mike Talbott, former director of the Harris County Flood Control District.

The claim, he said, that “these magic sponges out in the prairie would have absorbed all that water is absurd.” Rather, the region has suffered from some freakishly large recent rainfalls, and was having trouble handling them because of its geography. Houston relies on a network of bayous to funnel water outwards and into the Gulf. But because it is abnormally flat, these bayous don’t efficiently push water eastward, and are subject to overflowing.

“If Harvey happened in 1850 instead of today,” added historian Phil Magness on Facebook, “the results would be nearly identical in terms of land flooded…No zoning law or ban on parking lot construction would ever have ‘fixed’ anything about that.”

Magness later added a video from Texas Archive showing Houston’s central Buffalo Bayou after a 1935 flood, at a higher level than it is now, despite the city having far less impervious surface back then.

All the same, it doesn’t seem that tight regulations, or less development, have prevented flooding in other cities. When New Orleans was hit by Hurricane Katrina in 2007, it had far less impervious surface than Houston does now; in fact, its population had been declining in every decade since 1970. Alas, the tragedy wasn’t about that anyway, but about infrastructure that collapsed and spilled water into a flood plain–a flood plain that had been developed despite New Orleans’ strict zoning laws. When Hurricane Sandy hit New York City, it damaged a metro area that, overall, is both denser and more regulated than Houston. In the last decade alone, flooding has also hit Iowa, Georgia, Tennessee, Colorado, and various other regions with diverse geography and regulations.

If there’s a predominate takeaway from these examples, it is that mother nature doesn’t care about your city’s zoning code, or whether or not your city even has zoning.

Instead, larger forces–potentially spurred by climate change–are at play, and catastrophic weather events could become the new normal in urban America, to the extent that they haven’t always been. Some metros are particularly ill-equipped to handle this—Houston is abnormally flat, New Orleans is below sea level, and Miami’s soil is particularly hostile to funneling away water. But no city is immune.

If there is one macro-level land-use question that emerges from it–beyond the minutiae that different journalists are dwelling on–it is whether America should continue building near vulnerable coastal areas. It would be hard to answer no, because of how centered our economy is around the coasts. 13 of America’s 20 largest metro areas by GDP sit along one of the 3 major coastlines. As long as people depend on these metros for their livelihoods, it is impractical to stop housing growth. The key will be building it alongside infrastructure that can mitigate the risks of weather dramas that seem increasingly inevitable.

[This article was originally published by Forbes.]