Five reasons Houston is especially vulnerable to flooding

As many cities in the South and along the Atlantic and Gulf coasts have grown in recent decades, they have also become much more prone to flooding. Now, as Hurricane Harvey bears down on Texas’ Gulf Coast, Houston’s vulnerability is highlighted, as the city’s 800 miles of creeks and bayous—and its burgeoning developments—make storms a particular threat.

Houston’s geography makes rising waters particularly dangerous

The city is low-lying and most of the soil is clay, which drains poorly, said Samuel Brody, director of the Texas A&M University’s Institute for Sustainable Coastal Communities in Galveston. That is in contrast to Miami which has sandy, porous soils. In Houston, “the underlying physical conditions play a role in exacerbating the impacts of floods,” Mr. Brody said.

A recent construction boom has impeded drainage

Large-scale developments—such as apartment and office complexes, shopping malls and roads—have added vast stretches of pavement to the Houston area. These expanses of concrete and asphalt inhibit drainage and worsen flooding, as, when heavy downpours hit, the rain flows into other neighborhoods rather than into the soil.

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