“It is naturally prone to flooding,” said Don Riley, the former chief of the Army Corps of Engineers civil works division. “People have built in this massive flood plain. They have to understand that.”
Houston is built on what amounts to a massive flood plain, pitted against the tempestuous Gulf of Mexico and routinely hammered by the biggest rainstorms in the nation.
It is a combination of malicious climate and unforgiving geology, along with a deficit of zoning and land-use controls, that scientists and engineers say leaves the nation’s fourth most populous city vulnerable to devastating floods like the one caused this week by Hurricane Harvey.
“Houston is very flat,” said Robert Gilbert, a University of Texas at Austin civil engineer who helped investigate the flooding of New Orleans after Hurricane Katrina. “There is no way for the water to drain out.”
Indeed, the city has less slope than a shower floor.
Harvey poured as much as 374 billion gallons of water within the city limits, exceeding the capacity of rivers, bayous, lakes and reservoirs. Experts said the result was predictable.
The storm was unprecedented, but the city has been deceiving itself for decades about its vulnerability to flooding, said Robert Bea, a member of the National Academy of Engineering and UC Berkeley emeritus civil engineering professor who has studied hurricane risks along the Gulf Coast.