Dean Bixler used to go golfing near the top of Brickhouse Gully, a neglected drainage canal, at a course called Pine Crest. It was near his house in west Houston, and not a bad place to play until it closed down a couple of years back. In the months after Hurricane Harvey, savoring his $30,000 floodproofing investment, including metal doors with gaskets that had kept water out of his house, Bixler heard from a neighbor that the golf course was being developed. The neighbor was concerned that the new subdivision would replace low-lying grass with roofs and roads and that the runoff would flood their neighborhood in a heavy rain. In Brooklyn or Boston, residents worry new neighbors will take their sunlight or their parking spaces. In Houston, the concern is new neighbors will bring flooding.
Bixler downloaded Federal Emergency Management Agency maps and found something strange. For the past decade, the entire course had sat in the 100-year flood plain—land, usually near bodies of water, that has been assessed as having a 1 percent chance of flooding every year. What that official designation means is both practical risk to the homeowner and, for anyone with a Federal Housing Administration mortgage, a potentially onerous requirement to buy flood insurance. In most places in the U.S., a flood plain encompasses beach houses and ribbons of properties along fast-rising rivers. In Houston, the 100-year clings to the bayous, gullies, and ditches that give the city its natural character and duck beneath the roads and lurk behind houses. On a map, the flood plain is to the bayous as foliage is to a branching tree. The maps Bixler pulled indicated that, according to government-approved estimates, Pine Crest golf course could be expected to sit beneath 2 feet of water during what would be called a 100-year storm…