In April, Harris County experienced a historic series of storms; some areas were hit by more than sixteen inches of rain in a twelve-hour period. That downpour slid off the city’s roads, buildings, and tight clay soils and overwhelmed the bayous, inundating nearly 10,000 residences, killing eight people, and prompting a presidential disaster declaration. Any town would be stressed by such a storm, but Houston has become more vulnerable due to the paving and groundwater use that has come with rapid sprawl.