At first, Amanda Fuller thought she was one of the lucky ones. Then the water stopped running.

As Texas started dipping into single-digit temperatures overnight on Sunday, power companies began instituting blackouts across the state, but Fuller’s home just outside Austin stayed warm and bright. On Monday, though, as she was fixing a midmorning snack for her two children, ages one and six, the water from the tap suddenly “went to a trickle within a few seconds and was gone”, she said. It turned out the freeze had caused several water mains to break and disrupted power to the city’s primary water treatment plant...