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 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 mid-morning 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.

The family had a small stockpile of water intended to get them through summer heat blackouts, but not nearly enough for what turned out to be a five-day ordeal. On Wednesday, they decided to fill their bathtub with snow to use for flushing the toilet. To replenish their drinkable supply, they melted snow in the slow cooker and on their grill, boiling the meltwater and then running it through a coffee filter to get rid of impurities. “We kind of had our own little water treatment plant in the kitchen,’’ Fuller recalled. But the process was laborious. The snow was powdery and didn’t yield much liquid. Filling just one water jug could take three or four hours.

The Fullers’ experience is far from an aberration. By last Wednesday, the Texas Commission on Environmental Quality was reporting that 332 local water systems were affected by the storms, meaning that 7 million Texans either had no service or were receiving possibly contaminated water. Those numbers don’t include the countless others whose water supply is fine but whose pipes burst in the freeze. Drinking water supplies were also knocked offline in Ohio.

“We had a statewide failure of water infrastructure,” said Sharlene Leurig, chief executive officer of Texas Water Trade in Austin, calling the deep freeze “a huge wake-up call.” “It’s not just a hurricane, drought, flood, or cold temperature problem,” she said. “We have a resilience problem.”

This is far from the first extreme weather event in the U.S. to affect drinking water access. Hurricane Katrina affected the drinking water supply of millions across Louisiana and Mississippi; some New Orleans residents were instructed to boil their water for over a year after the storm to ensure that it would be safe to drink. Hurricane Maria compromised water for 2.3 million people when it struck Puerto Rico in 2017. The wildfires that torched California in recent summers spewed toxic ash that settled in the water supply, leading to concerns about contamination.

The is also far from a U.S. phenomenon. As the world warms, cities including Cape Town, South Africa and La Paz, Bolivia have had to ration water as extended droughts depleted their water supplies. In low-lying areas of Bangladesh, meanwhile, sea level rise threatens to inundate agricultural lands and groundwater reservoirs.