Cretaceous volcanic ash from eruptions in the Big Bend area.
Financial help is on the way. Texas has been allocated approximately $2.5 billion in federal funding earmarked for water infrastructure through the Infrastructure Investment and Jobs Act. And the state also allocated more than $2 billion to increase water supplies, fix failing infrastructure and prevent flooding. One billion of that will go toward the New Water Supply for Texas Fund and the Texas Water Fund if voters approve the idea in the fall election.
https://www.texastribune.org/2023/08/30/west-texas-water-residents-utlity/