One day last month, water in the community of Teviston, about 66 miles south of Fresno, suddenly stopped flowing.

The town’s services office fielded calls from residents who said their taps ran dry, and when city leaders opened their own faucets, nothing came out. Soon, officials realized  that the town’s main well had stopped working.

Crews sent a video camera below the ground to investigate what might have happened. Frank Galaviz, 77, said dirt and debris was discovered in the pumps.