In Texas, it’s called “witching,” and it works. My uncle used peach tree switches and never missed hitting water in always-dry West Texas.
It’s very common and accepted here in NC, too. Every house I’ve ever built and every house I’ve ever known to have a well dug, was “witched” beforehand. River Birch or Willow, here. Watery trees.
What’s even more interesting is to see often the same old guys witch a lost, buried power line with a copper coathanger.
I was taught to "witch" for water 60 years ago by an old man in a community very near Llano who before he retired was a medical doctor. He used a peach limb that had a fork in it. I, through trial and error, found that I could locate water, water pipes or any other source of underground water.
I still to this day cain't explain how it works but I would never drill for water unless I witched the location.
here in Indiana, we also call it witching for water. Everyone in my immediate family can do this to some extent. My dad, both of my brothers and me, our biological children, all have this ability. Some of us are stronger “watervanes” (that would be the descriptive my friend made up) than others, but we can all do it. My mother could not. We use branches or just a couple of metal clothes hangers.