This is about gas, not water, and not about dowsing. But it does have to do with little clues that humans can miss: The house next to me had a gas leak out by

This is about gas, not water, and not about dowsing. But it does have to do with little clues that humans can miss: The house next to me had a gas leak out by the street (or thought they did). PG&E came and cut down the tree, claiming that the roots had damaged the gas line. They ground up half the stump. Months elapsed. The leak was still there. They came back, dug a really deep hole, and still didn't find it. So they moved a little towards my house, and found that the pipe had just aged and sprung a leak. Eventually I'll get all new pipes to my house. Here's the "dowsing" part: I told the workers that they should just inject some bacon grease upstream from the leak, and my dog would find it by smell. They said that there actually are dogs who are trained to detect gas leaks. Why they didn't use one here, I have no idea. Anyhow, I would bet that dogs can be trained to detect underground water, too. Postscript: they did replace the tree, eventually.