Water dowsing has been practiced for centuries.

"Water dowsing" refers in general to the practice of using a forked stick, rod, pendulum, or similar device to locate underground water, minerals, or other hidden or lost substances, and has been a subject of discussion and controversy for hundreds, if not thousands, of years. 

Some water exists under the Earth's surface almost everywhere. This explains why many dowsers appear to be successful. To locate groundwater accurately, however, as to depth, quantity, and quality, a number of scientific techniques must be used.