How does a water diviner know that there is water underneath the ground at a paraticular spot?

Answer 1

they look at the vegetation... some trees/plants need water at a specific depth to survive.
They also look at the altitude, the geology of the place, the kind of rocks they're walking on... that kind of thing.

the rest (the stick trick) is just for show.

(And if they want to be sure, they use ecography to know precisely where the water is. That kind of technology is also used to find oil or almost any kind of mineral you might want)

Answer 2

I believe that the theory behind the divining rod is that there is a disruption in the earth's magnetic force where there are pools of water underground. I have seen the "trick" done and it does work. How big the source of water is would be questionable. It works the same way if you walk around the base of a tree, you can tell where the major root system of the tree is. Anywhere the earth is changed or moved the divining rod will cross. Kinda neat.

Answer 3

Six so-called water diviners were tested by James
Randi, a professional magician who offers a million
dollars to anyone who can demonstrate any ESP
ability. They all failed. Not only that, no two of
them agreed with each other when they were all
going over the same ground.

In many places in the world one will find water any
place he drills, if he goes deep enough. There are
places where you could not avoid striking water if
you didn't want to.

Answer 4

There is water under every ground. If not trees won't grow.

Answer 5

Here is a site with that information about water and lots more.

Answer 6

By using a divining rod, a "Y-shaped" stick.