What forms an artesian well?

An artesian well forms when water becomes trapped between two impermeable layers of rock. The pressure from the trapped water forces the water to rise up through a borehole that has been drilled into the ground. The water in an artesian well typically comes from an aquifer, which is a layer of porous rock or sediment that is saturated with water. Aquifers are often found deep underground, and the weight of the overlying rock creates the pressure that forces the water up through the borehole.

The term "artesian" is used to describe any well that is flowing without the use of a pump. This means that the pressure from the aquifer is enough to force the water up through the borehole. The flowing nature of artesian wells can make them a very valuable source of water, especially in areas where there is a limited supply of ground water.