When an artesian well begins to push out enough water that gravity causes it to flow to a lower region, the water forms a flowing artesian well. A flowing artesian well occurs when the pressure from the confined aquifer is great enough to force water up the well casing and out onto the land surface. This can happen when the aquifer is recharged by a higher elevation source, such as a mountain range, or when the aquifer is confined by a relatively impermeable layer of rock or sediment. Flowing artesian wells are often used as a source of water for irrigation, drinking, and other purposes.