A well drilled into a confined aquifer where water rises above the top of the aquifer under natural pressure.
An artesian well taps a confined aquifer — water trapped between impermeable layers and held under pressure. When the well is drilled, the pressure pushes water up the casing without a pump. A flowing artesian well actually overflows at the surface; a non-flowing artesian well rises partway up the casing. True flowing artesian conditions are uncommon in Utah but appear in pockets of Sanpete, Sevier, and Cache valleys.