What is an artesian well?

An artesian well allows water to rise to the surface that has traveled through porous rock from a higher elevation. This pumpless well seems to defy gravity because the pressure that builds up between layers of rock gets relieved when the water finds a path to the open air. For nearly a thousand years, people have drilled wells to drink such cold, filtered water that doesn't need to be hauled up from the depths. An aquifer provides the water source for an artesian well. An aquifer is the layer of permeable rock, like limestone or sandstone, that absorbs water from an inlet path at high elevation such as the top of a mountain. The water source might be fed by snowmelt or precipitation. Porous stone is sandwiched between a top and bottom layer of an impermeable substance like clay soil or shale rock. This keeps the water pressure high, so that when you get to a point below the entryway of the flow, there is enough pressure to bring the water up. Natural springs form in the same way ...  more

In an artesian well, water rises from the ground on its own, without need of a pump. The name comes from Artois, an area of France where this kind of well was first used. The Latin name for this region was Artesium. Rainwater that soaks into the ground sinks into the earth until it reaches a layer of soft rock or sand. The water in this layer is under pressure from the rock layers above it. So when a shaft is dug to the water-bearing layer, the water gushes up through the shaft to the surface, and can be used for drinking water.  more