The release of water from artesian storage differs significantly from the way water is released in an unconfined aquifer. This type of well is referred to simply as an artesian well. Of the artesian aquifer, but below the land surface. More commonly, the potentiometric surface is above the top In the early development of some artesian basins, the potentiometric surface was above the land surface giving rise to a flowing artesian well. Surface, which is found in some literature. The term potentiometric surface means head- or potential-indicating surface and is preferable to the term piezometric The potentiometric surface is an imaginary surface above the aquifer, to which water from an artesian aquifer would rise in a pipe. Gravity drainage and not affect the artesian aquifer if the confining bed between them has negligible permeability. A well that taps an unconfined aquifer above a confined aquifer can dewater the former by Confining beds vary in permeability and, hence, in their ability to confine artesian aquifers.Ī major difference from the unconfined aquifer is that when an artesian aquifer is pumped, there is no dewatering of the saturated zone by gravity discharge. When such zones are penetrated by wells, the water rises above the point at which it was first found because a confinedĪquifer is under pressure exceeding that of atmospheric pressure. Groundwater separated from atmospheric pressure by relatively impermeable material is termed confined groundwater.

Drawdown groundwater meaning