Artesian well

A well taps a confined aquifer where groundwater pressure raises water above the aquifer’s upper boundary. If water reaches the land surface without pumping, the well is flowing artesian.

Confined aquifer: An aquifer bounded above, and often below, by layers that greatly restrict groundwater flow. Its confining layers help maintain the pressure that lifts water in an artesian well.
Groundwater: Water stored beneath Earth’s surface in saturated soil and rock. Artesian wells draw groundwater from a pressurized subsurface reservoir.
Groundwater pumping: The removal of groundwater from an aquifer using wells or other extraction systems. Pumping can lower pressure and reduce flow from artesian wells.
Water well: A well constructed to obtain groundwater for domestic, agricultural, industrial, or public use. Artesian wells are one type within the broader class of water wells.
Great Artesian Basin: A vast groundwater basin beneath much of arid and semiarid Australia, containing numerous confined aquifers. Its many flowing bores made artesian groundwater a major water source across inland Australia.
Hydraulic head: The elevation to which water rises in a well or piezometer, representing groundwater’s mechanical energy per unit weight. The hydraulic head sets the level water reaches in the well.
Aquifer: A body of permeable rock or sediment that stores and transmits groundwater. The well must intersect an aquifer for groundwater to enter it.
Groundwater depletion: A sustained decline in groundwater storage caused when withdrawals exceed replenishment. Heavy withdrawals from a confined aquifer can diminish artesian pressure.
Dug well: A shallow, wide well excavated into ground to reach groundwater, often above the water table. A dug well generally draws from an unconfined aquifer rather than a pressurized confined one.
Floridan aquifer system: A carbonate-rock aquifer system extending beneath Florida and parts of neighboring southeastern states. Confined portions support artesian wells and springs across the region.

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