Groundwater that accumulates over an impervious soil layer from rainfall or other sources that finds release on bluff faces. Perched water is released on bluff faces as seeps or springs.

Zone of unpressurized water held above the water table by impermeable rock or sediment.

Unconfined groundwater held above the water table by a layer of impermeable rock or sediment

a localized zone of water which sits on top of an aquitard. A perched zone is typically unconfined and at a higher elevation than the regional aquifer system. Unsaturated conditions exist below a perched unit.

Ground water located above the level of the water table and separated from it by a zone of impermeable material.

smaller volumes of groundwater trapped between layers of porous and less porous material