Water Table

n. water level, point under surface of the ground where the ground is completely saturated with water, groundwater level

The water table or phreatic surface is the surface where the water pressure is equal to atmospheric pressure.A sustainable amount of water within a unit of sediment or rock, below the water table, in the phreatic zone is called an aquifer. The ability of the aquifer to store groundwater is dependent on the primary and secondary porosity and permeability.
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Noun
1. underground surface below which the ground is wholly saturated with water; "spring rains had raised the water table"
(synonym) water level, groundwater level
(hypernym) geological formation, formation

A molding, or other projection, in the wall of a building, to throw off the water, -- generally used in the United States for the first table above the surface of the ground (see Table, n., 9), that is, for the table at the top of the foundation and the beginning of the upper wall.
  

The level of groundwater.