The water table is the top of the saturated zone in an unconfined aquifer, where water pressure equals atmospheric pressure.
The water table is the level below which the ground is saturated in an unconfined aquifer. At this level the water pressure equals atmospheric pressure. In practice it is the level at which water stands in a shallow well that is open to the aquifer. The water table is not flat. It usually follows a smoothed version of the land surface, higher under hills and lower near valleys. Groundwater flows from high points to low points and often comes out as baseflow into rivers, or as springs and wetlands where the water table meets the ground. The level rises with recharge and falls with pumping, plant use and natural discharge. In monsoon climates it often swings by several metres between the dry and wet seasons, so levels from before and after the monsoon are compared to judge the state of an aquifer. India's Central Ground Water Board measures its monitoring wells four times a year for this reason. A long-term fall across several years, rather than a seasonal drop, is the usual sign that pumping is greater than recharge.