What is a "water table"?

A water table is best defined as the upper surface of the saturated zone in an aquifer where groundwater fills the pores of the soil and rock. This means that beneath the water table, all the spaces in the soil and rock are filled with water, which distinguishes it from other zones, such as the unsaturated zone above it where the soil may contain both air and water.

Understanding the water table is crucial for groundwater studies because it indicates the depth to groundwater in a given area, which can vary greatly based on local geology, topography, and precipitation patterns. The water table can rise and fall with changes in rainfall, drought conditions, or human activities such as excessive groundwater pumping.

The concept is integral in various fields such as hydrology, environmental science, and land use planning, as it influences water availability for ecosystems, agriculture, and human consumption.