What is Groundwater?

Groundwater is the water found underground in cracks and spaces in soil particles and rocks.

The area where water fills these spaces is called the "saturated zone" and the top of this zone is called the "water table." The water table may be one foot or hundreds of feet below the surface of the ground.

Groundwater has been around for a very long time, but only in recent decades have scientists been able to determine how much groundwater there is on the earth. We now know that groundwater is the largest source of fresh water available for use on the planet.

Groundwater is stored in, and moves slowly through layers of rock or sediment called "aquifers." Water in aquifers is brought to the surface through springs, discharged into streams or by a well drilled into the aquifer.

Groundwater supplies are replenished through rain and snow melt, but in some areas of the world, people face serious shortages because groundwater is used faster than it can be naturally replenished.