How is groundwater formed?

Groundwater is formed in one of several ways. It can trickle down through the sand and rock from the rain and other types of precipitation. Groundwater can also come from underground streams or rivers or even from the aquifer that is located beneath the rocks under the ground. This water has existed from the beginning of time and moves through a cycle. It evaporates, becomes rain, falls back to the Earth, and then continues into the ground.