At the third stage in the cycle, rainwater may take various paths.
Some of it may fall into lakes or return to the oceans via ‘surface runoff’.
The water cycle is the continuous movement of water in and around the Earth.
As previously mentioned, water never really goes away -- it just changes form.
But groundwater, which is the major source of our drinking water, can accumulate in aquifers over thousands of years.
Unconfined aquifers have the water table, or the surface where water pressure equals atmospheric pressure, as their upper boundaries.
Confined aquifers often lie below unconfined aquifers and have a layer of rock or other materials as their upper boundaries.
In the United States, the oldest groundwater, known as fossil water, is contained in the Ogallala Aquifer.
Because the climate of the Great Plains is arid, water in the aquifer is being used faster than it can be recharged.
That's why some scientists refer to using fossil water aquifers as water mining. Images from the Mars Global Surveyor spacecraft show what looked like gullies carved out by rivers of water on the surface of the planet.