Water Underground
Water Underground
Groundwater is water that is stored or travels through the materials beneath the ground surface. Groundwater occupies fractures in rock and the pore space in soils between sand and gravel particles below the ground surface, as illustrated in this image.
The area between the ground surface and the area where the pores are all saturated is called the vadose zone. The saturated zone is known as the aquifer. The water table is the top of the aquifer.
Some groundwater is “fossil” water, which was trapped underground over the course of geologic time and resides in deep aquifers. Some groundwater is near the surface and must be recharged regularly to maintain its flow. The hyphoreic zone is an area where water that seeps from a river or stream mixes with adjacent groundwater. The water table along a river may rise or fall in direct relation to the surface water level in the river.
As water moves through the soil, impurities are captured by tiny clay and soil particles. The water becomes cleaner the deeper it goes. Most of New Mexico’s drinking water supplies come from groundwater. Once water is pumped from the aquifer, it may take centuries or millennia for it to be replenished naturally.
