Groundwater Ages The age of groundwater can span anywhere from two weeks for very local flow systems to millions of years for deep, regional flow systems. For example, a shallow flow system would constitute recharge in a small upland area followed by discharge to an immediately adjacent low-lying area.

How long can groundwater last?

Estimated depth and residence time of the worlds water supplyWaterEquivalent depth (meters)Residence TimeGroundwater120~2 weeks-10,000 yearsIce caps/Glaciers6010-1000 yearsAtmospheric water.025~10 daysBiospheric water.001~1 week5 more rows

What percentage of groundwater is less than 50 years old?

The researchers found that less than 6 percent and possibly as little as 1 percent of the groundwater is close enough to the Earths surface to be readily useful to humans for drinking and agriculture. That water is considered modern groundwater, because its less than 50 years old.

Is there underground water everywhere?

Groundwater is everywhere beneath the soil surface and can be ever-present in many places if allowed to recharge. Groundwater has been an extremely important source of water for many years, especially in arid climates.

Where is most groundwater located?

Groundwater is the water found underground in the cracks and spaces in soil, sand and rock. It is stored in and moves slowly through geologic formations of soil, sand and rocks called aquifers.