For North America, groundwater is an important source of drinking and irrigation water. In the United States, even 60% of all water used for irrigation purposes comes from groundwater resources.
This dependency on groundwater, however, comes with its risks as well. Longer periods of extreme droughts, combined with an increasing demand for water, can lead to overexploitation and eventuelly depletion of aquifers. A recent example is the California drought affecting the High Plains aquifer and the California Central Valley Aquifer.