Water Q&A: How important is groundwater?

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Learn how important groundwater is to some communities.

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How important is groundwater?

Water Questions and Answers

Groundwater, which is in aquifers below the surface of the Earth, is one of the Nation's most important natural resources. Groundwater is the source of about 33 percent of the water that county and city water departments supply to households and businesses (public supply). It provides drinking water for more than 90 percent of the rural population who do not get their water delivered to them from a county/city water department or private water company. Even some major cities, such as San Antonio, Texas, rely solely on groundwater for all their needs. In 2015, about 48 percent of the water used for irrigation comes from groundwater. Withdrawals of groundwater are expected to rise as the population increases and available sites for surface reservoirs become more limited.

About 29 percent of the freshwater used in the United States in 2015 came from groundwater sources. The other 71 percent came from surface water. Groundwater is an especially important natural resource in those parts of the country that don't have ample surface-water sources, such as the arid West. It often takes more work and costs more to access groundwater as opposed to surface water, but where there is little water on the land surface, groundwater can supply the water needs of people.