How the USGS Measures Groundwater

Find out more about how the USGS measures groundwater levels.

The USGS collects data about the country's water resources including the quantity and quality of water in our streams, rivers, groundwater, and more.

As a non-existent proverb states: "Humans don't live by surface water alone." For thousands of years, people have also relied on groundwater to serve their every need. Groundwater is invaluable for many uses, from irrigation to drinking-water supply. But, you can't see groundwater, so how do water scientists know where it is in order to be able to drill wells and pump it out for use?

Groundwater is a valuable resource both in the United States and throughout the world. Groundwater depletion, a term often defined as long-term water-level declines caused by sustained groundwater pumping, is a key issue associated with groundwater use. Many areas of the United States are experiencing groundwater depletion.