Water Science School

Groundwater

Groundwater is one of our most valuable resources—even though you probably never see it or even realize it is there. There is water somewhere beneath your feet no matter where on Earth you live. Groundwater starts as precipitation, just as surface water does, and once water penetrates the ground, it continues moving, sometimes quickly and sometimes very slowly. Eventually groundwater emerges back to the surface and continues to participate in the global water cycle.

All Groundwater Science Topics

All Groundwater Science Topics

View a list of all of our science topics about groundwater.

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Groundwater and the water cycle

Groundwater and the water cycle

Large amounts of water are stored in the ground. The water is still moving, possibly very slowly, and it is a part of the water cycle.

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Filter Total Items: 34
Date published: December 3, 2018
Status: Completed

Base Flow in Rivers

When a drought hits and little or no rain has fallen in a long time, you might expect small streams and even larger rivers to just dry up, right? In many cases, they don't. Streamflow might lessen to a trickle or so, but water continues to flow. How is that possible? Read on to find out how "base flow", which is water seeping into the stream from groundwater, helps keep water in streams during...

Contacts: Ask USGS
Date published: November 8, 2018
Status: Completed

Groundwater True/False Quiz

How much do you know about the water below your feet? Take our Groundwater True/False Quiz and find out.

Contacts: Ask USGS
Date published: November 6, 2018
Status: Completed

Groundwater: What is Groundwater?

There is an immense amount of water in aquifers below the earth's surface. In fact, there is a over a thousand times more water in the ground than is in all the world's rivers and lakes. Here we introduce you to the basics about groundwater.

Contacts: Ask USGS
Date published: October 26, 2018
Status: Completed

Water Science Activity Center

This is the interactive section of our site where you can answer challenge questions, participate in opinion surveys about water issues, and take true/false quizzes.

Contacts: Ask USGS
Date published: October 10, 2018
Status: Completed

Groundwater Photo Gallery

Learn about groundwater using pictures.

Contacts: Ask USGS
Date published: August 9, 2018
Status: Completed

Water Properties True/False Quiz

How much do you know about water properties? Take our Water Properties True/False Quiz and find out.

Contacts: Ask USGS
Date published: June 28, 2018
Status: Completed

Groundwater Flow and the Water Cycle

Yes, water below your feet is moving all the time, but, no, if you have heard there are rivers flowing below ground, that is not true. Water moves underground downward and sideways, in great quantities, due to gravity and pressure. Eventually it emerges back to the land surface, into rivers, and into the oceans to keep the water cycle going.

Note: This section of the Water Science...

Contacts: Ask USGS
Date published: June 18, 2018
Status: Completed

Groundwater Storage and the Water Cycle

The ground stores huge amounts of water and it exists to some degree no matter where on Earth you are. Lucky for people, in many places the water exists in quantities and at depths that wells can be drilled into the water-bearing aquifers and withdrawn to server the many needs people have.

Note: This section of the Water Science School discusses the Earth's "natural" water cycle...

Contacts: Ask USGS
Date published: June 18, 2018
Status: Completed

Groundwater Use in the United States

Groundwater is one of our most valuable resource—even though you probably never see it or even realize it is there. Groundwater is essential for irrigation and human use in many parts of the country. The use of groundwater in the United States in 2015 is described below.

Contacts: Ask USGS
Date published: June 11, 2018
Status: Completed

How Do Hydrologists Locate Groundwater?

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...

Contacts: Ask USGS
Date published: June 11, 2018
Status: Completed

Groundwater Flows Underground

Millions of cubic miles of water exists in the ground. You can't see it, but not only is it there, it is always moving around -- mostly downward, but also horizontally. Moving groundwater helps keep rivers full of water and allows for people to draw out water via wells. Moving groundwater is an important part of the water cycle.

Contacts: Ask USGS
Date published: June 9, 2018
Status: Completed

Sinkholes

It is a frightening thought to imagine the ground below your feet or house suddenly collapsing and forming a big hole in the ground. Sinkholes rarely happen, but when they strike, tragedy can occur. Sinkholes happen when the ground below the land surface cannot support the land surface. They happen for many reasons; read on to educate yourself about sinkholes.

Contacts: Ask USGS