The Water Cycle, from USGS Water Science for Schools

The Water Cycle

Water-Cycle
Diagrams and Summaries

Our water-cycle diagram (about 150 kilobytes) is available in many languages. Text summaries are also available for some languages.

Earth's water is always in movement, and the water cycle, also known as the hydrologic cycle, describes the continuous movement of water on, above, and below the surface of the Earth. Although the balance of water on Earth remains fairly constant over time, individual water molecules can come and go in a hurry. Since the water cycle is truly a "cycle," there is no beginning or end. Water can change states among liquid, vapor, and ice at various places in the water cycle, with these processes happening in the blink of an eye and over millions of years.

To explore the water cycle, choose a topic from the diagram or text links below.

A summary of the water cycle on a single Web page is also available:
Complete summary • Text only • Quick summary

The Water Cycle: graphic showing the movement of water through the water cycle.

Streamflow    Surface runoff    Freshwater storage    Infiltration
Groundwater discharge    Groundwater storage    Precipitation    Springs
Water in the atmosphere    Evaporation    Evapotranspiration
Condensation    Sublimation    Ice and snow    Oceans    Snowmelt runoff

Printing options: A print-friendly image of the diagram is available.

Teachers:
A version of the diagram without text | a diagram where you have to place the terms is available.
The National Oceanic and Atmospheric Administration (NOAA) has a water-cycle game that teachers can use to have their students get actively involved in simulating the journey water molecules may take as they travel within the water cycle.

Follow a drop through the water cycle.

Where do YOU think the water cycle begins? Give us your opinion.

A place mat showing the water cycle—great for kids.

Water-cycle home

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