Where is Earth's Water?

How much water is there?

How much water is there?

Earth's Water

The Water Cycle

The Water Cycle

The water cycle

Water Basics Topics

Water Basics Topics

Topics

Science Center Objects

"Water, Water, Everywhere..."  You've heard the phrase, and for water, it really is true. Earth's water is (almost) everywhere: above the Earth in the air and clouds and on the surface of the Earth in rivers, oceans, ice, plants, and in living organisms. But did you know that water is also inside the Earth? Read on to learn more.

•  Water Science School HOME  •  Water Basics topics  •  The Water Cycle  •

Where is Earth's Water?

"Water, Water, Everywhere...."
You've heard the phrase, and for water, it really is true. Earth's water is (almost) everywhere: above the Earth in the air and clouds, on the surface of the Earth in rivers, oceans, ice, plants, in living organisms, and inside the Earth in the top few miles of the ground.

For an estimated explanation of where Earth's water exists, look at this bar chart. You may know that the water cycle describes the movement of Earth's water, so realize that the chart and table below represent the presence of Earth's water at a single point in time. If you check back in a million years, no doubt these numbers will be different!

  • Left bar: All water, freshwater and saline, on, in, and above the Earth.
  • Center bar: All freshwater
  • Right bar: Only the portion of freshwater residing in surface water (rivers and lakes, etc), snow and ice, and relatively-shallow ground water.

Here is a bar chart showing where all water on, in, and above the Earth exists. The left-side bar chart shows how almost all of Earth's water is saline and is found in the oceans. Of the small amount that is actually freshwater, only a relatively small portion is available to sustain human, plant, and animal life.

Bar chart showing the distribution of water on, in, and above the Earth.

Notice how of the world's total water supply of about 332.5 million cubic miles of water, over 96 percent is saline. And, of the total freshwater, over 68 percent is locked up in ice and glaciers. Another 30 percent of freshwater is in the ground. Fresh surface-water sources, such as rivers and lakes, only constitute about 22,300 cubic miles (93,100 cubic kilometers), which is about 1/150th of one percent of total water. Yet, rivers and lakes are the sources of most of the water people use everyday. (Credit: USGS, Public domai

  • In the first bar, notice how only 2.5% of Earth's water is freshwater - the amount needed for life to survive.
  • The middle bar shows the breakdown of freshwater. Almost all of it is locked up in ice and in the ground. Only a little more than 1.2% of all freshwater is surface water, which serves most of life's needs.
  • The right bar shows the breakdown of surface freshwater. Most of this water is locked up in ice, and another 20.9% is found in lakes. Rivers make up 0.49% of surface freshwater. Although rivers account for only a small amount of freshwater, this is where humans get a large portion of their water from.

     

One estimate of global water distribution
(Percents are rounded, so will not add to 100)

Water source Water volume, in cubic miles Water volume, in cubic kilometers Percent of
freshwater
Percent of
total water
Oceans, Seas, & Bays 321,000,000 1,338,000,000 -- 96.54
Ice caps, Glaciers, & Permanent Snow 5,773,000 24,064,000 68.7 1.74
Groundwater 5,614,000 23,400,000 -- 1.69
    Fresh 2,526,000 10,530,000 30.1   0.76
    Saline 3,088,000 12,870,000 --   0.93
Soil Moisture 3,959 16,500 0.05 0.001
Ground Ice & Permafrost 71,970 300,000 0.86 0.022
Lakes 42,320 176,400 -- 0.013
    Fresh 21,830 91,000 0.26 0.007
    Saline 20,490 85,400 -- 0.006
Atmosphere 3,095 12,900 0.04 0.001
Swamp Water 2,752 11,470 0.03 0.0008
Rivers 509 2,120 0.006 0.0002
Biological Water 269 1,120 0.003 0.0001

Source: Igor Shiklomanov's chapter "World fresh water resources" in Peter H. Gleick (editor), 1993, Water in Crisis: A Guide to the World's Fresh Water Resources (Oxford University Press, New York).