World Water Distribution

Nebraska Real-Time Groundwater Montoring Network

World Water Distribution

Groundwater is the 2nd largest available reservoir of fresh water. The diagram below shows that of the world's fresh water, the majority is locked away as ice in the polar ice caps, continental ice sheets and glaciers. Surface waters such as rivers and lakes only accounts for less that 1% of the worlds fresh water reserves whereas groundwater accounts for 12% of the worlds freshwater resources.

For a detailed explanation of where Earth's water is, look at the data table below. Notice how of the world's total water supply of about 326 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. Surface-water sources, such as rivers, only constitute about 300 cubic miles (about 1/10,000 th of one percent of total water).

World water distributution
Water source Water volume
in cubic miles
Water volume
in cubic kilometers
Percent of fresh water Percent of total water
Oceans, Seas, & Bays 321,000,000 1,338,000,000 -- 96.5
Ice caps, Glaciers, & Permanent Snow 5,773,000 24,064,000 68.7 1.74
Groundwater 5,614,000 23,400,000 -- 1.7
  Fresh 2,526,000 10,530,000 30.1 0.76
  Saline 3,088,000 12,870,000 -- 0.94
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
Total 332,500,000 1,386,000,000 - 100

Source: Gleick, P. H., 1996: Water resources. In Encyclopedia of Climate and Weather, ed. by S. H. Schneider, Oxford University Press, New York, vol. 2, pp.817-823.