Irrigation water use
Throughout the world, irrigation (water for agriculture,
or growing crops) is probably the most important use of water (except for
drinking and filling up swimming pools, perhaps). Almost 60 percent of all the
world's fresh water withdrawals go towards irrigation uses. Large-scale
farming could not provide food for the world's large populations
without the irrigation of crop fields by water gotten from
rivers, lakes, reservoirs, and wells. Without irrigation, crops
could never be grown in the deserts of California, Israel, or my
tomato patch.
This photograph shows farmland in Idaho being irrigated by a large spray-irrigation system. Picture was taken by Terry R. Maret. |
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When we use water in our home, or when an industry uses water, about
90 percent of the water used is eventually returned to the environment
where it replenishes water sources (water goes back into a
stream or down into the ground) and can be used for other
purposes. But of the water used for irrigation, only about one-half is
reusable. The rest is lost by evaporation
into the air, transpiration from plants, or is
lost in transit, by a leaking pipe, for example.
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| A lot of the crops in the U.S. are grown in areas that don't get a lot of
rainfall, which means that water for irrigation is a valuable and scarce
resource in many places. Since water is money nowadays, you can see
why farmers are always looking for more efficient ways to use
irrigation water. Look at our related topics listed below to see how
farmers traditionally irrigate, and how they are using newer and more
efficient methods.
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Water use
Water Science home pageUSGS home page
USGS Water Resources home pageThe URL for this page is http://ga.water.usgs.gov/edu/wuir.html Comments? Contact Howard Perlman Last Modified: Mar 17, 2004 |
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