Despite a 30 percent population increase during the past 25 years, overall water use has remained fairly stable, according to a new U.S. Geological Survey (USGS) report.
The United States is using less
water than during the peak years of 1975 and 1980, according to water-use
estimates for 2005. The report shows that in 2005 Americans used 410 billion
gallons per day, slightly less than in 2000. The declines are attributed to the
increased use of more efficient irrigation systems and alternative technologies
at power plants. Water withdrawals for public supply have increased steadily
since 1950 – when USGS began the series of 5-year trend reports – along with
the population that depends on these supplies.
Nearly half (49 percent) of
the 410 billion gallons per day used by Americans was for producing electricity
at thermoelectric power plants. Irrigation accounted for 31 percent and public
supply 11 percent of the total. The remaining 9 percent of the water was for
self-supplied industrial, livestock, aquaculture, mining and rural domestic
generation and irrigation together accounted for a massive 80 percent of our
water use in 2005, the improvements in efficiency and technology give us hope
for the future,” Castle says. “The report also underscores the importance of
recognizing the limits of the drinking water supplies on which our growing
population depends. While public-supply withdrawals have continued to increase
overall, per capita use has decreased in many States during recent decades.
The water-use estimates are
broken down by state, source and category of water use. California, for
example, is one of four states – joining Texas, Idaho and Florida – that
accounted for more than one-fourth of all fresh and saline water withdrawn in
the United States in 2005.
The largest uses of fresh
surface water were power generation and irrigation, and the states with the
largest fresh surface water uses were California, Texas, Idaho and Illinois.
The largest use of fresh ground water was irrigation, and the states with the
largest fresh ground water uses were California, Texas, Nebraska and Arkansas.
The majority of irrigation withdrawals and irrigated acres are in the western states,
but significant increases in irrigation have occurred in some southeastern states.
Irrigation application rates have decreased steadily from 1950 to 2005, and this
decline is attributable to the increased use of more efficient irrigation
The full report is available at http://pubs.usgs.gov/circ/1344.
United States Using Less Water than 35 Years Ago
November 3, 2009