November 3, 2009
A
report from the U.S. Department of the Interior reveals the United States
is using less water than during the peak years of 1975 and 1980. Water use
estimates for 2005 show that 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 report.
The
announcement was made by Assistant Secretary of the Interior Anne
Castle, who presented the report, “Estimated Use of Water in the
United States in 2005,” as part of her keynote speech at the Atlantic Water
Summit in the National Press Club.
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
five-year trend reports, along with the population that depends on these
supplies.
“The
importance of this type of data to the American public cannot be exaggerated,”
said Castle. “The Department of the Interior provides the nation with the best
source of information about national and regional trends in water withdrawals.
This information is invaluable in ensuring future water supplies and finding
new technologies and efficiencies to conserve water.”
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 uses.
“Because
electricity 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 said. “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.
“These are just a few examples of why, if we want to
understand and address the nation’s current water issues and prepare to answer
future water questions, we need the data provided in this report,” Castle
noted.
The
series of reports provides information 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. More than half (53
percent) of the total withdrawals of 45,700 Mgal/d in California were for irrigation, and 28
percent were for thermoelectric power.
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 groundwater was irrigation, and the states with the
largest fresh groundwater 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. This decline is attributable to the increased use of more
efficient irrigation systems.
The full
report is available at http://pubs.usgs.gov/circ/1344.
Additional water use information is available at http://water.usgs.gov/watuse/.
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