USGS Releases Estimated Use of Water in the United States in 2005

Demonstrates an Overall Decrease in Water Use

2009-11-03

USGS 2005 Water Use ReportOn October 27, 2009 the US Geological Survey (USGS) released the  Estimated Use of Water in the United States in 2005   report which indicates that the estimated total amount of water withdrawn in 2005 was slightly less than estimates in 2000.   Most of the savings appear to have come from reductions in withdrawals for agricultural irrigation (8 percent less than in 2000) largely due to irrigation efficiency improvements.  Water withdrawals for public supply (the primary focus of AWE and urban water conservation professionals) increased by 2% from 2000 to 2005 although the US experienced a 5 percent increase in overall population in that time.  This suggests small but measurable overall gains in urban water use efficiency over this five year period.  The USGS releases water use estimates every five years.

Here are some key results from the Estimated Use of Water in the United States in 2005   report:

  • Freshwater withdrawals in 2005 (surface and groundwater) accounted for 85 percent of the total withdrawals with the remaining 15 percent coming from saline sources.
  • Fresh groundwater withdrawals in 2005 were about 5 percent less than in 2000.
  • Fresh surface-water withdrawals were about the same as in 2000.
  • Withdrawals for public-supply and domestic uses (urban and municipal water supply) have increased steadily since estimates began, but at a slower rate than the increase in population.
  • Thermoelectric-power generation water withdrawals were about 3 percent more than in 2000.  Nearly all of the water withdrawn for thermoelectric power was surface water used for once-through cooling at power plants, but 29 percent of thermoelectric-power withdrawals were saline water from oceans and brackish coastal water bodies. 
  • Irrigation withdrawals in 2005 were about 8 percent less than in 2000 and approximately equal to estimates of irrigation water use in 1970.
  • Irrigated acreage increased from 25 million acres in 1950 to 58 million acres in 1980, then increased in 2000 and 2005 to more than 60 million acres. The number of acres irrigated using sprinkler and microirrigation systems has continued to increase and in 2005 accounted for 56 percent of the total irrigated acreage.

According to the report, irrigation water use includes water that is applied by an irrigation system to sustain plant growth in all agricultural and horticultural practices and also includes self supplied landscape irrigation uses such as golf courses, parks, nurseries, turf farms, cemeteries, etc.  Irrigation water use also includes self-supplied withdrawals and deliveries from irrigation companies, irrigation districts, cooperatives, or governmental entities.

The report found that self-supplied industrial water withdrawals continued to decline in 2005, as they have since their peak in 1970. Self-supplied industrial withdrawals decreased by an estimated 30-percent from 1985. Withdrawals for mining were 11 percent less than in 2000, and 18 percent less than in 1990.

Livestock water use was the smallest estimate since 1975, possibly due to the use of standardized coefficients for estimation of animal water needs. Water use for aquaculture was estimated to be nearly four times the amount withdrawn in 1985.

Water Use Trends

USGS-2005-water-use-trends-1The chart at left (reprinted from Figure 13 in the 2005 USGS report) shows estimated fresh water withdrawals in the U.S. from 1950 - 2005 on the first y-axis and US population on the second y-axis.  Freshwater withdrawals in the US peaked in 1980 then declined significantly in 1985 and have held essentially constant even though population has steadily increased.  Over the past five years, surface water withdrawals have increased slightly while groundwater withdrawals declined.  

Freshwater withdrawals in the US in 2005 are approximately the same as what they were in 1975 - 30 years ago.

USGS-2005-water-use-trends-2The second chart at left (reprinted from Figure 14 in the 2005 USGS report) shows the total water withdrawals from 1950 - 2005 by key categories.  Here it can be seen that reductions in the water withdrawals for thermoelectric power, agricultural irrigation, and "other" uses are largely responsible for the changes in demand estimated since 1980.  Public supply water withdrawals have steadily increased since 1950, but at a slower rate of growth than the population indicating an increase in water use efficiency.

The full report from the USGS provides significant detail on how these estimates were prepared, the components of each category, and key assumptions in the analysis.  Below is a list of links to resources regarding the USGS Estimated Use of Water in the United States in 2005.