Trends in Water Use in the United States, 1950-1990

Rural

Water used in suburban or farm areas for domestic and livestock needs. The water is generally self supplied, and includes domestic use, drinking water for livestock, and other uses, such as dairy sanitation, evaporation from stock-watering ponds, and cleaning and waste disposal.

Public supply

Water withdrawn by public and private water suppliers and delivered to users. Public suppliers provide water for a variety of uses, such as domestic, commercial, thermoelectric power, industrial, and public water use.

Industry

Water used for industrial purposes, such as fabrication, processing, washing, and cooling, and includes such industries as steel, chemical and allied products, paper and allied products, mining, and petroleum refining.

Thermoelectric

Water used in the process of the generation of thermoelectric power. The water may be obtained from a public supply or may be self supplied.

Irrigation

Artificial application of water on lands to assist in the growing of crops and pastures or to maintain vegetative growth in recreational lands such as parks and golf courses.

• Availability of water in a particular year, especially from precipitation and streamflow, strongly affects the quantity of water use for irrigation and hydroelectric power generation.
• Streamflows generally were less plentiful during 1990 than during 1985 because of less precipitation, especially in the West; this increased the dependence on groundwater in many areas and the need to irrigate in some areas.
• Withdrawals from the groundwater system can influence the pumping lift, availability, or quality of the water. Each of these factors, in turn, can influence the cost of water and make users, especially irrigators, more selective and efficient in their use of groundwater.
• Higher energy prices, improved application techniques, increased competition for water, declines in farm commodity prices, and a downturn in the farm economy in the 1980's reduced demands for irrigation water.
• New technologies requiring less water, improved plant efficiencies, increased water recycling, higher energy prices, the economic slowdown, and changes in laws and regulations to reduce the discharge of pollutants resulted in decreased requirements for industrial water and less water being returned to the natural system after use.
• The enhanced awareness by the general public to water resources and active conservation programs in many States have reduced water demands.

Water Use in the United States, 1990

Estimates of withdrawals by source indicate that during 1990, total water withdrawals were 408 billion gallons per day. Of this amount, 327 billion gallons per day were surface-water withdrawals and about 81 billion gallons per day were groundwater withdrawals. Based on these estimates, surface-water withdrawals increased by 1 percent from 1985 to 1990, while groundwater withdrawals increased by 9 percent over the same period.