Water withdrawals in the United States during 1985 were estimated to average 399,000 million gallons per day (Mgal/d) of freshwater and saline water for offstream uses--10 percent less than the 1980 estimate. Average per-capita use for all offstream uses was 1,650 gallons per day (gal/d) of freshwater and saline water combined and 1,400 gal/d of freshwater alone.
Offstream water-use categories are classified in this report as public supply, domestic, commercial, irrigation, livestock, industrial, mining, and thermoelectric power. During 1985, public-supply withdrawals were estimated to be 36,500 Mgal/d, and self-supplied withdrawals were estimated as follows: domestic, 3,320 Mgal/d: commercial, 1,230 Mgal/d; irrigation, 137,000 Mgal/d: livestock, 4,470 Mgal/d; industrial, 25,800 Mgal/d; mining, 3,440 Mgal/d; and thermoelectric power, 187,000 Mgal/d.
Water use for hydroelectric power generation, the only instream use compiled in this report, was estimated to be 3,050,000 Mgal/d during 1985, or 7 percent less than during 1980. This is in contrast to an increasing trend that persisted from 1950 to 1980.
Estimates of withdrawals by source indicate that, during 1985, total surface-water withdrawals were 325,000 Mgal/d, or 10 percent less than during 1980, and total ground-water withdrawals were 74,000 Mgal/d, or 12 percent less than during 1980. Total saline-water withdrawals during 1985 were 60,300 Mgal/d, or 16 percent less than during 1980; most was saline surface water. Reclaimed sewage averaged about 579 Mgal/d during 1985, or 22 percent more than during 1980.
Total freshwater consumptive use was estimated to be 92,300 Mgal/d during 1985, or 9 percent less than during 1980. Consumptive use by irrigation accounted for the largest part of consumptive use during 1985 and was estimated to be 73,800 Mgal/d.
A comparison of total withdrawals (fresh and saline) by State indicates that 37 States and Puerto Rico had less water withdrawn for offstream uses during 1985 than during 1980. California accounted for the most water withdrawn for offstream use, 49,700 Mgal/d, more than double the water withdrawn in either Texas or Idaho, the next largest users. A similar comparison by water-resources regions indicates that the California and the South Atlantic-Gulf regions accounted for nearly one-quarter of the total water withdrawn in the United States. Total withdrawals for offstream use in the eastern water-resources regions, which include the Mississippi and Souris Rivers, accounted for 53 percent of the Nation's total withdrawals, compared to 55 percent during 1980. Freshwater consumptive use in the East was about 11 percent of the freshwater withdrawn in the East and accounted for only 21 percent of the Nation's total freshwater consumptive use. By comparison, freshwater consumptive use in the West was about 41 percent of the freshwater withdrawn in the West.
The 1985 estimates of total water withdrawals and consumptive use were less than the 1980 estimates; this apparently further confirms a general trend indicated by a slackening in the rate of increase of total withdrawals from 1970 to 1975 and again from 1975 to 1980. Public-supply withdrawals during 1985 were 7 percent more than during 1980,
self-supplied domestic withdrawals were 4 percent less, irrigation withdrawals were 6
percent less, livestock withdrawals were 108 percent more, and thermoelectric power
Withdrawals were 13 percent less. The combined total for self-supplied industrial, commercial, and mining withdrawals (excluding thermoelectric power) was 30,500 Mgal/d
during 1985, or 33 percent less than withdrawals listed for 'other' industries during
1980, which also included commercial and mining uses.