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U.S. Geological Survey Fact Sheet 2018–3035, June 2018. By Molly A. Maupin.
Key points
- Total withdrawals in 2015 were 322 billion gallons a day — 9 percent less than in 2010 (354), continuing a decline since 2005.
- Since 2010 the population grew 4 percent while domestic use fell 3 percent, cutting per-person use to 82 gallons a day.
- Thermoelectric power, irrigation and public supply took 90 percent of all withdrawals.
- Consumptive use was 62 percent of irrigation water and 3 percent of thermoelectric water.
What changed since 2010
- The drop came mainly from thermoelectric power, down 28.8 billion gallons a day — 89 percent of the total decrease.
- Withdrawals fell in every category except irrigation (up 2 percent), mining (up 1 percent) and livestock (unchanged).
- Fresh surface water (198 billion gallons a day) fell 14 percent; fresh groundwater (82.3) rose about 8 percent. Saline surface water (38.6) fell 14 percent; saline groundwater (2.34) rose 5 percent.
- The population reached 325 million, up 12.4 million — a similar rise to 2005–10.
- For the first time since 1995, consumptive use for irrigation and thermoelectric power was reported: 73.2 and 4.31 billion gallons a day.
Where the water goes
Withdrawals by category and state in 2015, west to east, in million gallons a day. USGS.
Arranged from west to east, the states show a clear pattern: thermoelectric power dominates in the East, irrigation in the West, and public supply is largest where the big cities are.
| Use | Share of withdrawals | Details |
|---|---|---|
| Thermoelectric power | 41 percent (133 billion gallons a day) | almost all surface water, 72 percent of it fresh; plants with once-through cooling took 96 percent. More than a quarter of withdrawals and production were in Texas, Florida, Illinois and Michigan |
| Irrigation | 37 percent (118) | 42 percent of all fresh water withdrawn; about 52 percent from surface water; sprinkler or micro-irrigation on 63 percent of irrigated land; the 17 conterminous western states took 81 percent of irrigation water and had 74 percent of irrigated land |
| Public supply | about 12 percent (39.0) | 61 percent from surface water; systems serve homes, industry, businesses and others, and about 60 percent of it served 87 percent of Americans (283 million) at home |
| Self-supplied industry | almost 5 percent (14.8) | 82 percent surface water |
| Livestock and aquaculture | 3 percent together | livestock 2.00 billion gallons a day, 62 percent groundwater; aquaculture 7.55, 79 percent surface water |
| Self-supplied homes | about 1 percent (3.26) | wells and other sources for about 13 percent of Americans (42.5 million); 98 percent groundwater |
| Mining | about 1 percent (4.00) | 72 percent groundwater, mostly (65 percent) saline |
Trends since 1950
The USGS has compiled U.S. water use every five years since 1950, with state, federal and local agencies.
- Total withdrawals rose from 180 billion gallons a day in 1950 to a peak of 430 in 1980, dipped to 397 in 1985, held steady to 410 in 2005, then fell sharply to 354 in 2010 and 322 in 2015 — below 1970 and about the same as 1965 (310).
- Thermoelectric withdrawals rose to 1980, wavered to 2005, and have since fallen sharply as plants became more efficient and once-through cooling plants closed.
- Irrigation peaked in 1980 (150), held steady to 2005 (127), dipped in 2010 (116) and rose slightly in 2015 (118). Efficiency keeps improving: 10 percent more irrigated land used sprinklers or micro-irrigation in 2015 than in 2010, and flood irrigation fell 11 percent.
- Public supply, despite a steadily growing population, rose from 14 in 1950 to a peak of 44.4 in 2005, fell for the first time in 2010 (42.0), and fell a further 7 percent by 2015 (39.0). Domestic use per person dropped from 88 gallons a day in 2010 to 82 in 2015.
- Industry, mining, aquaculture and livestock combined were steady from 1950 to 1985, then declined — chiefly because industrial use fell sharply between 1980 and 1985 — even though livestock, mining and aquaculture use grew.
Why it matters
These estimates, from USGS Circular 1441, Estimated use of water in the United States in 2015, and its data release, give planners what they need to allocate water and weigh environmental effects nationally, regionally and by state. They also feed the water budgets of the USGS National Water Census, part of the Water Availability and Use Science Program, which also works to improve how water use is measured and estimated.
Sources
- Maupin, M.A., 2018, Summary of estimated water use in the United States in 2015: U.S. Geological Survey Fact Sheet 2018–3035. https://doi.org/10.3133/fs20183035 · https://pubs.usgs.gov/publication/fs20183035
- Dieter, C.A., and others, 2018, Estimated use of water in the United States in 2015: U.S. Geological Survey Circular 1441.
- The chart comes from the fact sheet's PDF.
- Rewritten in hubnx's own words.
Licenza: CC0 1.0 (pubblico dominio) · Tratto da pubs.usgs.gov
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