Alabama Water Science Center
2005 WATER USE
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Water Use Trends in Alabama
Since 1950 when the U.S. Geological Survey (USGS) first conducted water-use compilations, important changes in water use have occurred in Alabama. The early part of the history (1950 to 1980) showed a steady increase in water use. During this time, the expectation was that, as the population increased, so would water use. Contrary to this expectation, reported water withdrawals declined in 1985, remained relatively stable through 1995, and are increasing again, nearing the 1980 levels. Changes in technology, in State and Federal laws, and in economic factors, along with increased awareness of the need for conservation, have resulted in more efficient use of water from the rivers, lakes, reservoirs, and ground water in Alabama. Some differences in the water withdrawal estimates over time also can be attributed to changes in data collection and methodologies used to evaluate, calculate, and estimate water use.
Water withdrawals have more than doubled in Alabama from 1960 to 2005 from about 4,220 million gallons per day (Mgal/d) to 9,958 Mgal/d. The entire increase in withdrawals actually occurred from 1960 to 1980 (4,220 Mgal/d to more than 10,350 Mgal/d), while withdrawals in subsequent years have declined somewhat, then increased slightly, but remained nearly constant from 2000 to 2005 (8,593 Mgal/d in 1985; 8,074 Mgal/d in 1990; 8,286 Mgal/d in 1995; 9,990 Mgal/d in 2000; and 9,958 Mgal/d in 2005). Population increased about 19 percent from 1960 to 1980 and increased another 17 percent from 1980 to 2005. As a result of the leveling off of withdrawals as population has increased, gross per capita use has declined. The data indicate that gross per capita water use increased from about 1,292 gallons per day (gal/d) for 1960 to a high of about 2,661 gal/d for 1980, and then decreased to about 2,185 gal/d for 2005. The change in gross per capita water use is mainly attributable to the fluctuation.
More water continues to be withdrawn for thermoelectricpower generation than for any other use. Thermoelectric-power withdrawals are large, nearly exclusively from surface water, and, therefore, dominate the surface-water trends in Alabama. The dates of the operating schedules of the generating units at the power plants can be compared to the corresponding 5-year water-use data-collection cycle to explain changes in the thermoelectric-power trend. For example, Browns Ferry Nuclear Plant began operation in 1974, closed for review of procedures in March 1985 (the average daily withdrawal was 1,165 Mgal/d in 1985), and began generating power for one unit in July 1991 and a second unit in December 1995 (the average daily withdrawal was 776 Mgal/d in 1995). The water withdrawal for Browns Ferry in 2000 was 2,107 Mgal/d, and in 2005 was 1,990 Mgal/d. Commercial operation of a third unit, "Unit 1," began in May 2007.
Ground-water withdrawals slowly increased from 1960 to 2005, primarily because of increased ground-water withdrawals for public supply. Since 1985, public-supply withdrawals have accounted for more than 50 percent of groundwater withdrawals in the State.