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and transportation costs to places of use will make it impossible to extract all the water. Geologic studies indicate that although some of the basins have much less than 1,000 feet of saturated thickness, other basins have 3,000 to 5,000 feet or more. It must be emphasized that the saturated sediments are not uniform and where beds of low permeability predominate, the water levels will decline at an accelerated rate. Thus, a saturated thickness of 1,000 feet could be dewatered in much less time in some areas. A reduction in pumpage because of economic agricultural conditions, the capturing of additional water from the Colorado River, the use of desalinized water, or reduction of evaporation losses by artificial recharge of storm runoff to underground storage would prolong the future life of these basins. About 25 percent of irrigation water applied to the land in some areas may return to the aquifer. This recirculation of ground water will help prolong the life of the basins, although eventually the quality of the water will deteriorate. About 75 percent of the ground-water pumpage takes place in the Salt River Valley and the lower Santa Cruz basin where the water levels generally have continued to decline. It is obvious that the amount of water being pumped is many times the natural recharge. The accelerated demand for water in the state indicates the need for intensive evaluation of the water resources. As the economic growth of Arizona increases, water interests of diversified, and often conflicting groups, will require quantitative geohydrologic answers as a basis for equitable distribution.Epson Perfection 4870 Photo, 400 dpi, 8 bit, 14,039,040 byte