There is an important concept embodied in the terms sustainability and intergenerational equity—the idea that the present generation's children and grandchildren should have at least as much ability to use a resource as does the present generation. Intergenerational equity includes the sustainable use of water resources.
The committee's deliberations were limited to the area of the West Bank and Gaza Strip, Israel, and Jordan, referred to as "the study area" in this report. The study area has a hot, dry climate, and consists of a dry coast and strip of dry upland forest that grades into semidesert and desert. Most of the study area receives less than 250 millimeters (mm) of rainfall per year, about the same as or less than that received by Phoenix, Arizona, in the United States. The study area's highest rainfall amounts—those of more than 1,000 mm—fall in a small area of highlands in the northwestern part of the study area. By comparison, most of the United States east of the Mississippi River receives more than 800 mm of rainfall per year; much of the eastern United States and much of the Pacific Northwest west of the Cascades receive 1,000 mm or more. The landscape and hydrologic features of the study area are much like those of neighboring areas, which are sometimes included in definitions of the "Middle East," stretching as far south as Yemen, as far east as Pakistan, as far north as Turkey, and as far west as Morocco.
The study area has approximately 12 million inhabitants, with varying proportions in urban centers and holding a variety of occupations. In 1994, the study area's total average annual water use was estimated to be 3,183 million cubic meters (million m3), ranging from almost 2,000 million m3 in Israel to approximately 235 million m3 in the West Bank and Gaza Strip. The average annual per capita use in the area, while highly variable, was approximately 260 cubic meters in 1994, and has been increasing. For the study area as a whole, agricultural irrigation accounts for more than half the water use, from an estimated 57 percent in Israel to 72 percent in Jordan, without considering wastewater that may be reused for irrigation. The several problems of water and the environment are similar to those in some neighboring areas and in some distant regions, such as arid sections of the United States and Australia.
Long experience in predicting water use and associated economic