NONFICTION - Dec. 20, 1992

LAST OASIS: Facing Water Scarcity by Sandra Postel (W.W. Norton: $21.95; 239 pp.). Anwar Sadat, soon after agreeing to peace with Israel in the late 1970s, said, “The only matter that could take Egypt to war again is water,” and in 1990 Jordan’s King Hussein said virtually the same thing. The United States isn’t yet to the point where war and water are routinely linked, but after six years of drought, Californians, at least, no longer take water for granted. “Last Oasis,” the newest volume in the Worldwatch Institute’s Environmental Alert Series, is a summary of the causes of, and possible solutions for, what can only be called a looming global water crisis, and it is marked by lucidity, balance, levelheadedness and, at bottom--for this we can be thankful--optimism. Sandra Postel, a research executive at Worldwatch, describes in some detail the massive problems in many nations’ water supplies, but alarmist she is not; Postel gives equal time to the stunning progress that has been made, particularly in Israel and California, in water conservation and reclamation. What comes through most clearly in this volume is the sheer prodigality of our water use in the past--a prodigality best evidenced, perhaps, by the fact that manufacturing a car in the United States requires 50 times its weight in water.