Cadillac Desert: The American West and Its Disappearing Water

by Marc Reisner

In 1963, the Bureau closed the gates of Glen Canyon Dam. As Lake Powell filled, the flow of fresh water below it was greatly reduced. At the same time, the Welton-Mohawk drain was pouring water with a salinity content of sixty-three hundred parts per million directly into the Colorado. The salinity of the river—what was left of it—soared to fifteen hundred parts per million at the Mexican border. The most important agricultural region in all of Mexico lies right below the border, utterly dependent on the Colorado River; we were giving the farmers slow liquid death to pour over their fields. The Mexicans complained bitterly, to no avail. By treaty, we had promised them a million and a half acre-feet of water. But we hadn’t promised them usable water. By 1973, Mexico was in a state of apoplexy. The ruin of its irrigated agricultural lands along the lower Colorado was the biggest issue in the campaign of presidential candidate Luis Echeverría, who was elected by a wide margin in that year. Still, the United States continued to do nothing. But 1973 also saw the arrival of OPEC. Some new geologic soundings in the Bay of Campeche indicated that Mexico might soon become one of the greatest oil-exporting nations in the world. When Echeverría threatened to drag the United States before the World Court at The Hague, Richard Nixon sent his negotiators down to work out a salinity-control treaty. It was signed within a few months.