Cadillac Desert: The American West and Its Disappearing Water

by Marc Reisner

The Colorado River rises high in the Rockies, a trickle of frigid snowmelt bubbling down the west face of Longs Peak, and begins its fifteen-hundred-mile, twelve-thousand-foot descent to the Gulf of California. Up there, amid mountain fastnesses, its waters are sweet. The river swells quickly, taking in the runoff of most of western Colorado, and before long becomes a substantial torrent churning violently through red canyons down the long west slope of the range. Not far from Utah, at the threshold of the Great Basin, the rapids die into riffles and the Colorado River becomes, for a stretch of forty miles, calm and sedate. It has entered the Grand Valley, a small oasis of orchards and cows looking utterly out of place in a landscape where it appears to have rained once, about half a million years ago. The oasis is man-made and depends entirely on the river. Canals divert a good share of the flow and spread it over fields, and when the water percolates through the soil and returns to the river it passes through thick deposits of mineral salts, a common phenomenon in the West. As the water leaves the river, its salinity content is around two hundred parts per million; when it returns, the salinity content is sixty-five hundred parts per million. The Colorado takes in the Gunnison River, whose waters have also filtered repeatedly through irrigated, saline earth, and disappears into the canyonlands of Utah. Near the northernmost tentacle of Lake Powell, where the river backs ...