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Reviving a River

Among John Wesley Powell’s innovative conservation concepts was the management of water resources both through irrigation and by limiting the number of settlers living in the desert areas of the American Southwest. He could not have foreseen that his ideas would inspire the building of dams, power plants, and pipelines that would lead to a tremendous population growth in the region. Since Powell’s death in 1902, most major U.S. rivers have been harnessed for irrigation and electricity generation, sometimes to the detriment of the natural environment.

The first river to be controlled through a multipurpose dam–one that provides power for electricity, water for irrigation and recreation, and a means of flood control–was the Colorado. The earliest major development of the river began in 1928, when Congress passed the Boulder Canyon Project Act, authorizing construction of Boulder (now Hoover) Dam.

In 1963, the 710-foot-high Glen Canyon Dam, located 15.5 miles north of the Grand Canyon, was opened. Built as part of the development of a six-state region, the dam was bitterly opposed by conservationists. Although they failed to prevent the dam’s construction, its opponents’ efforts effected a change in the conventional wisdom away from the building of large dams and toward water management and the preservation of the environment, the very causes that Powell had championed eighty years earlier.

For millions of years, the Colorado River’s rich red sediment replenished the beaches along its shores, sustaining the habitat and wild life. The annual spring flood carried approximately 65 million tons of sediment downriver through the Grand Canyon, to Yuma, Arizona, before eventually emptying into the Gulf of California. But the opening of Glen Canyon Dam abruptly ended this cycle by trapping the sediment in the huge, man-made Lake Powell, adversely affecting the life of the river and turning the once-red Colorado to a pale green.

On March 22, 1966, however, an attempt was made to undo some of the damage by duplicating the natural spring flood and raising the water to pre-dam levels in the hope that restoration of the silt and sand to the riverbeds will rejuvenate the native flora and fauna for the first time in more than thirty years. Engineers at first released a steady 8,000-cubic-feet-per-second flow of water from the dam, increasing it four days later until a 45,000 cubic-feet-per-second flow-rate was established. The flood water–which took about 24 hours to flow down Glen Canyon, through the Grand Canyon and Lake Mead, to Hoover Dam–remained at that level until April 2, when it was gradually reduced. The test, which ended on April 7, was scheduled to be repeated every ten years.