Dams and Reservoirs

Passage One

The final critical ingredient to Phoenix growth is . . . water, the most storied, legendary, and litigated of the factors of arid region growth. Phoenix’s survival as a big city depends on two massive federally funded projects which relocate water from mountain watersheds to the Sonoran desert. The first of these, the Salt River Project (SRP), was the first major multi-purpose reclamation project authorized after the passage of Newlands Reclamation Act in 1902. It resulted in the dams and reservoirs of Central Arizona and both tamed the violent floods which had ravaged Phoenix in the 1890s and also impounded sufficient water to sustain the area’s significant agriculture base. The second great project, the Central Arizona Project (CAP), resulted in a nearly 350 mile long system of pumps, aqueducts, and reservoirs moving Colorado River water from Lake Havasu to central and southern Arizona.

^{Source: Gammage, Grady and Jonathan Fink. “The Phoenix Experiment.” March 1, 2004. http://west.stanford.edu/events/edge_conference/metrowestsouthwest.html}

Passage Two

A cash register dam was to be a dam with an overriding, if not a single, purpose: to generate electricity for commercial sales. If electricity would bring in many millions of dollars in annual revenues which could be used to subsidize irrigation projects that hadn't a prayer of paying back the taxpayers' investment. . . .

On a map of Arizona, the Colorado River can be seen making a wide circle around the northern and eastern half of the state. At every point along that six-hundred-mile sojourn, the populated center of the state is walled off from the river by mountains. . . . Regardless of where one located the point of diversion, to move a portion of the Colorado River to Tucson and Phoenix would involve a pump lift of at least twelve hundred feet. . . . The CAP was to be, first and foremost, an irrigation project, a rescue project to save the dying farmlands between Phoenix and Tucson; the cities would also get some water, but the farmers would receive the overwhelming share. Hardly anywhere on earth, however, is water lifted that high in order to irrigate crops, unless the water flows nearly as far downhill somewhere along its route as it was lifted uphill, so that much of the energy required to lift it can be recovered. Even then, the Second Law of Thermodynamics exacts a heavy toll: for every hundred units of energy expended to lift the water, only seventy or so can be recovered on the way back down. Using the most optimistic predictions--high-value crops, high crop prices, dirt-cheap power from preexisting dams--the Central Arizona Project was still likely to need more public welfare than anything the Bureau [of Reclamation] had built. . . .

Something would have to be done about the project's horrifically poor economic rationale. And something would ultimately have to be done about the fact that the river now seemed certain to dry up if the CAP was built. Something--but what? The obvious answer was a couple of big cash register dams that could generate enough power, and enough money, to give Arizona's irrigation farmers the 90-percent subsidy they would probably need.

^{Source: Reisner, Marc. Cadillac Desert: The American West and Its Disappearing Water. New York: Penguin Books, 1993. 134, 272-273.}