Excerpt from Vision and Enterprise: Exploring the History of Phelps Dodge Corporation [Written and published for and by Phelps Dodge Corp]

Phelps Dodge's search for water in the Southwest

In 1942, due to wartime expansions, it was imperative that Phelps Dodge locate an adequate amount of water for its new mill facilities. Prior to 1937, when only underground mines operated in the Clifton-Morenci area, the company had acquired water rights on Eagle Creek, Chase Creek, and the San Francisco River, all of which ran near the mining operations, to meet the needs of mining copper. Note that these streams are all tributaries of the Gila river.

When development began in 1937, Phelps Dodge anticipated that the usual sources could supply the extra water needed. That is, water would be pumped uphill to the mill from the river and creeks. However, when the federal government called for nearly twice the copper-producing capacity at Morenci to meet wartime demands, the company needed to locate still more water or trade for it. Phelps Dodge did not own any sizeable water rights on the Salt or Verde river systems, two of the most obvious sources of new water. Moreover, the broken and uplifted terrain around Morenci meant that transporting additional water from where it was available to where it was needed would involve a major feat of engineering.

Phelps Dodge carefully examined each piece of a puzzle that when fully assembled illustrated the exceeding complex nature of Arizona’s water resources. It noted that the Salt River Valley Water Users Association had constructed Barlett Dam in the late 1930’s to hold Verde River floodwaters that could later be used for irrigation and to protect downstream Phoenix from damaging overflows. Unfortunately, the capacity of Bartlett Reservoir was not always adequate to handle the deluge. As a result, every few years a major flood topped Bartlett Dam, inundated parts of Phoenix, and spilled precious water down the Gila River.

With that problem in mind, Phelps Dodge entered into an innovative agreement with the Salt River Valley Water Users Association, which also controlled other sources of water for the many irrigated fields and orchards around Phoenix. Phelps Dodge proposed to build Horseshoe Dam. farther upstream from Bartlett Dam, about forty miles northeast of Phoenix, to reduce flood danger significantly and provide additional water storage for farms and cities of the Salt River valley. In return, Phelps Dodge received credits to 250,000 acre-feet of water that it could take during the coming years from the Black River in eastern Arizona, some forty miles from Morenci. Lifted by pumps seven hundred feet to the rim of Black Canyon, the water then flowed by gravity through nearly six and a half miles of buried pipeline to Willow Creek from where it continued twenty-one miles to Eagle Creek and then another thirty miles to the Eagle Creek Pump Station near Morenci, where Phelps Dodge recovered it along with the creek's normal supply of water, as in the past. It required roughly two days for Black River water to complete its fifty-one-mile journey. Its delivery to Morenci under the Horseshoe Dam agreement became Arizona's first successful experiment in transmontane diversion of water.

Phelps Dodge completed construction of $2.5 million Horseshoe Dam in the mid-I940s, the cornerstone of a complicated system that collected, stored, distributed, and recycled water needed for both domestic and industrial uses at Morenci. Show Low Dam was next, its storage lake completed in 1953. It pumped surplus unappropriated water from a tributary of the Little Colorado River over uplands located about a hundred miles north of Morenci and into a tributary of the Salt River. That flow in turn enabled the company to pump still more water from the Black River. But Show Low proved an erratic source that some years yielded no water at all.

Phelps Dodge located additional water on East Clear Creek where in late 1965 it completed construction of Blue Ridge Dam, a thin inverted concrete arch 170 feet high, 600 feet wide, but only 6 feet wide at the top. Pumps lifted water from the reservoir formed by the dam to the top of the Mogollon Rim, from where it traveled down to the Verde River through seven miles of penstock and a hydroelectric plant that in turn generated power for the pumps (in effect coming close to creating a perpetual motion machine). By building Horseshoe, Show Low, and Blue Ridge dams, Phelps Dodge also provided Arizona with new lakes for public fishing, boating, camping, and recreation.

In all, the corporation's “replumbing” of Arizona meant building three large dams, reservoirs, pumping plants, pipelines, and other support facilities located in six different counties and at points as far distant from the Morenci mine as 180 miles. That was possible because of agreements negotiated with some thirteen different federal, state, and local agencies. Few, if any, American industries can claim to have developed a more extensive system for moving water than Phelps Dodge.

In the mid-1970’s when Phelps Dodge needed water for the Tyrone Mine conversion to a pit mine, they needed additional water. And they had prepared for it. In 1955, Phelps Dodge had used a Phoenix law firm and its own Pacific Western Land Company subsidiary to purchase thousands of acres of land used for agriculture and cattle along the Gila River—and thereby gained rights to fourteen thousand feet of water a year. “That was a monumental achievement not unlike building its extensive water-gathering system in Arizona.” The Gila River water was diverted into Bill Evans Lake, a sixty-five acre reservoir. The reservoir was completed in 1968 and pumped water more than 12 miles uphill to the Tyrone mine operations site.

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