Water Development, Extraction, and Diversion (page 5 of 6)

The Dam Building Decades

The Colorado River Compact

By 1920, southern California held most of the human population of the western United States and encompassed the largest and most productive agricultural regions in the west, including the Imperial and Coachella Valleys, and was quickly using up its existing water supplies. The Colorado Plateau’s mightiest river is, of course, the Colorado River, even though the Colorado does not rank among the nation’s top twenty-five rivers based on annual flow. However, in the dry lands of the West, this river is the key to prosperity and its waters have been coveted by many varied interests for over a century. The burgeoning state of California had the Colorado River in its sights, but was denied by Congress appropriative rights in the form of a huge diversion dam. The only solution was to negotiate the river’s water rights with its neighboring states. Delegates from California, Arizona, Nevada, New Mexico, Utah, Colorado, and Wyoming met in 1922 and negotiated for eleven months, with the result being the Colorado River Compact. The compact arbitrarily divided the seven states into two basins, divided at Lees Ferry, with the lower basin including Arizona, California and Nevada, and the upper basin including the other four states. Based on the Bureau of Reclamation’s estimated average annual flow of 17.5 million acre-feet (maf), 8.5 maf were alloted to the lower basin, 7.5 maf to the upper basin, and 1.5 maf were reluctantly reserved for Mexico.

After years of quarreling within and between the seven states, Congress decided to authorize Boulder Dam (later, Hoover Dam) and the All-American Canal (a giant canal to southern California) if six of the seven states would ratify the compact and if California would limit its annual diversion to 4.4 maf. This left 2.8 maf for Arizona and 300,000 for Nevada, a condition that Arizona refused to accept. However, the other six states ratified the compact and large-scale development of the Colorado River Basin ensued. Unfortunately, the figure of 17.5 maf as the average annual flow of the Colorado was based on 18 years of above-average flows and the longer-term average appears to be considerablyl less than that. Decades of drawn-out, contentious courtroom and Congressional battles were to come before today’s water rights were eventually established.

The First Big Dam: Hoover

The Salton Sea. Photo courtesy of the Bureau of Reclamation

One of the first diversion projects on the Colorado River was completed in 1901 to bring irrigation water to the Imperial Valley in southern California, a key agricultural region of the U.S. When in 1905 a series in floods washed out the flood gates, the entire Colorado River began to flow into part of the valley, creating the Salton Sea, still present today. This situation, as well as the growing need for irrigation across the Colorado Plateau, led to the Fall-Davis report, an extensive study on the possibilities of damming the Colorado River for irrigation and electrical power. Based on the report, Congress passed the Boulder Canyon Project Act in 1928, authorizing the construction of a high dam at or near Boulder Canyon and of the All-American Canal to bring water to the Imperial Valley. The All-American Canal was the first of several canal projects which eventually brought irrigation water to other agricultural regions of California and to southern Arizona.

Aerial view of Hoover Dam, ca. 1940. Image 4684a by Bill Belknap, courtesy of Cline Library Special Collections, Northern Arizona University.

Ultimately, the most suitable location for the dam was found to be in Black Canyon, 30 miles southeast of Las Vegas. Construction began in 1931 with the excavation of four diversion tunnels, requiring the removal of 3.5 million tons of rock. Six of the nation’s largest construction companies and thousands of workers worked under grueling conditions for four and a half years to build the dam. Considered one of the seven modern engineering wonders of the United States, the dam that came to be known as Hoover Dam changed the course of history in the West. Dedicated in 1935 by President F.D. Roosevelt, the dam would provide electricity to Arizona, Nevada, and southern California. Behind Hoover Dam grew Lake Mead, a 247 square-mile reservoir managed as a National Recreation Area. Click here for more on the making of the Hoover Dam, and its legacy in American history.

A Dam Building "Binge"

Glen Canyon Dam. Digital photo by John Grahame.

After the construction of Hoover Dam, water development agencies across the nation and particularly in the West, launched "a forty-year binge" of dam building (Reisner 1990). During this period, the Corps of Engineers built an average of ten large dams a decade, while thousands of smaller dams were erected. In addition to Hoover on the main channel of the Colorado River, the Bureau of Reclamation eventually built twelve tributary dams on the river system. The Great Depression and subsequent New Deal politics helped motivate the authorization of these numerous water development projects with the justification that such public works would help stimulate the economy and prevent future depressions. In addition to the financial hardships of the Depression, the 1930s mid-continent drought and its consequenses which became known as the Dust Bowl helped generate public support for water development projects.

This period of furious dam building culminated in the authorization of the Colorado River Storage Project (CRSP), first envisioned with the drafting of the Colorado River Compact of 1922, but not authorized until 1956. The purpose of the CRSP was to provide the Upper Basin states with a means to deliver to the Lower Basin no less than 7.5 million acre-feet of water in any period of 10 consecutive years, as the terms of the multi-state compact stated. In addition, the huge project would provide stored water for the development of the Upper Basin states, as well as hydroelectric power. The CRSP authorized the construction of Glen Canyon Dam, Flaming Gorge Dam, Navajo Dam, and numerous other projects. Glen Canyon Dam, the key feature of the CRSP, was completed in 1963, and was the last high dam to be built by the Bureau of Reclamation, and essentially ended the era of major dam building.

Despite its many reforms over the years, the Reclamation Act has provided huge subsidies for project beneficiaries: while they had to pay for water, they were exempt from paying interest on the government’s investments. In addition, the legislation was amended to allow subsidized hydroelectricity to farmers and repayment periods were eventually stretched out to fifty years. Unfortunately, many farmers, particularly those at high altitudes, were unable to make a profit and defaulted on their repayments. The problem was greatly exacerbated by the fact that except for the best land such as the Imperial and Central Valleys, most irrigated farming in the West was hugely unprofitable, despite the enormous expenditures by the government to provide water for transforming dry lands into fertile fields. Critics have called the Reclamation Act "the nation’s first piece of welfare legislation for the common man."

To offset the economic imbalances of western water development, the government responded by building more dams: large, high dams in steep western canyons where rapid changes in elevation over short lengths allowed for cheap hydroelectric power generation. These dams were called "cash register" dams whose main purpose was to subsidize lagging irrigation projects. Thus, the concept of river basin accounting was born. The Bureau of Reclamation began lumping all water development revenues from a watershed into a common pool, blurring the distinction between money-losing (usually irrigation projects) and money-making (usually hydroelectric) ventures. Dozens of projects, many of which were poorly planned and economically unjustified, were authorized under the precepts of river basin planning.

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