Controlling the River: The Impact of Infrastructure on the Colorado River

In this post, I will explore the development of the Colorado River and how engineering and infrastructure has made the Colorado River the most developed river in the United States. I will also look at the effects of dams on rivers and how the environmental movement has shaped the current management of the Colorado River. 

The Colorado River is considered one of the most controlled rivers in the world. Today, the Colorado River serves water to roughly 36 million people for agricultural, industrial, and domestic needs and without the engineering of various infrastructure, this would not be possible. There are over 29 major dams along the Colorado River with hundreds of miles of canals to divert and deliver the water. 

Please click the link below to visit an interactive Colorado River map showing the various dams and diversions.

Colorado River Map -- National Geographic

One of the most astonishing engineering manipulations of the Colorado River though, is the reservoir basins total storage capacity. Combining all of the reservoirs storage capability, an amount of four times the river’s annual flow can be stored along the river.  This fact has given the Colorado River the nickname, “America’s Nile.” 

Hoover Dam: A Modern Wonder of the United States

View of the Salton Sea within the Imperial Valley
Photo courtesy of marlimillerphoto.com

In 1901, one of the first diversion projects on the Colorado River was completed, the Alamo Canal.  The Alamo Canal’s primary purpose was to bring Colorado River water to the Imperial Valley in southern California in order to irrigate this growing agricultural region. However, in 1905, a series of floods hit this region and washed out the floodgates of the Alamo Canal, allowing the entire Colorado River to flow into the Imperial Valley. It took two years and more than 3 million dollars to close the breech, but not before a 45-mile-long lake was created in the Imperial Valley, now known as the Salton Sea. After this catastrophe, it was realized that a more permanent solution was necessary if the Colorado River was going to be utilized.

Construction of Hoover Dam
Photo courtesy library.unlv.edu

Hoover Dam’s location was decided on Black Canyon, about 30 miles southeast of Las Vegas. Construction on the dam began in 1931 with the removal of 3.5 million tons of rock. (1 ton = 2,000 pounds) Over the course of four and a half years, six of the nation’s largest construction companies and thousands of workers built Hoover Dam. The dam itself raises about 730 feet from its base (imagine a 70 story building) and is about 1,250 feet wide at its peak width across the top. Behind the dam sits Lake Mead, a 247 square-mile reservoir with a length of 112 miles across the largest stretch and the maximum water depth of 590 feet. The amount of water stored behind Hoover Dam would be enough to cover a state like Connecticut in 10 feet of water. 

Construction of Hoover Dam at night
Photo courtesy of library.unlv.edu

In 1928, after a series of investigations on the possibilities of damming the Colorado River, Congress passed the Boulder Canyon Act authorizing the construction of Boulder Canyon Dam, now Hoover Dam, and the All-American Canal to bring water to the Imperial Valley.

The construction of Hoover was a major step towards stabilizing the lower channel of the Colorado River, storing water for irrigation in times of drought, and providing much-needed flood control. Hoover Dam, for this reason, is one of the seven modern engineering wonders of the United States and changed the course of history for not only the Colorado River, but for the West.

Lake Mead behind Hoover Dam
Photo courtesy of wikimedia.org

Era of Dams

The Dust Bowl brought public approval for water projects
Photo courtesy of http://midatlanticgardening.com

Following the construction of Hoover Dam, an era of dam building began. Water developing agencies across the nation, particularly in the West, launched a “forty-year binge” of dam building. Until the mid 1970’s, around 1,000 large dams per year were under construction throughout the world, 500 of these being built in the United States. A large dam is defined as one higher than 15 meters (taller than an average 4 story building). The Great Depression and subsequent New Deal politics initiated the authorization of these water development projects, since such public works projects would stimulate the economy. Not only that, but the 1930’s mid-continent drought, known as the Dust Bowl, helped generate public support for water development projects.

A stretch of the Colorado River Aqueduct
Photo courtesy of lbwater.org

During this period, numerous projects occurred along the Colorado River. Projects not only to store water, but also to deliver water, for flood control, and to generate electricity. The Lower Basin states looked to develop the Colorado River for municipal purposes in this time of growing urban centers. Specifically, the Colorado River Aqueduct, completed in 1941, delivers water 250 miles to Los Angeles and due to the population growth in Las Vegas Valley from Hoover Dam, Las Vegas tapped a pipeline from Lake Mead in 1937. Colorado leads the Upper Basin states in water development projects, the most notable project being the Roberts Tunnel, which diverts water from the Colorado River to Denver.

Construction of the Roberts Tunnel to bring
Colorado River water to Denver, Colorado
Photo courtesy of Denver Water

Without the addition of surface water storage in the Upper Basin, there was no guarantee that the Upper Basin states would be able to use the full amount of water given to them by the compact and thus many reservoirs were built including the Lake Powell, Flaming Gorge, and Navajo. Projects like these were occurring around each bend on the river. In the growing West, water meant a future for urban cities to expand. However, in the 1980’s a new era began that closed the door on major dam building, the environmental movement.

Environmental Movement Shifts Infrastructure Future

The environmental movement began as a desire to manage the natural resources of the land and protect it from over-industrialization. Although the environmental movement began much earlier, the era of large dam building came to a close in 1969 with the formation of the National Environmental Protection Act (NEPA). NEPA set policies that directed all branches of the federal government to protect the environment. Any action planned by a federal agency has to be preceded by an Environmental Impact Statement (EIS), which details the effects of the proposed action upon the environment. The Act also requires an annual report on environmental quality from the President.

Various considerations are needed in the NEPA decision-making process
Photo courtesy of projectpermits.com

NEPA put a halt on large dam projects for a number of reasons. Specifically along the Colorado River, large dams such as Hoover Dam and Glen Canyon Dam have numerous environmental consequences that include direct impacts to the biological, chemical, and physical properties of the river and riparian (banks of the river) environments. Below is a list of some, not all, of the environmental impacts of large dams on the Colorado River.

• Dam walls block fish migrations, which in some cases completely separate spawning habitats from rearing habitats
• Dam walls trap sediments, which are critical for maintaining physical processes and habitats downstream of the dam
• Transformation upstream of the dam from a free-flowing river ecosystem to an artificial flow-restricted reservoir habitat impact aquatic and riparian life, sometimes destroying the system completely
• Changes in temperature, chemical composition, dissolved oxygen levels and the physical properties of a reservoir are often not suitable to the aquatic plants and animals that evolved with a given river system

Diagram of components on a free-flowing river and a dammed river
Photo courtesy of vtwaterquality.org

For these reasons, and many others, environmental groups have altered the management of the Colorado River by stepping in when new actions are proposed to alter the state of the river. Today, infrastructure managers and engineers are placed with the challenge of finding sustainable ways to supply water to the growing West, while also maintaining or bettering the conditions along the river. Unlike in the mid 1900s where the solution to water problems along the river was to build more, today the solution is not in constructing more projects, but rather to manage the current infrastructure in a more sustainable way.

A thriving and healthy Colorado River ecosystem is one
of the many environmental movement aspirations
Photo courtesy of secure2.edf.org 

In my next post, I will investigate the current issues surrounding both endangered species and invasive species along the Colorado River and what is being done in regards to these issues.