Hoover Dam

Photograph

By: Benjamin D. Glaha

Date: 1934

Source: Corbis

About the Photographer: Benjamin D. Glaha was an employee of the Unites States Bureau of Reclamation in the 1930s, and was assigned to document the construction of the Boulder Dam (now called Hoover Dam) by photographing all aspects of the project. He also photographed native Americans in the West, and some of these photographs reside in the United States National Anthropological Archives. Glaha's photographs were the subject of Hoover Dam: The Photographs of Ben Glaha by Barbara Vilander, published in 1999.

INTRODUCTION

The Colorado River originated high in the Rocky Mountains and flowed uncontrolled for about 1,400 miles (2,250 kilometers). It slowly but deliberately eroded lands for millions of years—forming such majestic landforms as the Grand Canyon—before finally emptying into the Gulf of California. The wild flow of the Colorado River was left in this natural state until mankind began to seriously populate its river-banks and outlying regions. Farmlands were regularly flooded in spring and summer when heavy snows in the mountains melted and violently raced along its downward route. It caused massive problems for farmers as it eroded valuable topsoil, destroyed planted crops, and uprooted trees and other vegetation. In the dry months, the river would diminish or even disappear, leaving farmers with no water supply to sustain their crops and domesticated animals. People within regions of the states of Arizona, California, and Nevada, as well as the country of Mexico, were especially hurt by the Colorado River's destructive rampages.

In the early 1900s, the U.S. federal government authorized studies to evaluate the possibility of controlling the river for the benefit of its western citizens. Then, in 1928, the U.S. Congress passed the Boulder Canyon Project Act, which authorized the construction of Hoover Dam near the border of Arizona and Nevada.

The primary purposes for the construction of the Hoover Dam were to control floods of fertile, but arid agricultural land, and to provide a reliable source of water and electrical power for millions of people in its adjacent areas. With a height of 726 feet (221 meters), length of 1,244 feet (380 meters), and thickness of 660 feet (201 meters) at its base, the dam, after about six years of construction, was dedicated by President Franklin D. Roosevelt on September 30, 1935.

PRIMARY SOURCE

HOOVER DAM

See primary source image.

SIGNIFICANCE

The U.S. Bureau of Reclamation used this and other photographs taken by Glaha to document the construction of the dam from start to finish. As the dam was built during the height of the Depression (1929–1941), these photographs appeared in press releases, books, advertisements, and pamphlets in order to illustrate that government money allocated to the dam was spent wisely.

When the Hoover Dam was being constructed, four primary reasons were cited by federal officials as to why the dam was being built: flood control, water conservation, domestic water supply, and power. By controlling floods and permitting a steady stream of water throughout each year, the Hoover Dam holds about two years of water flow behind its structure. Before the dam was built, the Colorado River irrigated about 660,000 acres (267,100 hectares) of land, subject to less acreage during low water months. By storing excessive waters from spring and summer runoff of melted snow, about 2.16 million acres (874,100 hectares) are now available to be irrigated. For example, the All-American Canal, with a width of 170 feet (52 meters), transports and supplies water from the Colorado River (near Yuma, Arizona) to the Imperial Valley of southern California. Many times, the amount of water is now available through the facilities of Hoover Dam; numerous new and varied crops are now able to be produced, such as cantaloupe, alfalfa, lettuce, barley, corn, small fruits, and cotton.

Due to the Hoover Dam's capacity to store water within Lake Mead, the reservoir created by the construction of Hoover Dam, billions of gallons of water are used to supply people with their daily needs for water. For example, the city of Las Vegas, Nevada, receives most of its drinking water from Lake Mead through the Southern Nevada Water Project. In addition, the original electrical power-producing capacity of the dam was about 1.803 million horsepower (1,345 megawatts). (At the end of 1992, the power capacity of the dam's generators were upgraded to about 2.681 million horsepower, or 2,000 megawatts).

The significance of the construction of the Hoover Dam is apparent from the description of the four aforementioned reasons that were declared during the construction of the dam. However, since then, there have been many negative environmental criticisms of the Hoover Dam. The environmental criticisms of the building of the Hoover Dam include disruption of ecosystems, decline of fish stocks and other animals found along the river, forced human resettlements, degradation of water quality, and introduction of diseases.

For example, fish are one of the primary creatures that were hurt by the Hoover Dam. Fish that once swam up and down its waters are now stopped from crossing the structure of the dam. In addition, changes in the flow pattern of the Colorado River increase the turbidity (the muddiness) and siltation (the actions of fine-grained sediment) of the river. Sediments such as gravel and pebbles are held back by the Hoover Dam, which because of its absence downstream causes the erosion of downstream banks. The landscape—including the ecosystem's flora and fauna—that the river flows through is also negatively affected by the damming of the river. Fluctuations in the water levels of the Colorado River, due to the dam, have also been scientifically shown to cause disruption to the habitat in and along the river.

There are many positive and negative aspects to the environmental effects that have occurred due to the construction of the Hoover Dam. Scientists are now delving into the impacts and benefits from the Hoover Dam—and other such dams constructed around the world—onto the environment and the people that use the dam for its various purposes.

FURTHER RESOURCES

Books

Mann, Elizabeth. Hoover Dam. New York: Mikaya Press, 2001.

Maxon, James C. Lake Mead-Hoover Dam. Las Vegas: KC Publications, 1980.

Stevens, Joseph Edward. Hoover Dam: An American Adventure. Norman, OK: University of Oklahoma Press, 1988.

Vilander, Barbara. Hoover Dam: The Photographs of Ben Glaha. Tempe, AZ: University of Arizona, 1999.

Web sites

"Fortune Magazine, September 1933." Lower Colorado Region, Bureau of Reclamation, Department of the Interior. 〈http://www.usbr.gov/lc/hooverdam/History/articles/fortune1933.html〉 (accessed March 8, 2006).

Moore, David. "The Hoover Dam: A World Renowned Concrete Monument." RomanConcrete.com, 1999. 〈http://www.romanconcrete.com/docs/hooverdam/hooverdam.htm〉 (accessed March 8, 2006).

Hoover Dam

In 1928, the U.S. Congress authorized the Boulder Canyon Project, later known as Hoover Dam. The project's success helped usher several decades of major water projects funded by the U.S. government.

Hoover Dam is located on the border between Arizona and Nevada. It is within Black Canyon on the Colorado River, near Las Vegas. The construction of Hoover Dam began in 1931. When completed in 1936, the dam was a major engineering achievement at a height of 221 meters (726 feet) and crest-width of 379 meters (1,244 feet).

The reservoir that formed behind the dam is Lake Mead, one of the world's largest artificially created bodies of water. It covers an area of 603 square kilometers (233 square miles), and its shoreline measures 885 kilometers (550 miles). The hydroelectric generators of Hoover Dam—capable of supplying nearly 1.5 million kilowatts of power—provide electricity to Arizona, southern California, and Nevada.

Construction and Benefits

Before the construction could start, the Colorado River had to be diverted through tunnels. These tunnels would allow the water to bypass the site of the dam foundation, and later would contain the electric plant generators. Building tunnels directly through the canyon rock walls required huge amounts of dynamite in order to remove rock, and enormous support structures to maintain the passageways. Once the first two tunnels where in place, cofferdams were built to divert the Colorado River. This accomplishment signaled that the actual dam construction could begin.

Base Surface.

Because of its importance in the overall integrity of the dam, the foundation was a major factor in building a structure that would be assured not to fail. This necessitated the removal of the mud and muck at the river bottom. Workers with the assistance of power shovels excavated over 382,300 cubic meters (500,000 cubic yards) of these deposits in order to reach bedrock , sometimes over 12 meters (40 feet) below. At the same time, workers called "high scalers" blasted the walls to create a smooth joining surface for the dam.

Pouring Concrete.

On June 6, 1933, the pouring of concrete began at the dam's base. Two-hundred-thirty blocks of concrete, totaling a volume of 2.49 million cubic meters (3.25 million cubic yards), were used to complete the base on May 29, 1935. This pouring process was necessary to allow the concrete to properly dry. It was stated that enough concrete was used to pave a 4.9-meter (16-foot) wide highway from San Francisco to New York City. The filling of Lake Mead now began.

Why Build?

The main reason for building Hoover Dam was to supply the electrical power necessary to transport 4.4 million acre-feet—over a quarter of the Colorado River's average annual flow—to California. Soon, the dam also would supply water to Las Vegas, whose revenue would be used to finance more water projects. Hoover Dam also allowed waterworks along the lower Colorado to be safely constructed and maintained as they operated upstream on a (now) tamely flowing river.

Benefits and Impacts.

Because of Hoover Dam, the Colorado River was controlled for the first time in history. Farmers received a dependable supply of water in Nevada, Arizona, and California. Numerous cities such as Los Angeles, San Diego, and Phoenix were given an inexpensive source of electricity, permitting population growth and industrial development. Hoover Dam also provided for flood control and irrigation . Even prior to its completion however, concerns were expressed over the potential impacts of Hoover Dam on aquatic systems.

Research performed in the ensuing years shows that significant changes have occurred to the chemical, physical, and biological processes of associated ecosystems , including declines in species of fish. Hoover Dam dramatically altered the hydrologic regime of the Colorado River, for example. Prior to the 1930s, it carried approximately 125 million tons of suspended sediment to its delta at the head of the Gulf of California. At present, the Colorado River does not discharge either sediment or water to the gulf.

see also Bureau of Reclamation, U.S.; Colorado River Basin; Dams; Economic Development; Fish and Wildlife Issues; Hydroelectric Power; Instream Water Issues; Reservoirs, Multipurpose.

William Arthur Atkins

Bibliography

Stevens, Joseph E. Hoover Dam: An American Adventure. Norman, OK: University of Oklahoma Press, 1988.

Internet Resources

Hoover Dam: An Engineering Wonder of the World. <http://www.sunsetcities.com/hoover-dam.html>.

Hoover Dam—National Historic Landmark. Bureau of Reclamation, U.S. Department of the Interior. <http://www.hooverdam.usbr.gov/>.

Simonds, William Joe. "The Boulder Canyon Project: Hoover Dam." Bureau of Reclamation History Program. Bureau of Reclamation, U.S. Department of the Interior. <http://www.usbr.gov/history/hoover.htm>.

HOOVER OR BOULDER?

Construction of the concrete arch-gravity type dam began as part of the Boulder Canyon project. Originally named after President Herbert Hoover, the dam was later called Boulder Dam, but in 1947 its initial name was restored.

Hoover Dam

The Colorado River bobs and jukes through the crisp sandstone of the western high plains. Earliest explorers saw it as a defining characteristic of Arizona and much of the semi-arid western United States. Today, the river is a monument to American riverine technology, as aqueducts and hydroelectric dams use the Colorado to make the American West a hydraulic society. The first of the incursions into the river is also the most famous: Hoover Dam.

Opened in 1935, Hoover Dam stands as a larger-than-life symbol of fluctuating meaning for generations of Americans. Even without such symbolic significance, the dam remains among the nation's most impressive engineering achievements.

A major part of the dam's significance derives from the structure itself. The dam, which has long-since repaid the $165 million cost for construction, is a National Historic Landmark and has been rated by the American Society of Civil Engineers as one of America's Seven Modern Civil Engineering Wonders. The structure contains over 4 million cubic yards of concrete, which if placed in a monument 100 feet square would reach 2.5 miles high—higher than the Empire State Building.

As proposed in 1910, the mammoth Boulder Dam (as it was first referred to) served as the linchpin of a western land-use policy known as reclamation. After policymakers and developers finally conceded that a serious lack of rainfall stood in the way of their dreams of the "garden of the West," they sought a way to turn their adversity into opportunity. Reclamation grew out of the impulse to "reclaim" these dry, barren regions by applying human ingenuity to the few existing waterways, including the Colorado. In 1912, five western states agreed on the Colorado Compact, which parceled up the great river's flow among the signees—including at least two states that never made contact with the river. Most of the flow, including the electricity made at Hoover Dam, would be managed by the Six Companies contractors to power development over 300 miles away in southern California. By the late 1990s, the majority of Hoover Dam's power is passed over wires to Los Angeles.

The symbolic significance of this immense structure became obvious immediately, which led developers to name it after President Herbert Hoover (an engineer who had been a great supporter of the project). Upon its completion in 1935, Hoover Dam became a symbol of America's technological prowess, firmly placing the United States with the great civilizations in world history. One observer described it as the "Great Pyramid of the American Desert, the Ninth Symphony of our day" and "a visual symphony written in steel and concrete…. magnificently original, strong, simple, and majestic as the greatest works of art of all time and all peoples, and as eloquently expressive of our own as anything ever achieved." Particularly during the Great Depression, Hoover Dam's restoration of national confidence led to its appearance throughout popular culture, including advertisements, Coca-Cola serving trays, and numerous collectible mementos.

Hoover Dam remains a symbol in contemporary America; however, the changing attitude of river-management technology has altered its image. In the 1990s, many observers saw Hoover Dam as the symbol of all the development that has prohibited the Colorado from reaching the ocean for over twenty years. As the great dams begin to clog with silt, many observers suggest that Hoover and the other dams may have only a limited life. Marc Reisner noted that "we set out to tame the rivers and ended up killing them." He suggested that Hoover and others might eventually be viewed as "uniquely productive, creative vandalism."

In terms of structural design, though, Hoover Dam will always serve as a symbol of the modern era. For many Americans, achievements such as this sleek yet powerful dam led the way to a century of innovation and development.

—Brian Black

Further Reading:

Jackson, Donald C. Building the Ultimate Dam. Lawrence, University of Kansas Press, 1995.

Reisner, Marc. Cadillac Desert. New York, Penguin, 1986.

Stevens, Joseph E. Hoover Dam. Norman, University of Oklahoma Press, 1988.

HOOVER DAM

HOOVER DAM. Located in the Black Canyon on the Colorado River, Hoover Damlies about thirty miles southeast of Las Vegas, Nevada. The federal government built it for flood control, navigation, irrigation, water storage, and power generation. Farmers in the region experienced disastrous Colorado River floods before the dam was constructed.

Herbert Hoover first proposed a dam for the Colorado River when he became secretary of commerce in 1921. At the time his plan involved a dam in Boulder Canyon. After he became president, Hoover proposed an "upper" and a "lower" basin, a compromise that made a dam possible by dividing the water among the states affected

by the river and its tributaries. Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming entered the Colorado River Compact in 1922, and in 1928 Congress authorized the construction of Boulder Dam, which later became the Hoover Dam.

During the Great Depression the government contractor, Six Companies, six formerly independent companies that had merged to get the job, constructed the dam, the highest concrete arch dam in the United States. Lake Mead, the reservoir the dam impounds, is one of the largest human-made lakes in the world, with an area of 247 square miles. The dam itself is 726.4 feet from the foundation rock on the roadway to the crest, with towers and ornaments extending another 40 feet above the crest. It weighs more than 6.6 million tons. With 17 turbines, the power facility has a nameplate capacity of 2.074 million kilowatts.

Of the thousands of people who worked on the dam between 1930 and 1936, ninety-six workers died from accidents directly relating to the building of the dam and dozens more from related ailments. Before the dam could even be started, Boulder City had to be built to house the workers, and miles of highways and railroads from the dam site to Boulder City and from there to Las Vegas had to be constructed. In the first step of building the dam, men attached to ropes were hoisted over the edge of the canyon, where they scraped loose rock from the canyon walls by hand. Four tunnels diverted the flow of the river, and a ton of dynamite was required to dig fourteen feet. The dam itself was made up of columns filled slowly with concrete. To cool the chemical heat released by the concrete, ice water ran through the equivalent of 582 miles of one-inch diameter pipes embedded in the concrete. After the columns were filled and cooled, grout was poured between them to make the structure monolithic.

The Hoover Dam was seen as a triumph of humans over nature. It was the first human-made structure to exceed the masonry mass of the Great Pyramid of Giza. By the twenty-first century the dam was regarded ambivalently, sustaining environmentalists' criticism that it in fact damaged or destroyed an ecosystem.

BIBLIOGRAPHY

Carothers, Steven W., and Bryan T. Brown. The Colorado River through Grand Canyon: Natural History and Human Change. Tucson: University of Arizona Press, 1991.

Dunar, Andrew J., and Dennis McBride. Building Hoover Dam: An Oral History of the Great Depression. New York: Twayne, 1993.

Stevens, Joseph E. Hoover Dam: An American Adventure. Norman: University of Oklahoma Press, 1988.

RuthKaplan

See alsoConservation ; Hydroelectric Power .

Hoover Dam

Proposed in 1910 as a way of fulfilling the dream of a "garden of the West," Hoover Dam was the first of many Colorado River dams proposed to help irrigate the dry land. It remains one of the engineering wonders of the twentieth century. Named after President Herbert Hoover (1874–1964), an engineer by trade, its four million cubic yards of concrete cost over $165 million to erect. From 1935 onwards, Hoover Dam brought water and electricity to communities in the dry western states.

Amidst the Great Depression (1929–41; see entry under 1930s—The Way We Lived in volume 2), the dam became a symbol of revival. It has appeared in films, in advertising (see entry under 1920s—Commerce in volume 2), and on collectibles of all kinds. The elegant curve of Hoover Dam is an enduring image of the American West. Unfortunately, this great monument to progress also helped kill one of the continent's natural wonders. By the 1980s, the Colorado River dams and developments had prevented the river itself from reaching the sea.

—Chris Routledge

For More Information

Dunar, Andrew J., and Dennis McBride. Building Hoover Dam: An Oral History of the Great Depression. Reno: University of Nevada Press, 1993.

Stevens, Joseph E. Hoover Dam: An American Adventure. Norman: University of Oklahoma, 1990.