Hoover Dam
Hoover Dam, a significant feat of modern engineering, was constructed between 1931 and 1936 on the Colorado River, marking it as one of the largest dams in the world. This monumental structure plays a crucial role in providing water for over a million acres in the U.S. and 400,000 acres in Mexico, while also generating more than 4 billion kilowatt-hours of hydroelectric power annually for Nevada, Arizona, and California. The dam was built during the Great Depression, offering employment to thousands of workers and demonstrating a remarkable blend of human ingenuity amid challenging conditions. Named after Herbert Hoover, who championed its development, the dam is a symbol of American resourcefulness. At 726 feet tall and 1,244 feet long, it creates Lake Mead, the largest reservoir in the U.S., which attracts millions of visitors each year. However, current challenges such as climate change and prolonged drought threaten its water levels and power production, highlighting the ongoing need for sustainable management of water resources in the region. The Hoover Dam stands not only as an engineering marvel but also as a critical infrastructure element for the southwestern United States.
Hoover Dam
Hoover Dam, one of America's Seven Modern Civil Engineering Wonders, is also one of the world's largest dams. Built on the Colorado River between 1931 and 1936, the engineering miracle was the first to harness the river, which now supplies water for more than a million acres of land in the US and 400,000 acres in Mexico. Generating more than 4 billion kilowatt-hours of electricity each year, Hoover Dam is also one of the nation's largest power plants. The dam supplies low-cost hydroelectric power for Nevada, Arizona and California. Made of concrete and costing $174 million to build, it contains more than 45 million pounds of steel and is capable of holding the flow of the Colorado River for two years.
History
Built in Black Canyon on the border of Arizona and Nevada during the Depression era, the Hoover Dam project put thousands of Americans to work for a few dollars a day. Prior to the dam's construction, the Colorado River often flooded the surrounding farms and towns in the spring when the snow melted. To prevent these disasters from occurring, the dam project (originally called the Boulder Canyon Project) was undertaken in 1928 by the US Bureau of Reclamation, which was commissioned to find ways to irrigate the western states. In March 1931, Bechtel Kaiser, Utah Construction, Pacific Bridge, MacDonald & Kahn, Morrison-Knudsen and J. F. Shea, also known as Six Companies, Inc., were hired to build the dam for $49 million.
Herbert Hoover
The dam was named after engineer, conservationist, and thirty-first president of the United States, Herbert Hoover. In 1922, as Secretary of Commerce under Warren G. Harding, Hoover spoke before Congress on issues such as flood control and the pollution of rivers and beaches. Known as "The Great Engineer," as well as "The Great Humanitarian," Hoover was concerned about the destruction caused by flooding of the Colorado River, and proposed the construction of a dam in Boulder Canyon. However, the states through which the Colorado River flowed were in perpetual disagreement about water rights. Hoover met with the governors of each state and proposed that water be divided equally between the upper and lower basin states, allowing each basin to decide respective state's water rights. In 1922, the governors signed this agreement and Hoover's vision began to take shape.
Secretary of the Interior Ray Lyman Wilbur announced in 1930 that the dam would be named after the president of the United States. However, when President Hoover left office, the dam was renamed "Boulder Dam" by the new Secretary of the Interior, Harold Ickes. The current name was restored by Congress on April 30, 1947 when President Harry Truman signed a resolution in honor of the dam's original architect.
Boulder City
Work on Hoover Dam, led by engineer Frank Crowe, began under arduous conditions. The temperature climbed to more than 140 degrees Fahrenheit during the summer, and fell well below zero in the winter. In addition, thousands of workers moved to the desert with their families, and housing for the project's 5,000-plus crew was in short supply. Houses, roads, and water lines were constructed for the workers and their families, and the surrounding area eventually became Boulder City. A railroad was also constructed to bring heavy equipment and materials from Las Vegas to the construction site.
Construction
Workers labored throughout three shifts a day, every day of the week, and suffered from carbon monoxide poisoning, dehydration, electrocution and other work hazards. Workers used sticks of dynamite to blast holes in the canyon walls for tunnels, trying to keep a safe distance from the blasts while dodging falling objects. They would eventually make "hard-boiled hats," or hard hats, for themselves by covering cloth hats with coal tar.
At the same time, workers called "high scalers" were lowered over the edges of the canyon to clear loose rock and to chip away at the canyon to make it smooth so the dam would adhere. Although they received higher pay than other workers, the work was tremendously dangerous, since one slip could mean a plunge of hundreds of feet into the river below. One famous rescue involved an engineer who fell from the canyon rim and was caught by two high scalers who swung out from the wall to catch him. The engineer was pulled to safety by workers who dropped a line from above.
In addition to blasting almost a mile through canyon walls to make four concrete-lined tunnels to divert the Colorado River, two power plants had to be built, and ten million cubic yards of rock removed. Workers wedged 16-ton blocks of concrete, lowered from the canyon rims, into place. Cooling the concrete was a complicated and time-consuming process. Engineers devised a system whereby the concrete was poured in rows and refrigerated water was pumped through columns of blocks in pipes, which were filled in after the concrete had cooled.
The dam was completed two years ahead of schedule, on March 23, 1935, and water from the Colorado River began to fill Lake Mead, the 225-square-mile reservoir created by the dam. The powerhouse was also completed later that summer. The completed dam stood at 726 feet high (twice the height of the Statue of Liberty), 1,244 feet long, and weighed 6.6 million tons.
Estimates of the death toll during the construction of the Hoover Dam vary between 96 and 112, with countless injuries suffered by workers. The last man to die on the project was Patrick Tierney, whose father, J. G. Tierney, was the first man to die during the dam's construction, thirteen years earlier. On September 30, 1935, President Franklin D. Roosevelt delivered an address on Dedication Day, to celebrate the completion of Hoover Dam. Calling Hoover Dam "an engineering victory of the first order—another great achievement of American resourcefulness, skill, and determination," Roosevelt reflected the sentiments of Americans nationwide.
Recreation
Hoover Dam impounds Lake Mead, which at 10 miles wide and 115 miles long is the largest reservoir in the United States. In 2023, the Lake Mead National Recreation Area attracted more than 5.8 million visitors. Guided tours into the dam are also available in the new Hoover Dam Visitor Center, which also includes an art gallery. Visitors may also view the dam from an observation deck located in the visitor center.
Future
Global warming, climate change, and periods of prolonged drought in the twenty-first century have all negatively impacted the water level of Lake Mead and threatened the future power production of the Hoover Dam itself. In 2021, amidst a severe drought that affected a large swathe of the western United States, the water level of Lake Mead dropped to 35 percent of its total capacity—the lowest value recorded since its construction. The severe dry conditions in the region, which experts classified as a megadrought after it had been identified as the driest twenty-two-year span in more than one thousand years, led to both an increased need for water as well as an overall lower level of precipitation—causing a rate of loss in Lake Mead faster than it could be replenished. Amidst the ongoing drought, National Aeronautics and Space Administration (NASA) data demonstrated that the overall water level of Lake Mead had largely trended downward since the turn of the century. The following year, Lake Mead reached a second record low after water levels were recorded at 27 percent capacity in the summer of 2022.
Bibliography
Czachor, Emily Mae. "Lake Mead's Water Level Has Never Been Lower, Here's What That Means." CBS News, 4 Sept. 2022, www.cbsnews.com/news/lake-mead-water-level-historic-low-drought-heres-what-that-means/. Accessed 10 Dec. 2024.
"Nevada and Arizona: Hoover Dam." National Park Service, 7 Nov. 2018, www.nps.gov/articles/nevada-and-arizona-hoover-dam.htm. Accessed 10 Dec. 2024.
Sutton, Joe, and Kelly McCleary. "Lake Mead at the Hoover Dam to Reach Lowest Water Level in Decades." CNN, 8 Jun. 2021, www.cnn.com/2021/06/08/weather/hoover-dam-lake-mead-water-level-drought/index.html. Accessed 10 Dec. 2024.
Thomson, Jess. "Lake Mean Gives Nevada $358 Million Boost." Newsweek, 28 Aug. 2024, www.newsweek.com/lake-mead-national-park-nevada-tourism-economy-1945417. Accessed 10 Dec. 2024.