The construction of the Hoover Dam was born out of the need for the development and utilization of the Colorado River in the early 20th century. The Colorado River is one of the longest rivers in western North America, flowing through seven U.S. states and two Mexican states, and is an important source of water for the region. However, the Colorado River is also an unstable river, sometimes swelling and sometimes drying up, causing great disasters and hardship to the cities and farms along its banks. In order to efficiently manage and distribute the Colorado River's water resources, as well as to harness its hydroelectric potential, the United States passed the Colorado River Basin Project Act in 1928, authorizing the construction of a dam, as well as a reservoir and a power station. This was the beginning of the Hoover Dam.
The construction of the Hoover Dam was also influenced by another important historical context, the Great Depression. The Great Depression was a global economic crisis between 1929 and 1939 that led to unemployment, poverty and despair for millions of people. The construction of the Hoover Dam provided these people with hope of survival and also contributed to the economic recovery and social stability of the United States. The construction of the Hoover Dam was carried out with the support of Franklin D. Roosevelt**'s New Deal program, a series of policies and measures aimed at promoting economic development and social welfare. The construction of the Hoover Dam was also the first project in American history to be called a "super project", which showcased the ability of American engineering technology and innovation, and also inspired national pride and confidence in Americans.
The design of the Hoover Dam was undertaken by a consortium called Liuhe Company, which included Warren Bechtel, the founder of the Becktel Corporation, and his son, Steve Bechtel. Liuhe won the bid to build the Hoover Dam in 1931 for $49 million (equivalent to $7 in 2022).$6.3 billion1) to commit to complete the work within seven years. Liuhe's design was to build a concrete arched gravity dam, a type of dam that uses its own weight and arch structure to resist water pressure. The advantage of this dam type is that it can save the amount of concrete, and at the same time, it can also adapt to the shape of the canyon and increase the stability of the dam. The design height of the Hoover Dam is 7264 ft (221.)4 m), with a top length of 1,244 feet (379 m) and a base width of 660 feet (200 m), for a total volume of 3.25 million cubic yards (2.48 million cubic meters). The design of the Hoover Dam also included a reservoir, Lake Medde, and a power station, as well as a series of locks, tunnels, pipelines, pylons, and other ancillary facilities. The design of the Hoover Dam not only considers the function and efficiency of the project, but also considers the aesthetics and art of the project, adopting an Art Deco style appearance, as well as some decorative elements such as sculptures, reliefs, lights, etc., making the Hoover Dam an architectural masterpiece with both practicality and beauty.
The construction of the Hoover Dam was an unprecedented challenge and an unprecedented undertaking involving thousands of workers, hundreds of machines, dozens of technologies, and countless difficulties and dangers. The construction process of the Hoover Dam can be divided into the following main phases:
Preparation phase: The main task of this stage is to prepare the necessary work for the construction of the dam, including the construction of infrastructure such as roads, railways, bridges, barracks, hospitals, as well as the excavation of tunnels, diversion channels, installation of sluices and other water conservancy facilities. This phase also included diversion of the Colorado River, which diverted water from the dam's construction site into four tunnels, bypassing the dam's location and flowing downstream into the river. This frees up space for the construction of the dam and also reduces the risk of flooding. This phase lasted more than two years, beginning in March 1931 and ending in May 1933.
Foundation Stage: The main task of this stage is to lay a solid foundation for the construction of the dam, including clearing the rocks of the canyon, filling in the cracks, laying concrete cushions, etc. The difficulty at this stage is to perform high-intensity labor in a high temperature and high humidity environment, while also preventing cracking and shrinkage of the concrete. To solve these problems, workers use a method called "high-pressure water jets", in which a high-pressure water gun washes away loose material from the rock surface, making the rock surface smooth and solid. At the same time, workers also used a method called "pre-cooling", in which the temperature of the concrete is lowered with ice water before it is poured to reduce the heat and shrinkage of the concrete. This phase lasted more than a year, beginning in June 1933 and ending in August 1934.