About The Hoover Dam
Hoover Dam, initially named Boulder Dam is a concrete arch gravity dam in the Balck Canyon and in 1936 upon its completion was the largest concret structure in the world, currently being the 35th biggest hydroelectric generating station. The dam in named in the honor of Herbert Hoover, the 31st President of the United States.
The contruction of the dam started in 1931 and was completed in 1936, while Lale Mead is the reservoir created by the dam.
The dam was designed to provide irrigation water flow, for flood control and for hydroelectric-power generation. After much debate, in 1928 the Boulder Canyon Project was approved and the initial appropriation for the construction was made in July 1930. The initial plans were the dam to be built in Boulder Canyon but it was in the end moved to Balck Canyon as it provided a better total control of the river.
The contract for building the dam was too demanding for just one company, so six construction companies formed the Six Companies, Inc. to acquire the bid. The contract was awarded to them on March 11, 1931 and construction started with the arrival dam builders from all over the country. The builders came with their families and a tent city was borned, having no electricity, poor sanitary conditions and poor water. To improve their life, the company was contracted to build a city, Boulder City, with schools, churches, post office as well as other facilities.
In order to avoid flooding the cosntruction site, two cofferdams were constructed. After the cofferdams were finished the excavation for the foundation of the dam started. The excavation work the foundation was completed in June 1933. To redirect the river around the construction site, four tunnels were made through the canyon walls with a combined lenght of almost 16,000 feet.
The two vertical foundations for the arch walls neede to be founded on sound virgin rock, so all the loose rock had to be removed with jackhammers and dynamite.
Concrete started to be poured into the dam on June 6, 1933. As no such huge structure had even been constructed, many innovative procedurs were used that were never tried nefore. To avoid uneven cooling and contraction of the concrete, the dam was built in a succession of interlocking trapeziodal concrete pours. The dam contains enough concrete to pave a two-lane highway from San Francisco to New York.
During the construction of the dam various accidents occured and 112 deaths are associated with the construction.
The total gross power rating for the plant is about 2080 megawatts. The Dam’s Hoover Powerplant started transmission of electricty on October 26, 1936, while additional generating units were added through 1961.
The hydroelectric power plants can vary the amount of generated power beased on the demand. The power generation allows the dam to repay the 50-year construction loan and continues to pay the huge yearly maintenance budget.
The construction of the Hoover Dam had a destructive impact on the Colorado River Delta at the mouth of the Colorado River. The dam stopped the natural flooding dangering many species adapted to the flooding.
The magnificent, massive and imposing structure is one of Las Vegas’ tourist attractions, being visited by millions of people each year. Hoover dam also has two lanes for automobile traffic on the top of the dam, serving as the Colorado River crossing for the highway U.S. Route 93.
For better highway capacity, a Hoover Dam bypass is set to completed in 2010, diverting the U.S. 93 traffic 1,500 feet downstream from the dam. As soon as the bypass is completed, no such traffic will be permitted across Hoover Dam.
