What Happened on July 7th – Hoover Dam

Five years to build but thirty years in the making, construction began on the Hoover Dam on July 7, 1930.  Over the next five years, 21,000 men would work to produce the largest dam of its time and the largest manmade structure in the world.

Workers on a “Jumbo Rig”; used for drilling Hoover Dam’s tunnels

The brainchild of an engineer with the Bureau of Reclamation, Arthur Powell Davis began his vision for the dam back in 1902.  His engineering report on the topic was the guiding document when plans were finally made to begin the dam in 1922.

 

Arthur Powell Davis

Herbert Hoover, the 31st President of the United States played a crucial role in making it happen.  As secretary of commerce in 1921, Hoover dedicated himself to the erection of a high dam in Boulder Canyon, Colorado to provide for flood control to prevent damage to downstream farming communities.  The dam would also allow for irrigated farming in the desert and provide dependable water supply for Los Angeles and other southern California communities.

Hoover Dam construction

Due to fights over water rights, Hoover had difficulty getting the approval from congress.  He negotiated the Colorado River Compact which broke the river basin into two regions so the water was divided between them before he could get the bill passed by congress.  The House and Senate finally approved the bill in 1928. In 1929, after becoming President, Hoover signed the Colorado River Compact into law.

The drawing shows how the completed Hoover Dam works. The Nevada wall of the Black Canyon (to the left) is shown solid, but the Arizona wall (to the right) shows with broken lines what the internal structures behind the wall look like. Credit: Encyclopædia Britannica, Inc.

After the preparations, the project moved forward and was completed two years ahead of schedule and millions of dollars under budget.  Today the Hoover Dam is the second largest dam in the country and the 18th largest in the world.  It generates enough energy each year to serve over a million people.