The Hoover Dam is one of the most impressive feats of engineering in the U.S. The history of Hoover Dam began in 1930 and, to this day, it remains one of the most important structures in the country. It’s even designated as a National Historic Landmark and is one of the U.S.’s Seven Modern Civil Engineering Wonders.
The creation of such a structure did not come without sacrifice and hard work, costing not only years of construction but also the lives of many of its workers. To date, this endeavor produces enough power to serve over 1.3 million people in multiple states and remains one of the most magnificent creations of its time.
The Purpose of the Hoover Dam
In the late 19th century, the U.S. began efforts to develop the American southwest, but the arid landscape proved difficult for local farms and towns. Developers and farmers wanted to use water diverted from the Colorado River in this area, but its erratic flow and frequent floods caused many projects to fail in the long term.
Then, in 1922, these plans were revisited by the Bureau of Reclamation as the need for water and energy grew along with nearby cities. This time, however, the plans also included using the Colorado River as an energy source. With rushing rapids, this river had extreme potential as a source of hydroelectric power.
The Bureau determined that an arch-gravity dam was best suited for the Black Canyon gorge, but this design had never been used on such a scale. Arch-gravity dams curve upstream, using the force of oncoming water to push the structure into the canyon walls.
After much lobbying, President Calvin Coolidge finally authorized the project’s beginning in 1928, originally called the Boulder Dam.
Preparing for the Hoover Dam
In 1930, construction on the Hoover Dam began. As this was the onset of the Great Depression, more than 10,000 individuals heard of the project and migrated to nearby Las Vegas and the surrounding area hoping to find work on this massive construction project. This move proved successful, as the Hoover Dam required the effort of over 20,000 laborers in its creation.
Thousands of migrants even lived in a makeshift encampment called Ragtown, until the government designed and built the still-active Boulder City, a town 5 miles away from the dam used to house workers.
Before construction began, the Colorado river had to be rerouted. Workers blasted open diversion tunnels to install 17-meter tubes to divert 5,600 cubic meters of water per second elsewhere. By the fall of 1932, the river had been rerouted and the second preparatory phase began.
Over 1,000,000 cubic meters of rock then needed to be cleared from canyon walls. This work was done by high scalers – workers who descended the cliffs on ropes and removed rubble with jackhammers and dynamite.
Building the Hoover Dam
Once the walls were cleared, it was time to build the Hoover Dam. As the then-tallest dam in the country, about 6.6 million tons of concrete was needed for the process. This is enough concrete to pave a road across the continental U.S.
Since this concrete couldn’t be poured at once, it was poured in interlocking blocks of different sizes. These blocks contained steel pipes flowing with cold water to help the concrete harden.
By 1935, most of the structure was completed – a whopping two years ahead of schedule! On February 1st, the diversion tunnels opened so water could rush into the dam’s reservoir.
At its completion, it stood as the tallest manmade structure in the world at 726 feet and spanned 1,244 feet across. It took 5 years to finish and completed the goal of taming the Colorado River and watering the parched landscape of the southwest.
The Cost of the Hoover Dam
Such a large endeavor cost the U.S. around $49 million, which would equal about $760 million in today’s world. Considering the cost of the power plant and generators would add an additional $71 million to the price tag. Even at this cost, the dam has since paid back its construction and then some with the sale of its electrical power over the years.
The highest cost of the history of Hoover Dam was not its infrastructure, but the over 100 people that died during its construction. Creating the reservoir also destroyed local communities, such as Saint Thomas, and devastated the Colorado River’s ecosystem.
The Power of the Hoover Dam
The Hoover Dam’s power plant contains one of the largest hydroelectric installations in America to this day. The day is powered by 17 turbines, which run at a combined horsepower of 3 million. Water rushes through four penstocks – two on each side of the Colorado River – into the turbines and generates about 4 billion kilowatt-hours of hydroelectric power annually.
The reservoir behind the dam is Lake Mead, which formed after damming the Colorado River. It is 233 square miles big. This lake can store up to 8.5 trillion gallons of water at its peak capacity, making it the largest reservoir in the U.S.
Overall, the Hoover Dam currently serves 1.3 million people in Nevada, Arizona, and California.
Fun Facts About the Hoover Dam
- The U.S. Bureau of Reclamation still operates the Hoover Dam today.
- Although President Calvin Coolidge authorized the project, the dam was built during the presidency of Herbert Hoover, hence its name change. It took some years for the name change to catch on, however, as there were some negative connotations with the Hoover name during the Great Depression.
- Boulder City was originally on federal land, being run by the Bureau of Reclamation. It wasn’t until 1960 that the government relinquished control of the city.
- The Colorado River basin has been experiencing a drought for the last 15 years, causing Lake Mead to currently stand at its lowest levels since it was first filled.
- During WWII, the dam was the target of a bomb plot by Germany, but the plan was luckily discovered and evaded.
The history of Hoover Dam is filled with challenges, great effort, and wonder, and it no doubt led to the construction of one of the most awe-inspiring infrastructures in U.S. history. With the ability to provide power to over a million Americans across three states, this engineering marvel remains a great example of the power of renewable energy even almost 90 years after its construction.