"The Greatest Dam in the World":  Building Hoover Dam--Reading 1
Reading 1:  The Bureau of Reclamation and
Hoover Dam
Before the building of Hoover  Dam, the Colorado River was dangerous and unreliable.  Melting snow in the mountains caused damaging  floods during the late spring and early summer.  Unpredictable flash floods could occur in any season.  By mid-summer, the river’s flow was barely  enough to supply the farms in southern California and Arizona that depended on  it.
In 1905, the Colorado River  flooded rich, irrigated farmland in the Imperial Valley in southern California.   It caused  enormous damage and permanently flooded thousands of acres.  Over the next 20 years, Congress spent over  $10 million trying to protect Imperial Valley farmers from floods.
Reclamation engineers began  to study the Colorado River soon after passage of the Reclamation Act in 1902.  They were looking for places to build dams to  store the water from the annual spring runoff, releasing it gradually during  the summer for irrigation.  Initially the  agency built some relatively small dams on the river’s tributaries.  By the early 1920s, most people thought that building  a big dam on the lower Colorado was the best way to store water to irrigate the  low-lying valleys of Arizona and southern California and to protect them from  floods.  By this time, too, developers in  Los Angeles and other rapidly growing cities in Southern California had added  their powerful support for the project.  They  saw the dam as a potential source of water and hydroelectric power for homes,  businesses, and factories.
In 1922, the seven states of  the Colorado River Basin met to decide how to divide the waters of the river.  Herbert Hoover, at that time the secretary of  commerce for Republican President Calvin Coolidge, led the discussions.  Most of the states were afraid California was  going to get more than its fair share of the water.  Ultimately, they managed to agree on a  document, called the Colorado River Compact.  The compact estimated that the river’s annual flow would be 16.5 million  acre-feet, allocated 7.5 million acre-feet each to the Upper Basin and the  Lower Basin, and set the amount of water each of the states in the Lower Basin  would receive.  The compact also  committed the U.S. government to providing some of the water to Mexico.  Some states were not happy about the compact;  Arizona did not ratify it until 1944.  It  did permit planning for the dam to proceed, however.
Also in 1922, congressional  representatives from California introduced a bill to authorize Reclamation to  build the big dam on the lower Colorado.  However, it took six more years before Congress passed the Boulder  Canyon Project Act.  The new law laid out  four goals for the new dam:  prevent floods,  improve navigation on the river, store and deliver the Colorado’s waters, and  generate electric power. 
Reclamation’s engineers were  looking forward to designing the huge dam.  By this time, they were among the most knowledgeable and experienced dam  builders in the world, but even they had never done anything this big.  Hoover Dam would be the highest dam in the  world, far taller than anything they had built so far.  The lake it created would be the largest in  the world.
The proposed dam would be so tall  and the pressure of the water it held back so great that many people were worried.  They weren’t sure that even Reclamation’s  engineers had enough knowledge and experience to make the dam strong and  safe.  Others wondered whether the  expected benefits would be enough to justify the enormous cost.  Despite these questions, planning and design went  forward. 
In March 1931, Reclamation  awarded the contract to build the dam to Six Companies, Inc.  Six Companies was a group of some of the  largest construction companies in the country.  They joined specifically for this project.  The contract divided the work between Six Companies  and Reclamation.  Reclamation engineers designed  the dam and created the hundreds of detailed plans and specifications that the  contractors would follow.  They paid for  all supplies and inspected the contractor’s work.  If the work was consistent with the plans,  they approved it for payment.  Six  Companies was responsible for converting Reclamation’s designs into actual  concrete and steel.  They hired and  housed the workers.  They transported  supplies to the dam site.  They were  responsible for keeping the project on schedule and within budget.
The plan was for construction  to start in the fall of 1931, in the depths of the Great Depression, which had  begun with the stock market crash of 1929.   Herbert Hoover, now president, wanted  to start work on the dam earlier, probably as a way to ease high unemployment.  Work actually began during the summer and  continued around the clock until the dam was completed in 1935, two years ahead  of schedule.  By this time, Franklin D.  Roosevelt, a Democrat, had been elected president.
The huge dam on the Colorado  captured the imagination of journalists, authors, and filmmakers.  It was conceived and launched under  Republican administrations, but for many people it seemed to represent  Roosevelt’s New Deal in action.  The New  Deal was famous for using public works projects to put Americans back to  work.  During a dark time, Hoover Dam seemed  to transcend Americans’ fears about the future. In the early 21st century, almost  a million visitors a year still come to see the great dam on the Colorado River.
Hoover Dam is 1,244 feet long  at the top.  It is 726 feet high from the  lowest point of the foundation to the crest.  The dam is 660 feet thick at the base and tapers to 45 feet thick at the  top.  Its reservoir was the largest  artificial lake in the world for decades and is still the largest in the United  States.  The huge volume of water stored  in the reservoir weighs so much that it deformed the earth’s crust, causing  more than 600 small earthquakes in the late 1930s.
Questions for Reading 1
1. Why did many people think something needed to be done to control the Colorado River?  What sort of problems did the river create?  What benefits would controlling it provide and to whom?
2. Why were congressional representatives from the state of California the leading supporters of a big dam on the Colorado?
3. Why do you think President Coolidge's secretary of commerce led the discussions leading up to the Colorado River Compact?  What role might the federal government be able to play in making decisions like this?
4. An acre-foot is the volume of water that would cover one acre one foot deep. Why do you think they used a measure like that, rather than something like gallons?  How many gallons of water are in an acre-foot?  How much would that weigh?
5. Why do you think Reclamation’s engineers were  excited about building the big dam?  What  were some of the concerns people had about its construction?
6. How did Reclamation and Six Companies divide the  work on the dam?
Reading 1 is adapted from  Joan Middleton, “Hoover Dam" (Mohave County, Arizona, and Clark County,  Nevada) National Register of Historic Places Registration Form (Washington,  D.C.: U.S. Department of the Interior, National Park Service, 1981); Joan  Middleton and Laura Feller, “Hoover Dam" (Mohave County, Arizona, and  Clark County, Nevada) National Historic Landmark documentation (Washington,  D.C.: U.S. Department of the Interior, National Park Service, 1985); William D.  Rowley, The Bureau of  Reclamation:  Origins and Growth to 1945, Vol. 1 (Denver CO: Bureau of Reclamation,  U.S. Department of the Interior, 2006); and Donald C. Jackson, “”Origins of  Boulder/Hoover Dam:  Siting, Design, and  Hydroelectric Power,” in The Bureau of Reclamation : History Essays from  the Centennial Symposium (Denver,  CO:  Bureau of Reclamation Department of  the Interior, 2008), 273-288.