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Hoover Dam

Building Hoover Dam
Hoover Dam is one of the great tourist sites of America’s south west, and was one of the 20th century’s greatest engineering projects. Originally called Boulder Dam, it was renamed for Herbert Hoover, President when construction was begun and himself a famous engineer. The dam created Lake Mead, the largest reservoir in the United States, and is today visited by more than a million people a year. Hoover Dam is operated by the Bureau of Reclamation of the U.S. Department of the Interior, which maintains a Visitor Center and offers tours of the dam and power plant.

The dam was built in the Black Canyon of the Colorado River, on the state line between Arizona. The project was begun in 1928, but construction took place between 1931 and 1936 and employed many workers idle because of the Great Depression. About 5,000 workers were involved in building the dam, and 112 men lost their lives during its planning and construction. The dam cost $49 million, which is equivalent to about $900 million today.

The concrete gravity-arch dam is 726 feet tall, 1244 feet long and 1232 feet above sea level at its crest. The dam has a volume of 3.5 million cubic yards, and its 2 spillways can release water at 400,000 cubic feet per second. Lake Mead, behind the dam, receives river water from 168,000 square miles, and is 112 miles long and 590 feet deep, with a surface area of 247 square miles. The power station at the dam contains 19 turbines of different sizes installed between 1936 and 1961, which generate approximately 4.2 billion kilowatt-hours of electricity per year.

Why Hoover Dam was Constructed?
The propensity of the Colorado River to flood and the need for water in the desert Southwest became apparent in the 19th century, and a number of canals were dug to divert water and control the floods before 1900. These were largely unsuccessful, and efforts focused after 1900 on damming the river up in the Black Canyon. The growing population of California and Arizona also needed electricity, and California electric utilities had developed several plans for dams capable of generating hydroelectric power but were not able to get these started and allowed their options on the land to lapse.

The Reclamation Service of the Interior Department, now the Bureau of Reclamation, had the idea around 1920 of dynamiting the Black Canyon and collapsing its walls into the river to dam it up, but abandoned this plan in 1922 in favor of constructing a concrete arch-gravity dam that was thick and the bottom and thin near the top, holding back water with a concave surface and allowing a highway to cross between Nevada and Arizona on the top. This was a construction project of almost unprecedented size, however, and it took several years to figure out how to do this; extremely hot weather also slowed the work for several years. Congress approved the project in 1928, but it took 3 years to award the work to a consortium of six companies.

Work was begun in 1931, and the small city of Las Vegas, then with a population of some 5,000 and not yet a gambling mecca, had hoped to be the center of construction and in fact closed down its principal industries of illegal liquor sales and prostitution. The Interior Department instead decided in 1930 to first build the “model town” of Boulder City at the dam site, but a railroad line was put in from Las Vegas. As the Depression worsened, as many as 20,000 unemployed men descended on Las Vegas in hopes of finding work, and several large camps were built to house them. Dam construction was at first slow, as the Colorado River had to be first to be diverted by a group of subsidiary dams into a group of tunnels, and there were delays because of strikes and lack of money.

There were stories at the time of men being entombed in concrete in these tunnels and within the dam itself, but there is no evidence that this actually happened. The project permanently changed the construction industry in one way: in order to protect themselves against falling objects, workers dipped their cloth hats in tar and allowed them to harden. The “hard-boiled” hats prevented serious head injuries, and under the name of “hard hats” the helmets became standard worksite headgear around the world.

Dissatisfaction also developed with the initial design of the dam, and Los Angeles architect Gordon Kauffman, Denver artist Allen Tupper True and Norwegian-born sculptor Oskar Hansen were brought in to redesign the dam’s exterior. Their work, combining Art Deco and native American motifs, became some of the most striking features of the dam. Unfortunately, the security restrictions put in place after the attacks of September 11, 2001 have made it impossible to see many of these decorations.

A large clock tower was also constructed, showing the time in Nevada, which is in the Pacific Time Zone, and Arizona, which is on Mountain Time; because Arizona does not observe Daylight Saving Time, the two clocks show the same time for half the year. The power station was begun in 1933 and was not finished when the dam was decorated but was completed about a year later, and was made bombproof with walls of concrete, rock and steel that are 3.5 feet thick.

Controversy behind Naming Hoover Dam
The dam was nevertheless finished about 18 months ahead of schedule in 1936. Although originally called the Boulder Dam Project, it had been decided to name the dam after President Hoover in accordance with U.S. custom. This was not agreeable to Franklin D. Roosevelt, who had defeated Hoover in the 1932 election and who dedicated the dam on September 30, 1935. Hoover was not invited to the ceremony, Roosevelt did not mention his name and the dam was christened “Boulder Dam”; in his speech that day, Interior Secretary Harold Ickes said “Boulder Dam” five times in 30 seconds. In 1947, however, Congress officially named the structure Hoover Dam.

There was enough water in the lake to operate the turbines by 1936, and the power station officially went on line in 1937. By 1939 the dam was the largest hydroelectric generating facility in the world, and the proceeds of power sales in California and Arizona paid off the 50-year construction loan well ahead of schedule and now covers the maintenance expenses of several million dollars a year. The river’s water is now distributed to 8 million people in California, Arizona and Nevada.

How to Get There and How to Get In
Hoover Dam is about 30 miles south of Las Vegas on U.S. Highway 93, and the trip takes about 45 minutes. The trip from Phoenix on Interstate 40 and the U.S. 23 takes about 4 hours. Vehicles can drive across the dam to viewpoints in Arizona, but can no longer get on Highway 93 in Arizona and must cross back into Nevada. It is now necessary to leave Highway 93 at Nevada route 172, and to undergo a security check, in order to drive to the dam. A four-lane Highway 93 bypass bridge was opened 1500 feet downstream in 2010, and this now connects Nevada and Arizona.

About 450 cars can park on the Nevada side of the dam, for a fee of $10. On the Arizona side, there are 4 free lots and one close in costing $10, and recreational vehicles and cars with trailers must park there. It is about a quarter-mile walk across the dam from the Arizona side. Admission to the Visitor Center is $10 for anyone over age 3; a one-hour tour of the dam and power house for visitors at least 8 years old is $30 and the 30-minute power plant tour is $15 for adults, $12 for those over 62 and 4-16 years old and free for children and military personnel.

Hoover Dam is well worth seeing as a National Historical Landmark and one of America’s Seven Engineering Wonders as designated by the American Society of Civil Engineers. At 80 years of age, it still symbolizes America’s ability to complete great projects in spite of adverse circumstances.