Hoover Dam and Lake Mead
When construction began on Hoover Dam in 1931 the consortium responsible for its completion, Six Companies Incorporated, were embarking on a project in which they would build the largest concrete structure yet attempted. They completed the project and handed Hoover Dam over to their customer, the United States government, in 1936, more than two years ahead of schedule. The building of the dam led to the creation of Boulder City as a community for the construction workers and Lake Mead, the largest water reservoir in the United States when it is at full capacity.
Hoover Dam provides hydroelectric power to Arizona, California, and Nevada, and water for irrigation across otherwise arid land. Three and one quarter million cubic yards of concrete were poured to create the arch-gravity dam, and as of 1995 the still curing concrete was continuing to strengthen. Over 100 workers died during the construction of the dam, three of whom were listed as suicides committed on the construction site. Diverted water from the Colorado River was allowed to flow to the base of the dam, beginning the creation of Lake Mead, in 1935 as concrete was still being poured. The powerhouse was completed as Lake Mead slowly filled.
Lake Mead was and is the largest water reservoir in the United States by volume when it is filled to capacity, which it has not been for decades. Extended drought and demands for water from the Colorado River have decreased the water levels of the lake. This has led to several of the power generators being replaced with new equipment designed to function efficiently with decreased water flow. Lake Mead provides water for the use of nearly 18 million people. It also is the source of irrigation water for over one million acres.
For most people unaware of the complex’s importance providing both water and power, Lake Mead and Hoover Dam are major tourist attractions. Visitors to the lake have found many boat ramps and docks have been moved from their original locations or closed permanently as the water level in the lake recedes. The lake, which receives the majority of its water through the melting of snow in the mountains, is expected to decline further during the next several years, and as of early 2018 was at just under 40% of its capacity. Continuing changes to climate and the resulting alteration of weather patterns are an increasing concern.
Las Vegas, Nevada, draws its drinking water from Lake Mead, and concerns over its ability to continue to do so led to the drilling of a water feed tunnel at the elevation of 860 feet, completed in 2015. The dam will cease electrical power generation if the water level drops below 950 feet, only about 100 feet less than its current level. Hoover Dam was a financial success, paying off its construction loans ahead of schedule due to the sale of the electricity it generated. It remains a highly visited landmark, and the water from its reservoir supported the growth of Las Vegas and other communities. Now both Lake Mead and Hoover Dam are threatened by the very success they created.