Wednesday, December 7, 2011

The magnificent HOOVER Dam

23rd June 2005  was a day to remember for us as the day started in Las Vegas, followed by a visit to the magnificent Hoover Dam and a delightful view of the Grand Canyon in the evening.  After breakfast in Las Vegas we started the journey to a place called Williams on the outskirts of Grand Canyon.  After about an hours drive in Nevada, we entered the meeting point of borders of Nevada, Arizona and California.


Colorado River rises in the snow capped mountains of north central Colorado and zig zags south west for over 1400 miles before reaching Gulf of California. The river was very unpredictable – flooding in spring, drying in winter. Its floods used to cause havoc and heavy loss of property. Seven western states and Mexico have interests in Colorado River basin comprising the river and its six tributaries. An agreement by name "Colorado River Compact" was entered into in Santa Fe, New Mexico on 24 th November 1922 by the seven participating states – Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming. Mexico was not originally included in the compact, but United States and Mexico entered into a treaty on 3 rd February 1944 under which Mexico is guaranteed of 1.5 million acres-feet of water annually, subject to increase or decrease according to circumstances. The Hoover Dam constructed as a result of these agreement/treaty stores 7.5 million acre feet of water annually and after apportioning 1.5 million acres-feet of water to Mexico, the remaining 6 million acre-feet of water is shared by the seven riparian states in an agreed proportion. An acre foot of water is equivalent to one foot water standing on an acre of land.  

The site for the project chosen is on the border of Nevada and Arizona and 30 miles south east of Las Vegas in the black canyon, on the present Interstate Highway 93. The dam stands on hard and durable rocks and considered stable. Civil construction of the dam was started on 6 th June 1933 by pouring the first concrete and completed in less than two years on 29th May 1935. Entire project from the drawing board stage to completion took five years as against seven years allowed to contractors. This is to be viewed in the background of ever repeating cost and time overruns of today's projects. The construction was itself done in a harsh and barren land in the middle of desert and rocky black canyon, in the background of the great depression after 1929. An average of 3,500 to 5,200 workers worked on the project. The dam was planned as a multi-purpose project to control floods, store water for irrigation, municipal and industrial use, and generate hydro electric power, recreation, fish and wild life habitat.

Some statistics about the project provide an insight into its gigantic structure and benefits derived from it. It was the biggest dam when construction was completed in 1935. Bigger dams have been constructed in the later years but this  dam is still considered as an engineering marvel and among the top twenty big dams around the globe. The construction was itself in the years after the great depression and work completed in a record five years against the target of seven years. Entire cost of the project was planned to be recovered from sale of the hydro electric power generated at the site.

The dam stands 726 feet high from the foundation rock to the roadway at the crest. Towers and ornamental constructions on the parapet walls rise another 40 feet above the crest gates. The dam weighs more than 6.6 million metric tons. The construction is called in engineering terms as "Concrete Arch Gravity Type", in which the enormous water load is carried by both gravity action and horizontal arch. More than 5 million barrels of cement was used for making 4.36 million cubic feet of concrete – the amount of concrete used would suffice to make a 16 feet wide highway diagonally across the country from New York in the north east to San Francisco down south in the west. The dam holds 7,500,000 acres-feet of water which is equal to a little over 9255 billion liters. The water is sufficient to cover the entire Pennsylvania state with one foot of water!  The 17 turbines in the generating stations at the dam site generate 2074 MW of electricity every year.

Herbert Hoover, being a Californian himself and witness to the devastation caused by the floods in the river Colorado took active interest in the multi-purpose project. An engineer himself, he foresaw the project's benefits to the seven participating states and as Secretary of Commerce in 1922, played a major role in bringing the participating states into agreement and sign the "Colorado River Compact" paving way for construction of the dam. The work was delayed and did not start until 1929. Herbert Hoover later on became the nation's 31st President and pursued the project implementation. He was a man of many interests –besides being an engineer and politician he was also a great humanitarian and took active part in relief and rehabilitation in the great floods of the Mississippi river. He laid emphasis on controlling flood damage,  clean beaches and environment. Dam constructed on the river Colorado was to be named after him but the administration referred the same as "Boulder Dam" or "Boulder City Dam", after the town that sprang up near the dam site during construction. In1947 a resolution was passed by the 80 th Congress to officially name the dam as "HOOVER" dam in honor of a man who worked closely for its construction.

A five level conducted tour of the dam started as we reached the dam site. There was a presentation on the dam in the auditorium at the visitor's center explaining construction of the dam and what it means to the west. From there we were led to the generating station. A guide explained about the various aspects of power generation in the plant. Thereafter it was a trip to see the dam from outside, from the road on the dam itself and a museum about the construction of the dam. We took many photos and enjoyed the scenery, guided tour and the vast expanse of water in the dam which has changed the life in the area for ever triggering growth in agriculture, industry, tourism and overall development of the vast area in its hinterland.

There are many bigger dams constructed later on, but Hoover Dam remains a fine piece of engineering wonder as well as a tourist's delight.

2 comments:

  1. Great Sir,

    We could follow the journey to HOOVER Dam site and view it within 15 minutes. Thank you.
    Basavaraju K

    ReplyDelete
  2. Dear Mr.Keshava Murthy,

    An exhaustive information and teh background for the dam construction and the man behind it.THank you. IT would be useful in understanding and appreciating it better when we visit the dam shortly.

    ReplyDelete