25 October 2011

Spectacular Dams around the World

The sight of a dam – some of the largest constructions that humanity has ever created – can be quite breath-taking. Take a look at some of the most spectacular of these structures.

The Hoover Dam
This was considered one of the marvels of the twentieth century when it was built and even though its size and energy generating capacity has been surpassed it is still possibly the most famous and iconic dam in the world. It was completed in 1936 and still has a gothic cum deco inspired feel to it which renders it art while many other dams simply have utility.

It is named after President Hoover who has an instrumental role in its construction. It has been a national historic landmark in the United States since 1985. Its statistics are impressive as well – it is two hundred and twenty one meters high and has a thickness at its base of two hundred meters (fifteen at its crest). That is quite a lot of concrete. Over a hundred people died in its construction including a father and son – JG Tierney a surveyor (popular history maintains he was the first person to die). His son, Patrick W died thirteen years to the day later and is purported to be the last to die on the project.

Grande Dixence
Switzerland is by no means the largest country in Europe but its gas the highest on the continent. Its job is to hold back a lake – the Lac des Dix – and when full it is almost a thousand feet deep and contains more than four hundred million cubic meters of water. As for its altitude, how about an amazing 2365 meters?

Strangely enough, the river upon which it is built is pretty small (the Dixence). However, water is collected in to a system of tunnels over one hundred kilometers in length which takes water from the river and from others. The water is mostly from glaciers. Filled in 1957, this current dam submerged the previous one which had stood since the nineteen twenties.

The Karun Dam – Iran
Whether or not you agree with the aims of the Iranian government to join the nuclear club (ostensibly to help with the massive power shortages of this populous nation) there can be no argument in terms of their attempts to meet the power demands of the country. The massive Karun 3 opened in 2005 and it does indeed go a long way to satiate the demand for electricity.

It is just over four hundred and sixty meters in length and stands at a height of two hundred and five meters. It is an arch dam, which is perfect for that rocky, narrow gorge in which it was built. The curve is more than just an aesthetic feature – the arch forces the water to press downwards against the dam. This strengthens its foundations. Simply amazing.

Dworshak Dam - USA
Construction of the Dworshak dam began in 1966 and it was completed only six years later with the generators up and running in 1973. It was built in the state of Idaho about six kilometers away from the city of Orofino. It is the highest straight axis dam in the western world and at two hundred and nineteen meters in height is the third tallest dam in the United States. The reservoir that was formed behind the dam is over eighty kilometers in length.

The Inguri Dam - Georgia
Georgia is well known for being the birthplace of Stalin (by now you will have guessed we are not referring to one of the United States) and this dam was built at the height of Soviet engineering. Although started in the early sixties it did not become functional until the nineteen seventies. This notwithstanding, the dam is still the highest concrete arch dam in the world.

It reaches two hundred and seventeen meters which is an astonishing eight hundred and ninety feet. With the collapse of the Soviet Union, when borders within the USSR were not really a problem, this dam found itself (still) inside the borders of Georgia. The hydroelectric power station, which is serves, however, is partially in the Republic of Abkhazia. Abkhazia and Georgia do not get on very well at all. Oops.

Nagarjuna Sagar Dam - India
Built across the Krishna River in the Andrha Pradesh area of India, the Nargana Sagar towers at one hundred and twenty four meters in height and is able to hold almost twelve million cubic meters of water. This makes it the largest dam in Asia – at the moment. It is also one of the oldest. Construction began in 1956 but it was a long time before it became fully functioning.

Modern construction equipment was not available in the fledgling democracy of India and so the dam was built with stone instead of concrete. As you can imagine this took some time and it was not until 1969 that the dam was completed and three years later that the crest gates were fitted in order to facilitate full usage. Up to seventy thousand people took part in its construction, with close to two hundred dying in dam related construction accidents.

Srisailam Dam
We will stay in India – and indeed the Krishna River, for now to visit the Srisailam Dam. It is part of the same project to bring hydroelectricity to the millions of people who live along the river and beyond. It is built in a huge gorge in the Mallamala hills and is over five hundred meters long.

It may seem to be over icing the cake, but when you realize that the region in which it is situated is extremely prone to drought you begin to understand why size is sometimes important. Although this image is not perfect it is one of the few copyright free photos available of this dam – special permission is needed to go near it.

Glen Canyon – USA
The stunning landscapes of Colorado provide a back drop for the Glen Canyon dam, which is build on the Colorado River in Arizona. As might be guessed by the surroundings, the place is arid and the mission of the dam is to provide water storage for this particularly dry part of the United States. It stands at two hundred and sixteen meters high and the crest of its arch has is four hundred and seventy fie meters long.

It has been criticized for the environmental impact it has had on the local flora and fauna (as have most of the dams on this list to be frank) but sustains large communities of people spread over three states.

Vajont – Italy
One hundred kilometers north of Venice there is the Vajont Dam, which was finished in 1959. One of the greatest dam tragedies of all time occurred in 1963 when the overtopped and a massive flood wiped several villages below the dam off the face of the earth and killed more than two thousand people. An enormous landslide fell in to the reservoir and displaced fifty million cubic meters of water. The wave that overtopped the dam has been estimated as over two hundred and fifty meters in height and the people below did not stand a chance.

It has been cited as one of the five worst man made disasters (caused by geologist and engineer failure). It stands a more than impressive two hundred and sixty two meters high and is twenty seven meters thick at its base. Ironically when the dam overtopped it was itself left pretty much intact – only the top meter or so was destroyed.

Sayano-Shushenskaya -  Russia
Ah, those Russians! The power plant that this dam supports is the fourth largest in the world and it was opened in 1978. Another example of the gravity arch dam, this one has a crest of almost eleven hundred meters in length. The arch itself is two hundred and forty five meters height. The dam itself forms a reservoir of the same name, which covers over thirty cubic kilometers and a surface area of over six hundred square kilometers. That is large, by any standards.

Almendra Dam – Spain
Salamaca, Spain is the home to the Almendra dam. It was named after the village of Almendra (which means Almond in Spanish) but, as with many of life’s little ironies, it interrupted the course of the river five kilometers away from the village.

The reservoir behind the dam covers almost ninety square kilometers and this makes for a breathtaking view. At a height of just over two hundred meters it is one of the tallest structures in the whole of Spain.

Itaipu – Brazil
The Itaipu dam of Brazil is given its name from a small island that used to exist near the site and it means “the sound of a stone”. One can only imagine what the dam sounds like when it releases its water. The length of the dam is a staggering 7235 meters and at its highest it is two hundred and twenty five meters. To be fair to the other dams on this list, however, it is actually three dams joined together to make one enormous structure.

Three Gorges Dam – China
Although China has many of the world’s largest dams their reluctance to allow people to take pictures of them means that its most famous and accessible – the Three Gorges – is the only one to make this list. To facilitate its construction one and a quarter million people had to be relocated. Although spectacular it is thought that it has contributed greatly to the functional extinction of the Yangtze River Dolphin, a creature which had been around for several million years. At what price, we can only wonder, do all these amazing structures come?