The Itaipu Dam
The Itaipu Dam is one of the most spectacular engineering achievements of the modern world. It is situated in Brazil and Paraguay and while it provides massive amount of power to both the countries, its amazing structure attracts over a million visitors each year. The visitors usually go through an organised tour where they are told about its history, regarding the construction of this monstrous structure which still stands as a marvel of modern technology.
What is Itaipu Dam?
The Itaipu Dam is a hydroelectric project on the Parana River located on the Brazil-Paraguay border. It was jointly constructed by both countries and is currently the second-largest hydroelectric dam in the world, exceeded only by the Three Gorges Dam in China.
The dam is nearly eight kilometres long and rises to a height of 643 feet, while its reservoir stretches nearly 161 kilometres upstream. The power plant provides some 94 per cent of Paraguay’s energy supply, while it generates about 20 per cent of Brazil’s electricity needs. As for the name, it was taken from an isle that existed near the construction site, meaning ‘the sounding stone’ in Guarani language.
It was during the 1960s that the governments of both Brazil and Paraguay decided to use the seventh largest river in the world — Parana River — for their electrical needs. Since it formed a natural border between the two nations, they readily agreed to build a massive dam that would take in the river’s energy and turn it into electrical power.
Work began on the project in February 1971 but then Argentina raised concerns, as it believed that the dam could be used as a weapon in the future. The Argentine government believed that if all the gates of the dam were opened, it would flood Buenos Aires, their capital city. Hence, in October 1979, all three nations entered an agreement on the amount of water that could be released from the dam at any given time.
Construction and planning
Some 40,000 workers helped construct this dam and a new settlement to house them was also constructed, including hospitals, schools, parks and churches. The massive scale of the project can be gauged from the fact that the amount of iron and steel that was used for the Itaipu Dam project was enough to build 380 copies of the Eiffel Tower and more than 15 times the amount used in building the English Channel!
The engineers working on the project believed that making one dam wouldn’t solve the electricity problems of both Brazil and Paraguay; therefore they decided to go for a series of dams nearly five miles long and 738 feet high. This idea helped in creating an immense lake that allowed the Itaipu to produce more hydroelectricity than any other dam in the world (at that time!).
The four dams consist of one earth-fill dam, one rock-fill dam, a main dam built with concrete and one concrete wing dam. All the dams hold back the water based on their huge size and sheer weight. What makes Itaipu different from the rest of the dams is its cross section that looks like a huge triangle. The water pressure is greatest at the bottom, and narrow at the top, just like it should be in a triangle.
Formation of the lake
After the dam’s work was completed and the side canal’s gates were closed, the formation of the plant’s reservoir began in October 1982. The reservoir was filled by natural means (heavy rainfall) and when the water level reached 100 metres, the gates of the spillway were opened. However, it wasn’t until May 1984 that the first generation unit at the dam started running.
The Itaipu Dam has been selected as one of the Seven Wonders of the Modern World by the American Society of Civil Engineers. It has a great design that can match any other structure in the world, but it wouldn’t have been possible had it not been for the engineers, architects and those 10,000 families who had to be relocated to make way for the growing reservoir.
And, last but not the least, the sacrifice of the spectacular Guaira Falls that had to be submerged under the lake and then blown up with dynamite so that the river could pass there safely. The total height of Guaira Falls was more than twice that of Niagara Falls and a water flow that was more than double!