The Guairá Falls were, until 1982, the largest waterfalls in the world by water volume. With 49 million liters per second, the 18 falls that formed them doubled the volume of the Niagara Falls and surpassed in 12 times that of the Victoria Falls.
They were located on the Paraná River, along the border between Brazil and Paraguay. The 18 falls were distributed in 7 groups, hence their name in Portuguese (Salto das Sete Quedas), the largest reaching 40 meters in height, and the noise they produced could be heard at a distance of 20 kilometers.
An agreement between the two countries in 1973 to build a joint hydroelectric dam condemned the falls to disappear under the artificial lake formed by it. From the beginning of the works, and during the 9 years that lasted, thousands of tourists, curious and neighbors of the nearby localities approached to contemplate for the last time the Guairá Falls.
By January 1982 the collapse of visitors was such that the 90-meter long Roosevelt suspension bridge, from which the best views were obtained, could not bear the weight. On the 17th the steel cables broke right in the middle of the bridge, and 32 people perished when they fell into the river.
On October 13, 1982, when the dam was finished, the closing of the floodgates began to bury one of the greatest shows on the planet. In 14 days the Guairá Falls had disappeared forever.
However, a new wonder had been born, this time from human engineering, the Itaipu hydroelectric dam. Listed as one of the 7 wonders of the modern world by the American Society of Civil Engineers magazine, it is the largest energy producer on the planet, surpassing in 2015 and 2016 the Chinese Three Gorges Dam (more than 103 million megawatts per hour in 2016). It produces so much energy that it exceeds the needs of Paraguay, which resells the surplus to Brazil, which is not satisfied with its share of the production.
The energy produced by the dam in 2016 would be enough to supply Paraguay for 12 years, or Argentina for an entire year.
Its 20 turbines have a combined capacity of 14,000 megawatts. Ten of them produce on the Paraguayan frequency of 50 Hertz, while the other ten produce on the Brazilian frequency of 60 Hertz.
The wall of the dam has a height similar to a 65-storey building, and in its construction both steel and iron were used as to build 300 Eiffel towers.