On November 11, 1982, President Joao Figueiredo of Brazil and President Alfredo Stroessner of Paraguay inaugurated the world’s largest hydroelectric scheme: the building of the Itaipu Dam across the Parana River. The ceremony also marked the droning, forever, of the world’s most voluminous waterfall.
The Parana River forms part of the border between Brazil and Paraguay. Some 118 miles upstream from the new dam, the river formerly flowed into a deep canyon, forcing the waters from a channel 1,250 feet wide into a gorge merely 200 feet in width. This sudden compression created the Guairá Falls, known in the Portuguese language of Brazil as the Sete Quedas (Seven Falls).
Brazil and Paraguay signed an agreement to build the Itaipu Dam in 1966, but work did not begin until 1978. The first step was to divert the Parana River. Workers dug a channel 1 ¼ miles long, 490 feet wide and 300 feet deep, the largest river diversion ever undertaken.