In 1973 the Yacyreta Treaty, signed by Argentine President Peron and the Paraguayan dictator Stroessner, envisaged the construction of the Yacyreta dam along the Parana River, on the border between the two countries. The dam would flood 100,000 ha of land and displace many communities, including the indigenous Mbya Guarani people, whose territory would be completely submerged. Residents opposing the dam construction protested against the loss of their property and land rights. Despite this opposition the dam began construction in 1979, but the floodgates were closed and the dam was filled for the first time in 1994, provoking the evacuation of another 20,000 local residents. The survivors still demand compensation they never received from the forced displacement. The project was originally budgeted at $2.5 billion, during the period of military dictatorships in Argentina and Paraguay. The project’s total cost has now exceeded $15 billion. During his presidential campaign, Argentina’s Carlos Menem called Yacyretá "a monument to corruption." As International Rivers denounces, "despite well–documented allegations implicating engineering and construction companies and politicians in siphoning off public funds in the building of Yacyretá, no one has ever been brought to justice.”

The water level is 76 meters high. The dam is 808 metres long and has 20 turbines. Installed power capacity: 3,100 MW