Ney Braga Hydroelectric Plant

The Governor Ney Braga de Barros Hydroelectric Plant, formerly known as Segredo, is a dam and hydroelectric power plant on the Iguazu River near Segredo in Paraná, Brazil. It is the fourth dam upstream of the Iguazu Falls and was constructed between 1987 and 1991 while being inaugurated in 1992. The power station has a 1260 MW capacity and is supplied with water by a concrete face rock-fill embankment dam.

It is owned and operated by Copel who renamed it after Ney Braga de Barros, governor of Paraná between 1961–1965 and 1979–1982. It was the first hydroelectric project in Brazil's history to provide an Environmental Impact Assessment.

History
Construction on the dam began in September 1987 with the diversion of the Iguazu River. The diversion tunnel was 778 m long and had a diameter of 13.5 m, it was completed in June 1988. Excavations for the dam's foundation began in September 1988 and was completed in December 1989. Construction was complete in 1992.

Ney Braga de Barros Dam
The Ney Braga de Barros Dam is 145 m high, 700 m long and is of concrete face, rock-fill design. Water from the Jordão River, 2 km southwest of the dam, is diverted through a 4703 m long and 9.5 m diameter tunnel and into the Ney Braga de Barros Reservoir. The Jordão River is dammed 4.5 km upstream of its mouth with the Iguazu River with a roller-compacted concrete dam. The water from the diverted river increases the reservoir inflows by 10%. The power station contains 4 x 315 MW generators.