Irapé Dam

Irapé Dam, the tallest dam in Brazil,  is an embankment dam on the Jequitinhonha River in the state of Minas Gerais. It is on the border of Berilo and Grão Mogol districts, about 26 km west of Virgem da Lapa. The dam was constructed between 2002 and 2006 for the purpose of hydroelectric power generation.

History
In 1963, the Jequitinhonha River was studied for its hydroelectric potential and the studies were reviewed in 1984. Brazilian power company CEMIG won the bid to build the Irapé Dam in 1998. Construction on the dam began in September 2002 and in September of that year, the power plant was officially renamed Juscelino Kubitschek Power Plant, after the former President of Brazil. The river diversion was complete by April 2003 with two 14 m diameter tunnels; one 1227 m in length and the other 1067 m. The dam's reservoir began to fill in December 2005 and the first of the power plant's generators was commissioned on 20 July 2006. The second generator was commissioned in August and the third in October 2006. At the time of its completion it was the tallest dam in Brazil.

Design
The dam is a rock-fill-type with a height of 208 m and length of 500 m. It is built within a steep canyon just upstream of a bend in the river. Total structural volume amounts to about 10300000 m3. The reservoir created by the dam has a surface area of 137 km2. Controlling overflow are three 634 m spillway tunnels. Each diverts water from the reservoir to the eastern side of a bend in the river. Two of the tunnels are located high above the valley while one is at an intermediate height. Each tunnel has a maximum discharge capacity of 2000 m3/s, making the total maximum discharge capacity of the spillway 6000 m3/s.

Juscelino Kubitschek Power Plant
Juscelino Kubitschek Power Plant is located at the dam's base and houses three 120 MW Francis turbine-generators for an installed capacity of 360 MW. The generators are rated to operate at 130 MW though, providing a maximum capacity of 390 MW.