Tucuruí Dam

The Tucuruí Dam is a concrete gravity dam on the Tocantins River located on the Tucuruí County in the State of Pará, Brazil. The main purpose of the dam is hydroelectric power production and navigation. It is the first large-scale hydroelectric project in the Brazilian Amazon rainforest. The installed capacity of the 25-unit plant is 8,370 megawatts (11,220,000 hp). Phase I construction began in 1980 and ended in 1984 while Phase II began in 1998 and ended in 2010. The dam was featured in the 1985 film The Emerald Forest.

Construction on Phase I began on November 24, 1975. Phase I called for the construction of the main dam, its dikes, the power house, spillway and upper portion of the navigation locks. On February 1, 1977, concrete-pouring began on site and in September 1978, the river diversion began. On September 6, 1984 the reservoir began filling and 206-days later it was at normal pool. Construction was completed 3 years behind schedule on November 10, 1984. The navigation lock that is part of the dam's design was only partially completed during Phase I with only the upper portion. The construction costs were predicted to be $3.6 billion but rose to over 5.5 billion by construction's end. Including interest during construction, the total cost for Phase I was $7.5 billion. Until 1999, Phase I produced an average of 21,428 terawatt-hours (77,140 PJ) of electricity.

Construction on the $1.35 billion Phase II began in June 1998. This phase called for the construction of the new power house for 11 x 375 MW (503,000 hp) Francis turbines and the completion of the navigation lock-system. The new power house is located to the left of the old one and the locks are on the north side of the dam's abutments. Phase II was expected to be completed in 2006 but is behind schedule. The second power house was completed in April 2007 but construction on the navigation locks is behind schedule.

The main portion Tucuruí Dam is a 78-metre-high (256 ft) and 6.9-kilometre-long (4.3 mi) concrete-gravity dam. The addition of the Mojú and Caraipé earth-fill dikes increases the total length to 12,515 metres (41,060 ft). The main dam's Creager-type service spillway is the second largest in the world with a maximum capacity of 110,000 cubic metres per second (3,900,000 cu ft/s). It is controlled by 20 floodgates measuring 20 by 21 metres (66 ft × 69 ft). More details