Serra da Mesa Dam

The Serra da Mesa Dam, once known as Sao Felix, is an embankment dam on the Tocantins River near Minaçu in Goiás, Brazil. The dam serves an associated hydroelectric power plant with a installed capacity. The dam creates the largest reservoir by volume in Brazil.
Background.
Eletrobrás Furnas began studies of the upper Tocantins River in 1981 and proposed constructing two large dams, one was at Serra da Mesa which had good geomechanical conditions. After years of studies, construction on the dam and power station began in 1986. On October 24, 1996, the dam began to inundate and create its reservoir and it was full in 1998; around the same time, the power station's generators became operational.
Dam and reservoir.
The Serra da Mesa Dam is a long and tall earth-fill embankment dam with a clay core and in total contains of material. The reservoir created by the dam has a capacity of and surface area of . Of the reservoir's volume, is active storage. The dam supports a spillway with five floodgates that are wide and high each. In total, the spillway has a discharge capacity.
Serra da Mesa Hydroelectric Power Station.
The dam supports the Serra da Mesa Hydroelectric Power Station, an underground power station and hydraulic circuit. Before reaching the turbines, water enters the intake near the dam's left abutment and proceeds along three long intake tunnels before reaching three long and diameter penstocks. Water then reaches the Francis turbines which power three generators. After exiting the turbines, the water is discharged from the power house via one long tailrace tunnel. The power house is long, high and wide. To mitigate water hammer when starting and stopping the turbines, it contains a long wide and tall surge chamber with a capacity.
Environmental impact.
The Serra da Mesa Dam was sharply criticized by environmentalists before and during construction. Organizations, such as the International Rivers Network criticized the dam and its reservoir for destroying a vast area of flora and fauna along with destroying the habitat of endangered species. In addition, the dam was criticized for flooding archeological sites and $15 million worth of timber that was not removed prior to flooding.