| Serra da Mesa Dam | |
| Name Official: | Usina de Serra da Mesa |
| Dam Crosses: | Tocantins River |
| Location: | Minaçu, Goiás, Brazil |
| Dam Type: | Embankment |
| Dam Length: | 1500m (4,900feet) |
| Dam Height: | 154m (505feet) |
| Dam Volume: | 12057558m2 |
| Spillway Type: | Service, gate-controlled |
| Spillway Capacity: | 15000m3/s |
| Construction Began: | 1986 |
| Opening: | 1998 |
| Cost: | $1.1 billion USD |
| Operator: | Eletrobrás Furnas |
| Res Name: | Serra da Mesa Reservoir |
| Res Capacity Total: | 54400000000m2 |
| Res Surface: | 1784km2 |
| Plant Turbines: | 3 x Francis-type |
| Plant Capacity: | 1275MW |
| Plant Annual Gen: | 6300GWh |
| Plant Commission: | 1998 |
| Location Map: | Brazil |
| Coordinates: | -13.8342°N -48.3044°W |
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.[1]
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.[2] 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.[1]
The dam is one of seven on the Tocantins River. The other six dams are: Tucuruí Dam (one of the world's largest), Cana Brava dam, São Salvador dam, Peixe Angical dam, Luiz Eduardo Magalhães (Lajeado) dam, Estreito dam, and Tucuruí dam).[3]
The Serra da Mesa Dam is a 1500m (4,900feet) long and 154m (505feet) 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 54400000000m2 and surface area of . Of the reservoir's volume, 43250000000m2 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.[1]
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 24m (79feet) long intake tunnels before reaching three 126m (413feet) long and 10m (30feet) 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 500m (1,600feet) long tailrace tunnel. The power house is long, high and wide. To mitigate water hammer when starting and stopping the turbines, it contains a 69m (226feet) long 20m (70feet) wide and 65m (213feet) tall surge chamber with a capacity.[2]
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.[4]