| Peixoto Dam | |
| Location Map: | Brazil |
| Coordinates: | -20.2847°N -47.0636°W |
| Location: | Minas Gerais, Brazil |
| Construction Began: | 1952 |
| Opening: | 1956 |
| Owner: | Eletrobras Furnas |
| Dam Height: | 50.6m (166feet)[1] |
| Dam Length: | 600m (2,000feet) |
| Dam Crosses: | Grande River |
| Spillway Type: | Gated overflow |
| Spillway Capacity: | 12450m3/s |
| Res Name: | Represa dos Peixotos |
| Res Capacity Total: | 4.04km3 |
| Res Capacity Active: | 2.5km3 |
| Res Surface: | 250km2 |
| Plant Turbines: | 2x 40MW 2x 48MW 4x 49MW 2x 52MW Francis-type |
| Plant Capacity: | 476MW |
Peixoto Dam, also known as Mascarenhas de Moraes Hydroelectric Plant, is a hydroelectric dam on the Grande River in the state of Minas Gerais, Brazil, about west of Delfinópolis.
Studies for a dam at the Peixoto site were first carried out in 1947 by the Companhia Paulista de Força e Luz, which obtained rights to develop the site in 1950. The dam was built between 1952 and 1957 with help from the United States and the dam dedicated on April 30, 1957 by Brazilian President Juscelino Kubitschek.[2] The first two Francis turbine-generators came online in 1957, and eight more were installed by 1968, bringing the plant to its full capacity of . Since 1973, the dam and hydroelectric power plant have been operated by Eletrobras Furnas. Peixoto was the first of a cascade of nine dams to be built on the Grande River.[1]
The dam consists of a central concrete arch section flanked by gravity wings, totaling high and long, impounding the 145km (90miles) long Represa de Peixoto (Peixoto Reservoir), with a storage capacity of 4.04km3 and a useful capacity of 2.5km3. The 210x power station is located on the south side of the dam and consists of ten vertical Francis turbines.[1]
Water is released from the dam through the power plant and two spillways. The service spillway, located on the north side of the dam, is an overflow structure with 11 gates, providing a maximum capacity of . The auxiliary spillway is located to the south and consists of a concrete chute controlled by two gates, with a capacity of .[1]