The Três Marias Dam, also known as Bernardo Mascarenhas, is an

embankment dam An embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil or rock. It has a semi-pervious waterproof natural covering for its surface ...

on the

São Francisco River The São Francisco River (, ) is a large Rivers of Brazil, river in Brazil. With a length of , it is the longest river that runs entirely in Brazilian territory, and the fourth longest in South America and overall in Brazil (after the Amazon R ...

near

Três Marias Três Marias is a Brazilian municipality located in the northwestern part of the state of Minas Gerais. In 2020 the population was 32,716 in a total area of 2,763 km2. Geography Três Marias is located at the north end of one of the lar ...

Minas Gerais Minas Gerais () is one of the 27 federative units of Brazil, being the fourth largest state by area and the second largest in number of inhabitants with a population of 20,539,989 according to the 2022 Brazilian census, 2022 census. Located in ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

. It was constructed for

hydroelectric Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

power production and

flood control Flood management or flood control are methods used to reduce or prevent the detrimental effects of flood waters. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and ru ...

. The dam was completed in 1961 and its first generator was operational in 1962. The dam's power plant is named after Bernard Mascarenhas who in 1889, built South America's first major hydroelectric power plant in Brazil, the

Marmelos Zero Power Plant The Marmelos Zero Power Plant is a decommissioned hydroelectric power plant on the Paraibuna River in Juiz de Fora, Minas Gerais, Brazil. Inaugurated in 1889, plant was the first major hydroelectric power plant constructed in South America, speci ...

Background

Construction on the dam began in May 1957 with a goal to stabilize the river's flow, improve navigation and to produce hydroelectric power. 10,000 people worked on the project and Brazilian President

Juscelino Kubitschek Juscelino Kubitschek de Oliveira (; 12 September 1902 – 22 August 1976), also known by his initials JK, was a Brazilian politician who served as the 21st president of Brazil from 1956 to 1961. Kubitschek's government plan, dubbed "50 years i ...

was influential in the dam's construction pace. The majority of the dam works were completed in January 1961 and its first generator was operational in 1962. The other five generators went online by 1969. The dam does not have a

fish ladder A fish ladder, also known as a fishway, fish pass, fish steps, or fish cannon, is a structure on or around artificial and natural barriers (such as dams, locks and waterfalls) to facilitate diadromous fishes' natural migration as well as mov ...

and effectively halted fish migration in the upper São Francisco River while also splitting it into two zones. When the reservoir was filled it formed an island that became the

Pirapitinga Ecological Station Pirapitinga Ecological Station () is an ecological station in Brazil, on an island in the lake formed by the Três Marias Dam in Minas Gerais. Location The reserve has an area of in the cerrado biome. It was created on 20 July 1987. It is manag ...

, with an area of about .

Specifications

The dam is a long and high embankment dam with a

spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure tha ...

off to its east-side and a

power plant A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the electricity generation, generation of electric power. Power stations are generally connected to an electr ...

at its east toe. The dam's

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

has a surface area of and a capacity of .

Bernard Mascarenhas Power Plant

The dam's power station, Bernard Mascarenhas Power Plant, contains six generators powered by

Kaplan turbine The Kaplan turbine is a propeller-type water turbine which has adjustable blades. It was developed in 1913 by Austrian professor Viktor Kaplan, who combined automatically adjusted propeller blades with automatically adjusted wicket gates to a ...

s for a total installed capacity of . There is additional room for two more generators in the power station which would increase the capacity to if installed. The Kaplan turbines used in the power station were designed by

Voith The Voith Group is a global technology company. With its broad portfolio of systems, products, services and digital applications, Voith trades in the markets of energy, paper, raw materials and transport. Founded in 1867, Voith today has aroun ...

and first installed in 1958. Each one has eight runner blades and is designed to operate with a

hydraulic head Hydraulic head or piezometric head is a measurement related to liquid pressure (normalized by specific weight) and the liquid elevation above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22, eq.3.2a. It is usually meas ...

as low as . The dam regulates downstream water flows to other reservoirs and power plants, keeping a normal discharge of .

References

{{DEFAULTSORT:Tres Marias Dam Dams completed in 1961 Dams in Minas Gerais Embankment dams Dams on the São Francisco River

Background

Specifications

Bernard Mascarenhas Power Plant

See also

References