The Serra da Mesa Dam, once known as Sao Felix, 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 and ...
on the
Tocantins River
The Tocantins River ( pt, Rio Tocantins, link=no , , Parkatêjê dialect, Parkatêjê: ''Pyti'' ɨˈti is a river in Brazil, the central fluvial artery of the country. In the Tupi language, its name means "toucan's beak" (''Tukã'' for "toucan ...
near
Minaçu
Minaçu is a Municipalities of Brazil, municipality in the north of the state of Goiás, Brazil. There is a large asbestos mine in the municipality.
Location and climate
It is located on the shores of the artificial lake, Cana Brava, created aft ...
in
Goiás
Goiás () is a Brazilian state located in the Center-West region. Goiás borders the Federal District and the states of (from north clockwise) Tocantins, Bahia, Minas Gerais, Mato Grosso do Sul and Mato Grosso. The state capital is Goiânia. ...
,
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
. The dam serves an associated
hydroelectric
Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...
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 generation of electric power. Power stations are generally connected to an electrical grid.
Many pow ...
with a installed capacity. The dam creates the largest
reservoir
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including contro ...
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
An underground power station is a type of hydroelectric power station constructed by excavating the major components (e.g. machine hall, penstocks, and tailrace) from rock, rather than the more common surface-based construction methods.
One or mor ...
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 turbine
The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency.
The proces ...
s 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.
See also
*
Tucuruà dam
References
{{reflist
Dams completed in 1998
Dams in Goiás
Earth-filled dams
Underground power stations