Punchiná Dam
Encyclopedia
The Punchiná Dam is an embankment dam
on the Guatapé River
17 km (11 mi) east of San Carlos
in Antioquia Department
, Colombia
. The dam creates Punchiná Reservoir which is part of the 1,240 MW San Carlos Hydroelectric Power Plant. The power plant was completed in two 620 MW stages, the first was completed in 1984 and the second in 1987. It is the largest power station in Colombia.
loan was approved to help fund the dam and both stages of the power plant. Construction began in 1979, the dam was completed in 1983 and the last generator of stage one was operational in 1984. Stage two's final generator was operational in December 1987. The commissioning of stage two was originally slated for 1984 and stage one for 1983 but was delayed due to financial problems and redesigns. The total cost of stage one was US$443.7 million and stage two US$166.3 million.
created by the dam has a capacity of 72000000 cubic metre, of which 52230000 cubic metre is active (or "useful) capacity. The surface area of the reservoir is 3.4 km² (1 sq mi). Initiating the flow of water towards the power station is two 54 m (177 ft) tall intake towers behind the dam in the reservoir. Each tower provides water to a respective stage of the power plant via tunnels. The two tunnels are each about 4.5 km (3 mi) long and to protect against water hammer
, each tunnel is equipped with a surge tank
. The underground power house is 400 m (1,312 ft) below the surface and 203 m (666 ft) long, 19.65 m (64 ft) wide and 27.5 m (90 ft) high. Adjacent to the power house is another cavern that holds the transformer
s and is of similar dimension. Once the water reaches the power house, each tunnel supplies the four 155 MW Pelton turbines of its respective stage. Once the water leaves the turbines, each stage releases it into their own 1.5 km (0.93205910497471 mi) long tailrace tunnel where the water is discharged into the Samaná Norte River
. The tunnels have a combined maximum discharge of 330 m3/s.
Embankment dam
An embankment dam is a massive artificial water barrier. It is typically created by the emplacement and compaction of a complex semi-plastic mound of various compositions of soil, sand, clay and/or rock. It has a semi-permanent waterproof natural covering for its surface, and a dense, waterproof...
on the Guatapé River
Guatapé River
The Guatapé is a river in Antioquia Department, Colombia and a tributary of the Samaná Norte River. The Jaguas , Las Playas and San Carlos hydroelectric power plants are located on its stem....
17 km (11 mi) east of San Carlos
San Carlos, Antioquia
San Carlos is a town and municipality in the Colombian department of Antioquia, part of the subregion of Eastern Antioquia. Is called, the hydro-electrical capital of Colombia, because it has many dams and it produces lots of energy.-History:...
in Antioquia Department
Antioquia Department
Antioquia is one of the 32 departments of Colombia, located in the central northwestern part of Colombia with a narrow section that borders the Caribbean Sea. Most of its territory is mountainous with some valleys, much of which is part of the Andes mountain range...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
. The dam creates Punchiná Reservoir which is part of the 1,240 MW San Carlos Hydroelectric Power Plant. The power plant was completed in two 620 MW stages, the first was completed in 1984 and the second in 1987. It is the largest power station in Colombia.
Background
The project was initiatied by Interconexion Electrica S.A. in 1973 and appraised in 1978. In May 1978, a World BankWorld Bank
The World Bank is an international financial institution that provides loans to developing countries for capital programmes.The World Bank's official goal is the reduction of poverty...
loan was approved to help fund the dam and both stages of the power plant. Construction began in 1979, the dam was completed in 1983 and the last generator of stage one was operational in 1984. Stage two's final generator was operational in December 1987. The commissioning of stage two was originally slated for 1984 and stage one for 1983 but was delayed due to financial problems and redesigns. The total cost of stage one was US$443.7 million and stage two US$166.3 million.
Design and operation
The Punchiná Dam is a 70 m (230 ft) tall and 800 m (2,625 ft) long embankment-type dam with 6000000 m³ (7,847,704 cu yd) of fill and a crest elevation of 785 m (2,575 ft). The reservoirReservoir
A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...
created by the dam has a capacity of 72000000 cubic metre, of which 52230000 cubic metre is active (or "useful) capacity. The surface area of the reservoir is 3.4 km² (1 sq mi). Initiating the flow of water towards the power station is two 54 m (177 ft) tall intake towers behind the dam in the reservoir. Each tower provides water to a respective stage of the power plant via tunnels. The two tunnels are each about 4.5 km (3 mi) long and to protect against water hammer
Water hammer
Water hammer is a pressure surge or wave resulting when a fluid in motion is forced to stop or change direction suddenly . Water hammer commonly occurs when a valve is closed suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe...
, each tunnel is equipped with a surge tank
Surge tank
A surge tank is a standpipe or storage reservoir at the downstream end of a closed aqueduct or feeder pipe to absorb sudden rises of pressure as well as to quickly provide extra water during a brief drop in pressure...
. The underground power house is 400 m (1,312 ft) below the surface and 203 m (666 ft) long, 19.65 m (64 ft) wide and 27.5 m (90 ft) high. Adjacent to the power house is another cavern that holds the transformer
Transformer
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
s and is of similar dimension. Once the water reaches the power house, each tunnel supplies the four 155 MW Pelton turbines of its respective stage. Once the water leaves the turbines, each stage releases it into their own 1.5 km (0.93205910497471 mi) long tailrace tunnel where the water is discharged into the Samaná Norte River
Samaná Norte River
The Samaná Norte is a river in Antioquia Department, Colombia and a tributary of the of the Magdalena River.-References:...
. The tunnels have a combined maximum discharge of 330 m3/s.