Pulangi IV Hydroelectric Power Plant
Encyclopedia
The Pulangi IV Hydroelectric Power Plant, also known as the Pulangi Dam, is located on the Pulangi River
near Maramag in Bukidnon
province on the island of Mindanao
in the Philippines. It uses two reservoirs, produced by damming
the Pulangi River, to supply water to a run-of-the-river hydroelectric power plant; the power plant is capable of generating 255 MW of power. Construction began in 1982; the first two generators became operational in December 1985, with the last generator being commissioned in 1986.
The upper (pondage
) reservoir located at 7°47′11"N 125°1′25"E diverts water into a power channel which parallels the river until it reaches the lower reservoir (surge pool) at 7°42′56"N 125°1′25"E, 7.5 km (5 mi) to the south. At the lower reservoir, water is fed to each of the three 85 MW Francis turbine
-generators via a penstock
. The Pulangi IV power plant provides 23% of the hydroelectric power generated on Mindanao.
Since operation, the reservoirs associated with the power plant have received an estimated 1500000 cubic metre of sediment annually. Of the reservoir's combined 67000000 cubic metre active capacity, 23000000 cubic metre has been filled with silt. The unexpected siltation threatens safe operation of the dams and power generation, in addition to drastically shortening the predicted operational lifespan of the dam. At first, the minimum and maximum water levels were raised and, in 2007, dredging work was performed around the head work of the upper reservoir's head. Selective dredging in the upper reservoir began in 2010, and continues as of 2011.
Pulangi River
The Pulangi River , also spelled Pulangui, is the longest river in Bukidnon. It is one of the major tributaries of the Rio Grande de Mindanao, an extensive river system in Mindanao, Philippines...
near Maramag in Bukidnon
Bukidnon
Bukidnon is a landlocked province of the Philippines located in the Northern Mindanao region. Its capital is Malaybalay City. The province borders, clockwise starting from the north, Misamis Oriental, Agusan del Sur, Davao del Norte, Cotabato, Lanao del Sur, and Lanao del Norte.Bukidnon is...
province on the island of Mindanao
Mindanao
Mindanao is the second largest and easternmost island in the Philippines. It is also the name of one of the three island groups in the country, which consists of the island of Mindanao and smaller surrounding islands. The other two are Luzon and the Visayas. The island of Mindanao is called The...
in the Philippines. It uses two reservoirs, produced by damming
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
the Pulangi River, to supply water to a run-of-the-river hydroelectric power plant; the power plant is capable of generating 255 MW of power. Construction began in 1982; the first two generators became operational in December 1985, with the last generator being commissioned in 1986.
The upper (pondage
Pondage
Pondage usually refers to the comparably small water storage behind the weir of a run-of-the-river hydroelectric power plant. It is considerably less storage than the reservoirs of large dams and conventional hydroelectric stations which can store water for long periods such as a dry season or year...
) reservoir located at 7°47′11"N 125°1′25"E diverts water into a power channel which parallels the river until it reaches the lower reservoir (surge pool) at 7°42′56"N 125°1′25"E, 7.5 km (5 mi) to the south. At the lower reservoir, water is fed to each of the three 85 MW Francis turbine
Francis turbine
The Francis turbine is a type of water turbine that was developed by James B. Francis in Lowell, Massachusetts. It is an inward-flow reaction turbine that combines radial and axial flow concepts....
-generators via a penstock
Penstock
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydraulic turbines and sewerage systems. It is a term that has been inherited from the technology of wooden watermills....
. The Pulangi IV power plant provides 23% of the hydroelectric power generated on Mindanao.
Since operation, the reservoirs associated with the power plant have received an estimated 1500000 cubic metre of sediment annually. Of the reservoir's combined 67000000 cubic metre active capacity, 23000000 cubic metre has been filled with silt. The unexpected siltation threatens safe operation of the dams and power generation, in addition to drastically shortening the predicted operational lifespan of the dam. At first, the minimum and maximum water levels were raised and, in 2007, dredging work was performed around the head work of the upper reservoir's head. Selective dredging in the upper reservoir began in 2010, and continues as of 2011.