Magat Dam

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Magat Dam is a large rock-fill dam on the island of Luzon in the Philippines. The dam is located on Magat River, a major tributary of Cagayan River. Constructed in 1983, Magat Dam is one of the largest dams in the Philippines and has two primary purposes: as a source of irrigation water and as a provider of hydroelectric power.

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[edit] Geography

The Magat Dam is located on the Magat River between the municipalities of Alfonso Lista in the province of Ifugao and Ramon in Isabela both on the island of Luzon. The Magat River is the largest tributary of the Cagayan River, the longest river in the country.

[edit] Magat River

Main article: Magat River

The Magat Dam is located on the Magat River, which is the largest tributary of the Cagayan River on the island of Luzon.[1] Cagayan is the longest river in the Philippines.[1] The Magat River has an estimated yearly water discharge of 9,808 million cubic meters and has an approximate length of 150 kilometers with its headwaters in the province of Nueva Vizcaya and its confluence with the Cagayan in the province of Isabela, 55 kilometers from the mouth of the river.[1]

The portion of the Magat River on which Magat Dam is located forms part of the boundary between the provinces of Ifugao and Isabela and this is the reason for the dispute between the local governments of the two provinces over the jurisdiction of Magat Dam. (See the History section of this article for details.)

[edit] Reservoir

Upstream from the dam is a 117 square kilometer reservoir[2]. The reservoir has a normal level of 178.3 meters and a maximum of 193 meters.[3] The critical value at which the water level at the reservoir is considered low is 160 meters.[3]

[edit] Structure and facilities

The Magat Dam is a multi-purpose dam which serves as a source of hydroelectric power and as a source of irrigation water for about 85,000 hectares of agricultural lands.[2]

The hydroelectric power plant is a four-unit powerhouse with a rated capacity of 360 megawatts and a water head of 81 meters.[2] The hydroelectric plant is a peaking power plant,[2] which means that it only operates when there is a high demand for electricity in the Luzon power grid, to which the plant is connected.[3] The water stored in the reservoir is enough to supply about two months of normal energy requirements.[2]

[edit] History

Magat Dam was constructed in 1983[2] and started operations in 1984.[3] It was Southeast Asia's first largest multipurpose dam.[4] The dam is part of the Magat River Multipurpose Project (MRMP) which was financed by the World Bank and whose purpose is to improve on the existing Magat River Irrigation System (MARIS) and to triple the production of rice in the Cagayan River basin.[2]

The irrigation facilities, including the reservoir, the intake gates to the hydroelectric plant, and the dam itself, is owned and managed by the National Irrigation Authority (NIA) while the hydroelectric plant itself was owned by the National Power Corporation (Napocor).[2] Under the Electric Power Industry Reforms Act of 2001 (Republic Act No. 9136), the Magat Dam hydroelectric plant underwent a privatization process. As a result, the plant's ownership and operation was turned over to SN Aboitiz Power Inc. (SNAP), a joint venture of a local company, Aboitiz Equity Venture (AEV), and the Norwegian SN Power Invest (SN Power) in April 2007.[2] SNAP won the privatization bidding in 2006.[5]

After the privatization of the hydroelectric plant, the provinces of Ifugao and Isabela had a dispute over the tax resulting from the transfer of the plant to SNAP. An agreement was made to divide the tax evenly, about 57 million pesos each, though some further disputes remain over the jurisdiction of various elements of the dam.[5]

The dam was constructed to last for 50 years but increased siltation and sedimentation in the reservoir, slash-and-burn farming, illegal logging ang fish-caging resulted to the deterioration of the dam's watershed. The massive 1990 Luzon earthquake also contributed to the increased siltation in the Magat River system. Because of this, President Gloria Macapagal-Arroyo instructed various government agencies to create a rehabilitation plan to improve the lifespan of the dam system.[4]

[edit] References

  1. ^ a b c "The Cagayan River Basin" - PAGASA. Accessed on 2008-04-21.
  2. ^ a b c d e f g h i "Magat Hydro: Environmental & Social Review Summary" - International Finance Corporation (World Bank)
  3. ^ a b c d Visaya, Villamor Jr.. "Gov't starts cloud-seeding over Magat dam", INQUIRER.net, Philippine Daily Inquirer, 2007-07-29. 
  4. ^ a b "Arroyo orders officials to formulate plan for massive rehabilitation of Magat Dam", Manila Bulletin, 2006-01-06. Retrieved on 2008-04-21. 
  5. ^ a b "Ifugao, Isabela share natl wealth tax over Magat dam after legal battle", GMANews.TV, GMA Network, 2008-04-04. Retrieved on 2008-04-21.