Magat Dam is a large rock-fill
dam
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ...
in the island of
Luzon
Luzon (; ) is the largest and most populous island in the Philippines. Located in the northern portion of the Philippines archipelago, it is the economic and political center of the nation, being home to the country's capital city, Manila, as ...
in the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
. The dam is located along the
Magat River
The Magat River is a river in the Philippine island of Luzon with a total length of . It originates in the Nueva Vizcaya municipality of Aritao, where the Santa Fe River joins the Marang. It is the largest tributary of the Cagayan River by disc ...
, a major tributary of
Cagayan River
The Cagayan River, also known as the Río Grande de Cagayán, is the longest river and the largest river by discharge volume of water in the Philippines. It has a total length of approximately and a drainage basin covering . It is located in t ...
. The construction of the dam started in 1975 and was completed in 1982. It is one of the largest dams in the Philippines. It is a multi-purpose dam which is used primarily for irrigating about of agricultural lands,
flood control
Flood control methods are used to reduce or prevent the detrimental effects of flood waters."Flood Control", MSN Encarta, 2008 (see below: Further reading). Flood relief methods are used to reduce the effects of flood waters or high water level ...
, and power generation through the Magat Hydroelectric Power Plant.
The water stored in the reservoir is enough to supply about two months of normal energy requirements.
History
The construction and appurtenant structures was authorized by Presidential Decree No/ 693 signed on May 7, 1975 by then President
Ferdinand E. Marcos
Ferdinand Emmanuel Edralin Marcos Sr. ( , , ; September 11, 1917 – September 28, 1989) was a Filipino politician, lawyer, dictator, and kleptocrat who was the 10th president of the Philippines from 1965 to 1986. He ruled under martial ...
. The Magat Dam was constructed in 1978 and inaugurated by Marcos on October 27, 1982
and started operations in 1983.
Implementation of this multipurpose project was based on the preliminary study conducted in 1973 by the
National Irrigation Administration
The National Irrigation Administration (NIA) ( fil, Pambansang Pangasiwaan ng Patubig) is a Philippine government-owned and controlled corporation primarily responsible for irrigation development and management in the country.
History
NIA was ...
(NIA) with the assistance of the
United States Bureau of Reclamation
The Bureau of Reclamation, and formerly the United States Reclamation Service, is a federal agency under the U.S. Department of the Interior, which oversees water resource management, specifically as it applies to the oversight and opera ...
(USBR) and the
United States Agency for International Development
The United States Agency for International Development (USAID) is an independent agency of the U.S. federal government that is primarily responsible for administering civilian foreign aid and development assistance. With a budget of over $27 bi ...
(USAID).
Subsequent detailed and extensive dam site investigation and engineering studies further confirmed the feasibility of what is now known as NIA's most daring infrastructure project and one of Asia's biggest dams today.
It was
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
's first large multipurpose dam.
The dam is part of the Magat River Multipurpose Project (MRMP) which was financed by the
World Bank
The World Bank is an international financial institution that provides loans and grants to the governments of low- and middle-income countries for the purpose of pursuing capital projects. The World Bank is the collective name for the Interna ...
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
The Cagayan River, also known as the Río Grande de Cagayán, is the longest river and the largest river by discharge volume of water in the Philippines. It has a total length of approximately and a drainage basin covering . It is located in t ...
basin.
The project was jointly financed by the
Philippine Government
The Government of the Philippines ( fil, Pamahalaan ng Pilipinas) has three interdependent branches: the legislative, executive, and judicial branches. The Philippines is governed as a unitary state under a presidential representative and d ...
and the
World Bank
The World Bank is an international financial institution that provides loans and grants to the governments of low- and middle-income countries for the purpose of pursuing capital projects. The World Bank is the collective name for the Interna ...
which extended a US$150M loan to finance the foreign exchange requirement. In addition, a US$9M loan from
Bahrain
Bahrain ( ; ; ar, البحرين, al-Bahrayn, locally ), officially the Kingdom of Bahrain, ' is an island country in Western Asia. It is situated on the Persian Gulf, and comprises a small archipelago made up of 50 natural islands and an ...
was obtained for the purchase of other equipment for the diversion tunnel, soil laboratory and model testing. The total project cost is US$3.4B (yr. 1975).
The dam was constructed to last for 50 years but increased
siltation
Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or ...
and
sedimentation
Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to the ...
in the reservoir,
slash-and-burn
Slash-and-burn agriculture is a farming method that involves the cutting and burning of plants in a forest or woodland to create a field called a swidden. The method begins by cutting down the trees and woody plants in an area. The downed vegeta ...
farming,
illegal logging
Illegal logging is the harvest, transportation, purchase or sale of timber in violation of laws. The harvesting procedure itself may be illegal, including using corrupt means to gain access to forests; extraction without permission, or from a pro ...
and fish-caging resulted in the deterioration of the dam's watershed. The
1990 Luzon earthquake
The 1990 Luzon earthquake struck the island of Luzon in the Philippines at 4:26 p.m. on July 16 ( PDT) or 3:26 p.m. ( PST) with an estimated moment magnitude of 7.7 and a maximum Mercalli intensity of IX (''Violent'') and produced a 1 ...
also contributed to the increased siltation in the Magat River system. Because of this, on January 2006, then President
Gloria Macapagal Arroyo
Maria Gloria Macaraeg Macapagal Arroyo (, born April 5, 1947), often referred to by her initials GMA, is a Filipino academic and politician serving as one of the Deputy Speaker of the House of Representatives of the Philippines, House Deputy Spe ...
instructed various government agencies to create a rehabilitation plan to improve the lifespan of the dam system.
The non-power components such as the dam, reservoir, and intake gates are owned, operated, and managed by the
National Irrigation Administration
The National Irrigation Administration (NIA) ( fil, Pambansang Pangasiwaan ng Patubig) is a Philippine government-owned and controlled corporation primarily responsible for irrigation development and management in the country.
History
NIA was ...
(NIA). The hydroelectric plant was formerly owned by the
National Power Corporation
The National Power Corporation ( fil, Pambansang Korporasyon sa Elektrisidad, also known as Napocor, NPC or National Power), is a Philippine government-owned and controlled corporation that is mandated to provide electricity to all rural areas of ...
(NAPOCOR).
Under the Electric Power Industry Reform Act of 2001 (
Republic Act
This article contains a partial list of Philippine laws.
Sources of Philippine laws
;Notes
: *Customs may be considered as supplementary source of law, however, customs which are contrary to law, public order or public policy shall not be ...
No. 9136), the Magat hydroelectric power plant underwent a
privatization
Privatization (also privatisation in British English) can mean several different things, most commonly referring to moving something from the public sector into the private sector. It is also sometimes used as a synonym for deregulation when ...
process. As a result, the plant's ownership and operation was turned over to
SN Aboitiz Power-Magat, Inc. (SNAP-Magat), a joint venture of a local company,
Aboitiz Power Corporation
Aboitiz Power Corporation also known as AboitizPower (AP), a subsidiary of Aboitiz Equity Ventures (AEV), is a holding company engaged in power distribution, generation and retail electricity services.
Background
Aboitiz Power Corporation was ...
(AP), and a Norwegian firm
SN Power
SN Power is a defunct company that invests in clean, renewable energy on a commercial basis in emerging markets. SN Power was acquired by Scatec on 29th of January 2021.
History
The company was established in 2002. Along with Norfund, the Norwe ...
in April 2007.
SNAP won the bidding in 2006.
Geography
The dam is located within the boundaries of Namillangan,
Alfonso Lista
Alfonso Lista, formerly known as Potia, officially the Municipality of Lista is a 3rd class municipality in the province of Ifugao, Philippines. According to the 2020 census, it has a population of 34,061 people.
History
Potia was created as th ...
,
Ifugao
Ifugao, officially the Province of Ifugao ( ilo, Probinsia ti Ifugao; tl, Lalawigan ng Ifugao), is a landlocked province of the Philippines in the Cordillera Administrative Region in Luzon. Its capital is Lagawe and it borders Benguet to the wes ...
and
Ramon,
Isabela, approximately north of
Metro Manila
Metropolitan Manila (often shortened as Metro Manila; fil, Kalakhang Maynila), officially the National Capital Region (NCR; fil, link=no, Pambansang Punong Rehiyon), is the capital region, seat of government and one of three List of metrop ...
.
Magat River
The Magat Dam is on the
Magat River
The Magat River is a river in the Philippine island of Luzon with a total length of . It originates in the Nueva Vizcaya municipality of Aritao, where the Santa Fe River joins the Marang. It is the largest tributary of the Cagayan River by disc ...
, which is the largest tributary of the
Cagayan River
The Cagayan River, also known as the Río Grande de Cagayán, is the longest river and the largest river by discharge volume of water in the Philippines. It has a total length of approximately and a drainage basin covering . It is located in t ...
on the island of
Luzon
Luzon (; ) is the largest and most populous island in the Philippines. Located in the northern portion of the Philippines archipelago, it is the economic and political center of the nation, being home to the country's capital city, Manila, as ...
.
[The Cagayan River Basin]
– PAGASA. ''Accessed on April 21, 2008.'' Cagayan is the longest river in the Philippines.
The Magat River has an estimated yearly water discharge of 9,808 million cubic metres and has an approximate crest length of with its headwaters in the province of
Nueva Vizcaya
Nueva Vizcaya, officially the Province of Nueva Vizcaya ( ilo, Probinsia ti Nueva Vizcaya; gad, Probinsia na Nueva Vizcaya; Pangasinan: ''Luyag/Probinsia na Nueva Vizcaya''; tl, Lalawigan ng Nueva Vizcaya ), is a landlocked province in the ...
and its confluence with the Cagayan River in the province of
Isabela.
Features
Spillway
* Length:
* Width:
* Discharge capacity: 30,600 cubic meters
* Radial Gates: 7 sets
* Orifice Gates: 2 sets
Diversion tunnels
* Number: 2
* Diameter:
* Average length:
Reservoir
* Storage Capacity at Full Supply Level (FSL): 1.08 billion cubic meters
* Elevation at FSL: 193 masl
* Minimum Supply Level: 160 masl
* Maximum Flood Level: 193 masl
Power
* Installed capacity: 360
MegaWatts
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Watt ...
* Turbine: 4 units, Francis vertical shaft
* Generator: 4 units x 90 MW, vertical synchronous
Access
It is connected by an all-weather road to San Mateo–Santiago Road at Oscariz, Ramon, Isabela some north of Metro Manila.
Magat Hydro
The Magat
hydroelectric power
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 ...
plant is a four-unit powerhouse with an installed capacity of 360
megawatt
The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units, International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), ...
s.
[Magat Hydro: Environmental & Social Review Summary]
– International Finance Corporation (World Bank) It is designed to accommodate two more units that will allow it to generate up to 540 megawatts. The hydroelectric plant is a
peaking power plant
Peaking power plants, also known as peaker plants, and occasionally just "peakers", are power plants that generally run only when there is a high demand, known as peak demand, for electricity. Because they supply power only occasionally, the power ...
,
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.
It is capable of providing ancillary services for the stability of the grid.
SN Aboitiz Power-Magat, Inc. completed the half-life refurbishment of the Magat Hydroelectric Power Plant in 2014. Refurbishment began in 2009 and was completed in June 2014.
Half-life refurbishment ensures that the power plant facility remains available throughout its life span.
Discharge-induced floods
In November 2020,
Typhoon Vamco
Typhoon Vamco, known in the Philippines as Typhoon Ulysses, was a powerful and very destructive Category 4-equivalent typhoon that struck the Philippines and Vietnam. It also caused the worst flooding in Metro Manila since Typhoon Ketsana i ...
(locally known in the Philippines as Typhoon Ulysses) crossed the country, dams from all around Luzon neared their spilling points, forcing them to release large amounts of water into their impounds including Magat Dam. The dam opened all of its 7 gates at 24 meters, releasing over 5,037 cubic metres (1,331,000 US gal) of water into the Cagayan River resulting to numerous riverside towns experienced massive flooding. Waters under the
Buntun Bridge
Buntun Bridge ( itv, Talletay ta Buntun; ilo, Rangtáy ti Buntun; fil, Tulay ng Buntun) is a river bridge that stretches from Tuguegarao City to Solana in Cagayan and spans the Cagayan River, the largest river basin in the Philippines. It form ...
went up as high as 13 meters, flooding the nearby barangays up to the roofs of houses., Prior to the flooding, The National Irrigation Administration said Sunday it had already warned residents of Cagayan and Isabela of Magat Dam's water release two days prior Typhoon Ulysses' landfall on November 11. As a result of the catastrophe, the National Irrigation Administration said that it will review its protocols regarding the release of water in Magat Dam and improve its watershed.
References
{{Dams in the Philippines
Dams completed in 1983
Dams in the Philippines
Hydroelectric power plants in the Philippines
Buildings and structures in Isabela (province)
Tourist attractions in Isabela (province)