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. Construction of the dam started in 1975 and completed in 1982. 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.
The construction and appurtenant structures was authorized by P.D. 693 signed on May 7, 1975 by the late President Ferdinand E. Marcos. The Magat Dam was constructed in 1978 and inaugurated by the Late Pres. Ferdinand E. 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 (NIA) with the assistance of the United States Bureau of Reclamation (USBR) and the United States Agency for International Development (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's first large multipurpose dam. 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.