Pulangi Dam

Pulangi Dam
Location of Pulangi Dam in Philippines
Official name	Pulangi IV Hydroelectric Power Station
Country	Philippines
Location	Maramag, Bukidnon
Coordinates
Status	Operational
Construction began	1982
Opening date	1986
Owner(s)	National Power Corporation
Dam and spillways
Type of dam	Gravity/embankment
Impounds	Pulangi River
Spillway type	Tainter gate-controlled
Reservoir
Creates	Pulangi IV Reservoir (upper and lower)
Active capacity	67,000,000 m3 (54,318 acre·ft)
Catchment area	18,000 km2 (6,950 sq mi)
Surface area	19.85 km2 (8 sq mi)
Power station
Name	Pulangi IV Hydroelectric Power Plant
Coordinates
Commission date	1985/86
Turbines	3 x 85 MW Francis-type
Installed capacity	255 MW

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 megawatts (342,000 hp) 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 diverts water into a power channel which parallels the river until it reaches the lower reservoir (surge pool) at , 7.5 km (5 mi) to the south. At the lower reservoir, water is fed to each of the three 85 MW (114,000 hp) 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 1,500,000 m³ (1,216 acre·ft) of sediment annually. Of the reservoir's combined 67,000,000 m³ (54,318 acre·ft) active capacity, 23,000,000 m³ (18,646 acre·ft) 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.