Bhumibol Dam

Bhumibol Dam
File:Bhumibol dam front.jpg
Location of Bhumibol Dam in Thailand
Country	Thailand
Location	Amphoe Sam Ngao, Tak Province
Coordinates
Status	In use
Construction began	1958
Opening date	1964
Owner(s)	Electricity Generating Authority of Thailand
Dam and spillways
Impounds	Ping River
Height	154 m (505 ft)
Length	486 m (1,594 ft)
Width (crest)	8 m (26 ft)
Reservoir
Creates	Bhumibol Reservoir
Total capacity	13,462,000,000 m3 (10,913,821 acre·ft)
Active capacity	9,762,000,000 m3 (7,914,182 acre·ft)
Catchment area	26,400 km2 (10,193 sq mi)
Surface area	300 km2 (116 sq mi)
Power station
Commission date	1964-1996
Turbines	6 x 76.5 MW Francis-type, 1 x 115 MW Pelton-type, 1 x 175 MW Francis pump-turbine
Installed capacity	749 MW

The Bhumibol Dam (formerly known as the Yanhi Dam) is a concrete arch dam on the Ping River, a tributary of the Chao Phraya River, in Amphoe Sam Ngao district of Tak Province, Thailand. It is about 480 km (298 mi) north of Bangkok and was built for the purposes of water storage, hydroelectric power production, flood control, fisheries and saltwater intrusion management. The dam was named after King Bhumibol Adulyadej and was Thailand's first multi-purpose project.

Background

The Bhumibol Dam, among others in the Chao Phraya basin, was constructed beginning in the 1950s to exploit the agricultural and hydroelectric potential of the basin. Construction on the dam began in 1958 and was finished in 1964. The reservoir was completely filled in 1970. The first two generators were commissioned in 1964. In 1972, the Sirikit Dam was completed on the Nan River, one of two major tributaries of the Chao Phraya including the Ping. The Bhumibol and Sirkit Dams control 22 percent of the Chao Phraya's annual runoff combined. Both dams also help provide for the irrigation of 1,200,000 ha (4,633 sq mi) in the wet season and 480,000 ha (1,853 sq mi) in the dry season.

In 1991, the Lower Mae Ping Dam () was constructed 5 km (3 mi) downstream to create a lower reservoir for the one pumped-storage turbine that was installed. When constructed, the Bhumibol Dam contributed 22 percent of Thailand's power generation and in 2003 that number was 2 percent.

During the 2011 Thailand floods, rainfall for March 2011 over the area of northern Thailand was an extraordinary 344 percent above normal. Bhumibol Dam in particular got 242.8 millimetres (9.56 in) of rain, 224.7 millimetres (8.85 in) above the mean of 25.2 millimetres (0.99 in) and since 1 January had accumulated 245.9 millimetres (9.68 in), 216 millimetres (8.5 in) or 186 percent above normal.

Design

The dam is an arch-gravity type and is 154 m (505 ft) tall, 486 m (1,594 ft) long and 8 m (26 ft) wide at its crest. It withholds a reservoir of 13,462,000,000 m³ (10,913,821 acre·ft) of which 9,762,000,000 m³ (7,914,182 acre·ft) is active or "useful" storage. The dam's catchment area is 26,400 km² (10,193 sq mi) while its surface area is 300 km² (116 sq mi). The Lower Mae Ping Dam is 8 m (26 ft) high, 300 m (984 ft) long and has a storage capacity of 5,000,000 m³ (4,054 acre·ft). In off-peak hours, the one pump-turbine returns water back into the Bhumibol (upper) reservoir and when demand is high, the pump serves as a generator for power production.

Power station

The power plant contains eight turbines for an installed capacity of 749 megawatts (1,004,000 hp). Six are 76.5 megawatts (102,600 hp) Francis-type, one is a 115 megawatts (154,000 hp) Pelton turbine and one is a 175 megawatts (235,000 hp) Francis pump-turbine.

The dam's power house underwent extensive upgrades and renovations in the 1990s.

See also

• List of power stations in Thailand
• King Bhumibol Adulyadej

External links

• Bhumibol Dam at Electricity Generating Authority of Thailand
• WMO Climate Normals: Bhumibol Dam