Dachaoshan Dam

Dachaoshan Dam
Location of Dachaoshan Dam
Country	China
Location	Yunnan Province
Coordinates	24°01′28″N 100°22′09″E / 24.02444°N 100.36917°E / 24.02444; 100.36917Coordinates: 24°01′28″N 100°22′09″E / 24.02444°N 100.36917°E / 24.02444; 100.36917
Status	In use
Construction began	1997
Opening date	2003
Construction cost	RMB￥8.87 billion ($1.3 billion USD
Owner(s)	Yunnan Dachaoshan Hydropower Co., Ltd.
Dam and spillways
Type of dam	Gravity, roller-compacted concrete
Height	111 m (364 ft)
Length	460 m (1,509 ft)
Volume	1,126,700 m3 (39,789,035 cu ft)
Impounds	Lancang (Mekong) River
Spillways	5
Type of spillway	Controlled, crest overflow
Reservoir
Creates	Dachaoshan Reservoir
Capacity	940,000,000 m3 (762,070 acre·ft)
Catchment area	121,000 km2 (46,718 sq mi)
Power station
Commission date	2001-2003
Hydraulic head	72.5 m (238 ft) (rated)
Turbines	6 x 225 MW
Installed capacity	1,350 MW
Annual generation	5931 GWh

The Dachaoshan Dam (Chinese: 大朝山大坝) is a gravity dam on the Lancang (Mekong) River in Yunnan Province, China. The sole purpose of the dam is hydroelectric power production as it supplies water to a power station containing six 225 MW generators for a total installed capacity of 1,350 MW.

Background

Initial construction preparations on the dam began in 1993 before it was approved ready for construction in 1994. On August 4, 1997, the project was approved for construction commencement and on November 10, 1997, the river was diverted. Between 2001 and 2003, the dam was complete and all six generators went operational.^[1]

Design

The dam is a 111 m (364 ft) tall and 460 m (1,509 ft) long gravity dam.^[2] It is composed of 1,126,700 m³ (39,789,035 cu ft) of concrete, 756,600 m³ (26,719,077 cu ft) is roller-compacted concrete. The reservoir created by the dam has a capacity of 940,000,000 m³ (762,070 acre·ft). To release water downstream, the dam has five 14 m (46 ft) x 17 m (56 ft) crest openings along with three mid-level openings and one bottom flushing outlet. With these openings, the design flood discharge capacity of the dam is 18,000 m³/s (635,664 cu ft/s) while the maximum is 23,500 m³/s (829,895 cu ft/s).^[1]

The dam's power station is underground and supplied with water via six 179.5 m (589 ft) long penstocks. Once through the six turbines, the water exits back to the river by means of two tailrace tunnels, one 1,355 m (4,446 ft) long and the other 1,248 m (4,094 ft). ^[1]

See also

• List of power stations in China

External images
	Front view the dam with crest spillway discharging

References

1. ^ ^{a b c} "A BRIEF INTRODUCTION TO DACHAOSHAN HYDROPOWER PROJECT". China Water. http://www.chinawater.net.cn/icold2000/st-a5-01.html. Retrieved 8 January 2011. 
2. ^ "Dachaoshan Hydropower Project". Chinese National Committee on Large Dams. http://www.chincold.org.cn/dams/rootfiles/2010/07/20/1279253973998192-1279253974002813.pdf. Retrieved 8 January 2011.