The Dongjiang Dam is an arch dam

Arch dam

An arch dam is a type of dam that is curved and commonly built with concrete. The arch dam is a structure that is designed to curve upstream so that the force of the water against it, known as hydrostatic pressure, presses against the arch, compressing and strengthening the structure as it pushes...

 on the Lishui River

Lishui River

Lishui River is a river in Hunan province of China, one of the Yangtze River's four largest tributaries in the province....

 14 km (9 mi) southwest of Zixing

Zixing

Zixing is a city with more than 100,000 inhabitants in Chenzhou, Hunan, China. It is twinned with Laredo, Texas U.S....

 in Hunan Province, China. The dam was constructed between 1978 and 1992 and supports a 500 MW hydroelectric power station. The dam also provides for flood control, navigation

Navigability

A body of water, such as a river, canal or lake, is navigable if it is deep, wide and slow enough for a vessel to pass. Preferably there are few obstructions such as rocks or trees to avoid. Bridges must have sufficient clearance. High water speed may make a channel unnavigable. Waters may be...

 and water supply. The dam's first generator was operational in 1987 and the reservoir forced the relocation of 5.2 million people.

Design

The Dongjiang is a 157 m (515 ft) tall and 438 m (1,437 ft) long variable-radius arch dam. The dam is 7 m (23 ft) wide at its crest, 35 m (115 ft) at its base and has a curve radius of 302.3 m (992 ft). Situated at the head of a 4719 km² (1,822 sq mi) catchment area

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

, the dam can withhold a reservoir of up to 9565000000 cubic metre of water. The dam's power station lies at its base and contains four 125 MW Francis turbine

Francis turbine

The Francis turbine is a type of water turbine that was developed by James B. Francis in Lowell, Massachusetts. It is an inward-flow reaction turbine that combines radial and axial flow concepts....

-generators. The height of the dam affords each generator an effective hydraulic head

Hydraulic head

Hydraulic head or piezometric head is a specific measurement of water pressure above a geodetic datum. It is usually measured as a water surface elevation, expressed in units of length, at the entrance of a piezometer...

of 118.5 m (389 ft). The dam is also equipped with a boat/lumber lift.