The Dongfeng 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 Wu River 65 km (40 mi) northwest of Qingzhen

Qingzhen

Qingzhen is a county-level city under the administration of Guiyang in Guizhou province of the People's Republic of China.-External links:*...

 in Guizhou Province, China. The primary purpose of the dam is hydroelectric power generation and it supports a 570 MW power station. Construction on the dam began in 1989 and the first generator was operational in 1994, the last in 1995. The generators were up-rated between 2004 and 2005; bringing their capacity from 170 MW each to 190 MW.

Design and operation

The Dongfeng is a 162 m (531 ft) tall and 254 m (833 ft) long parabola

Parabola

In mathematics, the parabola is a conic section, the intersection of a right circular conical surface and a plane parallel to a generating straight line of that surface...

-shaped arch dam. The dam is 6 m (20 ft) thick at its crest and 25 m (82 ft) at its base. It sits at the base of a 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...

 covering 1816 km² (701 sq mi). The total reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

 capacity is 1025000000 cubic metre while 491000000 cubic metre is for regulating. At the reservoir's normal elevation of 970 m (3,182 ft) above sea level, the reservoir capacity is 864000000 cubic metre. The dam has several discharge facilities; three spillway

Spillway

A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. In the UK they may be known as overflow channels. Spillways release floods so that the water does not overtop and damage or even destroy...

 gates near the crest, three intermediate orifice openings, one chute spillway on the left bank and beside it, one spillway tunnel. The maximum discharge capacity of the spillways is 2565 m3/s while all openings, including the power station tailrace, can discharge 12369 m3/s. The power station is located underground

Underground power station

An underground power station is a type of hydroelectric power station constructed by excavating the major components from rock, rather than the more common surface-based construction methods....

 on the right bank of the dam. The intake releases water to three headrace tunnels which transfer into penstock

Penstock

A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydraulic turbines and sewerage systems. It is a term that has been inherited from the technology of wooden watermills....

s and supply each of the 190 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. Water is discharged back into the river via one tailrace tunnel.