The Shapai 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 Caopo River

Caopo River

The Caopo River is a tributary of the Minjiang River in Wenchuan County, Sichuan Province, China. It is interrupted by the Shapai Dam....

 in Sichuan Province, China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. The dam is 130 metres (427 ft) tall and composed of roller-compacted concrete

Roller-compacted concrete

Roller-compacted concrete or rolled concrete is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for Portland cement. RCC is a mix of cement/fly ash, water, sand, aggregate...

. There are no spillways on the face of the dam but two tunnels are utilized with a discharge capacity of 453 m3/s. A single 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....

feeds water to a power station 5 kilometres (3 mi) downstream. The power station contains 2 x 18 MW generators with a combined capacity of 36 MW.