The Longyangxia Dam is a concrete arch-gravity dam at the entrance of the Longyangxia canyon on the Yellow River in Gonghe County, Qinghai Province, China. The dam is 178 metres (584 ft) tall and was built for the purposes of hydroelectric power generation, irrigation, ice control and flood control. The dam supports a 1,280 MW power station with 4 x 320 MW generators that can operate at a maximum capacity of 1400 MW. Controlling ice, the dam controls downstream releases to reservoirs lower in the river, allowing them to generate more power instead of mitigating ice. Water in the dam’s 24.7 billion m3 reservoir provides irrigation water for up to 1,000,000 hectares (2,471,054 acres) of land.
The dam is composed of its main body and a gravity pier and secondary dam on both its left and right flank. The dam’s service spillway contains two 12 metres (39 ft) wide gates that discharge water into two 260 metres (853 ft) and 280 metres (919 ft) long chutes. Downstream discharges are also controlled by a similar single-chute middle outlet and the lower outlet works.