The Ertan Dam () is an arch dam on the Yalong River, a tributary of the Yangtze River in Sichuan Province, in southwest China.
The dam has six hydroelectric generators, each with a generating capacity of 550 MW. The total generating capacity of the facility is 3,300 MW, one of the largest hydroelectric stations in China. The annual production is 17 TWh, and until December 5, 2006, it has produced over 100 TWh of electricity. Construction of the dam started on September 1991 and was completed on December 26, 1999. A total of of material was excavated during construction.
The Ertan Dam was designed by the China Hydropower Engineering Consulting Group Survey and Design Institute in Chengdu, and was constructed and is currently operated by Ertan Hydropower Development Company Limited, the owners of the dam. The company is invested by State Development and Investment Company (52% share) and Sichuan Chuantou Energy Limited (48% share).
Design
The Ertan Dam is a high and long double-curvature arch dam. The dam withholds a normal reservoir of with a drainage area of and normal surface area of . The dam has four different ways to discharge water downstream. First, the dam's spillways which contain 7 x floodgates at the crest and two flood tunnels can discharge and respectively. The dam also contains 6 x middle outlets and 4 x bottom outlets that can discharge and respectively. The dam's power station is located underground along with its transformer room which is in a separate cavern. Additionally, the power station is supported by an underground surge chamber as well.