|Construction began||September 1991|
|Opening date||26 December 1999|
|Owner(s)||Yalong River Hydropower Development Company, Ltd.|
|Dam and spillways|
|Type of dam||Arch|
|Height||240 m (787 ft)|
|Length||774.7 m (2,542 ft)|
|Dam volume||5,857,000 m3 (206,838,003 cu ft)|
|Spillway type||7 x crest outlets, 2 x flood tunnels|
|Spillway capacity||6,260 m3/s (221,070 cu ft/s)|
Tunnels:7,400 m3/s (261,329 cu ft/s)
|Total capacity||5,800,000,000 m3 (4,702,137 acre⋅ft)|
|Catchment area||116,400 km2 (44,942 sq mi)|
|Surface area||101 km2 (39 sq mi)|
|Hydraulic head||189 m (620 ft) (max gross)|
|Turbines||6 × 550 MW Francis turbines|
|Installed capacity||3,300 MW|
|Annual generation||17 TWh|
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 12,638,000 m3 (446,306,758 cu ft) 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).
The Ertan Dam is a 240 m (787 ft) high and 774.7 m (2,542 ft) long double-curvature arch dam. The dam withholds a normal reservoir of 5,800,000,000 m3 (4,702,137 acre⋅ft) with a drainage area of 116,400 km2 (44,942 sq mi) and normal surface area of 101 km2 (39 sq mi). The dam has four different ways to discharge water downstream. First, the dam's spillway's which contain 7 x floodgates at the crest and two flood tunnels can discharge 6,260 m3/s (221,070 cu ft/s) and 7,400 m3/s (261,329 cu ft/s) respectively. The dam also contains 6 x middle outlets and 4 x bottom outlets that can discharge 6,930 m3/s (244,731 cu ft/s) and 2,084 m3/s (73,596 cu ft/s) 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.