The Ertan Dam (simplified Chinese: 二滩大坝; traditional Chinese: 二灘大壩; pinyin: Èrtān Dàbà) is an arch dam on the Yalong River, a tributary of the Yangtze River in Sichuan Province, southwest China.

Flood discharge of Ertan
Ertan Dam
Ertan Dam and intake.jpg
Ertan Dam is located in China
Ertan Dam
Location of Ertan Dam in China
Official name二灘大壩
LocationSichuan, China
Coordinates26°49′15″N 101°46′52″E / 26.82083°N 101.78111°E / 26.82083; 101.78111Coordinates: 26°49′15″N 101°46′52″E / 26.82083°N 101.78111°E / 26.82083; 101.78111
Construction beganSeptember 1991
Opening date26 December 1999
Owner(s)Yalong River Hydropower Development Company, Ltd.
Dam and spillways
Type of damArch
ImpoundsYalong River
Height240 m (787 ft)
Length774.7 m (2,542 ft)
Dam volume5,857,000 m3 (206,838,003 cu ft)
Spillway type7 x crest outlets, 2 x flood tunnels
Spillway capacity6,260 m3/s (221,070 cu ft/s)
Tunnels:7,400 m3/s (261,329 cu ft/s)
CreatesErtan Reservoir
Total capacity5,800,000,000 m3 (4,702,137 acre⋅ft)
Catchment area116,400 km2 (44,942 sq mi)
Surface area101 km2 (39 sq mi)
Power Station
Hydraulic head189 m (620 ft) (max gross)
Turbines6 × 550 MW Francis turbines
Installed capacity3,300 MW
Annual generation17 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.[1][2] 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).

General layout of Ertan hydroelectric scheme[3]


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.[3]

Main Features[3]Edit

Project Location On the Yalong River, Sichuan province,

P. R. China

Project Purpose Hydroelectric Power Generation
Years of Construction 1987-1999
Construction of Main Dam
Type Double-curvature Arch Dam
Height 240 m
Crest Length 774.69 m
Construction of Power plant
Maximum gross head 189 m
Installed Capacity 6×550 MW (Francis)
Power Conduits 6 steel embedded in concrete

I.D.=9.0 m

Catchment and Reservoir
Catchment Area 116,400 km2
Mean Annual Runoff 1,670 m3/s
Reservoir Area at FSL 101 km2
Storage at FSL 5,800 million m3
Active Storage 3,370 million m3
Discharge Capacity
Crest Outlet 7 / 6,260 m3/s
Mid Level Outlet 6 / 6,930 m3/s
Bottom Outlet 4 / 2,084 m3/s
Flood Discharging 2 / 7,400 m3/s
Project Developers
Owner Ertan Hydropower Development


Designer CHIDI,

now POWERCHINA Chengdu

Contractor EJV, SGEJV, GYBD
Main Equipment Suppliers
Turbines GE Canada, Dongfang Electrical

Machinery Co, Ltd., Harbin Electric

Machinery Co, Ltd.

Generators & HV


GE Canada, Dongfang Electrical

Machinery Co, Ltd., Harbin Electric

Machinery Co, Ltd.

Gates &


Jiajiang Hydraulic Machinery Works,

China Gezhouba (Group) Corporation,

Sinohydro Bureau No.8,

See alsoEdit


  1. ^ Ertan Hydroelectric Dam
  2. ^ 我国西部的最大水电站二滩水电站全面建成投产
  3. ^ a b c "Ertan Hydropower Project" (PDF). Chinese National Committee on Large Dams. Retrieved 8 January 2011.