China is home to half of the world’s dams.

That means more than 22,000. It is the result of 30 years of a flurry of construction. The Ertan Dam, located at a height of 1,200 metres, on the Yalong River, near the city of Panzhihua, serves as a reminder of the country’s response to the economic and demographic challenges it faced at the time of its construction.

It was the first to be co-financed by international institutions like the World Bank. It was also the first hydropower project for which the country invited foreign companies including Webuild to bid in a tender.

In operation since 1999, it is still one of the biggest hydropower projects to have been built in the country. At 240 metres in height and 775 metres in length, Ertan belongs to a network of 11 dams that make the most of the region’s hydroelectric potential. The dam is set well into the sides of the river valley to resist the water pressure. It is a concrete double-curvature arch dam, well anchored into the rock. Its construction involved interrupting the flow of the river by collapsing stone bridge and building a transversal dam.

Ertan still stands as the world’s 18th highest dam. The top spot is held by another dam in China, located nearby on the Yalong River: Jinping-I at a height of 305 metres. Ertan has an annual production capacity of 17,000 gigawatts, supplying clean and sustainable electricity to the 85 million people who live and work in the Sichuan region.