From Wikipedia

Three Gorges Dam

 The Three Gorges Dam is a hydroelectric dam that spans the Yangtze River by the town of Sandouping, located in the Yiling District of Yichang, in Hubei province, China. It is the world's largest electricity-generating plant of any kind, and second in production, only exceeded by Itaipu Dam, Brazil and Paraguay's electricity-generating plant.

 The project produces electricity, increases the river's shipping capacity, and reduces the potential for floods downstream by providing flood storage space. From completion through September 2009 the dam has generated 348.4 TWh (1,254 PJ) of electricity, covering more than one third of its cost.

The Chinese state regards the project as a historic engineering, social and economic success, with the design of state-of-the-art large turbines, and a move toward limiting greenhouse gas emissions. However, the dam flooded archaeological and cultural sites and displaced some 1.3 million people, and is causing significant ecological changes, including an increased risk of landslides. The dam has been a controversial topic both in China and abroad.