What's inside the world's largest Three Gorges Dam?

Construction began in 1994 and was completed in 2012. The Three Gorges Dam brought many economic benefits but also received much criticism for its impact on the surrounding environment.

The Three Gorges Dam is the world's largest hydroelectric dam, blocking the Yangtze River, China's longest. The dam is located between Yichang City (Hubei Province) and Peiling (Chongqing City). This is a winding and dangerous location, but has an abundant amount of water all year round. (Photo: SentinelHub).

The dam was built with three main purposes: flood control, clean energy production and improved waterway transportation. Construction began in 1994 and all functions were put into operation in July 2012. The Three Gorges Reservoir alone began filling with water in June 2003 with a total volume of about 39.3 km3 ^, the normal dam water level is 175 m above sea level, 110 m higher than the water level downstream. (Photo: Britannica).

The main wall of the Three Gorges Dam was completed in 2006, measuring 2,355 meters in length and crest 185 meters above sea level. According to Ibiblio, the project used about 27 million cubic meters of concrete and 463,000 tons of steel (enough steel to build 63 Eiffel Towers). (Photo: Britannica).

With a reservoir capacity of up to 39.3 km3, the dam is determined to reduce the flood rate from 1/10 year to 1/100 year. However, according to Probe International, the Three Gorges Dam will gradually lose its flood prevention function due to the loss of forest ecosystems in the river basin, and at the same time because the dam has retained about 530 million tons of mud/year, causing the volume of the reservoir to decrease significantly. At 2:00 p.m. on July 2, the Three Gorges Dam was forced to open 3 gates to release floodwaters due to prolonged rain, with a maximum flow of 53,000 m3/s. (Photo: Britannica).

The Three Gorges Dam is also the world's largest hydroelectric power plant. The dam's 34 generators can generate 22.5 million kilowatts of electricity. The main generators weigh about 6,000 tons each and are the product of many leading technology joint ventures such as Alstom, ABB Group, General Electric, Siemens, etc. Most of the machines have water or air cooling systems, which are more economical and easier to maintain. (Photo: Pinterest).

On the right side of the Three Gorges Dam, there is a separate passageway for ships. The structure is a "five-story staircase" that uses a hydraulic system to lower or raise ships traveling on the Yangtze River. An estimated 130 vehicles pass through the dam every day. (Photo: Pinterest).

The Three Gorges Dam also has a 'water elevator' for smaller boats or for emergency use. Called 'the ship lift ,' it is capable of lifting a 3,000-ton ship with a total capacity of 15,500 tons in just 10 minutes. (Photo: SKF).

Despite its economic benefits such as providing clean electricity and improving waterways, the Three Gorges Dam has also received a lot of criticism. For example, it has affected the surrounding ecosystem, the rising water level of the reservoir has forced 1.3 million people to relocate, and more than 1,600 businesses and mining operations have stopped. In 2019, a photo of the Three Gorges Dam distorted by the impact of flooding caused many people to worry about the risk of the dam collapsing, after which the Chinese government denied the information and affirmed "There is no problem at all". (Photo: Dailymail).