Top 10 Largest Hydroelectric Dams in the World

Guri Dam, standing at 162 meters, is the primary source of electricity for Venezuela. Since the 1960s, Venezuela has minimized its use of oil for electricity production, focusing instead on oil exports, which made hydroelectric power the country's main energy source. By 2006, the electricity produced at Guri Dam was even being exported to Colombia and Brazil.

However, in recent years, prolonged droughts have caused river levels to drop, leading to insufficient electricity production to meet domestic needs. As a result, the government has had to implement power outages of 2 to 4 hours per day. While Guri Dam plays a vital role in the economy, it has had significant environmental impacts, including the destruction of thousands of square miles of biodiversity-rich rainforest around the Caroni River.

Design Capacity (MW): 10,235.
Location: Caroni River, Venezuela.

Tucurui Dam is a concrete gravity dam located on the Tocantins River in the Tucurui district of Para, Brazil. Its primary purpose is to generate hydroelectric power and regulate water flow. It was the first large-scale hydroelectric project in Brazil's Amazon rainforest. The plant is equipped with 25 turbines and has a total installed capacity of 8,370 megawatts (11,220,000 horsepower). Construction began in 1980, with Phase I completed in 1984, and Phase II finished in 2010. The dam was featured in the 1985 film *The Emerald Forest*.

The main structure of the Tucurui Dam is 78 meters high and 6.9 kilometers long. The Mojú and Caraipé embankments extend its total length to 12.515 kilometers. Tucurui Dam provides electricity to 13 million people, with 60% of the power serving industrial sectors, and generates around 2,000 jobs. However, its construction led to a large influx of migrants, which contributed to deforestation and other negative environmental impacts. Tucurui Dam marked the first major hydroelectric project in the Amazon region. Despite its benefits, it has caused significant ecological damage, particularly through deforestation.

Design Capacity (MW): 8,370.

Location: Tocantins River, Brazil.

Grand Coulee Dam is a gravity dam located on the Columbia River in Washington State, USA. It was built to generate hydroelectric power and provide irrigation. Construction took place from 1933 to 1942, initially with two power plants. A third plant was added in 1974 to increase energy production. It is the largest electricity-producing facility in the USA and one of the largest concrete structures in the world.

After visiting the construction site in August 1934, President Franklin Delano Roosevelt shifted his support from a cheaper "low dam" option to a more beneficial "high dam" design. The high dam proposal was approved by the U.S. Congress in 1935, and construction was completed in 1942, with the first water flowing over the spillway on June 1 of that year.

The Grand Coulee Dam serves as the largest hydroelectric power plant in the United States, located on the Columbia River in Washington. Besides generating electricity, its purpose includes providing water for irrigation. During World War II, the power generated by the dam helped fuel the rapid industrial growth in the Pacific Northwest. Due to rising demand, the facility was expanded with an additional plant. However, the dam had severe consequences for indigenous tribes who relied on fishing, as it completely blocked the migration routes of fish species.

Design Capacity (MW): 6,809.

Location: Columbia River, USA.

Xiangjiaba Dam is a massive gravity dam located on the Jinsha River, a tributary of the Yangtze, in the provinces of Yunnan and Sichuan in southwestern China. This hydroelectric plant features eight Francis turbines, four units with a capacity of 812 MW, and four units generating 800 MW, for a total installed capacity of 6,448 MW. It ranks as the third-largest hydroelectric dam in China, following the Three Gorges Dam and the Xiluodu Dam. Construction began in November 2006, and the first turbine came online in October 2012.

The final turbine was commissioned on July 9, 2014. The majority of the electricity produced by the Xiangjiaba Dam is supplied to Shanghai. Its power output is connected to the ± 800 kV HVDC transmission line, which forms part of the Xiangjiaba-Shanghai HVDC system, transmitting the bulk of its energy to the city.

Design Capacity (MW): 6,448.

Location: Jinsha River, China.

Longtan Dam is a roller-compacted concrete (RCC) gravity dam located on the Hongshui River in the Guangxi Zhuang Autonomous Region, China, a tributary of the Xijiang and Zhujiang Rivers. Standing at 216.2 meters tall and stretching 849 meters in length, it is the tallest concrete gravity dam in the world. The dam features seven spillways, two bottom outlets, and an underground power station. The Longtan Ship Lift, part of the dam complex, is set to become the world’s highest ship lift system.

The dam was initially planned in the 1950s and construction officially began in July 2001. By 2009, the final power unit was commissioned, bringing the total installed capacity to 6,426 MW, with an estimated annual energy output of 18.7 TWh. The Longtan Dam is the tallest gravity dam in the world at 216 meters, built primarily for power generation, flow regulation, and flood control.

Design Capacity (MW): 6,426.

Location: Hongshui River, China.

Sayano-Shushenskaya Dam is located on the Yenisei River, near Sayanogorsk in Khakassia, Russia. It is the largest hydroelectric power station in Russia and the 10th largest in the world by installed capacity. The dam is incredibly robust, designed to withstand the impact of earthquakes up to 8 on the Richter scale. It is also listed in the Guinness World Records as the most earthquake-resistant hydroelectric dam in the world.

As Russia’s largest hydroelectric facility, Sayano-Shushenskaya Dam plays a critical role in the nation's economy, supplying 25% of Russia's total hydroelectric power. However, during its operation, the dam has faced several serious incidents, including a catastrophic explosion in 2009, among other challenges.

Design Capacity (MW): 6,499.

Location: Yenisei River, Russia.

Krasnoyarsk Dam is a hydroelectric dam spanning the Yenisei River in northern Divnogorsk, Russia. It was constructed from 1956 to 1972 and has an installed capacity of 6,000 MW, primarily used for supplying power to KrAZ. Both the power plants and aluminum operations are managed by RUSAL. As a result of the dam's construction, the Krasnoyarsk Reservoir was created, also known as the Krasnoyarsk Sea. This vast body of water covers an area of 2,000 km² and has a volume of 73.3 cubic kilometers. The reservoir stretches 388 km in length, 15 km in width, with an average depth of 36.6 meters, reaching depths of up to 105 meters near the dam.

Krasnoyarsk Dam has a significant impact on the local climate. Typically, the Yenisei River would freeze in the harsh Siberian winter, but due to the constant release of water from the dam, the river remains ice-free along a stretch of 200 to 300 kilometers. During winter, the cold air interacts with the warmer river water, creating fog that envelops Krasnoyarsk and downstream areas.

The Krasnoyarsk Dam is the second-largest hydroelectric facility in Russia, located on the Yenisei River. Standing at 124 meters tall, it was built between 1956 and 1972. The construction of the dam has also contributed to changes in the regional climate, with the continuous release of non-freezing water during winter interacting with the frozen river, creating mist that affects Krasnoyarsk and surrounding areas.

Design Capacity (MW): 6,400

Location: Yenisei River, Russia.

The Three Gorges Dam is the largest hydroelectric project in the world, located on the Yangtze River, the longest river in Asia. Construction of the dam took 14 years, from 1994 to 2008, with a staggering investment of $75 billion. The power generated by the Three Gorges Hydroelectric Plant not only serves the central Chinese power grid, including the provinces of Henan, Hubei, Hunan, and Jiangxi, but also supplies electricity to the Chongqing and Sichuan regions. However, the dam's construction has faced criticism due to concerns over environmental impacts, ecological balance, water level control, and potential disaster risks associated with the project.

Adjacent to the dam is a visitor center showcasing a model of the dam. This model offers a comprehensive view of the project's engineering feats for visitors. Just a short walk from the display area leads to a high observation deck, providing a panoramic view of the entire dam site. The electricity generated by the Three Gorges Hydroelectric Plant will not be confined to the central Chinese grid but will also be transmitted westward and along various routes to the eastern and southeastern coastal regions. Two major HVDC transmission lines, the Three Gorges–Changzhou and Three Gorges–Guangdong, will deliver electricity to the east (towards Shanghai) and south (towards Guangdong Province).

Design Capacity (MW): 22,500.
Location: Yangtze River, Hubei Province, China.

Itaipu Dam is a hydroelectric dam located on the Paraná River, straddling the border between Brazil and Paraguay. The name "Itaipu" comes from a nearby island where the dam was constructed. The Itaipu Hydroelectric Plant set a world record for electricity generation, producing 103,098,366 MWh, surpassing the output of the Three Gorges Dam in 2015 and 2016. With an installed capacity of 14 GW, the plant operates 20 turbines. Ten turbines, running at a frequency of 50 Hz, supply power to Paraguay, while the other ten, operating at 60 Hz, serve Brazil.

The amount of concrete used for the dam's construction is estimated to be enough to build 210 football stadiums and 380 Eiffel Towers. Under a joint agreement, both Brazil and Paraguay receive 50% of the generated electricity, although Paraguay consumes only a small portion of its share and is required to sell the surplus to Brazil at the production cost.

Although Itaipu's design capacity is smaller than that of China's Three Gorges Dam, its annual electricity production leads the world, generating 10% more than the Three Gorges. Itaipu was constructed to meet the energy demands of both Brazil and Paraguay, currently fulfilling about 15% of Brazil's electricity needs and 75% of Paraguay's consumption.

Design Capacity (MW): 14,000.
Location: Paraná River, Brazil-Paraguay Border.

Xiluodu Dam is an arch dam located on the Jinsha River, a tributary of the Yangtze River in China. Positioned near Xiluodu Town in Yongshan County, Yunnan Province, the dam itself is situated in Leibo County, Sichuan Province. In addition to generating electricity, the dam plays an essential role in flood control, sediment management, and regulated water discharge to improve downstream water quality. Construction of the dam and its power station began in 2005. It is operated by China Yangtze Power and currently ranks as the third-largest hydroelectric plant in the world, with the fourth tallest dam.

The Xiluodu Dam is a concrete arch structure built on the Jinsha River in the upper reaches of the Yangtze, spanning Sichuan and Yunnan provinces. Completed in 2014, the dam initially aimed to provide power with a design capacity of 13,860 MW. Over time, it has also contributed to flood regulation, sediment control, and flow management to enhance water quality downstream.

Design Capacity (MW): 13,860.
Location: Jinsha River, China.