The ten largest human-made reservoirs ranked by nominal volume, from Lake Kariba's 180 km³ on the Zambezi to the Zeya Reservoir in Russia.
Quick answer: 1. Lake Kariba, 2. Bratsk Reservoir, 3. Lake Volta, 4. Manicouagan Reservoir, 5. Guri Reservoir, 6. Lake Nasser, 7. Millennium Reservoir (GERD), 8. Williston Lake, 9. Krasnoyarsk Reservoir, 10. Zeya Reservoir.
Reservoirs are human-made or regulated lakes created by damming rivers to store water for drinking, irrigation, hydroelectric power, and flood control. The largest ones hold more water than many natural lakes, with the top five exceeding 100 cubic kilometres of storage capacity. This list ranks the world's largest reservoirs by nominal volume (total capacity at maximum water level) in cubic kilometres. The ranking excludes natural lakes that have been augmented with a minor dam — only reservoirs created by major dam construction are included.
Lake Kariba on the Zambezi River is the world's largest reservoir by volume, with a nominal capacity of 180.6 km³. Created by the Kariba Dam between Zambia and Zimbabwe, it was completed in 1959 and stretches 280 km long. The dam's hydroelectric plant provides power to both countries and is one of the largest in Africa.
The Bratsk Reservoir on the Angara River in Siberia, Russia, holds 169.3 km³ of water. Created by the Bratsk Dam and completed in 1964, it is one of the largest artificial lakes in the world by surface area at 5,470 km². The reservoir was formed by flooding the Angara River valley and required the relocation of thousands of residents.
Lake Volta in Ghana, created by the Akosombo Dam on the Volta River, has a nominal volume of 150 km³. Completed in 1965, it is the largest reservoir by surface area in the world at 8,502 km² — roughly 3.6% of Ghana's total land area. The dam provides hydroelectric power to Ghana and neighbouring Togo and Benin.
The Manicouagan Reservoir in Quebec, Canada, holds 141.85 km³ of water behind the Daniel-Johnson Dam on the Manicouagan River. Completed in 1968, the reservoir occupies the ring of an ancient impact crater 214 million years old — one of the largest visible impact craters on Earth, now filled with water.
The Guri Reservoir in Venezuela, formed by the Guri Dam on the Caroní River, has a capacity of 135 km³. Completed in 1986, Guri Dam is one of the world's largest hydroelectric plants by installed capacity at 10,235 MW, historically supplying over 70% of Venezuela's electricity.
Lake Nasser, created by the Aswan High Dam on the Nile River, holds 132 km³ of water. Straddling the border between Egypt and Sudan, the reservoir was completed in 1971 and stretches 550 km long. Lake Nasser is named after former Egyptian President Gamal Abdel Nasser, who spearheaded the dam's construction.
The Millennium Reservoir behind the Grand Ethiopian Renaissance Dam on the Blue Nile River in Ethiopia has a nominal volume of 79 km³. Filling began in 2020 and continued through 2024, making it the newest and largest reservoir in Africa. The dam is the continent's largest hydroelectric project at 5,150 MW capacity.
Williston Lake in British Columbia, Canada, holds 74.3 km³ of water behind the W. A. C. Bennett Dam on the Peace River. Completed in 1967, it is the largest reservoir in British Columbia and the third largest in Canada. The dam's hydroelectric plant has a capacity of 2,730 MW.
The Krasnoyarsk Reservoir on the Yenisei River in Siberia, Russia, has a nominal volume of 73.3 km³. Created by the Krasnoyarsk Dam and completed in 1967, the reservoir stretches 388 km long and is one of the largest in Siberia. The dam's hydroelectric plant has an installed capacity of 6,000 MW.
The Zeya Reservoir in the Amur Oblast of Russia, formed by the Zeya Dam on the Zeya River, holds 68.4 km³ of water. Completed in 1978, the reservoir is located in the Russian Far East and is a key component of the region's hydroelectric infrastructure. The dam's plant has a capacity of 1,330 MW.
| # | Name | Country | River | Dam | Year completed |
|---|---|---|---|---|---|
| 1 | Lake Kariba | Zambia & Zimbabwe | Zambezi | Kariba Dam | 1959 |
| 2 | Bratsk Reservoir | Russia | Angara | Bratsk Dam | 1964 |
| 3 | Lake Volta | Ghana | Volta | Akosombo Dam | 1965 |
| 4 | Manicouagan Reservoir | Canada | Manicouagan | Daniel-Johnson Dam | 1968 |
| 5 | Guri Reservoir | Venezuela | Caroní | Guri Dam | 1986 |
| 6 | Lake Nasser | Egypt & Sudan | Nile | Aswan High Dam | 1971 |
| 7 | Millennium Reservoir (GERD) | Ethiopia | Blue Nile | Grand Ethiopian Renaissance Dam | 2023 |
| 8 | Williston Lake | Canada | Peace River | W. A. C. Bennett Dam | 1967 |
| 9 | Krasnoyarsk Reservoir | Russia | Yenisei | Krasnoyarsk Dam | 1967 |
| 10 | Zeya Reservoir | Russia | Zeya | Zeya Dam | 1978 |
Reservoirs are ranked by nominal volume in cubic kilometres (km³) as reported in the Wikipedia list of reservoirs by volume, which draws on data from the Chao Global Reservoir and Lake Database and the Avakyan Inventory of Large Reservoirs. Nominal volume represents the total water storage capacity at the maximum designed water level. Only reservoirs created by a major dam are included; natural lakes with minor outlet control are excluded.
Nominal volume is the total water storage capacity at the maximum designed water level. Active volume is the portion that can actually be used for its intended purpose (hydroelectricity, irrigation, etc.), minus the 'dead pool' volume that remains below the outlet level. Active volume is typically smaller than nominal volume.
Reservoir volume estimates vary between sources because of differences in measurement methodology, the year of the survey, and whether the figure represents nominal or active volume. Where multiple estimates exist, the primary figure from the Chao Global Reservoir Database is used as the reference.
Some natural lakes, such as Lake Superior, have minor outlet control dams that regulate water levels. However, the great majority of the lake volume is natural. The table above excludes such augmented natural lakes — only reservoirs created by major dam construction are included.