Largest Dams in the World: Top 10

The largest dams in the world, ranked here by reservoir capacity, hold back artificial lakes so vast that Kariba alone stores about 181 cubic kilometres.

Size can be measured in several ways. A dam can be enormous because of the water it impounds, because of the rock and earth piled into its body, or because of how far it towers above the riverbed. This Finepedia ranking, framed as of October 2026, uses the first test: how much water each structure holds back at full supply level. Height belongs to a separate list of the tallest dams, which Finepedia will cover on its own.

The result is a Top 10 spread across Africa, Russia, Canada and South America, with one newcomer that began full operation only in September 2025. Several of these reservoirs are longer than many natural lakes, and a few reshaped the economies of whole nations. If you enjoy comparing giant bodies of water, our guide to the deepest lakes in the world makes a natural companion read.

How We Ranked the Largest Dams

Every dam was ranked by the gross (total) storage capacity of its reservoir, measured in cubic kilometres (km3). One cubic kilometre equals one billion cubic metres, so a reservoir of 100 km3 holds roughly 100 trillion litres. Where the dam owner or operator publishes a capacity figure, we used it and cross-checked it against at least one independent reference such as Encyclopaedia Britannica or a specialist engineering publication.

Two exclusions matter. Owen Falls Dam in Uganda, now called Nalubaale, regulates the outflow of Lake Victoria, but Lake Victoria is a natural lake, so counting it would distort the comparison. Tailings dams, such as the Syncrude structure in Canada's oil sands, retain mine waste rather than a water reservoir, so they sit in a different category.

Installed generating capacity, completion year, river and country appear in each entry for context. Figures are rounded sensibly and are correct to the best of published sources available as of October 2026. Reservoir levels change with rainfall and drought, so the capacities below describe how much each lake can hold when full, not how much it holds on any given day.

Largest Dams in the World at a Glance

The Grand Ethiopian Renaissance Dam and the W. A. C. Bennett Dam both store roughly 74 km3. Under our tie-break rule the Ethiopian dam ranks seventh because its 5,150 MW of installed capacity is far larger than the Canadian station's.

1. Kariba Dam

Kariba holds the top spot by a comfortable margin. Its reservoir, Lake Kariba, is generally described as the largest artificial lake on Earth by volume. The Zambezi River Authority, which manages the dam for both countries, gives total storage of about 181 km3, rising to around 185 km3 at the maximum retention level.

History and Construction

The dam was planned by the Federation of Rhodesia and Nyasaland, a colonial federation that later split into Zambia, Zimbabwe and Malawi. Work at the narrow Kariba Gorge began in the mid-1950s, and the concrete arch was finished in 1959. The lake then took several years to fill, reaching capacity for the first time in 1963.

Two power stations sit on opposite banks. The south bank station on the Zimbabwean side came first, while the north bank station on the Zambian side followed in the 1970s. Both have since been expanded, and today the scheme is jointly owned through the Zambezi River Authority, which Zambia and Zimbabwe hold in equal shares.

Key Features

• A slender double-curvature arch that bends both horizontally and vertically to push the water's load into the gorge walls
• Six spillway sluice gates set high in the wall to pass major floods
• A reservoir about 280 km long and roughly 5,580 km2 in area at full level
• Live storage of about 65 km3, the slice of water actually available for generating power
• Separate Zambian and Zimbabwean powerhouses fed by the same lake

Significance

Kariba supplies a large share of the electricity used in Zambia and Zimbabwe, including power for the Zambian Copperbelt. Because only the top layer of the lake can be used for generation, long droughts hit output hard. The authority's own reports show usable storage falling below 1 percent at the end of 2022, which forced deep cuts in turbine releases.

The project came at a human cost. Tens of thousands of Tonga (BaTonga) people living along the Zambezi were moved away from the river valley. Britannica notes that more than 30,000 were resettled on the Zambian side alone. Rising water also stranded wildlife on new islands, prompting a famous rescue effort.

Interesting Facts

• The wildlife rescue during the lake's filling, known as Operation Noah, moved thousands of large animals between 1958 and 1961.
• Kapenta, a small sardine-like fish, was brought from Lake Tanganyika in the late 1960s and now supports a major commercial fishery.
• The weight of the new lake triggered reservoir-induced earthquakes during filling, including notable tremors in 1963.
• A multi-year rehabilitation project reshaped the plunge pool below the spillway in 2024, and spillway gate refurbishment was in its final stage during 2026.

2. Bratsk Dam

Bratsk is the giant of Siberia's Angara River and the second-largest reservoir in this ranking. Britannica and specialist engineering references agree on a capacity of about 169.27 km3, only a little behind Kariba.

History and Construction

Planning was approved in 1954, and the city of Bratsk grew up alongside the construction camp. Builders faced extreme conditions. Britannica records winter temperatures falling to about minus 58 °C and frost on roughly 281 days of the year, all at a site far from factories and supply lines.

The reservoir began filling in the early 1960s while generating units were installed in stages. The dam itself was completed in 1964, a decade after planning was approved.

Key Features

• A combined concrete and earthfill structure stretching more than 4 km along the crest
• A railway line and a road running across the top of the dam
• Eighteen large Francis turbines in a single turbine hall
• A reservoir with a surface area of roughly 5,500 km2
• A place in a cascade of four Angara stations, alongside Irkutsk, Ust-Ilimsk and Boguchany

Significance

Bratsk was a showcase of Soviet industrial planning. Its cheap electricity attracted heavy industry, especially aluminium smelting, and it ranked among the most powerful hydro plants of its era.

The reservoir flooded long stretches of the Angara valley. As with other Siberian megaprojects of the period, reliable public figures on displacement are hard to find, so this article does not quote one.

Interesting Facts

• Britannica singles out the reservoir as unusually large.
• Trains and cars cross the Angara on the dam crest itself.
• Bratsk is the second of four power stations stepping down the Angara River.
• The reservoir holds more water than Lake Nasser's nominal capacity, despite Aswan's greater fame.

3. Akosombo Dam

Akosombo created Lake Volta, which is the largest reservoir on Earth by surface area. Britannica's dam entry and other references give a capacity of about 148 km3, though Britannica's separate Lake Volta article quotes 153 km3, so the true figure sits in that narrow band.

History and Construction

The project grew out of Ghana's plan to build an aluminium industry after independence in 1957. President Kwame Nkrumah backed a hydroelectric scheme that could power a smelter at the port of Tema. Work at the Akosombo gorge started in 1961, financed jointly by Ghana, the World Bank, the United States and the United Kingdom.

Flooding on the Volta in 1963 halted work for several months, but the dam was completed in 1965. Lake Volta then spread roughly 400 km upstream, covering about 8,500 km2, or around 3.6 percent of Ghana's land area.

Key Features

• A high rock-fill embankment with a crest roughly 640 to 660 m long
• A structural volume of about 7.9 million cubic metres
• A reservoir long enough to serve as a shipping route between northern Ghana and the coast
• Six generating units, upgraded in 2006 to a combined capacity of about 1,020 MW

Significance

Akosombo became the backbone of Ghana's electricity system and supplies power to neighbouring countries such as Togo and Benin. Lake Volta also supports fishing, irrigation and transport.

The social cost was very high. Britannica records that the lake flooded about 740 villages, and roughly 80,000 people had to move into resettlement townships that later studies found poorly planned. In September and October 2023, after heavy rain, controlled releases from the dam caused serious downstream flooding that displaced tens of thousands of residents.

Interesting Facts

• Lake Volta's surface area exceeds that of any other reservoir on the planet.
• The original output of 912 MW exceeded early demand, allowing Ghana to export electricity.
• The dam is also known simply as the Volta Dam.
• Lake Volta is navigable along much of its length and serves as a cheap freight corridor.

4. Daniel-Johnson Dam

Daniel-Johnson is the most striking-looking dam on this list. Hydro-Québec calls it the largest multiple-arch-and-buttress dam in the world, and its reservoir fills the ring of an ancient meteorite impact crater. Hydro-Québec gives total reservoir volumes of 137.9 and 138.8 billion cubic metres on different pages, while other references quote up to about 142 km3.

History and Construction

Hydro-Québec launched the Manicouagan-Outardes development in the late 1950s, and work at the dam site began in 1959. Construction took about a decade and was completed in 1968.

The dam, originally known as Manic-5, was named after Daniel Johnson, who was Premier of Quebec at the time. A second powerhouse, Manic-5-PA, was added later to boost peak output.

Key Features

• Thirteen arches supported by fourteen buttresses
• A crest length of about 1.3 km
• Roughly 2.2 million cubic metres of concrete
• Two powerhouses with a combined 2,660 MW
• A reservoir covering close to 2,000 km2 inside a circular impact structure

Significance

The Manicouagan Reservoir is one of Hydro-Québec's key storage basins. By releasing stored water through a chain of downstream stations, it helps supply electricity across Quebec and beyond during winter peaks.

The broader Manicouagan-Outardes development, with several dams on two rivers, reshaped large river systems in Quebec's north shore region and became a symbol of the province's engineering ambitions in the 1960s.

Visiting

Hydro-Québec runs free public tours of the Manic-5 generating station and the Daniel-Johnson dam. The site lies roughly 200 km north of Baie-Comeau.

Interesting Facts

• The crater holding the reservoir was formed by an asteroid impact about 214 million years ago.
• Canada Post issued a stamp honouring the dam in 2000.
• The reservoir is about 200 km long.
• At 214 m, it is one of the tallest dams in Canada, although height is not the measure used here.

5. Guri Dam

Guri, officially the Simón Bolívar Hydroelectric Plant and formerly named after President Raúl Leoni, combines one of the largest reservoirs on Earth with one of the most powerful hydro stations. Specialist references give 135 km3, while Britannica quotes 138 km3 after the final enlargement.

History and Construction

Feasibility studies began in the early 1960s, and construction started in 1963 in the Necuima Canyon on the lower Caroní. The first stage, completed in 1969, was a 106 m dam with 1,750 MW of capacity.

Demand rose so quickly that a second stage, begun in 1976, combined two planned expansions into one. When work finished in 1986, the dam stood 162 m high, a second powerhouse had been added, and the reservoir had grown dramatically.

Key Features

• A long composite structure of concrete gravity sections and earth and rock embankments
• Two powerhouses with a combined capacity above 10,000 MW
• A reservoir covering roughly 4,000 to 4,250 km2
• Space for flood storage as well as generation

Significance

Guri produces a large share of Venezuela's electricity, so its water level is a national concern. During a severe drought in 2016, the reservoir dropped close to the level at which turbines must stop, and the government introduced nationwide power rationing for several weeks.

The reservoir submerged the original village of Guri and large areas of forest. Because so much of the national supply depends on one river, dry years quickly become electricity emergencies.

Interesting Facts

• Guri was for a time ranked among the world's most powerful hydro stations before Itaipu surpassed it.
• Rationing ended in mid-2016 only after rains helped the reservoir recover.
• A modernisation programme has been refurbishing turbines since the early 2000s.
• The final enlargement raised the dam from 106 m to 162 m.

6. Aswan High Dam

The Aswan High Dam is the most famous dam in Africa and the one with the most complicated capacity figures. Comparative reservoir tables usually list Lake Nasser at 132 km3, the figure used for this ranking. Britannica, however, gives a gross capacity of 169 km3, and other references put total storage near 162 km3 once flood space and dead storage are included. On those maximum-level figures, Aswan would move up to third place.

History and Construction

The dam was built about 6 to 7 km upstream of the older Aswan Low Dam of 1902. After Western lenders withdrew from the project in 1956, the Soviet Union supplied financing and engineering design. Construction ran through the 1960s, the structure was completed in 1970, and it was formally inaugurated in January 1971.

Lake Nasser stretches roughly 480 km along the Nile, with its southern part extending into Sudan.

Key Features

• A massive rock-fill embankment about 111 m high and 3,830 m long
• A structural volume of roughly 43 to 44 million cubic metres
• Twelve turbines with a combined capacity of 2,100 MW
• A spillway able to pass about 11,000 cubic metres per second

Significance

For the first time in history, the annual Nile flood came under human control. The dam stores floodwater and releases it when crops need it, expanded irrigated farmland, improved navigation, and cushions the country against years of low Nile flow.

The trade-offs are well documented. Silt that once fertilised fields along the river now settles in the reservoir, so farmers rely on artificial fertiliser, and the delta has suffered from coastal erosion and salinisation. Estimates of the number of Egyptian farmers and Sudanese Nubians who had to move range from about 90,000, the figure Britannica gives, to more than 100,000.

Visiting

The dam lies close to the city of Aswan, a long-established base for Nile tourism. The rising lake forced the international rescue of Nubian monuments, and the relocated temples of Abu Simbel on Lake Nasser's shore are among Egypt's most visited heritage sites.

Interesting Facts

• The Abu Simbel temples were cut into blocks and reassembled on higher ground to escape the rising water.
• Under a treaty between Egypt and Sudan, about 55.5 km3 of the Nile's yearly flow is allocated to Egypt.
• The older Aswan Low Dam downstream was once among the largest dams in the world.
• The project cost about 1 billion US dollars.

7. Grand Ethiopian Renaissance Dam

The Grand Ethiopian Renaissance Dam, often shortened to GERD, is the newest entry in this ranking and Africa's largest hydroelectric project. Ethiopian Electric Power, the main contractor Webuild and international reporting all describe a reservoir of about 74 km3 and an installed capacity of 5,150 MW.

History and Construction

Work began in 2011 close to the border with Sudan. Ethiopia financed most of the project domestically, including through bonds and public contributions, after international funding was not secured. The first turbine started generating in 2022, and output was increased in stages while the reservoir filled.

On 9 September 2025, the dam was officially inaugurated at a ceremony attended by Ethiopian leaders and several African heads of state. Reuters reported that the plant reached its full 5,150 MW on the day of the inauguration.

Key Features

• A main dam built from roller-compacted concrete, with more than 10 million cubic metres placed
• A large saddle dam that closes a low point in the reservoir rim
• Two powerhouses at the foot of the main dam, holding 13 Francis turbines
• A reservoir about 1,875 km2 in area, stretching roughly 172 km according to the builder
• Expected annual output of about 15,700 GWh

Significance

GERD is expected to greatly expand Ethiopia's electricity supply and to support exports to neighbouring countries. For millions of Ethiopians without reliable power, the project is a symbol of national development.

Downstream, Egypt and Sudan have raised concerns about how the reservoir is filled and operated, especially during droughts, and negotiations over a binding agreement have continued for years. This article takes no position on the dispute; it simply records the dam's size and function as of October 2026.

Interesting Facts

• The reservoir has been named Nigat Lake.
• Construction lasted about 14 years, from 2011 to 2025.
• Its builder describes it as the largest roller-compacted concrete gravity dam in Africa by volume.
• Power generation began three years before the official opening.

8. W. A. C. Bennett Dam

The W. A. C. Bennett Dam created Williston Lake, the largest body of fresh water in British Columbia. Its gross storage matches GERD at about 74 km3, so it ranks eighth on the tie-break for installed capacity. BC Hydro lists active storage of about 39.5 km3, the portion that can be drawn down for power.

History and Construction

The dam was a centrepiece of Premier W. A. C. Bennett's plan to develop both the Peace and Columbia rivers for hydropower. Construction began in 1961, and the earthfill embankment rose across the Peace River canyon through the decade. The G.M. Shrum Generating Station came into service in 1968.

Key Features

• One of the world's highest earthfill dams, at about 183 m
• An underground powerhouse with 10 generating units
• A reservoir of about 1,770 km2 at full pool
• A crest roughly 2 km long

Significance

G.M. Shrum is BC Hydro's largest generating station and supplies a significant share of the province's electricity. Williston Lake acts as a giant battery, storing water in wet seasons for use in high-demand winters.

The flooding of the valley in the late 1960s submerged forest and displaced residents, including members of the Tsay Keh Dene First Nation. The impact on Indigenous communities remains an important part of the dam's legacy.

Visiting

BC Hydro operates the W. A. C. Bennett Dam Visitor Centre near Hudson's Hope, which explains the dam's construction and the region's history.

Interesting Facts

• The reservoir is named after Ray Williston, a cabinet colleague of Premier Bennett.
• The dam honours W. A. C. Bennett, Premier of British Columbia from 1952 to 1972.
• Williston Lake is BC Hydro's largest storage reservoir.
• Its gross storage is almost twice its active storage, because much of the water sits below the lowest intake level.

9. Krasnoyarsk Dam

Krasnoyarsk is the second most powerful station in this Top 10 after Guri, and its reservoir, nicknamed the Krasnoyarsk Sea, is the second largest in Russia after Bratsk. Operator data and engineering references agree on about 73.3 km3 of storage.

History and Construction

Construction ran from 1956 to 1972 on the Yenisei upstream of the city of Krasnoyarsk. On completion, the station ranked among the largest single power plants in the world, and its electricity has long supported aluminium production in the region.

Key Features

• A concrete gravity wall about 124 m high
• Twelve generating units totalling about 6,000 MW
• A reservoir roughly 388 km long and about 2,000 km2 in area
• A ship lift that carries vessels past the dam on a wide inclined track

Significance

Krasnoyarsk anchors power supply in central Siberia, and the reservoir supports fishing, ferries and some irrigation. The dam also changed the local climate. Water released from deep in the reservoir is warmer than the winter air, so a long stretch of the Yenisei below the dam no longer freezes, and the open water produces dense winter fog downstream.

Interesting Facts

• The dam appears on the reverse of the Bank of Russia's 10-ruble banknote.
• Researchers describe an ice-free corridor of roughly 250 km downstream in winter.
• Building the dam and power station took 16 years.
• Locals nicknamed the reservoir the Krasnoyarsk Sea.

10. Zeya Dam

Zeya rounds out the Top 10. Russian state water records, RusHydro reporting and engineering references give a total reservoir volume of about 68.42 km3 at normal maximum level, comfortably ahead of the next contenders in Quebec and Siberia.

History and Construction

Construction began in the mid-1960s in the Russian Far East, north of the Chinese border, and the first units started generating in 1975. The station is operated by RusHydro, Russia's largest hydropower company.

Key Features

• A concrete buttress-gravity dam across a narrow valley
• Four 225 MW and two 215 MW turbines
• A reservoir about 225 km long with an area of roughly 2,420 km2
• Storage large enough for multi-year as well as seasonal regulation of the river

Significance

Zeya generates electricity for the Russian Far East and, just as importantly, stores floodwater that would otherwise surge down the Zeya into the Amur River basin. Its multi-year storage lets operators hold back water in wet years and release it in dry ones.

Interesting Facts

• Russia's state water register lists the full static volume as 68,420 million cubic metres.
• The reservoir is more than 200 km long.
• The Zeya is a major tributary of the Amur, which forms much of the Russia–China border.
• Construction took roughly a decade before first power in 1975.

Largest Dams by Other Measures

Reservoir capacity is only one way to define the largest dams in the world. The table below shows which structures lead on other common measures, so readers can see why lists from different publishers often disagree.

Honourable Mentions

Older internet lists mixed several measures together and sometimes repeated errors. One common mistake places the ancient Kallanai dam on the Nile in Egypt. In fact, Kallanai, also called the Grand Anicut, crosses the Kaveri River in Tamil Nadu, India. It is attributed to the Chola king Karikala around the second century CE and is described as India's oldest dam still in use, although British engineers remodelled it in the nineteenth century.

Big water projects often go hand in hand with bold transport engineering. For more record-breaking structures, see our list of the most dangerous bridges in the world, and for natural geology on a grand scale, explore the rarest rock formations in the world.

Frequently Asked Questions

Which is the largest dam in the world?

By reservoir capacity, the Kariba Dam on the Zambezi between Zambia and Zimbabwe is the largest. Lake Kariba holds about 181 km3 of water according to the Zambezi River Authority. By installed power the leader is China's Three Gorges Dam, and by embankment volume Pakistan's Tarbela Dam is usually named instead.

How do you measure the size of a dam?

There are three common measures: reservoir capacity, structural volume and height. Reservoir capacity tells you how much water the dam can store. Structural volume counts the concrete, earth and rock in the dam itself. Height measures the wall from foundation to crest. Each measure produces a different list.

Why is the Three Gorges Dam not in the Top 10?

Three Gorges is the most powerful hydroelectric station on Earth, with 22,500 MW installed, but its reservoir holds about 39.3 km3. That is far less than the reservoirs behind Kariba, Bratsk or Akosombo, so it misses a ranking based on storage. It would top any list of dams ranked by generating capacity.

Is the Aswan High Dam bigger than Bratsk?

It depends on which figure you use. Comparative tables list Lake Nasser at about 132 km3, which places Aswan sixth. Britannica gives a gross capacity of 169 km3 at the highest flood level, close to Bratsk's 169.27 km3. We used the nominal figure for consistency with the other entries in this ranking.

Which country has the most dams in this Top 10?

Russia has three entries: Bratsk, Krasnoyarsk and Zeya, all in Siberia or the Russian Far East. Canada has two, Daniel-Johnson in Quebec and W. A. C. Bennett in British Columbia. Africa contributes four, with dams in Zambia and Zimbabwe, Ghana, Egypt and Ethiopia, plus Guri in Venezuela.

What are the main problems caused by very large dams?

Large reservoirs can displace tens of thousands of people, flood forests and farmland, trap fertile sediment, change river ecosystems and sometimes trigger earthquakes during filling. They also deliver flood control, irrigation and low-carbon electricity, so most assessments weigh these benefits against the social and environmental costs case by case.

Conclusion

The largest dams in the world are measured best by the water they hold. On that test, Kariba leads, followed by Bratsk, Akosombo, Daniel-Johnson and Guri, with Aswan, the Grand Ethiopian Renaissance Dam, W. A. C. Bennett, Krasnoyarsk and Zeya completing the Top 10 as of October 2026.

Each of these structures turned a river into an inland sea, bringing electricity, irrigation and flood control along with displacement and ecological change. Read the capacities as a snapshot of engineering ambition rather than a final verdict: new projects, sediment build-up and fresh survey data can all shift the order in the years ahead.