Dams are impressive feats of engineering but also serve a number of crucial functions. They facilitate flood control, provide irrigation to farms, and generate hydroelectric power. These man-made structures can be found all over the world. However, some are larger than others. Curious as to which ones? Read on to learn all about the seven largest dams in the world.
Fort Peck Dam, United States
Fort Peck Lake, the fifth-largest man-made reservoir in the United States, resulted from the building of Fort Peck Dam. The dam was a public works project commissioned by President Roosevelt — it provided jobs for 10,000 workers between 1933 and 1940. Fort Peck Dam even broke records during its building, when laborers created shale bedrock walls that were over 2.5 miles in length.
The dam is by far the largest hydraulically filled dam in the world. In addition to providing sorely needed jobs during the Depression era, the dam helped regulate flooding, a common occurrence along the Missouri River.
If you're interesting in learning more about the dam, consider visiting the Fort Peck Power Plant Museum. You can also pitch a tent at one of the dam's campgrounds and hike the Beaver Creek Nature Trail near the dam. If you'd rather drive, be sure to take the Leo B. Coleman Wildlife Exhibit route to see possible sightings of elk and bison.
Oahe Dam, United States
The word "Oahe" comes from the Lakota Sioux language and translates to "a foundation." The Oahe Dam is certainly that, a sturdy foundation for the fourth largest man-made lake in the country, Lake Oahe.
The dam was completed in 1962, after 14 years of work on its construction. It is 242 feet tall and 9,300 feet long. Like the Fort Peck Dam, the Oahe Dam helps with drainage and flood control. It also provides a continuous supply of irrigation water and power to numerous states in the Midwest.
Lake Oahe is 231 miles long and purportedly has a maximum depth of 205 feet deep. It's a popular spot for fishing excursions, recreational boat trips, and even water-skiing activities. You'll find several campgrounds and picnic areas near the lake. The lands surrounding Lake Oahe are also popular hunting spots, with hunters reporting generous harvests of sharp-tailed grouse and Canadian geese.
Tours of the dam and power plant are available during limited months of the year, while the Visitor Center is staffed year round.
Garrison Dam, United States
This North Dakota dam is the foundation for Lake Sakakawea, the third largest reservoir in the country and 42nd largest in the world. The lake was named after the Shoshone woman Sacagawea, who used her knowledge of the landscape and native peoples to assist Lewis and Clark in their westward expeditions. Lake Sakakawea stretches over 178 miles and has a depth of approximately 175 feet.
The Garrison Dam was completed in 1953. It's 11,300 feet long and 210 feet tall. Fishing is a popular activity in this area. In fact, the Garrison Dam National Fish Hatchery is located nearby and is responsible for restocking fish for state waters in Wyoming, Idaho, North Dakota, and Nevada. Essentially, the hatchery provides quality fishing opportunities for fishermen throughout the Great Plains region.
If fishing isn't your style, try exploring the nearby Audubon National Wildlife Refuge, which features exhibits of local wildlife.
Three Gorges Dam, China
Located along China's Yangtze River, the Three Gorges Dam measures 7,660 feet long and 607 feet tall. It was completed in 2006 and was the largest dam in the world at the time of its construction.
The Three Gorges Dam, however, had its fair share of controversy when plans were first introduced for its building. Critics were concerned about the risk of the dam collapsing and were angry about the fact that over a million people living along the Yangtze River had to be displaced for the dam to be built. Due to both national and international outcry, over 40 years elapsed between the dam's conception and its actual construction. The World Bank even refused to help fund the project because of environmental concerns and the destruction of socially significant excavation areas.
Despite the surrounding controversies, the engineers were given the go-ahead to proceed with construction. The dam's generators became operational in 2012. Today, the dam is the world's most productive hydroelectric power plant.
Atatürk Dam, Turkey
The Atatürk Dam is one of five dams located along the Euphrates River. It's 5,971 feet long and 603 feet tall, and its reservoir is the third largest in Turkey. This dam was originally named the Karababa Dam but was renamed to honor the first president of Turkey, Mustafa Kemal Atatürk.
It's also a critical part of a larger environmental agenda — called the Southeastern Anatolia Project — to build a series of dams along the Tigris, Euphrates, and Upper Mesopotamia basins. The goal of the project is to double the availability of irrigation land and increase the country's electric output. The project is also supposed to supply employment to approximately two million people.
The prospect of building dams along the Euphrates has caused some contention, as the river flows through Turkey, Syria, and Iraq. In 2009, however, these countries began discussions to address concerns about the ramifications of the project.
Aswan High Dam, Egypt
The Aswan High Dam was completed in 1970 and measures 12,562 feet long and 364 feet tall. The building of the dam required the relocation of 90,000 people. Humans weren't the only obstacles in the way. The ancient Abu Simbel temples (which housed colossal statues of Ramses II) also needed to be moved so that they wouldn't be flooded during construction. It took millions of dollars to dismantle and reconstruct the temples on higher ground.
The dam has been both a blessing and a curse to Egypt's economy. Sure, it generates incredible amounts of energy, increases fishing opportunities, and provides irrigation to farmlands. However, its building, originally intended as a means of regulating the Nile's annual floods, has led to a decrease in soil fertility. This is due to the fact that the river's fertilizing silt is no longer deposited on surrounding lands but is instead trapped in canals and reservoirs.
Guri Dam, Venezuela
One of the largest dams in the world, the Guri Dam is 37,222 feet long and 531 feet tall. It was initially built in 1969 but renovations in 1986 exponentially increased its size. The need for size was precipitated by a 1960s government initiative to reduce Venezuela's use of fossil fuels and increase its dependence on sustainable forms of energy. About 80 percent of the country's energy needs are currently met by the Guri Dam power plant.
However, depending so heavily on a single source of energy has its risks. In recent years, the reservoir's water levels have begun to decline, leading to widespread concern about an energy crisis. In March of 2019, a power line transporting energy from the Guri Dam went down, causing an enormous blackout that impacted schools, hospitals, and public transportation systems.