Few man-made wonders are as remarkable as the colossal concrete dams of the world. Not only do many of these feats of engineering produce hydroelectric power to help light our planet, they are built to withstand enormous pressures. Climbing to incredible heights, holding back powerful rivers, and surviving the seismic activity caused by earthquakes, these dams stand as testament to the brilliance and skill of their engineers. What’s more, the monumental scale of these dams is never more magnificent than when viewed from above.
10. Chirkey Dam, Russia
Although Russia’s Chirkey Dam is not the tallest covered here, its 763-foot (232.5-m), near-vertical drop is both breathtaking and beautiful. Chirkey is the tallest arch dam in Russia and is built on the rugged landscape of the Sulak River, Dagestan. In fact, the rocky cliffs surrounding the area had to be blasted away during construction in order to block the river. Massive explosions were used to fell over 213,255 cubic feet (65,000 m3) of rock. Fortunately for locals, those days of blasting are over and the dam now provides a perfect way for them to drive their sheep to summer pastures. In addition to supporting a 1,000 MW power station, the dam is also a tourist destination, boasting a stunning combination of man-made and natural wonder.
9. Ertan Dam, China
Ertan Dam has not only brought employment and foreign investment to one of China’s poorer regions; it has also set several records in the process. This 787.4-foot (240-m) dam was built in a mere ten years, between 1991 and 2000, setting the record for fastest construction of a hydroelectric plant. This double-curvature dam has an underground powerhouse and a 2,829-foot (1,167-m) diversion tunnel, one of the longest in the world. Forty-seven countries and 700 specialists have been involved in making the project a success. And a success it surely is, generating almost 3.5 MW a year and helping make China one of the largest producers of hydroelectric power in the world.
8. Sayano Shushenskaya, Russia
Sayano Shushenskaya, a Russian arch-gravity dam, soars to a height of 807 feet (246 m). It was built to withstand earthquakes with a magnitude of eight on the Richter Scale and it’s a good thing too. Since its completion in 1978, the dam has suffered four significant accidents. Pressure on the dam was so great during the spring flooding of 2009 that water flooded the turbine room. The explosion that followed shook the dam to its foundations, damaging all ten turbines and completely destroying three. Seventy-four people died, 40 tons of oil spilled into the river, and the dam was out of operation for about a year. Although the dam is running again and, when fully functional, produces over a quarter of Russia’s hydroelectric power, it is a clear example of the risk involved in harnessing nature’s energy.
7. Deriner Dam, Turkey
Turkey’s Deriner Dam was built to harness one of our planet’s most savage rivers, the Coruh. With its world-class rapids and incredible speed, the Coruh is a ferocious force for anyone to reckon with. But reckon the engineering team did, constructing one of the tallest and strongest dams in the world. Since the horseshoe shape of most dams would not provide the necessary strength to hold back such a wild river, the Deriner was built as a concrete, double-curved arch, forming one of nature’s strongest forms: the dome. And, as if holding back a 500 billion-gallon reservoir and withstanding the river’s enormous pounding pressure weren’t enough of a challenge, the region is also prone to earthquakes. Fortunately, the engineers were able to design a way to pre-shrink the concrete, creating innovative earthquake-proof seals. Oh, and at a height of 817 feet (249 m) - more than twice the Statue of Liberty - this dam is sure to give visitors vertigo. [View panoramic images]
6. Laxiwa Dam, China
Located on the majestic Yellow River, China’s Laxiwa Dam is part of a dual effort to deal with soil erosion and to generate electrical power. The Yellow River, also known as China’s mother river, suffers from one of the most serious soil erosion problems worldwide. In one year, 1.6 million tons of mud and sand are lost to the encroaching current. Laxiwa is one of a mind-boggling 160,000 dams that have been built along the Yellow River in response to the problem, helping to conserve both soil and water. At 820 feet (250 m) tall, this concrete double-curvature arch dam is also a major source of power for West China. It is both the tallest and the highest voltage-producing dam on the river.
5. Mauvoisin Dam, Switzerland
While some dams can be the source of catastrophes when they fail to function properly, the Mauvoisin Dam in Switzerland was built to prevent them. The dam was built as a man-made replacement for the Giétro Glacier. The glacier acted as a natural dyke, but the lake behind it was prone to burst through in destructive floods. When the water broke through in 1818, everything in the valley was washed away, resulting in around 40 deaths. The dam itself was not built until the 1950s, but it protects the surrounding area from natural disasters and is also a source of hydroelectric power. Built to a staggering height of 820 feet (250 m), this concrete arch dam is surrounded by the strikingly beautiful scenery of the Swiss Alps.
4. Vajont Dam, Italy
Although the Vajont Dam reaches a dizzying height of 860 feet (262 m), it is, unfortunately, most famous for disaster. This soaring structure was built beneath Monte Toc in Italy. During construction, the area suffered several landslides and earthquakes, proving that the mountain was unstable. However, the dam was filled all the way up in any case, and this, combined with heavy rain, resulted in a massive landslide that struck on October 9, 1963. So much water was displaced that a gigantic, 820-foot (250 m) high wave surged over the top of the dam and crashed into the valley below. The structure of the dam was left intact, but the villages downstream suffered incredible damage. Approximately 2,000 people died due to the huge wave. The powerful blast of air caused by the wave’s impact was so intense that it entered the dam’s downstream powerhouse and wrecked its machinery. The dam, unsurprisingly, has not been used since.
3. Inguri Dam, Georgia
Even if you’re fond of heights, looking down at this scary drop is quite a challenge! The Inguri Dam is a concrete arch dam which produces hydroelectric power for both the country of Georgia and Abkhazia (a highly disputed area whose government is in exile). This massive structure is the second highest concrete arch dam in the world and reaches a dizzying height of 892 feet (272 m). Construction began in the 1960s and finished in 1987, but a mere seven years later the dam was found to be in a dangerous state of disrepair. Thanks to several loans from the European Union, the Georgian government, and the government of Japan, the dam was refurbished and brought back up to safe standards. The investment has been well worth it, too, as this imposing dam represents a whopping 46% of Georgia’s electrical supply.
2. Grande Dixence Dam, Switzerland
The Grande Dixence Dam is the world’s tallest gravity dam, and tipping the scales at 15 million tons, it weighs more than the Great Pyramid of Cheops. With a 935-foot (285-m) drop from top to bottom, this dam is an adrenaline-inducing masterpiece of engineering. The six million cubic meters of cement that went into building it would be enough to make a small wall all the way around the equator. And no wonder! Not only is the Dixence incredibly tall, it is also 656 feet (200 m) wide at the base. And, if that weren’t inspiring enough, this dam is located in the stunningly beautiful Valaisian mountains of Switzerland. The gorgeous blue water of the reservoir is collected from the melted run-off of 35 glaciers in the surrounding area.
1. Xiaowan Dam, China
The Xiaowan Dam is the tallest concrete dam in the world, standing at a dizzying 958 feet (292 m) tall, a mere 105 feet (32 m) shorter than the Eiffel Tower! This dam sits on the Lancang (otherwise known as the Mekong) River in China, and it’s of significant benefit to its country. The Xiaowan is a major source of hydroelectric power and has a guaranteed output of 19 billion kWh per year. Construction took 11 years, from 1999 to 2010, and cost the equivalent $3.9 billion. Due to the creation of dam’s reservoir, over 137,500 acres of land are now underwater while more than 30,000 people were displaced. That said, the dam prevents floods and provides irrigation to the surrounding region, and it must surely be considered an engineering marvel.
11. (Bonus) El Cajón, Honduras
Sometimes solving a dangerous flaw can be as much of a challenge as designing and building a dam in the first place. This was the case with El Cajón, a 741-foot (226-m) high dam in the western region of Honduras. The dam’s double-arch design spreads the weight of the water in the reservoir to the canyon walls, which act as buttresses. To everyone’s chagrin, however, this didn’t prove enough to prevent leaks. In 1993, just eight years after the dam was completed, 1,600 litres of water were leaking per second, eroding the limestone bedrock beneath the structure. If the leaks were not stopped, the powerhouse would flood, and the dam’s integrity could be compromised. After a year of fruitless efforts, a specialist team came up with a bizarre solution: plastic balls and grain sacks. By filling the cavities with these unusual items, engineers were able to keep the grout material in place until it could harden and plug the holes. Leakage was reduced to 100 litres per second, and the dam and power station were able to work at full capacity again. Now that’s innovation! [More information]
