Grande Dixence Dam

This is a very big wall in Switzerland.

It is a huge dam made of concrete. It holds back a very large lake. This lake gets water from melting ice.

The water flows through tunnels to make power. This power helps many homes turn on lights. The dam is very tall and wide. It is the tallest dam of its kind. It is a very amazing place to see.

The Grande Dixence Dam is a giant wall in Switzerland.

It is a concrete gravity dam. This means its heavy weight holds back the water. It is the tallest gravity dam in the world.

The dam holds back a big lake called Lac des Dix. Most of the water comes from melting glaciers in the summer. Four pumping stations move water from other rivers into the lake through long tunnels.

This dam helps make electricity. This is called hydroelectric power. The water travels through large pipes called penstocks. These pipes lead to four power stations. Inside the stations, the water spins parts called Pelton turbines. These turbines make power for 400,000 Swiss homes.

One station is the Bieudron Power Station. It was built between 1993 and 1998. It cost 1.2 billion US dollars. The Bieudron station holds three world records. It uses the high pressure of falling water to make a lot of power. Workers built the main dam from 1950 to 1961. At that time, it was the tallest dam in the world.

The Grande Dixence Dam is a massive wall in the Valais canton of Switzerland.

It is a concrete gravity dam, which means its own huge weight holds back the water. This dam is very important because it creates electricity for many people. It can power about 400,000 Swiss households every year. The dam holds back a large lake called Lac des Dix. This lake is the largest one in the Alps located above 2,000 meters.

Making electricity here is a clever way of using moving water. Most of the water comes from glaciers melting during the summer. Four different pumping stations move extra water into the lake. These are the Z’Mutt, Stafel, Ferpècle, and Arolla stations. They send water through tunnels that are 10 kilometers long. From the lake, the water travels down through large pipes called penstocks. These pipes carry the water to four different power stations. The rushing water spins parts called Pelton turbines to make power.

Building such a giant structure took many years of hard work. Construction on the main dam began in 1950. By 1961, about 3,000 workers had finished pouring the concrete. The dam was officially ready to work in 1965.

At the time it was finished, it was the tallest dam in the world. It stood 285 meters high. Later, the Nurek Dam in Tajikistan became taller in 1972. However, Grande Dixence is still the tallest gravity dam on Earth.

Many different groups worked to build this complex system. A company called Energie Ouest Suisse started with small power stations in 1922. They built a smaller first dam that was finished in 1935. That old dam was later covered by the new lake. Later, a company called Grande Dixence SA helped build the new, larger dam. They also worked on the Cleuson-Dixence project in the 1980s. This project added new tunnels and the Bieudron Power Station. This helped make even more electricity for the region.

The Bieudron Power Station is a very special part of the system. It was built between 1993 and 1998. This project cost 1.2 billion US dollars to complete. The station holds three different world records for its power. It uses the height of the falling water to spin its turbines. You can think of the whole system like a giant machine. It uses the natural cycle of melting ice and gravity. This turns simple mountain water into light for your home.

The Grande Dixence Dam is a massive concrete gravity dam located in the Valais canton of Switzerland.

As a gravity dam, it uses its immense weight to hold back the massive pressure of the water behind it. It sits on the Dixence river at the head of the Val d'Hérémence. This structure is a vital part of the Cleuson-Dixence Complex. Currently, it holds the title of the tallest gravity dam in the world. It is also the tallest dam in Europe and the seventh tallest dam overall. The dam creates a large reservoir known as Lac des Dix, which is the largest lake in the Alps located above 2,000 meters altitude.

The system works by capturing and moving water to generate hydroelectric power. Most of the water in the reservoir comes from glaciers melting during the summer months. To keep the reservoir full, four different pumping stations—Z’Mutt, Stafel, Ferpècle, and Arolla—transport water through 10-kilometer-long tunnels.

Once the water is stored, it is released through three large pipes called penstocks. These penstocks carry the water down to four different power stations: Chandoline, Fionnay, Nendaz, and Bieudron. Inside these stations, the rushing water spins Pelton turbines, which are machines designed to capture energy from high-pressure water jets. This process converts the movement of the water into electricity.

The Cleuson-Dixence Complex consists of several distinct parts that work together. The primary dam holds the Lac des Dix, which has a surface area of 4 square kilometers. At its peak capacity, the reservoir contains approximately 200 million cubic meters of water. The depths of the lake can reach up to 240 meters. The system also includes the Cleuson Dam to the northwest, which sends water from its own reservoir, Lac de Cleuson, into the main system. While the complex moves water between different reservoirs, it is not technically classified as a pumped-storage scheme.

The history of this site began in 1922 with the establishment of Energie Ouest Suisse (EOS). The company sought to use the water from Switzerland's many glaciers to create electricity. In 1929, EOS acquired the license for the upper Dixence basin and began building a smaller dam. This first dam was completed in 1935 and supplied the Chandoline Power Station. However, as industries grew after the Second World War, a much larger project was needed. Construction on the current Super Dixence Dam began in late 1950.

By 1961, 3,000 workers had finished pouring the concrete. The original 1935 dam was eventually submerged by the rising waters of the new reservoir.

Engineering details make the dam a remarkable feat of construction. The dam is wide at both its base and its crest, which reaches an altitude of 2,475 meters. It contains approximately 365 million cubic meters of concrete. To ensure the structure stays secure, engineers used a grout curtain. This is a deep layer of material that surrounds the dam and reaches 100 meters into the foundation. It extends on each side of the valley to anchor the dam to the ground. When the dam was finished, it stood 285 meters high. It held the record for the world's tallest dam until 1972, when the Nurek Dam in Tajikistan reached 300 meters.

The power stations within the complex vary in size and capability. The Chandoline Power Station is the smallest, using five Pelton turbines to produce 50 MW. The Fionnay Power Station is larger and receives water through a tunnel with a 10% gradient. After passing through a surge chamber, the water enters a penstock with a steep 73% gradient. This water spins six Pelton turbines to generate 110 MW. The Nendaz Power Station is the second-largest in Switzerland. It uses six Pelton turbines to produce 150 MW.

Finally, the Bieudron Power Station is a massive facility that generates 425 MW.

The Bieudron Power Station is particularly significant for its technical achievements. It was built by Grande Dixence SA and EOS between 1993 and 1998 at a cost of US$1.2 billion. This station holds three world records related to its immense power output. These include the height of its head, the output of each individual Pelton turbine, and the output per pole of its generators. Although a penstock rupture caused it to stop working in 2000, it became partially operational in 2009 and fully operational in 2010. The entire complex is incredibly productive, generating about 2,000 GWh of electricity annually. This is enough to power approximately 400,000 Swiss households.

This massive project connects several different fields of science and engineering. It combines hydrology, the study of how water moves, with civil engineering to build the dam. It also relies on physics to turn the kinetic energy of falling water into electrical energy. The seasonal cycle of the glaciers provides a natural rhythm to the electricity production. The reservoir is usually at its highest in late September and reaches its lowest point around April. By managing these natural resources, the Grande Dixence Dam serves as a giant, controlled engine for the region.