Since the beginning of the 19th century, the Swiss Confederation has been operating dams and hydroelectric power stations, mainly in the Alpine cantons, including the Valais.
With more than 600 power stations producing at least 300 kilowatts and more than 200 dams, 90% of which are used for energy production, 70% of Switzerland’s electricity consumption comes from water.

Let’s take a closer look at the dams in the Valais, which are mainly located on tributaries of the Rhône River.

Dams in the Swiss Valais: electricity production and imposing constructions

From the High Matterhorn to the green valleys of the Rhône, via the Mont Rose massif and the Pointe Dufour, the dams of the Swiss Valais are scattered along the Alpine foothills.

Often perched on the mountainside, they are giant structures that produce hydroelectric power while offering a breathtaking view of the region and the surroundings where they sit.

In Europe, the Valais is an alpine region with many dams. These dams hold back large quantities of water to produce electricity from the water’s power.

The most famous of these are the 285-metre-high Grande-Dixence gravity dam, the 780-metre-long Mattmark embankment dam and the 40-million-cubic-metre Salanfe gravity dam.

These giants of concrete and iron stand proudly in the Alpine landscape, demonstrating a certain architectural complexity and a considerable economic weight for the region.

Grande-Dixence: the highest gravity dam in Europe

Grande-Dixence is considered to be the highest gravity dam in Europe, with a height of 285 metres and a length of 478 metres, all at an altitude of 2,364 metres in the Val des Dix.

The capacity of this artificial lake is estimated at around 400 million cubic metres of water stored over a length of 5 kilometres. It provides up to 4% of the electricity supply in French-speaking Switzerland, or the equivalent of two reactors in a conventional nuclear power plant.

The dam is fed by the Dixence River, a tributary of the Borgne, which in turn is a tributary of the Rhône.

Valais dams: Grande-Dixence
Lake Dix of the Grande Dixence dam

The Mattmark: a unique earth dam

Situated at 2,197 metres above sea level, it is one of the few high-altitude embankment dams in the world. It is located upstream of the municipality of Almagell in the Saas Valley and is designed to hold 101 million cubic metres of water.

With an estimated maximum capacity of 37,000 kilowatts, it provides a reliable and sustainable supply of hydroelectric power to the local and tourist communities, including the valley’s resorts and ski areas.

The dam is fed by the river Visp from Saas or Saaser Vispa in German.

Valais dams: Mattmark
Mattmark dam lake in winter, Saas Valley

Other notable dams in the Valais Valley

Other important dams in the Valais region are the Mauvoisin and Emosson dams, which have a capacity of 210 million and 227 million cubic metres of water respectively.

In total, the canton of Valais produces* nearly 10,000 Gigawatt-hours (GWh) through 117 hydroelectric power stations with a capacity of 4,557 Megawatts (MW).

Impacts of Valais dams on the environment and the local economy

The large dams built in the Valais are not only a spectacular landscape enrichment for visitors and tourism, but also an important source of energy for the Swiss hydroelectric industry, contributing to the country’s energy production and the development of the local economy.

Swiss Valais dams

Renewable energy production and reduction of CO2 emissions

The Valais dams have contributed to the transformation of the Swiss electricity supply towards a renewable and sustainable energy source, while producing less greenhouse gas emissions than conventional thermal power plants.

In addition, dams are very profitable, especially for the companies operating them, which receive subsidies from the cantonal authorities for their contribution to the energy supply, in addition to the income from the sale of electricity.

Effects on ecosystems and biodiversity in the Alpine valleys

Despite their importance for local populations, dam construction can sometimes have negative impacts on the environment. Migratory fish can be blocked by these structures, which has led to the introduction of conservation and compensation measures to minimise their effects on aquatic and terrestrial species.

In addition, rehabilitation works are also carried out to protect local fauna and restore habitats disturbed by hydroelectric structures.

Economic role of dams in the Valais

Dams in the Valais also contribute to local employment thanks to the numerous jobs created by their construction and maintenance.

Thanks to the tourism generated by the activities linked to the large artificial lakes, the shops and services of the rural communities concerned also see their revenues increase considerably.

Additional opportunities have been created with the arrival of water sports enthusiasts and outdoor activities encouraged by these incredible picturesque natural landscapes, which are open to the public as privileged holiday resorts.

Hydroelectric dams in Switzerland

Visiting the dams of the Valais: a must for lovers of alpine engineering

The dams offer a myriad of activities for all those who want to fully enjoy the Swiss mountains and admire their exceptional engineering.

Whether contemplating the Lac des Dix from the Grande Dixence, walking through the picturesque trails of the Saas Valley near Mattmark or exploring the nooks and crannies of the Mauvoisin and Emosson dams, visitors are sure to enjoy the spectacular alpine scenery offered by these imposing structures.

With such economic and environmental importance, it is clear that the Valais dams are both a source of pride for local communities and a key element in the supply of renewable energy to the whole of Switzerland.

Location of the dams in the Valais

Map with the main hydroelectric dams of the Valais canton in Switzerland:

The dams of the Valais in video

Set in beautiful natural settings that have been dramatically transformed by the hand of Man, the Swiss dams are a favourite destination for walks in French-speaking Switzerland.

A Loisirs CH video:

Along the Rhône

  • Visit the Grande-Dixence, official website
  • Visit the power stations of the company ALPIQ
  • The Nant de Drance hydroelectric power station, France3 (French)
  • List of dams in Switzerland, Wikipedia
  • Hydroelectricity in Switzerland, Wikipedia (French)
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Activities, visits, tickets, leisure
Activities, visits, tickets, leisure