Located at the Col de la Gueulaz, the Emosson dam is the most important structure in the facility. It is fed with water from the Val Ferret via the East collector and artificially by the collectors of the Mont Blanc massif and the Aiguilles Rouges.
The Emosson vault dam is nestled in the town of Finhaut, on the left bank of the Rhône, above Martigny. Located on the Franco-Swiss border, its design and dimensions make it a remarkable structure.
This giant 180-high dam (the fifth tallest in Switzerland) is located at an altitude of 1930 metres. The capacity of the Emosson dam is 225 million cubic metres (225 billion litres), making it the second highest volume dam in Switzerland after Grande-Dixence. Its double curvature closes the gorge dug by the Barberine in the natural rock lock blocking the Emosson plain.
A whole series of devices adorn the walls in the eight control tunnels of the Emosson dam. Platform temperatures, standard or inverted pendulums, rocmeters, hydrometers, piezometers, drainage systems, dilatometers. The majority of its data is transmitted in real time to the Bâtiaz control room.
An external network of concrete platforms also makes it possible to carry out geodetic measurements at regular intervals.
The crown (summit) can move up to 9 centimetres depending on the fill level of the Emosson dam.
Technical file
| Construction year | 1967-1973 |
| Put into operation | 1975 |
| Municipality | Finhaut |
| Volume | 225 million m³ |
| Annual intake | approx. 350 million m³ |
| Altitude | 1930m. |
| Type | Vault |
| Renovated | Drained in 2012 |
| Height | 180m. |
| Length | 560m. |
| Spillway type | Free weir |
| Catchment area | 176km² (excluding SBB) |
The Emosson dam
The Émosson dam is a hydroelectric dam located in Switzerland in the canton of Valais. It’s the fifth highest dam and the second largest reservoir in Switzerland.
The Emosson dam in pictures
The Emosson dam in pictures
