The history of Emosson dams

Do you know the secrets of Emosson? Exploring the history of this site reveals what lies hidden behind the landscape.

1, 2, 3 dams – a story of water and electricity

Barberine Dam

The oldest and most discreet: built in 1925 to support the electrification of the Swiss Federal Railways (SBB), the Barberine Dam now lies submerged beneath Lake Emosson. In spring, when water levels are low, its summit reappears – offering a rare glimpse of this historical structure.

See a few images of the little-known Barberine Dam.

Vieux-Emosson Dam

In the 1950s, rising electricity demand led to the construction of a new dam 300 metres higher up: the Vieux-Emosson Dam, completed in 1955. It created a second, separate reservoir.

A hike to the Vieux-Emosson mountain hut offers a fine view of the lake and the dam.

Emosson Dam

In 1975, a third and much larger dam was completed: the Emosson Dam. It became Switzerland’s second-largest artificial water reservoir. Its construction required moving the French–Swiss border and led to the complete submersion of the original Barberine Dam.

A guided tour of the dam offers the chance to step inside the concrete giant.

The Historic Châtelard Power Station

Easily visible from the funicular departure station, this power plant made of local stone is still operational. It uses water from the Emosson Dam to generate electricity for the Swiss railway system.

Inside, the CFF Châtelard–Barberine Hydropower Museum presents the region’s rich electrical history.

Today

Beneath the Emosson mountains lies one of the most powerful hydroelectric complexes in Europe. Located 600 metres underground, the Nant de Drance power station plays a key role in stabilising the European power grid.

The Emosson and Vieux-Emosson dams are connected in a closed-loop pump storage system. Water is pumped uphill when there is excess electricity, then released to produce power when demand increases.

All of this happens quietly, deep beneath the mountain.