by Wim Hordijk
The Tallest Gravity Dam in the World
With a height of 285m, the Barrage de la Grande Dixence in Switzerland
is the tallest gravity dam in the world.
Its lake, Lac des Dix, can hold up to 400 billion litres of water. And not only are the dam's sheer size and capacity impressive, so are its surroundings with several glaciers and 3000+ metre peaks.
The view of the Barrage de Grande Dixence from high up
A gravity dam compensates for the pressure of the water pushing against it by the weight of the dam itself. And with a total weight of 15 million tonnes
, the Grande Dixence dam is heavier than the great pyramid in Egypt
! It took more than 10 years to construct, and was put into service in 1964. The water from the lake serves four different power stations, which together generate about 2,000 GWh every year. This is enough to supply 400,000 households with electricity.
The barrage close up
The Grande Dixence dam is located at almost 2400m altitude in the Swiss Alps, in the Canton of Valais
. A narrow and winding road leads up to the bottom of the dam, where there is an information centre and historical exhibition. Guided tours (including a visit inside the dam) are offered four times daily from mid-June until the end of September. The nine-storey building that used to house the construction workers has been transformed into a comfortable hotel and restaurant. And if you do not want to walk the 285m uphill trail, there is a small cable car that takes you up to the top of the dam, with impressive views.
An easy and level walking path follows the western side
of the lake to its far end, a total distance of 6km. This walk offers even better views of the surrounding mountains and glaciers. From the end of the lake a steep hiking trail continues up into an even higher valley
from where you can see the beautiful Glacier de Cheilon, just one of several glaciers that feed into Lac des Dix. Towering directly above this glacier is the Mont Blanc de Cheilon, with its peak at 3870m. A little further up the valley you can reach the Cabane des Dix (at just over 2900m), an alpine hut where you can spend the night.
Looking across Lac des Dix from the top of the dam
During the 1980s, the original hydro-power project was improved and expanded into the Cleuson-Dixence Complex
. This led to a more than doubling of the original power-generating capacity. The Barrage de Cleuson is actually in the next valley over, and can be reached from Grande Dixence by a strenuous but spectacular hike up and over the Col de Prafleuri and along the Grand Désert glacier.
Alternatively, you can simply drive all the way around, down one valley and up the next. Either way, the view from the Cleuson dam, across its turquoise lake, is highly worth it too.
The Mont Blanc de Cheilon and its glacier
All in all, the Grande Dixence area is a worthwhile destination with many impressive sights
, both natural and man-made. A fine piece of Swiss engineering, in a spectacular natural setting.
How to get there
The Grande Dixence dam is located at the southern end of the Val d'Hérémence (Canton Valais) and can be reached by private car, public transport or organized coach tours (Theytaz Excursions, Sion):
- By car: A9 (from Montreux or Visp) to Sion Est exit, then follow the signs to Grande Dixence, approx. 28km from Sion;
- By postal bus: End of June to end of September from Sion to the Hotel du Barrage at the foot of the dam - stop is called "Dixence, Le Chargeur" (just a bit over one hour from Sion) - then by cableway up to the dam.
Wim Hordijk, the wandering scientist, is an avid hiker and has been trekking all over the world. Please visit his website for hiking and walking experiences in Switzerland, especially in the Western and Southern part of the country.