Once a month, dam operator Steve Fellay has an appointment with the Mauvoisin Dam situated in the Haut Val de Bagnes. Besson Immobilier invited itself to spend a day with him and his team, to discover their universe in the heart of the concrete giant.

It is 7:00 am and we are ready at the Fionnay power station. The teams are forming, and the 3 operators are getting ready. We take off in a snowcat as the day breaks to reach the hamlet of Mauvoisin, a site inaccessible during winter except for the employees of the FMM (Forces Motrices de Mauvoisin) or a few mountaineering or ice climbing enthusiasts who have come to master these ephemeral sculptures. The conditions are ideal: no avalanche danger and the cloudless sky is perfectly blue and bright. The negative temperatures make the snow crystalline and nature takes advantage of this freezing cold to show off with its air of Himalayan landscapes.

The trip lasts 45 minutes and gives us time to get to know Steve Fellay. This 36-year-old Bagnard, father of two small children, has been working at the FMM for 13 years as a mechanic and dam operator. Steve Fellay is a true enthusiast. He loves his job and wouldn’t change it for the world. It seems the thought has never crossed his mind. The area is large and the profession varied. You have to be meticulous, leave nothing to chance. Any mishandling can have serious consequences.

Steve describes his role as a dam operator, which consists of quantifying the deformations undergone by a dam over time. Thus, he performs a whole series of protocol measurements, namely, calculating the deformations undergone by the dam according to the water level using pendulums, calculating the infiltration water flow rate, the temperature of the concrete, the pressure, settlements, etc.

Today, Steve and his colleagues will focus on taking measurements on the pendulums. A day crisscrossing the recesses arranged at regular intervals over the entire height of the wall and, transversely, along the dam, allowing them to obtain values thanks to these giant plumb lines hanging from the crown.

Here we are at the barge operators’ chalet in the hamlet of Mauvoisin. The first rays of the sun lick the sharp ridge that connects the summits of the Combins massif. After finishing our meal and drinking coffee, we reach the foot of the dam by motorbike via a winter tunnel. Steve, former motocross champion in the Dupasquier team, is as comfortable on two wheels as on his two feet. It is a feat because the tunnels are narrow and we discover riddled with holes. The interior temperature is pleasant, an average of 7°C all year round with a humidity level approaching 100%.

Steve begins his measurements with the help of a colleague. We carefully follow the team for fear of getting lost in the maze of 500 m of tunnels.

We take the elevator, walk from one point to another, retrace our steps, and finally are swallowed into tunnels via vertiginous ladders. A good physical effort for the operators because they sometimes have to make a round trip. We stop at strategic points in order to take measurements. A good knowledge of the construction is essential.

Along the way, Steve explains to us that at the beginning of his career he obtained a federal maintenance agent certificate. But for him, the profession of barge operator is learned mainly on the ground and allows you to never stop evolving. He will always remember his first rookie mistake that could have gone wrong with the flange of a valve. But he also evokes with us a memory that will remain forever inscribed in his memory: not being able to immediately descend by helicopter at the end of a series of winter measurements on the Giétro glacier, at an altitude of nearly 2800 m by -22C°, the dam team which included a mountain guide, decided to walk back down to the dam. Equipped with crampons, harness, rope and ice axe, the return under the glacier was a daunting moment but of pure happiness for Steve and his team.

Then, Steve, always animated by the desire to welcome us in his world, takes us to visit the hydroelectric power station then the coloured rooms sheltering the butterfly valves, the flood gates, the intermediate gates and bottom drain. It is a unique experience tinged with the special atmosphere of the place and which makes us relive the great era of water mastery and the hydroelectric industry.

Going up the dam without admiring the lake in the middle of winter would have been a sacrilege. We thus left the tunnels, were able to take a little height in order to admire the splendour of the lake, of its hoarse, crisp, singing and whistling ice. This lake in winter is a sight that bears no resemblance to that of summer. Time stood still just as our minds seemed to have frozen. Then, it was time for us to head back down to the valley. We leave Steve and his team, our heads full of beautiful images, and our hearts filled with joy at having been able to experience this adventure in the depths of our beautiful Val de Bagnes, in the company of these men working in the shadows.

It is possible to visit the dam in summer with the FMM. Here is also a link to an idea for a summer hike above the dam or e-bike around the dam.

At Besson Immobilier we love to tell you stories about life and short trips in our region! Discover even more articles, hiking ideas, new and unusual insights and information on the Verbier and Val de Bagnes region in our Besson mag. That way, you can plan your trip to our beautiful region with greater peace of mind.