‘How can we better protect our installations?’

The Saas Valley in the canton of Valais was hit by two severe storms this summer. The consequences were devastating and can still be felt today.

On 29 June 2024, a record was set in the southern Saas Valley: never before in its almost 60 years of operation has so much water flowed into the Mattmark reservoir in such a short time. ‘Almost a tenth of the total volume,’ says plant manager Philippe Ruffiner in amazement. The storm was extraordinary, with up to 150 litres of rain falling per square metre in 24 hours. A catastrophe: fatalities, destroyed houses, mudslides and flooded industrial areas in the Rhone Valley.

Considerable damage

The exceptional weather did not spare the facilities of the Mattmark power plants either. At least, ‘the dam and the facilities were always in a safe condition’. Nevertheless, the damage was considerable. Nine water catchments were partially buried and had to be temporarily taken out of service. In addition, a large mudslide blocked the access road to the dam. Fortunately, the water level was low at the time, so the lake was able to retain significant amounts of water. ‘We were able to make an important contribution to flood protection’.

There was also heavy rain on 5 September, when a second storm hit the Saas Valley. ‘It was very heavy, especially locally.’ The cantonal road between Stalden and Saas-Balen had to be closed due to a mudslide, and the Saas Valley was cut off for days. And this time too, the facilities of the Mattmark power stations were affected, especially the Trift and Almageller-Tal water catchments. Philippe Ruffiner suspects a connection with the first storm. ‘In June, many streams burst their banks and brought with them a lot of debris, which is now in the catchment area of the water catchments,’ he says. This material is not solid and can be set in motion by even small amounts of precipitation.

And what does all this mean for the employees? A lot of work. For weeks they were kept busy with intensive maintenance work, some of which was still ongoing in September. And then the second storm undid all their efforts at the affected water catchments, and they had to start all over again. ‘A bit demoralising,’ as Philippe Ruffiner diplomatically puts it.

So what can be done to ensure that the power plants don't have to be repaired over and over again? ‘How can we protect our facilities better?’ Philippe Ruffiner asks himself. The focus is on technical and structural measures, such as building more solid water catchments. Or equipping them with systems so that they can be drained remotely in an emergency.

Very strong sense of community

What the storms have also shown: experienced employees who know the area are essential for managing such extreme situations. And: the sense of community in the Saas Valley is very strong. There was immediate support for those affected. Ruffiner: ‘The community, mountain railways, crisis team, local businesses – everyone worked together unbureaucratically and took the necessary measures’. Ruffiner also extends special thanks to his 20 employees and the employees of the contracted companies who have shown enormous commitment – and repair water catchments twice in an emergency...