Forecasted rain raises fresh concerns in Swiss valley disaster zone

Al Etihad

31-05-2025

31 May 2025 16:11
GENEVA (dpa)Although the situation in Switzerland's disaster-stricken Lötschental valley has eased since the enormous glacier collapse earlier this week, residents were anxiously watching the weather forecast on Saturday.Rain is expected to start on Sunday and the ice is melting - all of which could destabilise the mass of debris that has buried the village of Blatten and is partially blocking the flow of the mountain river Lonza.Officials said earlier that the Lonza, dammed up behind ice, rock and debris since the disaster on Wednesday, had sought new paths into the valley in the Swiss canton of Valais, rather than causing a feared flood wave.But fresh rain could increase the risk of a mudslide, precipitating a huge slide of detritus down the valley and jeopardising communities further downstream.
Nature is in ChargeThere is little authorities can do to prevent such disasters. "Nature sets the rhythm," said Stéphane Ganzer, a state councillor in Valais, during an interview with RTS radio. Current high temperatures are accelerating snow melt while forecasts warn of heavy rainfall next week - both factors directly affecting the unstable mass of debris.The catastrophe ensued after rockfalls at a height of 3,000 metres smashed into the Birsch Glacier below, causing it to sheer off on Wednesday afternoon.The collapse deposited millions of cubic metres of ice and rock debris into the Lötschental valley, burying most of Blatten. Some of the village's 300 inhabitants had previously been brought to safety.No one is believed to have died in the incident, although one man was still unaccounted for on Friday.The municipalities of Gampel and Steg informed residents during the night that construction machinery was operating to ensure the controlled run-off of accumulated water and solids that had blocked the Lonza."The aim is to ensure the smooth flow of debris and alluvial debris through the bed of the Lonza stream within the villages," municipal authorities said.The resultant debris cut off the river's flow at around 1,500 metres elevation, with water pooling behind the almost 2-kilometre-long debris cone.The situation along the Lonza River remained stable at the start of the weekend, according to the local command centre.Officials report that the volume of water entering the dammed area is roughly equal to the amount flowing out, helping to stabilise the situation for the time being.However, nearly all the houses in Blatten that were initially spared have now been submerged in the rising reservoir.To manage the risk of further downstream flooding, a retention basin is expected to trap debris and sediment washed down from the damaged area.As a precaution, the power station operator has been instructed to continue releasing water from the reservoir to maintain capacity.If the volume of water exceeds the reservoir's limits, several mountain communities with more than 2,000 residents located about 20 kilometres downstream from Blatten could be at risk.Measuring instruments have been deployed throughout the area to monitor the water levels around the clock.
While no evacuations are currently planned, authorities remain on high alert.