A massive landslide in the Swiss Alps devastated the village of Blatten earlier this week. The collapse originated from the Birch glacier and sent a torrent of rock, ice, and mud into the Lötschental valley on Wednesday. The debris destroyed much of the village, while buildings that were not buried were left submerged due to the sudden formation of a lake caused by the damming of the Lonza River.
River Carves Path Through Debris, Slowly Reducing Lake Level and Associated Risks
The accumulation of debris blocked the Lonza River, causing the formation of a temporary lake and raising concerns about further flooding or structural collapse. However, by Friday, the river had begun carving a channel through the blockage. According to Valais state authorities, the water has been flowing steadily through the entire length of the debris, reducing immediate pressure on the natural dam.
Swiss Alps Landslide Wrecks Village of Blatten as River Slowly Eases Flood RiskGeologist Raphaël Mayoraz reported that the lake’s water level had dropped by approximately one meter, thanks to the gradual erosion of the debris by the river. He emphasized that the slow rate of erosion was beneficial, as rapid erosion could destabilize the channel and trigger secondary landslides. While this slow drainage has helped relieve some of the danger, officials stress that it’s too early to declare the area completely safe.
Authorities Monitor Situation Closely as Evacuees Await Support and Further Safety Measures
Local authorities remain vigilant. Blatten’s mayor, Matthias Bellwald, expressed cautious optimism but warned that it was premature to assume that the danger had passed. To manage the flow of water and reduce downstream risk, a dam in Ferden—normally used for hydroelectric power—was partially opened on Friday evening. Though the threat to downstream communities appears low, evacuation plans are still in place as a precaution.
Prior to the landslide, authorities evacuated around 300 people and livestock from Blatten. The early evacuation likely prevented greater human loss. Swiss President Alain Berset acknowledged the destruction on Friday and assured that the federal government is exploring ways to assist the displaced residents. As recovery efforts continue, the focus remains on monitoring environmental conditions and supporting those affected.