A huge ice, mud, and rock landslide engulfed the Swiss village of Blatten on Wednesday, forming a dam behind a wall of glacial debris that held millions of cubic meters of water captive and raised the specter of catastrophic downstream flooding. The tragedy occurred after one side of the mountain behind the Birch Glacier collapsed, burying houses and blocking the River Lonza.
Blatten’s 300 residents were evacuated in advance since the mountain was unstable. Rescue operations have been looking for a missing 64-year-old man but have suspended operations temporarily because of risky conditions.
The landslide created a debris heap almost 2 kilometers wide, which blocked the Lonza River and created a lake behind it. This prompted concerns about the risk of breaking debris dam, which could trigger instant floods and order more evacuations. Officials cautioned residents in downstream villages of Gampel and Steg to prepare for potential evacuations on Thursday.
By Friday evening, authorities reported some of the water trapped behind the debris had started to seep into the resulting plug, decreasing short-term risks of flooding. Local authorities, such as Christian Studer, indicated that everything was under control and it would not worsen. In the meantime, the Swiss army is on standby with heavy equipment such as pumps and diggers to ease pressure off the river block once it will be safe to do so.
The magnitude of the devastation has stunned the local community and scientists say the event is indicative of the escalating threat posed by climate change to the Alpine region. The Swiss Insurance Association estimated the extent of the damage was in the realm of several hundred million Swiss francs but added that it was too soon for an exact evaluation. The number of insured houses in Blatten is still unknown.
Authorities continue monitoring the situation closely to protect residents and prevent further damage.
