Swiss authorities expressed concern that the formation of an artificial lake could cause flooding following Wednesday’s collapse of a massive glacier that destroyed almost an entire village in southern Switzerland.
The lake was created after the collapse of the Birch Glacier and is growing larger by the hour, leading to concerns it could cause flooding downstream, Swiss authorities said on Thursday.
“Today we will try to assess its [the lake’s] dimensions,” Antoine Jacquod, a civil and military security official for the Canton of Valais, told Keystone-ATS news agency.
“There is a serious risk of an ice jam that could flood the valley below,” the official said, referring to the accumulation of rocks, ice, and earth blocking the Lonza River, which flows to the floor of the Lötschental Valley.
As a precaution, 16 people were evacuated on Wednesday evening from two villages located downstream from the disaster area, but there are fears that more people may lose their houses.
Earlier in the day, the glacier collapse largely destroyed the village of Blatten, the highest village in the valley, leaving its 300 residents without homes.
READ ALSO: VIDEO: Swiss village partially destroyed after glacier collapses
“The blockage extends about two kilometres on the Lonza River… it’s like a mountain, and of course, it’s creating a small lake that is getting bigger and bigger,” said Raphaël Mayoraz, the cantonal official in charge of natural hazard management, on Wednesday evening.
An artificial dam was preemptively emptied to contain the water pushed back by the wall of ice, earth, and rubble.
If the water were to overflow from this artificial dam, then the valley may need to be evacuated.
Geologist and social scientist Marcos Buser agreed that the greatest danger now came from the Lonza River. He explained to Swiss daily 20 Minuten the devastating consequences of the water building up and sweeping away the dam.
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“Such events have occurred in the past; depending on the course, the debris flow can then be carried kilometres down into the valley,” he told the paper.
The Valais cantonal government has asked the army to provide pumps to secure the riverbed and clearing equipment.
“When we’ll be able to actually intervene remains a big unknown at the moment,” said Jacquod.
One person still missing
The Birch Glacier collapse largely destroyed the small village of Blatten in south Switzerland and left one person missing, authorities said.
The glacier’s collapse had been expected for several days, as numerous rockfalls had already occurred in the mountainous area above it.
The missing person is a 64-year-old local resident who, according to information from the Valais cantonal police, was in the affected area at the time of the incident.
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A search and rescue operation was launched, with three rescue specialists airlifted to the scene, while a drone with a thermal imaging camera was also used.
“Despite significant efforts, the man has still not been found,” police said on Wednesday.
Footage posted on YouTube showed a huge cloud of ice and scree hurtling down the mountain slope and into the valley where the village is located. The mud and rockfall hit the houses.
The force and speed of the cloud were such that it continued its course down the opposite slope of the valley.
And the phenomenon was recorded by all the country’s seismic stations.
Mayoraz said that three million cubic metres of material had accumulated on the glacier, and then tumbled down into the valley.
