In October 2000, the small Upper Valais village of Gondo was cut in two by torrents of mud which swept away a dozen houses. Thirteen people had lost their lives.
On October 14, 2000, a torrent of mud cut the small Upper Valais village of Gondo in two and swept away a dozen houses in its path. Thirteen people lose their lives.
Between October 11 and 15, 2000, some 800 millimeters of rain fell on the region. Never seen. The torrents are in flood, the soils saturated with water and the authorities record several landslides in the Upper Valais, on maximum alert. The firefighters are on the verge of war, tells Keystone-ATS the president of the municipality of Zwischbergen of which Gondo is a part, Roland Squaratti.
In Gondo, around 10,000 cubic meters of sediment accumulates behind a reinforced concrete wall. This wall, about fifteen meters long and 6 meters high, made up of six blocks embedded in one another, should protect the national road from falling rocks from the impressive cliff overlooking the village.
The pressure of the flow increased and on October 14, three blocks of 600 cubic meters each tumbled abruptly forward. A first remains upstream of the village, a second crashes against the Stockalper tower and the last descends the slope at more than 60 km / h, crossing the whole town to the flooded Doveria. It is 10:30 am, Gondo is devastated.
The village is also inaccessible: the Simplon road is closed from the pass to Italy, the helicopters are grounded by the weather and the telephone lines are partly cut. Iselle station is under water and rail traffic is interrupted.
Rhone in fury
On October 14, guides, dogs, firefighters and doctors managed to reach Gondo shortly after noon. Of the 161 inhabitants of the village, around 100 were present at the time of the disaster. Forty of them, refugees in civil protection shelters, find themselves stranded inside by dirt. All were evacuated at the beginning of the afternoon.
The help is trying to free survivors. A buried woman calls for help for several days. The whole of Switzerland is holding its breath. It will not be enough. In the days which follow the tragedy, eleven bodies are released. Two inhabitants will never be found.
The conditions are appalling and landslides follow one another across Valais. In Neubrück, four houses were destroyed. Two women are swept away by the torrents of mud; one of them will be found dead in the Rhône near Martigny. The latter enters a hundred-year flood and gets out of its bed in several places. Its flow reaches 900m3 per second at Sion, more than double its usual flow. Across the canton, more than 3,000 people were evacuated.
Concrete blocks involved
In Gondo, the fall of the concrete blocks explains the devastating power of the landslide which killed thirteen people and carried away a dozen houses. “Without that, the toll would not have been so heavy. The flow composed of loose and lighter materials would not have caused a victim and would have resulted in less material damage, ”Jean-Daniel Rouiller, cantonal geologist at the time of the incident, told Keystone-ATS.
The Confederation-funded rockfall protection wall has since been reinforced. But above all, a channel has been dug in order to evacuate the water in the event of bad weather and prevent it from running down the rock face. And thanks to an unprecedented wave of solidarity in Switzerland, the Chaîne du Bonheur was able to donate 14.5 million francs for the reconstruction of the border village.
But the drama has left its mark. Last Saturday the rain was raging and Roland Squaratti, already in post in 2000, decided to stay and sleep in Gondo to make sure everything was fine. “Being there also shows residents that they are safe,” explains the man who normally lives in Zwischbergen. On Wednesday, a remembrance mass will be celebrated as every year on the same date since 2001. During the event, a commemorative bell, which only rings on the anniversary date, will be heard throughout the village.
A unique case
The case of Gondo is unique and difficult to transpose elsewhere in Valais, explains the former cantonal geologist. But Jean-Daniel Rouiller notes that, in recent years, the bad weather has been increasingly severe and despite the many surveillance systems in place or under study, the risks of other tragedies, such as the one that occurred in Chamoson ago. a year, are not zero.
“The day we have completed the third correction of the Rhône, we will have better guarantees”, explains the former cantonal geologist. It will still be necessary to analyze the right bank in order to predict the possible washout of materials in the event of heavy rains. History to anticipate rather than having to react after the fact, he concludes.