Authorities have revealed the details of a drainage tunnel designed to stop the village of Brienz from sliding into the valley.
On Monday, experts presented the tunnelling project proposed to give residents of the village in the southwestern Swiss canton of Graubünden some relief. Brienz/Brinzauls had recently made the headlines because of the threat of a landslide over the village in the Albula Valley that could have buried it.
The village itself also stands on unstable rock and is sliding downhill at an increasing rate. To put the brakes, a drainage tunnel will be drilled into the mountain to west of the village. The aim is to extract water from the rock below the village which will help stabilise the surrounding area.
"The tunnel is meant to stop the movement of the rock below the village and also that of the mountain above," explained engineering geologist Reto Thöny at a press conference on Monday.
According to the geologist, there is no comparable drainage project of its kind anywhere else. Nevertheless, the geologists and residents of Brienz/Brinzauls are optimistic that the landslide movements can be slowed down enough to keep the village habitable.
"We are confident that the landslide will come to a complete halt," said Daniel Albertin, mayor of Albula/Alvra municipality to which Brienz belongs.
An exploratory tunnel has already been drilled to give geologists and engineers a chance to test the plan. This will be extended to 1.6km and the entire project is estimated to cost CHF40 million ($45.5 million).