Oberwil, 16.05.2023

Boulder continues to threaten Zug's villa district

After the rockfall last week, the Weidlistrasse has been reopened to non-motorised traffic. A large boulder continues to threaten the residential area, however.

More than a week ago, a rockfall above the Räbmatt settlement in Oberwil raised safety concerns: around 40 cubic metres of rocks and boulders broke loose from a rock face in the Nüeflue and thundered downhill into the forest on 2 May (we reported at the time). Various protective measures were then taken, and there is currently no longer any acute danger – and the Weidlistrasse is now open to traffic again.

The situation in the area was assessed by a geologist, as the Canton of Zug now writes in a statement. The geologist did not identify any acute danger from further rock sections in immediate danger of falling.

This boulder thundered down to the Weidli road                                 Photo: PD

Unstable boulder to be removed
It was discovered, however, that there is a second unstable rock block of an estimated 20 cubic metres next to the excavation site. In the medium term, this  poses a "considerable danger" to the Räbmatt settlement below - a residential area in Oberwil near Zug. This boulder is to be removed as part of a rock clearance operation. More specifically, the boulder is to be removed in a controlled manner at the end of May or beginning of June, and the material is to be taken to the top of the slope with the help of a transport cableway.

A small earth wall has already been built above the Waldstrasse, which should, in future, hold back stones and small boulders from the rock face at the end of the outflow section. This permanent protective embankment, a temporarily installed rockfall protection net and steel palisades placed on the road will provide triple protection for the buildings during the upcoming rock clearance.

During the rock removal, the Weidli road, which is currently open again, will be temporarily closed. A footpath diversion will be signalled.