Flood risk in Zurich

In May 2024, work began with the tunnel boring machine to excavate the tunnel from the Sihl Valley to Lake Zurich. With the breakthrough, extreme flood peaks of the Sihl will be diverted through the new relief tunnel into Lake Zurich from 2026. After around seven months of construction through the Zimmerberg, the tunnel boring machine arrived at Lake Zurich in Thalwil on November 26, 2024 and returned to daylight. It not only broke the circular tunnel out of the rock, but also lined it with prefabricated concrete elements. What remains is a prefabricated concrete tube. Work to complete the inlet and outlet structure will now continue until the end of the construction period.

Where to put the excavated material?

TR Trans Rail AG is responsible for the removal of the excavated material for this project. During this time, we have removed approx. 60,000 tons of excavated material. We are delighted to be part of this project of the century.