Rewilding with excavated material at Lake Uri
Around 3.5 million tonnes of rock material from the excavation of the second tube will be transported by train to Flüelen, where it will be used to rewild the shallow water zones in Lake Uri. Rewilding is the process of restoring close-to-nature habitats, thereby promoting biodiversity.
Image source: Seeschüttung Urnersee, Kanton Uri
River biodiversity in the canton of Uri
The rivers in the canton of Uri are not just tourist attractions and recreational areas. They also play an important role as a source of renewable energy and supplying drinking water, and provide a habitat for animals and plants, some of which are endangered.
The channelling of the River Reuss and gravel extraction at the beginning of the last century led to the disappearance of shallow water zones in the Reuss delta into Lake Uri. Shallow water zones are areas in the lake up to 10 metres deep that receive a lot of light. Lake Uri’s shallow water zones are being restored by dumping material excavated during tunnelling in road construction projects.
New shallow water zones
A third round of dumping
During the construction of the Gotthard Base Tunnel (AlpTransit) and the N4 bypass tunnel in Flüelen between 2001 and 2008, excavated material was used to create valuable shallow water zones, groups of islands and a richer biodiversity in Lake Uri.
In summer 2017, further dumping to create new shallow water zones at the lake was approved. The material excavated from the Sisikon tunnel during the construction of the new A4 Axenstrasse and from the second tube of the Gotthard road tunnel is being used for this purpose.
The first test dumping took place in the spring of 2023. The infrastructure, procedures and processes could be tested, meaning everything could be coordinated by the time the large quantities of material started arriving in autumn 2024.
Further information on creating shallow water zones at Lake Uri can be found on the project's official website: www.seeschuettung.ch
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