Landslide remediation works, Müllera reservoir, Plasselb

The project

Location: Plasselb (FR)
Customer: The municipality of Plasselb
Phases: Landslide remediation works at Müllera reservoir, modification of protection zones
Duration: 2016
Building costs: -


Heavy rain caused a landslide at Müllera reservoir. Due to the slippage of the surface layers, surface water was able to find its way quickly into Müllera reservoir, jeopardising the quality of drinking water. In addition, it was not possible to rule out that the area of slippage would further extend up the slope as a result of erosion. In order to prevent further expansion of the area affected by the landslip, and to ensure that the reservoir was not adversely affected by surface water run-off, the rock face exposed by the landslide was sealed with a clay layer some 0.2 metres thick, which was covered with bentonite mats. Drainage pipes were laid over the clay/bentonite mat layer in order to drain the surface water run-off from the immediate protection zone. Thanks to the remediation works undertaken, the water source can continue to be used for drinking water.


Our services

  • Geologic and hydro geologic investigations
  • Groundwater tracing, vulnerability mapping in the vicinity of the landslide
  • A risk assessment of the reservoir
  • Preparation of a remediation project
  • Management of the remediation works


  • Low-tech equipment (forestry machinery, manual labour) had to be used to carry out the remediation works necessary at the reservoir, which is located on remote, steep terrain.
  • The work undertaken had to be adapted to the weather conditions.
  • Specific protection measures were required in the groundwater protection zones S2 in order to carry out the construction work.

Project manager:

Stefan Fuchs Partner, Fribourg branch manager
Diploma in Geological Sciences BENEFRI UniFR Geologist CHGEOL +41 26 422 39 55 More