R. Aare Flood Protection and Revitalisation Project, Olten-Aarau

Extensive flood protection and revitalisation measures were implemented on a 13 km stretch of the River Aare crossing the territory of 10 communities. A new side channel and bank support structures were constructed along a total stretch of 4.7 km. New dams and defensive walls were needed along 3.7 km. A total of 550,000 m3 of material had to be moved and 17 ha of woodland cleared. It was possible to work with intervention lines on large sections. The project required a comprehensive material management concept. Substantial added ecological value could be achieved by generously structuring the side channel with deadwood, microgroynes, root wads, trees etc.

Main Data

  • New side channel: 4.7 km
  • New dams / walls: 3.7 km
  • Material movements: 550,000 m3
  • Woodland cleared: 17 ha


Solothurn Canton, Department of Environment


IUB Engineering AG in consortium

Construction period

2014–2017 (Lots 1-3 and 5)

Construction costs

Total project CHF 27 million, Lots 1-3 and 5 CHF 24 million

Scope of services

  • Design for construction project
  • Design for regulatory approval
  • Tendering
  • Implementation