SMA1 and BLV2 weirs are located on the Arve river, in the Haute-Savoie department. Each weir is composed of:
– A water intake equipped with screens to protect fishes and facilitate waste removal
– A riprap-protected paved inlet tunnel
– 2 VLH (Very Low Head) turbines that do not interrupt fish migrations or movements
– A fishway and a notch for raft or kayak use
– A production plant nearby
– An unloading platform with an assembly area
– A storage area, used during the construction and operation process
– A permanent footpath to access the weir (maintenance / operation)
– A 20 kV transmission line to transfer the energy to the nearest electrical substation
– a removable weir, with weir valves
– A concrete abutment (reinforced concrete)


Setec was tasked with the following:
- Assisting with bathymetric and hydrometric measurements near the weirs
- Assisting in the geotechnical recognition phase (topographic assessment, authorization application procedures etc.)
- Writing the Environmental Impact Assessment report
- Conducting a preliminary study: write-up of the report and map production (2D and 3D)
- Conducting a 2D hydraulic study of weirs and their surroundings: operational phase, construction phase, and flooding events



Key figures

Period of services

May 2018-July 2020

Key challenges

Creating a BIM (Building Information Modeling) / 3D model was very useful in enabling the stakeholders to better understand the project, as well as in facilitating exchanges with the client. Those models were also used in the authorization process for illustration purposes.

From very early on, the BIM model made it possible to calculate the investment cost of the project with greater precision