Géosel and Transéthylène restore  weir n° « 5 bis » on the Durance River  (Provence, France) : an exemplary construction project for biodiversity

To ensure the protection of three strategic pipelines crossing the Durance River, Geosel and Transthylene carried out a major restoration project last summer on weir n°5 bis, located between Pertuis and Le Puy-Sainte-Réparade, in Provence, France.

Built in 1977, this hydraulic structure plays a key role in maintaining the river’s profile and ensuring soil stability.

A project approach focused on environment

From the design phase onward, the project was conceived to minimize its impact on the natural environment.
An ecological survey conducted by the environmental consultancy Naturalia revealed the presence of the European water vole—a protected species—on the left bank of the site. Géosel and TransEthylène therefore chose to limit the rehabilitation works to two-thirds of the structure, focusing interventions on the most degraded areas on the Pertuis side in order to preserve the natural habitat of this semi-aquatic mammal.
In parallel, a macro-rough ramp was integrated into the structure to facilitate the passage of eels and other migratory fish, thereby supporting the ecological continuity of the watercourse.
The French Office for Biodiversity (OFB) confirmed the compliance of this installation during an on-site inspection.

A safe and exemplary construction site
Under the supervision of Géostock and contractor Buesa, a rigorous HSE (Health, Safety, Security andEnvironment) management system was deployed: control plans, daily safety talks, safety drills, and environmental awareness sessions. The result was zero accidents or incidents recorded over the entire duration of the works, which were carried out under strictly controlled hydrological conditions, from July 15th to September 24th, 2025.

Sustainably restoring the river Durance
Beyond the consolidation of infrastructure, this project reflects the commitment of Géosel and its partners to reconcile industrial safety with ecosystem preservation.
The weir restoration works strengthen the hydraulic resilience of the Durance River while safeguarding its biodiversity, demonstrating that responsible management of industrial assets can be a concrete driver of environmental protection.