As part of a dam construction project located in the municipality of Chertsey, CHG Groupe Conseil mandated Opaysage to green the engineering solution initially proposed. A predominantly mineral intervention was considered undesirable, and the preservation of a more natural character, integrated into the existing landscape, was strongly sought by the local community.

Our mandate involved developing landscape solutions aligned with best practices in bioengineering, through the preparation of plans and specifications. The proposed design responds to both the technical requirements of the dam infrastructure and the social and aesthetic expectations expressed by the community.

The proposed interventions aim to integrate the structure into the surrounding landscape by drawing inspiration from natural systems. The culvert is designed as a reconstructed watercourse, using grouted stone that supports water flow while allowing for the establishment of vegetation. A vegetated arched mesh installed directly over the culvert helps green the structure while ensuring its stability.

The slopes, initially armoured with riprap for stability purposes, are covered with a layer of ramial chipped wood (RCW), allowing for direct planting within the material. This approach promotes moisture retention, soil protection, and the gradual establishment of a durable vegetative cover.

Lastly, wood debris generated from site clearing—such as logs and branches—is retained and repositioned along the slopes to enrich the soil, support biodiversity, and contribute to the overall naturalization of the site.