Transforming the Aproz wastewater treatment system into a playground by En-Dehors

Located along the Rhône River in Aproz, Switzerland, the above-ground sedimentation basin is a remnant of the 1960s wastewater treatment plant, the first of its kind in Valais. Abandoned in 1994, the structure became an overlooked void amid expanding residential areas. To address the need for public spaces in the rapidly growing village, local authorities commissioned En Dehors, who soon proposed investing in the volume of the abandoned basin, thereby preserving the surrounding plot for future development.

Rather than opting for demolition, the project aims to transform this once hostile and unsuitable site into an inviting and playful public space. To achieve this, a thorough analysis of the existing structure was conducted, and its features were integrated into the new design. The transformation involved the creative reuse of materials: steps were crafted from the cutting of the south facade, railings were repurposed. This approach not only minimized waste but also highlighted the basin’s original character.The site directly inspired the project, which continued to evolve throughout the construction process. Every piece was appreciated and considered on-site, gradually shaping the final result. The outcome is a unique in -site playground rather than a conventional public square. The design reflects sustainability, resourcefulness, and adaptive reuse, turning a defunct industrial site into a vibrant, imaginative community asset.

• Project typology:

Public playground

• All landscape architecture offices involved in the design of landscape:

En-Dehors

• Other credits:
Project management
City of Sion and Nendaz

Landscape gardener:
Jardin alpin, Haute-Nendaz, Valais, CH
Civil engineer: Masserey & Voide, Sion
Concrete cutting:
Discobéton, Conthey

• Location of the project
Impasse Bord’Eaux 6, 
1994 Nendaz, Valais, 
Switzerland