The project to renaturalise the Pétrusse valley is a major undertaking by the City of Luxembourg, in collaboration with the ministry for the environment, climate and biodiversity. It is being carried out in two phases, the first of which was completed at the end of 2024 and the second of which has just been launched. The aim is to remove the Pétrusse from its concrete bed and make ecological improvements to the river and its banks. This approach will also reduce the risk of flooding, while improving biodiversity, adapting to the challenges of climate change and respecting the visual appearance of the fortifications, which are a Unesco World Heritage Site. The works also include the refurbishment and installation of rest and leisure areas.

A successful phase one

The first section between Place St Ulric and Bourbon Lock is now complete and its effects are already visible. Natural conditions for the watercourse have been recreated and the Pétrusse can now meander freely, reducing the risk of flooding. Vegetation has quickly established itself around the watercourse and will continue to develop, reinforcing biodiversity and the ecological balance. Between May and October, this section will also host the Luxembourg Urban Garden (Luga) and its various stations and temporary gardens created for the occasion.

A complex second phase

Preparatory work for phase two began in February, and the actual work will start in the spring and last for two and a half years. The budget for this second wave of works is estimated at almost €15m. This new section is complex to implement, as it is made up of several sub-projects, some of which can be carried out independently. Others, however, are spatially dependent and require complex construction processes.

The preparatory works phase consists of preparing the banks, with the necessary felling of some trees (offset by the planting of 56 new trees). Then the heavy work begins.

The main features of this second phase of works are measures to develop the park and amenities for users, including a new multi-sports pitch. There are also plans to build an underground relief pipe to protect a private property in the event of overloading of the watercourse. In addition, steps and balconies will be installed at various points along the banks, paths will be renewed, rest and recreation areas will be created, and four new bridges will be built (one for vehicles, three for pedestrians).

For the duration of the works, the paths along the Pétrusse will be inaccessible to pedestrians and cyclists. To compensate, a cycle lane will be installed in the opposite direction to Rue de la Sémois, which will become a one-way street.

The park is scheduled to open in full in September 2027.

This article was originally published in .