Bords de Seine

The Bords de Seine project will reinvent the Terrasses 3-5 and Echangeur sites and create new links between La Défense and Nanterre.

Bords de Seine: an area marked by history

The Seine and Mont Valérien were decisive factors in the early settlement of Nanterre. This site, with its exceptional geography, has seen a succession of major infrastructure projects, particularly in the 20th century, forgetting the specific characteristics of the area and its people, and generating a large number of wastelands, which have been both cut-off points and lands of opportunity where a number of initiatives have emerged. Today, the area reconciles the heritage of the historic axis with the new Raison d'être of Europe's leading business district.

As an integral part of the Seine-Arche mixed development zone, the Bords de Seine form a complex area covering 3 main sites:

• République-Université, from the edge of the University to the Anatole France housing estate,
• Terrasses 3-5, between Terrasses 7-17 (Grande Arche side) and the Chemin de l'Île departmental park,
• The A14/A86 interchange, which extends the Terrasses and includes the Chemin de l'Île departmental park.

14, A86, slip roads, railway lines, RER A viaducts... over the last few decades, the banks of the Seine have inherited a wealth of infrastructure that has shaped a landscape of contrasts. Although the topography is made up of bridges, embankments and other hoppers, a bucolic nature emerges upstream from the Seine and the Parc du Chemin de l'Île.

Terrasses 3-5: the natural extension of the historic axis

Slightly offset from the historic axis, Terrasses 3-5 is its natural extension. Located between the RATP tracks of the RER A and Avenue de la République, Terrasses 3-5 takes its name from the urban concept devised by urban planners Treuttel-Garcia-Treuttel when the ZAC Seine-Arche was created. This public space is made up of 17 landscaped terraces stretching from the Grande Arche de Lla Défense to the lower loop of the Seine.

The site forms an unexpected tree-lined green space within a dense urban fabric, despite the A14 motorway junction. The aim is to reconnect this site with the surrounding neighbourhoods and offer a cultural and agricultural programme in line with the raison d'être of Paris La Défense. Set up in 2008 on the Terrasses 3-5 site, the Paranda Oulam - La Ferme du Bonheur association has occupied this wasteland to run agricultural activities with a vegetable garden, pens (geese, pigs, sheep), beehives and dry stone walls.

n 2024, a new association of prefiguration should take place on this site, to prefigure the vocation and the collegial programming approach to come.

The Terrasses 3-5 redevelopment project involves the various stakeholders in the area in building a project that meets several objectives:

• Enhancing biodiversity: Terrasses 3-5 has a wealth of plant life and biodiversity that needs to be preserved and enhanced. It is home to more than a third of Nanterre's biodiversity: woodland, hedgerows and meadows provide shelter and food for wildlife (insects, mammals, birds). As a biodiversity relay, it is a link in Nanterre's ecological network, which the development project will aim to strengthen.
• Improving accessibility: Between rue Anatole France and avenue de la République, a pedestrian and cycle path known as the "low link" will cross Terrasses 3-5. It will be connected to the most important footpaths in the Bords de Seine sector and, beyond that, in Nanterre and La Défense. This link will make it possible to reconcile the development of nature in the city, inter-neighbourhood links and the discovery of a hitherto confidential sector. Direct access to the site from the east will be provided by a footbridge spanning the RER A tracks towards the Grande Arche, continuing the historic route. This crossing of the RER tracks will complete the district's pedestrian links while redesigning them, and should be operational by 2027.
• Defining new uses: The future programme for Terrasses 3-5, the start of the Delta Vert, should be supported by the "le Pré" association set up by Patrick Bouchain, winner of the Grand Prix de l'Urbanisme, to consolidate the site's agricultural and cultural vocation and its long-term management arrangements. This association plans to run educational workshops for architecture students in particular, who will have to reflect on the site as part of the project.

The interchange

With the recent removal of the motorway ramps, the momentum at the Echangeur site offers significant opportunities for an emblematic project that is both inhabited and oriented towards the city and nature.

A site marked by urban divide

From the Parc Départemental du Chemin de l'Île to Avenue de la République, the Echangeur site covers around 12 hectares. It lies at the crossroads of sectors that have been almost entirely redeveloped (Hoche district, Cœur de quartier, Terrasses 7-17) and more disparate entities (ZAC des Papeteries, Anatole France sector, Terrasses 3-5) awaiting interconnection. It is occupied :

• to the west, by the entry and exit ramps of the A14 - A86 interchange,
• to the north, by the RER A viaduct,
• to the south, by the Chemin de l'Île departmental park, which runs alongside the A14.

Between 2018 and 2021, the French government and Paris La Défense will be burying the B5 slip road and redeveloping the Avenue de la Commune de Paris.

A place accessible to the public

Following the example of the République-Université and Terrasses 3-5 sectors, opening up the site involves creating new connections and opening it up to the city. Landscaped areas and pedestrian links will be created on the A86 overpass and/or the gaps in the RER A viaduct.

This opening will provide new access to the Chemin de l'Ile departmental park, through the creation of an extension currently under discussion with the Hauts-de-Seine department, thus enhancing the site's wildlife and rich biodiversity. The green corridor from the Terrasses will finally be completed with this last link connecting it to the banks of the Seine. The project also includes consideration of new housing developments.