Aulnat (FR)

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Aulnat (FR)

Scale urban and architectural
Team representative architect, urbanist and landscape architect
Location Aulnat – Puy-de-Dôme (63)
Population 4112 inhabitants
Strategic site 200 ha - Project site 0,5ha (site 1), 5ha (site 2), 50ha (site 3)

Site proposed by ville d’Aulnat, Clermont Auvergne Métropole
Actors involved ville d’Aulnat, Clermont Auvergne Métropole, Agence d’Urbanisme et de Développement
Owner(s) of the site ville d’Aulnat (site 1+2), Clermont Auvergne Métropole (site 3)

Commission after competition urban studies (master plan, guide plan, construction). Urban and architectural contract according to the selected projects

More Information

Urban City Strategy

Aulnat is located at the interface of the great plain of Limagne, where large intensive cereal crops are grown and the entrance to the intense heart of the metropolis of Clermont-Ferrand. This small residential town of 4,112 inhabitants is well known in the metropolis for being its airport address. The 3 proposed sites each have strong potential for specific transformations.
On a first scale, that of the city itself, the Chapelles site calls for a proposal for innovative forms of housing capable of offering new ways of living here, of stimulating the quality of the urban fabric that surrounds and participate in structuring public space (former school demolished).
On a second scale, metropolitan scale, the strategy is to take advantage of the availability of land next to the stop of the railway line to create a new interface between the city and the airport by relying on the arrival of a High Service Level Bus line (BHNS). Identified as a project site in the new mobility plan for the metropolis, this station is intended to transform into a new crossroads and meeting place for both Aulnat and the airport (site 2).
Finally, the site of the former Bourdon sugar refinery (site 3), on the hold of Clermont-Ferrand at the limit of Aulnat, refers to a larger scale both landscape and territorial, by the size of its hold and the potential of the programs it can accommodate. Attached to a large system of lagoons bordering the motorway, a veritable landscape infrastructure linked to water management and the irrigation of crops in the plain, this site rather calls for forwardlooking thinking. If three sites are thus identified, while responding to the specificity of the challenges of each of them, a global reflection on the new stimulating interfaces between these different places can bring out a new future in Aulnat and new metropolitan energies.

Site Definition

Aulnat cultivates several particularities. That of being a small residential town bordered on its different facades by large metropolitan neighbors, the airport, the intensive cereal farming of Limagne, a former industrial tenement and the motorway. But also that of maintaining both an immediate proximity with the metropolitan heart of Clermont-Ferrand and being part of the constellation of peri-urban municipalities of the metropolis which mark out the eastern territory of Limagne.
Another particularity is that of the 2,000 housing units that compose it, 640 are made up of a large group of social housing from the end of the 1960s which contrasts with the residential fabric of village houses that border it and the more recent one, suburban, which gradually surrounded it by extending over the agricultural lands.
With the income rate among the most modest in the metropolis, the urban revitalization of Aulnat is a major challenge to fight poverty and support inclusion.

How Must Metabolism and Inclusivity Be Developed and Connected?

However, many assets exist here for a city of 4000 inhabitants: the airport, industrial and agricultural activities, a train station, a highlevel service bus planned directly connected to the urban center of Clermont-Ferrand, land available for urban projects, a gateway to the metropolitan center or even the presence of water with the Artière and the large irrigation ecosystem of the plain.
By integrating each of the metabolisms involved, new urban dynamics can redefine this margin to the east of the metropolitan heart.

Questions on the site

Are there any plans of Aulnat with contour lines or spot heights?

The documents with a raster and qgis of the curves at 1m are available for download in the folder 0-New_Docs_After_Launch, of the complete site folder : FR-AULNAT-SS-M5 TO M8

On the site of Bourdon it is indicated on the site brief that the factories have closed since 2020. All the buildings are currently booked (without any function)?

The site is no longer occupied since the shutdown of the refinery and is therefore effectively free.

Do you have any maps of the urban development of the city of Aulnat (old maps, historical maps, etc.)?

Maps are available for download in the 0-New_Docs_After_Launch file of the complete site folder: FR-AULNAT-SS-M9 TO M14

Do we know why the site is called Les Chapelles? Have there been any recent archaeological excavations on the site? Is it possible to have information on the nature of the subsoil of the site?

Concerning the name of the Chapelles site, we do not have this answer.

Concerning the archaeological excavations, the site is not at this time identified as being at stake on this question. For your information, the operation of small social housing units located directly north of the Chapelles site has not been the subject of archaeological excavations, unlike other sites in the commune which have recently made the news on these issues.

What is known about the possible need for liberal in the district/city? What do we know about the possible needs in terms of education (nursery, schools, ...) in the district/city? Thank you

The municipality is currently well endowed as far as school facilities are concerned. The facilities that could be added to Aulnat's offer would be a micro-creche and a small auditorium with retractable bleachers and a stage with a small capacity of 60-70 seats. The social center is to be moved to a part of the Claude Félix school.

What are the urban planning rules regarding the proximity of the airport: maximum building heights, noise standards, etc.? On the Chapelles site, do we have to scrupulously respect the rules in force in the PLU of the commune/metropolis? Thank you

Yes, the PLU of Aulnat applies (regulations on the geoportal of urbanism) but it remains possible to consider an adaptation in connection with the elaboration of the PLUI which leaves possible to some extent to open the proposals.

In addition to the previous question, we would like to know more about the railroad easement and the distance(s) to be respected for the constructions (on both sides of the tracks but also above the tracks). Do we already know where exactly the BHNS stops will be located? Thank you

Concerning the railway easements, it is necessary to refer to the PLU regulation which integrates them:

Concerning the stops of the BHNS, the presumed locations are for Aulnat :

  • The Chapelles site
  • The railway station
  • The Roger Claustre High School
  • Volcans (small commercial center on avenue Jean Jaurès)
  • The traffic circle terminus of Saint-Exupéry street.

Could we have more details on the offer of the Metropolis in terms of Park&Ride, if we have understood correctly the documents provided, only projects are in progress but no P&R exist yet? Thank you

The P+R Strategy is currently being developed and does not allow for a definite answer today.

Concerning the Bourdon factory. Who exactly has control of the land: does the private actor wish to sell or keep its property? What is the strategy of Clermont Métropole in the long term? Does it wish to acquire all or part of the site? Does the commune of Aulnat want to/could it acquire all or part of the site? Thank you

The owner Cristal Union sells its site a priori in several parcel units (of which 1 for the lagoons) and that must still be the subject of decision of the Board of directors of the group at the beginning of next July. It is recalled that the vocation of the Bourdon site is oriented towards economic activities.

Concerning the Bourdon factory. Was there any pollution diagnosis(es): soil, water, asbestos... Has there been any clean-up work, cleaning of the site's installations? Are demolition works planned in the near future on the former industrial site? Thank you

No visit possible as the site remains private, and there have been no soil studies carried out/authorized at this stage (potential candidates for the takeover have indicated that they have not had any authorizations).

Concerning the Bourdon factory. Are the waters coming from the treatment plant still polluted?, is there a depollution process that takes place in the basins? Who controls the quality of the water in these basins? Thank you.

The water from the water treatment plant that feeds the lagoons today is treated in the lagoons. The water treatment system that existed when the refinery was in operation for the reprocessing of water used for beet processing is no longer needed today.

The following document, which can be consulted online, can help you understand the functioning and structure of the lagoons:

Concerning the Bourdon plant. Was there an ecological diagnosis of the lagoons? Are there endemic species (fauna/flora) or species that stop there during migration (birds...)? Are there problems of invasive species (fauna/flora)? Thank you.

The lagoons, like any wetland, lead to an ornithological presence that is noticeable on the site. The LPO has done a lot of work on the site, especially for migratory birds. This has not been recorded recently, at least not since 2012 at the takeover of Crystal Union which led to limit access for safety reasons on the industrial site food.

Concerning the floristic aspect, some areas are left with reeds, especially for birds, and the other parts are maintained as grassy areas.

Concerning the Bourdon factory. What is the state of the buildings? Are the roofs in good condition for example? Is it possible to visit the old Bourdon site? Maybe a virtual visit? Are photos/videos available? How is the sewage sludge from the plant currently used? Co-composting, burying or other? Thank you.

Concerning the Bourdon factory, it is not possible to visit the site, which remains private to this day, and there is no precise information on the state of the buildings.

Concerning the wastewater treatment plant and its functioning, the Clermont Auvergne Métropole website provides a certain number of answers:

Is there an ambitious project concerning the bicycle and its infrastructure on the scale of the Clermont-Ferrand metropolis which would influence Aulnat ? (dedicated tracks, parking lots, self-service stations C.Vélo) Thank you

The bicycle development plan is currently being prepared.

Is it currently possible to reach Clermont on foot from Aulnat (in a safe and pleasant way)? Same question for Malintrat, Lempdes and Pont du Château? Thanks

These links exist in practice but are not considered comfortable in their use:

  • One to the North by the road to Gerzat
  • The other to the South along the old departmental road and through the Brezet area.

We understand that an urban-architectural project is expected at the scale of the site study site. But are the candidates asked for a detailed urban-architectural project on each of the 3 project sites, or do the candidates have to choose and make only one?

The level of expectations of the urban-architectural project is linked for each of the sites respectively to the issues it carries. The reflection on the perimeter can lead to the elaboration of an overall strategy for the development of Aulnat that links these three project scales, the issues, although different on each of the sites, must be able to articulate an overall project. The level of intensity of the response can be thought of as follows:

  • On the Chapelles site: a precise response on the question of housing, its innovative forms in relation to the context, the types of products to be proposed, the links with the city center...
  • On the station site: an overall response that integrates the links with the airport and downtown Aulnat and that allows new uses to be revealed on this interface. 

The city of Aulnat is still waiting for a precise proposal. The site of the train stop is identified in the InspIre project (future BHNS) as a project issue site.

  • On the site of the refinery: it is a question of proposing a strategic vision of the future development of this sector and of opening up the potential, of offering a transformation of the view while integrating the fact that this sector is at stake in economic development. In other words, the answer is to propose elements of definition for this site and to be able to demonstrate how to link it to the urban issues of Aulnat.

What are the depths of the different lagoons? Thank you

On the 18 ha of ponds intended for the irrigation of Limagne, the capacity of the ponds reaches 300,000m3 at full capacity. On average, the depth of the ponds is 1 to 1.5m, allowing ultraviolet treatment on the surface, except for the first storage ponds which are deeper. 

The following document, which can be consulted online, can help you understand the functioning and structure of lagoons:

Could you enlighten us on the future of Clermont Auvergne airport for the years to come? We are wondering about this, especially in light of the bill currently being debated on the abolition of domestic flights of less than 2.5 hours. Are transformations of the activity of this airport to be expected and integrated into the project?

A few months before the COVID crisis, the Syndicat Mixte Région-Département-Métropole, which manages the airport, wished to undertake a study to define the future (horizon 2030) of the airport. At that time, air transport was growing overall but had been stagnating locally for several years. The aim of the study was to find new sources of air traffic in Clermont-Ferrand...  The study aimed to see how freight traffic could develop and also how the platform could accommodate more economic activities.

To date, there is still an objective to develop the platform in all directions: passenger traffic, freight traffic, economic activities on the site (workshop, maintenance plant, offices, services, etc.)... Concerning "passenger traffic", the development of the site is however questionable with this "2h30 barrier", and more globally with the impact of a societal view that may have changed with regard to the use of airplanes.

Technically on the subject of 2h30, here is what we can say: 
- The citizen's climate convention recommended a threshold of 4H except for flights feeding connecting hubs (Roissy). This would have affected almost all flights between Paris-Orly and the main provincial cities (except for Toulouse and Nice) but not those departing from Paris-Roissy. It would also have affected flights between provincial cities. In this case, the Paris-Orly - Clermont line would have been affected.
- The government wished to lower this threshold to 2h30... thus limiting the number of affected lines
- But, even if the ban does not affect Clermont, the reality of the market on this route and on others means that air transport operators do not necessarily relaunch routes between Paris-Orly and cities at "3 hours". The Paris-Orly - Clermont route has not existed for over a year. Even if there is a very strong will of the political and economic actors to bring it back, the question of the economic viability of such a service compromises its reintroduction. For example, Air France and Easyjet have abandoned the Basel-Mulhouse line with Paris-Orly. These companies believe that the train is the best solution for center-to-center travel and prefer to use their planes on other routes (Basel-Mulhouse is connected to Paris-Roissy).
- It should also be noted that the 2.5 hour threshold blocks any reopening of a line between Clermont and Lyon, which is a strong demand of the region, especially to allow for easier connections.

This site is connected to the following theme

Stimulating Interfaces

New energy has to be found for these sites through a treatment that respects the existing environment introducing specific elements and actions able to develop a resilient city.
These sites are at a crossing-point of different areas, making them important mediators, but also in-between places that can stimulate the quality of the neighbouring areas.

Specific documents

Questions on the site

Fr. 18 June 2021
Deadline for submitting questions

Fr. 2 July 2021
Deadline for answers

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Aerial view of the sites perimeters
View of the airport and rue Gagarine from the  footbridge of the Aulnat station
Site 1 - Les Chapelles
View of the Puy mountains from the station footbridge
Site 2 - Aulnat train station
Site 3 - Former Bourdon refinery