Environmental analysis and ecological engineering
Biodiversity in development projects in France
Faced with the collapse of biodiversity, international cooperation has been organized. Treaties have been signed by many countries to encourage the conservation of biological diversity, the restoration of ecosystems, and their sustainable management. The European Union has joined this movement by incorporating biodiversity preservation into its body of legislation, thereby strengthening or stimulating member countries’ regulations in this area.
As the destruction of natural habitats due to human activities is one of the main factors contributing to biodiversity loss, developers have been encouraged to incorporate these objectives into their practices. As a result, the way these projects are designed and implemented has changed significantly, with environmental analysis and ecological engineering gradually being added to traditional engineering services. Four ecologists and environmentalists from Artelia, Estelle Briard, Sarah Gremilliet, Caroline Jankowski, and Jérémy Judic, discuss their experience in France in the field of biodiversity.
How have regulations promoting biodiversity evolved in Europe and France?
Sarah Gremilliet
Environmental regulations, both European and French, have become increasingly stringent since the 1970s, leading to a strengthening of the investigating authorities, which have expanded their regulatory files by becoming more demanding and more precise. Today, in France, the regulatory framework is based on the Law on the Restoration of Biodiversity, Nature, and Landscapes (2016), which requires every project developer to ensure that their development does not lead to the destruction of protected species and habitats. It makes project developers accountable, exposing offenders to criminal penalties. Another important regulation, originating in the EU, is the Water Framework Directive (WFD), which aims to restore the good ecological and physico-chemical status of rivers. It encourages states to restore ecosystems in and around water bodies.
Caroline Jankowski
I began working on these issues in 2009 when the Grenelle 2 law (2010) was being drafted, which included a set of measures aimed at preserving biodiversity (regulating pesticide use, establishing green and blue corridors to ensure ecological continuity, etc.). Since then, there has been significant progress in taking biodiversity into account in projects. The 2016 Biodiversity Act introduced the implementation of the principle “avoid,” “reduce,” and “compensate” impacts, to which it had been added, ‘accompany’ and “monitor” projects. This approach has been supported by institutions such as Cerema, Dreal, and OFB (French Office for Biodiversity), which have published guides for development stakeholders.
Jérémy Judic
There is also the Habitats Directive, enacted by the EU in 1992. It led to the establishment of the Natura 2000 ecological network, a common reference framework for European countries on the status of natural habitats and species. Within this framework, special conservation and protection areas have also been created. And let’s not forget that, alongside regulation, there is also societal acceptability, as European citizens’ awareness of biodiversity issues has also increased significantly.
What do your duties as ecologists involve? What types of projects do you work on?
Sarah Gremilliet
All our studies are based on these regulations. Project developers must now carry out an assessment to evaluate the environmental issues, estimate the impact of their projects on biodiversity, and identify appropriate avoidance, reduction, and compensation measures. As biodiversity is one of Artelia’s areas of expertise, we help them to inventory and analyze the existing situation, assess the impacts caused, and then take the right measures to preserve biodiversity and prevent their projects from being blocked at the regulatory stage. We then provide support for the implementation of these measures.
Jérémy Judic
The key word is “anticipate”. It is really important to intervene early on to “avoid” impacts as much as possible and to be able to steer our clients in the right direction from the outset. We then provide comprehensive support for projects from a biodiversity perspective until their completion. We are at the heart of project design, working closely with the various engineering disciplines. We provide environmental assistance during the construction phase to ensure that the measures planned during the design phase are actually implemented. We also carry out post-construction monitoring, at 5 or 10 years, to evaluate the results of the measures applied. We are therefore involved throughout the entire life cycle of a project and in all types of projects (urban, coastal, and river development, buildings, linear rail and road infrastructure, etc.).
Caroline Jankowski
Large linear infrastructure projects can lead to the fragmentation of territories and habitats, with the risk of population loss and a reduction in the gene pool. They therefore need to set an example in terms of their environmental approach. We work regularly with motorway companies and SNCF Réseau, the French national rail network company, on these issues to ensure that biodiversity is taken into account.
We provide support for a variety of development projects (railways, roads, buildings) to ensure the preservation of biodiversity, and we carry out ecological restoration operations. These may be planned as a measure to offset the impact of a project, or they may be carried out by water management associations or communities of municipalities that want to restore certain natural environments to improve the ecology of their territory, generally in line with the Water Framework Directive (WFD).
We also work on specific issues, such as the fight against invasive alien species, which pose a real problem for local areas. These species are very difficult to eradicate, as there are always a few roots or seeds left in the soil that can restart flowering and spread again. We are currently developing a tool to facilitate their identification and management.
What role does the flora, fauna, and habitat inventory play in your approach?
Jérémy Judic
These inventories are essential because they establish the baseline condition of the site where the development or ecological restoration project will take place. It’s a huge debate: where do we start, and what ecosystem do we want to return to? Any project can provide opportunities for biodiversity conservation.
Beyond simply identifying the species present, the challenge is to provide support in the form of expertise and advice. We analyze and describe how species use the space and how their habitats can be delineated on the study sites for different functions (rest, transit, reproduction) during different seasons. Based on this assessment, it is then possible to examine the initial project objectives: how will the environments react to certain changes, for example if the water supply, topography, or shade are modified?
Sarah Gremilliet
The inventory is the preliminary step. Project developers must take biodiversity issues into account and therefore carry out these inventory studies of fauna, flora, and habitat in order to then take the appropriate measures. This is now an essential step in regulatory procedures. These studies require a thorough knowledge of the environments and species specific to each territory, while also being able to take into account, on another scale, categories of fauna whose movements and migrations may be much wider.
Caroline Jankowski
It is based on this baseline assessment of the site or plot that we can determine the scale of avoidance, reduction, and compensation measures. We then monitor the construction phase to ensure that the populations identified are not impacted by the works.
What does ecological engineering involve and how does it fit into your approach?
Sarah Gremilliet
Ecological engineering brings together all design and development professions involved in the restoration of natural environments.
Jérémy Judic
We particularly call upon ecological engineering when there are residual impacts that need to be offset or in the context of projects dedicated to ecological restoration. We are currently project managers, on behalf of Les Sables-d’Olonne and the Conservatoire du littoral, for a project to restore dunes where a motor racing circuit had been built. Wetland restoration is another area that has seen significant progress and in which we are regularly involved.
Caroline Jankowski
For every project, there are essential construction rules. We are therefore regularly confronted with technical limitations that make it impossible for us to avoid certain impacts. In such cases, ecological engineering allows us to find solutions by relocating species and recreating habitats. This involves, for example, restoring a wetland, a woodland, a hedge, a meadow, or a specific habitat for a particular species, or creating nesting boxes for bats or hibernacula for species found in the surrounding area.
We recently had a case like this during the construction of a viaduct. It was impossible to change its route, so before work began, we replanted the wallflowers (a flowering plant) that were present along the route in another area. Or, for a highway company, we designed wildlife crossings, large bridges designed to restore the ecological continuity interrupted by the infrastructure.
These measures vary greatly. In industrial wasteland, where the ground is bare, there are generally few issues, unlike other sites that may be home to areas rich in biodiversity and are therefore more sensitive to the changes caused by development. However, we must remain cautious, as we have already encountered colonies of bats in disused buildings and discovered species that had settled in artificial spaces where they were not expected.
Jérémy Judic
Compensation measures, which can be implemented after avoidance and reduction measures, can be complicated to implement when they require a large amount of land, which can call into question the environmental feasibility of projects. In some cases, they can be much more costly in terms of finances, planning, and social acceptability than a major overhaul of the project. Once the land has been identified, a complete cycle of studies and inventories must be carried out. If it meets the project’s ecological debt, it must then be acquired and secured, the measures must be scaled, detailed design studies must be carried out, and the implementation of the measures must be monitored. It is then necessary, over a generally long period of time (30 to 50 years), to verify whether the objectives have been achieved and to ensure their sustainability.
For all development projects, there is also the issue of construction work, which is always disruptive in terms of image and therefore public sensitivity. It creates shock, even if, with biodiversity, resilience can be fairly rapid. Upstream support through clear communication, backed up by concrete feedback on the effectiveness of the proposed measures, is imperative.
What conclusions can we draw from these past few years, during which biodiversity conservation has gradually become an integral part of development projects? What are the main achievements, limitations, and progress that still needs to be made?
Estelle Briard
I think there has already been a very positive change. Today, we focus on avoiding and reducing impacts. We only take compensation measures if we are unable to reduce the impact completely. This was not the case a few years ago, when project developers were very quick to turn to compensation.
Another major advance is that ecological issues are now taken into account much earlier in the project cycle. Environmental studies are becoming more expert, inventories are becoming more exhaustive, and project developers are now incorporating biodiversity more into their decisions, sometimes as early as the feasibility phase. This anticipation makes it possible to achieve more effective, less costly and better-accepted solutions.
Among the limitations is the lack of feedback to identify which measures work best, as some have only been implemented recently. And, in general, this approach to biodiversity generates additional costs for project leaders. In a tense economic environment, this is not necessarily seen as a priority, even though, in the longer term, this loss of biodiversity has an enormous cost for our societies and must be stopped.
The real challenge today is both to provide the best possible support to stakeholders in the field and to develop ecological engineering in the regions. We also need to succeed in conveying the idea that preserving biodiversity is not an additional constraint, but a sustainable investment for the future.
Sarah Gremilliet
We are all familiar with the figures on biodiversity loss and the challenges it poses. We are living in a time when we no longer have a choice. We must take these challenges fully into account and be extremely vigilant, hence the pressure from the investigating authorities and our own efforts to change practices. Let’s be clear, any development has an impact, and recreating something with the same functionality as a “natural” environment is extremely complicated. Implementing measures that are proportionate to the loss of biodiversity can quickly become expensive, and project developers rarely have the budgets to match this ambition. It will still take time, but we are moving in the right direction.
Jérémy Judic
We have never been listened to as much as we are now. It’s true that, in the past, biodiversity was only considered at the very end of the project design process, once everything was pretty much finalized. So there has been a real turning point in how this aspect is taken into account. The rollout of avoidance measures is a real step forward. We are also talking more and more about environmental feasibility, and we encourage contractors to carry out inventories so that they know their sites and have the visibility they need to understand the land and the issues involved in the long term.
One of our main difficulties is that we work with living organisms. We rely on rigorous studies and call on experts, combining the perspectives of ecologists, environmentalists, and landscape architects to also discuss the living environment, but we must remain very humble, because there is an inherent element of uncertainty when dealing with living organisms. This requires a great deal of education on the part of all stakeholders, from project leaders to citizens, from our own colleagues in other disciplines to construction companies.
Caroline Jankowski
It is essential to engage in ongoing dialogue and continue to raise awareness, particularly among teams involved in implementation. This is how we grow and move forward. Despite the progress made, we still see significant differences between stakeholders in their understanding of biodiversity. The difficulty is that the issue of protecting life touches on fundamental personal and collective positions, societal questions about what we should do, accept or reject.
Published on March 13, 2026