Mediterranean at risk: 55,000 homes threatened, a coastline to rethink!
A coastline under pressure: between attractiveness and vulnerability
With 1,700 km of coastline, or one third of the metropolitan French coastline, the Mediterranean is both an attractive territory and a threatened space. Its population of 3.3 million inhabitants is expected to increase by 13% by 2050, intensifying the pressure on an already fragile coastline.
In its report published on January 24, 2025, the Cour des comptes warns of the increasing socio-environmental tensions in this region:
Coastal erosion: retreat of the coastline that jeopardizes homes and infrastructure.
Marine submersions and flooding: exacerbated by climate change and rising waters.
Uncontrolled urbanization: constructions in high-risk areas, lack of long-term vision.
Deficit in risk anticipation: lack of planning in development policies.
55,000 homes threatened by 2100 due to the retreat of the coastline, including nearly half in Occitanie, according to Cerema.
In the face of these challenges, the Cour des comptes calls for a redesign of coastal development policies and better risk anticipation to avoid tremendous economic and social costs.
An unsustainable cost of inaction: towards a major financial shock
If nothing is done, economic losses related to coastal risks will explode:
11.5 billion euros: value of assets threatened by rising waters by 2100.
54 billion euros: total cost of compensations by 2055, according to insurers.
Cost of maintaining protective structures: increasingly high for limited effectiveness.
Experts warn: the insurance system will not be able to absorb these losses. It is therefore urgent to invest in adaptation to limit the impact of future disasters.
Public policies still too fragmented and insufficient
Despite the existence of coastal risk prevention plans, updated after the Xynthia storm (2010), the Court of Auditors notes that:
These plans do not cover the entire Mediterranean coastline.
The risks of submersion and erosion are still underestimated in spatial planning.
Local inconsistencies persist: certain urban planning decisions contradict prevention recommendations.
The inter-municipal scale is underutilized, whereas it would be the most suitable for managing these global issues.
Problem: many municipalities refuse to transfer 'urban planning' authority to inter-municipalities, complicating the establishment of a coherent strategy at the level of living areas.
7 key measures for a more resilient coastline
The Court of Auditors proposes 7 recommendations to anticipate and better manage coastal risks:
Strengthen information for real estate buyers
Requirement to indicate the risk of value decrease of properties exposed to erosion and inundation.
Why?
Residents and investors must be fully aware of the risks before purchasing a property.
Better map the financial vulnerabilities of territories
Include in risk maps projections on destruction costs, interruption of activities, and reconstruction.
Why?
Elected officials and planners need economic data to make informed decisions and avoid risky investments.
Transfer 'urban planning' authority to inter-municipalities
Remove the ability of certain municipalities to block the transfer of the Local Urban Plan (PLU) to the inter-municipal level.
Why?
A global and coherent vision is necessary to avoid contradictory local decisions and better organize the territory in light of risks.
Make a Local Integrated Coastal Management Strategy (SLGITC) mandatory
Require the most threatened municipalities to adopt an adaptation strategy to manage coastal erosion.
Why?
Currently, planning relies on voluntarism, which slows down the implementation of essential measures.
Develop Partnership Development Projects (PPA)
Encourage a broader approach, integrating coastal municipalities and their hinterlands into risk management.
Why?
Coastal adaptation should not be thought of solely along the coastal strip. Interior territories must also be included in planning strategies.
Better utilize the GEMAPI tax (Management of aquatic environments and flood prevention)
Finance prevention and adaptation projects with an allocation more suited to the actual needs of coastal territories.
Why?
Currently, this resource is underutilized, yet it could be a driving force for implementing sustainable solutions.
Establish land agencies dedicated to coastal reconstruction
Creation of specific land structures in PACA and Occitanie to manage the purchase, resale, and relocation of exposed infrastructures.
Why?
Without a suitable land tool, it will be impossible to organize the relocation of threatened populations and infrastructures.
The State and local authorities must act now
The report from the Court of Auditors is clear: we can no longer wait. Local authorities must accelerate the implementation of adaptation strategies, and the State must structure an interregional vision to ensure an effective and sustainable transition.
The question is no longer whether we should act, but how and with what means.
Concrete solutions to support territories facing these challenges
At UrbanThink, we are already supporting several local authorities and coastal stakeholders in their adaptation strategy with ThinkCities®, our digital twin for territorial management.
Vulnerability assessment for the Camping de Kerpenhir
As part of our commitment to coastal campsites, we conducted a climate vulnerability report for the Camping de Kerpenhir, located on the Locmariaquer peninsula. Thanks to ThinkCities®, we have mapped the risks associated with marine submersions, storms, and water restrictions, while identifying concrete measures to improve the site's resilience. This analysis has allowed the manager to adopt targeted adaptation strategies, thereby optimizing the safety of the infrastructure and ensuring the sustainability of their establishment in the face of upcoming climate challenges.
Simulation and adaptation scenarios
Thanks to ThinkCities®, we have assisted Lyon Confluence and other territories by simulating various urban resilience scenarios. These tools allow us to assess the economic and environmental impacts of adaptation strategies (relocation of infrastructure, building elevation, nature-based solutions).
Energy optimization and ecological transition
Our solutions have also enabled outdoor hospitality stakeholders, such as the Domaine des Ormes, to monitor and reduce their energy consumption, a key issue for coastal campsites facing rising temperatures and water restrictions.
Data integration and real-time monitoring
We are working on projects where we connect real-time sensors (water levels, air quality, temperature) for proactive infrastructure management in coastal areas.
Thinking about the coastline of tomorrow, starting today
Coastal risks are not a fatality. With advanced technological solutions and a strategic vision, we can support the transformation of territories by combining resilience, sustainability, and proactive adaptation.
