Protecting the barrier beach from Sète to Marseillan

Sète – France

Project leader: Sète Agglopôle Méditerranée

Dates : 2004-2019

Classification

Risks

Solutions

Actors

Costs

Summary

The barrier beach from Sète to Marseillan suffers particularly from coastal erosion (nearly 45 ha were lost between 1954 and 2000) while the 100-year storm of 1982 caused significant damage. The natural coastal erosion and the sedimentation reduction along the facilities of the Gulf of Lion are compounded by the high use of the site. To curb the increasing erosion of the coastline while preserving and developing economic and human activities that depend on it (tourism, boat traffic), Sète Agglopôle Méditerranée has implemented a set of measures integrating soft and nature-based solutions as well as the relocation of activities. The agglopôle has decided upon a strategic retreat of the coastal road by 100 meters and undertaken work to restore the beach, built a dune ridge using sand reloads, installed a swell reducing device and preserved the site’s pristine nature.

Actions

The shoreline has completely been redesigned, leading to the relocation of existing infrastructures and the creation of new assets. For instance, the coastal road was relocated by 100 metres. At the same time, car parks were installed along a safe road and walkways across the dune strip, sanitary facilities and a cycle path were designed to preserve the naturalness of the site.

Beach and dune systems were restored notably through beach nourishment operations. 

These operations were combined with the installation of a drainage system under the beach to naturally collect waters and direct them to a pomping station. By drying up the sand, drains should prevent the sand carried by the waves from being washed back into the sea.

Along these operations, a wave attenuator was installed 350 metres away from the shore to mitigate wave impacts.

Outcomes

The Sète to Marseillan beach barrier is the first site in Languedoc-Roussillon that had acted upon an adaptative approach. The idea was to adapt to the natural evolution of the site and relocate threatened activities rather than confronting the hazard. This voluntarist approach has allowed a complete rethinking of the area’s development. Local actors are now considering using the ecological potential of this site in terms of green and cultural tourism in a more sustainable way.

The restoration of the beach and the dune system have enabled the beach restoration of 70 to 100 metres wide. The wave attenuator has allowed a gain of 12 metres of beach in 3 years. In terms of human activities impacts, parking facilities are now monitored while the attractiveness to tourists and economically beneficial activities is maintained. Eventually, the project allowed the preservation of the pristine nature of the site. 

The State financed 80% of the project and the partners’ open-minded attitude throughout the project were pivotal. Local authorities have been heavily involved for ten years in the political and financial support of this major European project and the DREAL has been mobilised for its technical expertise to bring the project to fruition. The project has mobilised high-level technical and scientific stakeholders, so that it has benefited from high-level monitoring for the implementation of innovative techniques (regional universities, researchers, CETE, BRGM, etc.).

Partners

Technical partners: State, Sète agglopôle, Europe, Région Languedoc-Roussillon, Conseil Général Hérault, Universities and scientific institutions

Financial partners: FEDER, FNADT, Région Languedoc-Roussillon, Département de l’Hérault, Sam

Resources