Le Signal's collapse and coastal erosion

Le Signal, a building in Soulac-sur-Mer, France, collapsed due to coastal erosion, with its distance from the ocean shrinking from 200 meters to less than 20 meters in less than 40 years. This event highlights the growing threat of coastal erosion in the region.

Erosion forces evacuation and demolition

The erosion of dunes submerged 180 meters of land between 1967 and 2023, leading to the evacuation of 75 co-owners in 2014 without compensation from the Barnier fund. The building was finally demolished in early 2023 after a decontamination process in 2019.

Construction and early confidence

In 1965, the prefect of the Gironde issued a building permit for Le Signal, a four-floor residential project with 78 apartments and a view of the Atlantic. At the time, the building was 200 meters from the shore, considered a safe distance from the ocean.

Unexpected erosion and early warnings

By the 2010s, the ocean began touching the base of the dune on which Le Signal rested. High tides made the erosion visible, turning a theoretical concern into a tangible threat that forced the eventual evacuation of the building’s residents.

Coastal erosion rate and its impact

The coastline of Soulac-sur-Mer experiences an average retreat of 4 to 8 meters per year, much faster than other parts of France. Over decades, this erosion led to the disappearance of 180 meters of dune, making the building's collapse inevitable.

Efforts to combat erosion

Mechanical sand movements reduced the erosion rate by three times but failed to provide long-term protection. In response, a massive hydraulic recharge project moved 200,000 cubic meters of sand from the Gironde estuary at a cost of 2.9 million euros, though it came after Le Signal's destruction.

Evacuation and legal challenges

A series of storms in 2013-2014 led to the evacuation of the 75 co-owners. They sought compensation through the Barnier fund but were denied by the Constitutional Council and the Council of State, leaving them without financial support for their now-uninhabitable homes.

Demolition and future implications

The building was demolished in early 2023 after a decontamination process. Its collapse is part of a larger trend, with 5,200 homes potentially threatened by 2050. Public authorities have expanded urban planning regulations to 371 communes to address coastal retreat, recognizing the increasing risk to coastal areas.