Swiss village of Blatten deemed too risky to rebuild after massive landslide

The canton of Valais has announced that the hamlet of Ried, Valais, and parts of the municipality of Blatten (Lötschental) in Switzerland will not be rebuilt, following a massive landslide on 28 May 2025 that destroyed most of the village. Approximately five and a half months after the disaster, authorities revised the region’s natural-hazard map, placing 70% of the municipality in the highest-risk “red zone” where construction is no longer permitted. 

The landslide, triggered by the collapse of the Birch Glacier and failure of adjacent mountain slopes above Blatten, buried most buildings and infrastructure in the alpine settlement. In light of the event, the cantonal government determined that the former village center and surrounding areas are no longer safe for habitation or reconstruction. 

The classification comes after comprehensive geological surveys and hazard assessments conducted by cantonal authorities. The announcement allows the municipality to begin updating its land-use and planning regulations accordingly. Due to the catastrophic scale of the debris deposit, comprising rock, ice, and soil tens of meters thick, traditional rebuilding has been ruled out for large portions of the site. 

Residents of the hamlet of Ried and the upper valley face a long-term relocation process. The new hazard map identifies the former settlement zone as subject to dynamic instability, frequent rockfall, and potential secondary failures. While heritage and community leaders are exploring options, reconstruction on the original footprint is considered unsustainable and unsafe.

Authorities emphasized that the decision reflects evolving science in mountain-hazard management, especially as warming climates and glacier-rock interactions increase slope instability. They stressed that rebuilding efforts would now focus on alternative, safer locations within the valley or relocation outside the highest-risk zone.