Fregnoley Galery (Switzerland) - Singular Structures

The "Galerie Fregnoley" refers to a planned covered gallery (a protective tunnel-like structure) designed to span the torrent du Fregnoley in the Val de Bagnes, located in the canton of Valais, Switzerland.

This infrastructure project aims to secure road access between Champsec and Lourtier by protecting against recurrent debris flows (known as "laves torrentielles" in French), which are rapid mixtures of water, mud, rocks, and earth—essentially avalanches of earth and rock as described in the query. The area around the torrent has a history of such events, triggered by heavy rainfall, snowmelt, or geological instability, often linked to climate change effects like permafrost degradation.

The State of Valais, in collaboration with the Department of Mobility (SDM), is planning to build a road tunnel and raise the dykes above it to channel the Fregnoley torrent and prevent future torrential lava flows.