IIVQIn France, they envision a situation similar to what is happening in #Blatten. The Ruines de Séchilienne (https://fr.wikipedia.org/wiki/Ruines_de_S%C3%A9chilienne) have been "hanging" since 1983, with a nearby village being evacuated in 1997-2011, and a tunnel (https://www.openstreetmap.org/way/571566159) dug to divert the river Romanche in the event of a blocking landslide.
The main reason for this tunnel are the #Jarrie and #Point-de-Claix chemical plant sites. The tunnel as dug is not enough to evacuate the entire #Romanche river in spring (when it's at it's highest levels), but gives enough leeway to have three days to evacuate those sites of chemicals before a burst dam could do damage. The Point-de-Claix site was recently in the news as #Arkema is leaving it behind, the Jarrie site has railroad-style warning lights for "Gaz Toxique" (toxic gases). Scary.