Landslide dams and debris in sensitive clays of eastern Canada: review of characteristics and consequences.

Highly retrogressive landslides as well as rotational landslides commonly occur in Quebec’s post-glacial sensitive clay deposits. Due to their scale, debris from these landslides often partially or totally obstruct the watercourses along which they occur, leading to significant water retention upstream. Beyond the immediate hazards posed by the sudden release of these water masses, the resulting temporary dams cause long-term disruptions to the natural environment, sometimes lasting for decades. This paper examines several cases of landslide-induced dams in Québec, highlighting their economic, environmental and societal impacts and exploring the various ways, sometimes catastrophic, but generally gradual, in which water flow was eventually restored.