Valley-blocking landslides are comparatively common in the deep and narrow glaciated valley of the Italian Dolomites. There are numerous instances of such landslides in the historical record, and some that have survived to the present day (i.e. have not been overtopped, of if overtopped, have not been removed) with a surviving lake. The hydraulic head differential across these dams, or dam remnants, is frequently exploited for hydroelectric power generation. The paper gives a review-of some landslide dams in the course of the rivers Piave, Cordevole and Tagliarnen to and in-an abandoned former course of the river Piave, showing how the river morphology is modified by landslide dams, and how-this facilitated the development of hydropower there. The paper considers the survival of landslide dams to the present day, and the factors that give rise to that survival.