River landscapes were largely used for energy generation. Along the 20th century, two forms have particularly marked creating new landscape archetypes : large dams and their reservoirs ; nuclear power plant and their cooling towers. The first should created “mirror lake”, the second “cathedral of the 20th century”, as conceived by the impact studies. Each time such equipment is built, some landscapes disappear, and others are constructed. These great works produce debates and conflicts taking part in the construction of landscapes. There are two processes : negatively, the mobilisation and the discourses “anti” bring a recognition of aesthetic and ecological values ignored. Positively, they create new forms and new practices that can bring ...