Many large-scale hydropower systems utilising ultrahigh arch dams have been built in China over the past decades. The construction and operation of these giant power plants may perturb and destabilise the surrounding rock slopes, threatening the safety of hydropower systems and human habitats. In this project, we conduct scientific investigations into the mechanisms that govern the long-term behaviour of meta-stable rock slopes in Chinese hydropower systems and develop predictive approaches to forecast their future performance over the lifespan of hydropower plants. We carry out field monitoring, computer simulation and laboratory experiment to study the processes leading to irreversible deformation and progressive destabilisation of these rock slopes under natural and human activities. Our research stems from the urgent need for practitioners to have enhanced predictive capabilities regarding future geohazards in hydropower systems. This demand has recently come to the fore in China, where hydropower development has started to pass its rapid construction phase and shift to the lengthy operation stage. We also view this project as a uniquely situated stepping stone from which the Swiss researchers transfer related experiences gained from European Alps studies to the investigation of Earth’s surface processes in mountainous areas of China.