Hydroelectricity, generated by harnessing the power of moving water, is France’s main source of renewable energy. To ensure hydropower energy is generated safely across the country, we conducted hazard studies of 40 hydro dams operated by Électricité de France (EDF). This involved conducting preliminary risk evaluations and detailed analyses of complex hydropower facilities on the Rhine River in line with French hydropower safety regulations, including a hydroelectric factory, mobile dam and locks, from the French Alps and the Pyrenees to French Guiana. We also held risk evaluation meetings with EDF and wrote dam safety reports, working with the client to ensure the reliability and safety of what is fast becoming one of the country’s most sustainable energy sources.