Traditional hydropower creates a number of adverse environmental effects, nowadays largely recognized but still in conflict with rights granted in previous era of development. The Upper Rhone River basin is heavily developed for hydropower generation. As this region undergoes a period of new concession grants, environmental legislation should eventually be implemented to its full extent. This turning point also allows changes in dams' ownership and institutional setting, and these aspects attract much of the political attention. The article compares the US hydropower regulatory framework and the country's experience in dam relicensing to highlight shortcomings in the Swiss regulatory framework and possible outcomes of the concession reversion process in Canton Valais.