Discharge dynamics in snow-dominated environments are still poorly understood. Stable water isotopes have become popular to study spatial and temporal dynamics of discharge but this remains challenging in high Alpine environments, especially during winter. In this paper we present a new detailed stable water isotope data set from a Swiss catchment located between xx and xx m asl. (xx km2), covering two entire hydrological years, including winter. We discuss in detail what we can learn from the isotope data set that we cannot learn from discharge gaugings along (at the outlet, along the stream) or from electrical resistivity measurements.