This study has monitored the ecological response of the Spöl River, Swiss National Park, to experimental high flows since 1999. The Spol flows from Livigno Reservoir, where the stored water is used for hydropower generation. Two high flows are implemented in spring and autumn each year to mobilize bed sediments and improve the ecological integrity of the river. Monitoring has included redd counts of brown trout, macroinvertebrates, periphyton and water physico-chemistry at periodic times during each year. Specific projects have focused on individual flood responses (before, during, after floods), long-term sediment dynamics, longitudinal response patterns, food webs and whole ecosystem metabolism.