ECOLOGICAL FLOWS AS A DRIVER FOR FUTURE HYDROPOWER DEVELOPMENT

At the intersection of environmental protection and energy transition, Italy is called tofind new approachesto safeguard river ecosystems while modernizing its hydropower infrastructure. Achieving this balance under the new Ecological Flow (EF) framework requires integrated strategies that reconcileecological integritywith energyefficiency.This study evaluates the eco-hydrological and operational implications of redefining EFs for run-of-river (RoR) plants, exploring synergies between new EF regimes and potential plant re-powering through increased maximum water abstraction capacity. Focusing on three Alpine rivers (Ayasse, Brenve, and Savara), EF design was based on the mesohabitat simulation model (MesoHABSIM) and on the Habitat Integrity Index (IH), an ecologically meaningful indicator composed of five quality classes. Hydropower performance was assessed by computing the corresponding total volume of water diverted to turbines.Results showed that improving habitatquality from “Bad” to “High” requiredbase flow (BF) increases of 1.6-9.4 times current rates, reducing diverted water volumes by 8-28%. However, coupling higher BF with expanded water abstraction capacity enhancedhydropower production by 124-169% while preservingriver ecological integrity. This framework supports the design ofRoR configurations that harmonize ecological sustainability, economic feasibility, and climate resilience.