Multicriteria Analysis for the Assessment of Flow Release Scenarios from a Hydropower Plant in the Alpine Region

The Alpine region is an area of conflict between the significant demand for hydropower (HP) generation and the protection of landscape and aquatic ecosystems. Decision Support Systems, like multicriteria analysis (MCA), represent suitable tools to support decision-makers and stakeholders in managing the use of water resources in a more sustainable way. Based on a set of “quality indexes” identified in a previous study, the present paper analyzes the use of MCA in a real case study of HP sustainable management in Aosta Valley, one of the most important Italian regions for HP production. The Simple Additive Weighting (SAW) methodology was applied to quantify the flow to be released by an existing HP plant, in order to balance production needs and watercourse environmental conditions protection considering four criteria (Energy, Environment & Fishing, Landscape, and Economy). The decisional process was developed within a collaborative and participatory framework, involving key stakeholders in every decision-making step, and the obtained results were officially adopted by the Regional Government. In the paper, some innovative aspects of the case study are presented and discussed, like the elaboration of reactive indicators related to the watercourse discharge, progressively updated with the stakeholders along the process, and the definition of “real-time” alternatives, relating the flow releases to the natural discharges in the watercourse. Finally, some weaknesses of this MCA approach are identified and suggestions for improvements in future experimentations are proposed.