Decision-relevant rendering of water- supply climate-change scenarios: a co-produced portfolio

Droughts are intensifying due to climate change, yet hydrological scenarios to anticipate future water availability remain far less common than climate projections, making it difficult to translate scientific results into information that is both interpretable and operationally useful. The IT-WATER project addresses this gap by developing the first national-scale water-resource scenarios for Italy through a co-creation process that places stakeholders and their needs at the core of its methodology. Beginning with a webinar and survey in early 2025 and culminating in an in-person workshop in Bologna with representatives of water authorities, research institutions, and public and private operators, the engagement process gathered practical insights and critically reviewed proposed indices for representing hydro-climatic futures. Furthermore, efforts were focused on developing advanced visualization methods for the indicators to ensure their seamless integration into decision-making workflows and to enhance their effectiveness in supporting planning activities. The resulting shared portfolio of indices constitutes a co-designed, practice-oriented reference framework that supports the communication of climate-change impacts on water resources and informs future planning and adaptation strategies.