How will snow, glaciers, soil moisture and river discharge change across Italy in the coming decades? At the 2026 Water Festival, organised by Utilitalia, some of the first results from IT-WATER are being presented for the first time. Coordinated by CIMA Research Foundation, the project develops high-resolution national scenarios of water resources through 2070.
On 30 September, at the Roma Convention Center La Nuvola, IT-WATER – High-Performance Computing of Future Drought and Water Resource Scenarios in Italy is featured in the session “A New Water Balance in a Changing Climate”, dedicated to the impacts of climate change on water systems and to the tools that can support planning, safety and resilience.
Luca Ferraris, President of CIMA Research Foundation, and Edoardo Cremonese, drought expert at the Foundation, open the presentation of the project results.
IT-WATER is coordinated by CIMA Research Foundation in partnership with Agenzia ItaliaMeteo and Fadeout Software and is funded under Italy’s National Recovery and Resilience Plan (PNRR) within the National Centre for HPC, Big Data and Quantum Computing.
From climate to the water cycle
The project represents a step change in scale by combining high-resolution climate scenarios, physically based models of the water cycle and high-performance computing capabilities to build a consistent representation of the future evolution of water resources across Italy.
Using CIMA Research Foundation’s models S3M, which simulates snow and glaciers, and Continuum, which simulates hydrological processes, climate scenarios are translated into information on what happens to water once it reaches the land surface.
This means looking not only at how temperature and precipitation will change, but also at how much water will be stored as snow, how snowmelt will evolve, how glaciers may change, how evapotranspiration and soil moisture will vary, and how much water could be available in Italy’s major rivers. This information can be analysed at different spatial scales, including regional and major river-basin scales.
First results: snow and glaciers
The first results presented at the Water Festival show that water resources stored as snow could decrease across Italy, with reductions reaching around 50% or more at elevations below 2,000 metres.
This is a substantial decrease, particularly considering that elevations between 1,500 and 2,000 metres account for most spring snowmelt, when the irrigation season begins. The largest decreases are expected in the Apennines, due to their greater vulnerability and lower elevations compared with the Alps.
Regarding glacier water resources, the results show a marked decline under both scenarios considered. In the Aosta Valley, for example, projections to 2070 indicate that glacier water resources could be halved even under the scenario consistent with the Paris Agreement. Similar, or even more pronounced, changes are projected for the other glacierised regions of northern Italy.
IT-WATER will also provide maps of evapotranspiration, soil moisture and river discharge at the main outlet sections of Italian rivers. Taken together, these outputs will provide a comprehensive picture of the water cycle across the entire country, at a spatial resolution of 200–500 metres.
Information to support water management
The indicators were not defined solely within the scientific community. Throughout the project, more than thirty representatives from institutions, research organisations, water utilities, and public and private operators were involved, highlighting three recurring needs: more robust data and monitoring, effective decision-support tools, and more integrated approaches to water management.
“The challenge is not only to know how the climate will change, but to understand what those changes will mean for the water that will actually be available to us,” says Luca Ferraris, President of CIMA Research Foundation. “With IT-WATER, we bring future climate scenarios into the water cycle, connecting the dots so that those responsible for managing water resources can plan, adapt and make decisions.”
The work has also required significant computational capacity: simulations using snow and hydrological models have been transferred to High-Performance Computing (HPC) infrastructures, making it possible to continuously and consistently reconstruct the different components of Italy’s hydrological cycle and explore how they may evolve in the future.
The project’s outputs will include the publication of a dataset on Italy’s water resources covering the period 1980–2070, together with a portfolio of impact indicators developed with stakeholders. The dataset is scheduled for release in early 2027.
“In a context where the impacts of climate change are increasingly affecting water availability,” explains Annamaria Barrile, Director General of Utilitalia, “it is essential for water service operators to be able to rely on a broad, comprehensive and reliable data base. From this perspective, long-term projections are a key element in planning interventions and, consequently, investments.”
The presentation at the Water Festival therefore represents not only an opportunity to share the results of a scientific project, but also a step towards addressing a question that is becoming increasingly important for Italy: how can we use today’s knowledge of tomorrow’s climate to manage a resource that is already changing?
