In 2025, water resources declined compared to 2024. ISPRA monitors and updates their evolution
Precipitation and water availability data
In 2025, total precipitation in Italy amounted to 963.4 mm (approximately 291 billion m³), a decrease of about 9% compared to 2024, which was a particularly rainy year. However, 2025 shows a slight increase of 2% compared to the average annual precipitation for the 1991–2020 period, the most recent climatological 30-year period, which amounts to about 285 billion m³.
In 2025, renewable water resources—defined as precipitation minus losses due to evapotranspiration—were estimated at around 128 billion m³. This represents a decrease compared to historical averages: more than 7% lower than the long-term annual average (about 138 billion m³), 4% lower than the average of the most recent climatological 30-year period, and approximately 19% lower than in 2024.
The current update of the hydrological balance therefore continues to confirm the negative trend observed from 1951 to the present, particularly with regard to the availability of renewable water resources at the national level.
This, in summary, is the overall picture emerging from the assessments produced by ISPRA through the BIGBANG model, which provides estimates of the components of the national hydrological balance, the quantitative framework of water resources, and, more generally, the hydrological situation in 2025, by analyzing trends and deviations from the long-term average values for the period 1951–2025 and the climatological 30-year period 1991–2020.
The detailed assessment will be presented on March 24 during the workshop “Hydrological balance and water resource availability: 2025 update, seasonal forecasts and climate projections” organized by ISPRA on the occasion of World Water Day
Maria Alessandra Gallone, President of ISPRA and SNPA:
“Faced with the data before us, we can neither postpone nor resign ourselves—we must act in a proactive and forward-looking way. Water is a national priority, and ISPRA will help raise awareness through its scientific system, strengthening the culture of water resource management and supporting institutions and local territories. It is essential to inform people about how to reduce waste, promote a culture of sustainable water use, and encourage the reuse of wastewater. The mission of ISPRA and its community of scientists and technologists is prevention through monitoring systems, helping to protect what we have and to plan with determination. The data speak clearly and provide a solid basis for guiding decisions in this direction.”
Additional data emerging from ISPRA monitoring for 2025
March 2025 was the wettest month (114.3 mm), with a positive anomaly of +48% compared to the long-term average for 1951–2025 (77.3 mm), followed by November (just over 95 mm), typically among the wettest months, which, however, recorded a –20% deviation from the long-term average. July and August, generally the driest months nationwide, instead showed a surplus in precipitation of 35% and 42%, respectively, compared to long-term averages.
At the district level, the largest deficits compared to the most recent climatological 30-year period were observed in the Southern Apennines District (–10% precipitation and –21% water resources) and the Central Apennines District (–7% precipitation and –30% water resources). In the Sardinia and Sicily districts, water resources decreased, with deficits of –12% and –13%, respectively. In central-southern Italy and the major islands, drought conditions persisted, although less severe than in previous years, still leading to issues related to water scarcity and the ability to meet human and ecological water demands.
Managing water sustainably—a resource as valuable as it is vulnerable—requires continuous and systematic monitoring, along with analyses of its spatial and temporal distribution, in order to provide a timely and comprehensive picture of its current and future availability from a forecasting perspective. Adequate knowledge bases are essential to effectively guide water management policies and to protect ecosystems and the services that depend on them.
The ISPRA national hydrological balance model is one of the tools that supports decision-making. The BIGBANG model not only provides useful and reliable information for identifying critical issues across the entire national territory, but also serves as a knowledge tool to support the definition of prevention and adaptation measures necessary for the sustainable management of a precious resource in a context that is continuously evolving, also due to climate change.