Time-series of groundwater recharge, Tiber Riber Basin, Italy from 801 CE to the present day

Groundwater, essential for water availability, sanitation, and achieving Sustainable Development Goals, is shaped by climate dynamics and complex hydrogeological structures. Here, we provide a time-series of groundwater recharge from 801 CE to the present day in the Tiber River Basin, Italy, using historical records and hydrological modelling. Groundwater drought occurred in 36% of the Medieval Climatic Anomaly (801-1249) years, 12% of the Little Ice Age (1250-1849) years, and 26% of the Modern Warming Period (1850-2020) years. Importantly, a predominant warm phase of the Atlantic Multidecadal Oscillation, aligned with solar maxima, coincided with prolonged dry spells during both the medieval and modern periods, inducing a reduction in recharge rates due to hydrological memory effects. This study enhances understanding of climate-water interactions, offering a comprehensive view of groundwater dynamics in central Mediterranean and highlighting the importance of the past for sustainable future strategies. Leveraging this understanding can address water scarcity and enhance basin resilience.