Understanding the historical context of rainfall erosivity enhances comprehension of climate and environmental changes, guiding strategies to address global environmental challenges. However, the understanding of the interplay between modern-era environmental hydrology, climate change, and storm evolution remains limited, despite the pivotal role of storm disasters in global environmental change, especially in inland-basin areas. To address this knowledge gap, we present the longest interannual rainfall erosivity history in France, with a specific focus on the area of Clermont-Ferrand, covering the period 1858-2022. Using the Integrated Rainfall Erosivity Model (IREM) approach, refined with process-based insights and expert knowledge, we analyzed the erosivity data and correlated them with environmental and climatic changes. Our findings indicate a rapid and abrupt change in rainfall erosivity around 1964, which we attribute to the negative phase of the North Atlantic Oscillation and a positive phase shift of the Dipole Mode Index. Moreover, the Mann-Kendal statistic demonstrates a significant positive trend in extreme rainfall erosivity (95th percentile) over the entire time-series. A notable finding is the strong coevolution observed between the erosivity density indicator and particulate organic carbon, modulated by multidecadal environmental hydrology in the Rhone River Basin (RRB). These results shed light on the complex interactions among storms, climate, and sediment organic matter, offering insights for environmental management and conservation strategies in the RRB and other regions with similar hydrological characteristics.