Diversity challenges the pan-European assessment of drought impacts on public water supply

Droughts degrade water quantity and quality. They affect multiple sectors, and public water supply is among the most impacted sectors due to its essential societal role. Despite evidence that drought can disrupt household supply, impacts on public water supply remain less systematically studied. Understanding the sector’s vulnerability to drought is crucial for safeguarding drinking water and informing adaptation strategies. Here, we analyse text-based records from the European Drought Impact Database (EDID) to evaluate the occurrence, diversity, and severity of drought impacts on public water supply. We assess temporal and spatial patterns across Europe and examine relationships with potential vulnerability factors, including climate, population density, water management, and groundwater’s contribution to national supply. Reported impacts range from minor demand-management measures to severe supply interruptions and emergency provisions. Impact reports often extend beyond drinking water and mention prioritization issues affecting multiple sectors. The EDID severity scoring system differentiates three severity levels, providing a semi-quantitative measure of drought effects. Extremely severe impacts are more frequent in Mediterranean regions, while central and northern Europe show predominantly moderate to severe impacts. While refinement and further testing are needed, this approach offers a first harmonized framework for quantifying impacts, establishing a baseline for cross-country comparisons, and supporting targeted, adaptive water-management strategies across Europe.