Mapping drought impacts to municipal water supply in Sweden using news media and text-mining

Climate change is expected to increase the risk of drought in parts of the Nordic region. Although the region is considered water-rich, events such as the 2018 European-scale drought have shown that the combination of warm temperatures, low rainfall, and growing household water consumption during the summer season can put pressure on municipal water systems and cause seasonal water shortages. In Sweden, where water management is largely decentralized, there is currently no long-term or national-level overview of the impacts of drought on municipal water supplies. To create this spatiotemporal overview, we used public communication on water savings and water use restrictions, which are the most common municipal responses to drought and are typically published in Swedish news outlets. We extracted the dates, locations, and cited causes of the water use reduction measures from approximately 10,000 articles published between 2006 and 2025, applying both simple (keyword-based detection) and advanced text-mining methods (Large Language Models (LLMs)). While simple approaches were sufficient to extract locations and dates, LLMs performed better in classifying the causes of the demand-management measures (e.g., meteorological, hydrological, anthropogenic drought). The results show that around 50% of Swedish municipalities implemented demand-reduction measures in the summer of 2018 due to prolonged dry and warm weather. In 2023, a dry start of the summer and precautionary measures caused 20% of the municipalities to adopt such measures. Overall, dry weather, high temperatures, low groundwater levels, as well as high water consumption, water systems reaching maximum capacity, and precautionary principles were among the most common reasons for municipalities to issue water use restrictions. These results not only demonstrate the potential of text-mining approaches to uncover drought impacts to water supply, but also highlight the human dimension of drought. They can thereby inform drought risk management and solutions to ensure more robust and sustainable water supplies in the future.