Risks of Future Droughts and their Impacts on Scottish Private Water Supplies

In recent years, Scotland has been experiencing lower-than-average rainfall in the spring and summer seasons leading to water scarcity in many parts of the country, especially during the summer months. Climate change is likely to exacerbate these dry conditions even more in the future, presenting significant risks to water resources management. Businesses and households, especially those relying on Private Water Supplies (PWS) in rural areas, such as boreholes and springs, have already observed noticeable changes in the quantity and quality of water during the dry periods. Around 3.5% of the Scottish population relies on PWS which includes households, industries, agriculture, and the tourism industry. This study aims to project future drier periods from 2041-2080 across Scotland on a 1-km grid, using the Standardised Precipitation and Evapotranspiration Index and the observed meteorological data from 1981-2020 as the baseline. Results suggest low to extreme drought conditions in all 1-km cells , with increases in dry conditions likely to be highest in the eastern parts of Scotland, showing a distinct spatial variability in drought characteristics across Scotland. In future work, past and future drought occurrences will be linked with the water quality characteristics of PWS to understand the likely impact of future droughts on Scotland’s water security. The water quality dataset has been made available from the Drinking Water Quality Regulator for Scotland for the period 2006-2020 for nearly 6000 PWS locations. These PWS have been monitored twice a year on an average for their water quality. They span across 25 administrative areas in Scotland and represent roughly 27% of the total PWS in Scotland.  Water quality variables such as faecal coliforms, E.coli, iron, turbidity, lead, pH, colour, nitrate and phosphate will be included in the analysis to facilitate planning for effective, resilient water resources management and ensure access to clean water to maintain health and livelihoods.