Water Scarcity in Coastal Areas of Sweden : Assessment of water availability and reservoir sensitivity in Vindö, Värmdö municipality, based on climate change scenarios

Sammanfattning: A groundwater assessment of north Vindö in Värmdö municipality has been conducted using a spatial analysis tool that is under development. Vindö is a coastal community characterized by surfaced-, or shallowly covered crystalline rock. Water testing in the area implies that over extraction takes place in several locations as 30 % of the private wells in the area show increased concentration of chloride, pointing towards saltwater intrusion. The tool is based on the theoretical background of the GW-Bal program and provides the user with visual maps presenting reservoir water content on a pixel basis. The assessment is made in the lights of projected climate change for Stockholm County, presented by the United Nations International Panel for Climate Change in their 5 th assessment report released in 2013. The results show a large spatial variance in remaining water content over the year. Many areas remain intact even over the summer season when the inhabitants of the community triples, and some areas show severe reservoir water content impact already in the beginning of the season. Further, the results show that the localization of the wells plays has more significance to the reservoir water content than the specific climate scenarios. The study points to the need for the spatial aspect in groundwater assessment, especially in areas where aquifer quality is sensitive to unbalance and the supply heterogeneity is great – such as in coastal areas with reservoirs in crystalline rock.