The reality that climate change inevitably affects our world at present is taken into consideration and adaptation to climate change studies are becoming more pronounced at international scale. Although there are some studies related to the determination of adaptation measures in our country and in the world, there is still no common methodology for adaptation on a measurable basis. In this study, a new approach developed under the “Effects of Climate Change on Water Resources Project” was used to execute a sectorial vulnerability analysis. Sectorial vulnerability analyses have great importance in terms of determining the most vulnerable sector to climate change and of the related policy. In this study, the methodology of sectorial vulnerability analysis is explained in water intended for human consumption sector for 2060s and at the scale of Büyük Menderes River Basin. The results showed that the impact level was expected as “medium” for the water intended for human consumption sector.