This chapter examines water security in the Barents Region and highlights the reciprocal and changing relationship between water security and the diverse dimensions of human security. Climate change, human activity, and globalisation exacerbate water security across its four dimensions. The availability of water is determined by assessing the quantity and quality of water that is produced, stored, processed, and distributed. Groundwater assessments and studies should also be conducted to determine the quantity and quality of groundwater resources and to establish a baseline. Abandoned mines also leach toxic waste into the environment and contaminate water resources, adversely impacting human health. As the Arctic warms, human activity is changing as well. Dynamic shifts such as demographic trends, globalisation, mining, resource development and shipping are increasing water insecurity in the Barents Region. In the Barents Region, there is a great need for more data regarding hydrological characteristics of Arctic rivers and watersheds, and for improved measurement of precipitation.