Adaptation is a significant human response to climate change. Adaptive capacity is an evolutionary process; it requires planning and implementing effective strategies, adjusting against the emerging climatic conditions, and hence promoting accumulated knowledge and new and modern technologies against future environmental risks, such as in the water resources management sector. This chapter provides an overview of the main European Union (EU) water-related policies and their linkage to climate change adaptation strategies. It, further, demonstrates the importance of Integrated Water Resources Management. Particular emphasis is placed on the evolution of the EU adaptation strategy to climate change and on the guidelines on mainstreaming the adaptation policy into water sector measures and actions at the national scale. A roadmap for the implementation process of the National Adaptation Strategy and National Adaptation Plans in Greece is provided as an indicative case study. Finally, the current and potential obstacles that could jeopardize the process of integration of adaptation into the EU environmental policy are also discussed.