After having adopted the UN Sustainable Development Goals (SDGs) in 2015 including once again the right to water (rtw) for all by 2030 implementation issues are growing in importance now. It is widely acknowledged that even EU Member States, in general, are faced with this challenge. However, any implementation of the rtw requires a sound specification first. Since the rtw commonly refers to enabling sufficient “access” to water the crucial question here is under what conditions “access” ever might be “denied”. Up to now, little progress has been made to give a clear and convincing answer to this question. This article offers an innovative analytical framework of “sustainable access” taking explicitly into account potential barriers to access that may or not refer to sustainability requirements themselves. Thus, social concerns are confronted with aspects of functionality. This allows for an explicit assessment of water supply situations with respect to the rtw in an overall sustainability framework which is particularly in line with the SDG approach.