This chapter analyses adaptive management and its compatibility with the rule of law, legal system, and judicial protection in the EU in its Water Framework Directive (WFD). First, post-regulatory rule-making and the Common Implementation Strategy are explained, as is the Court of Justice of the European Union’s Weser ruling (the Weser case) and the system of river basin management plans with its quality elements. With the example of the legal system of Finland, the chapter describes the four ways in which further congruence could be found in this science and law interface where scientific uncertainty and learning meet the requirements of judicial review and judicial protections. The non-deterioration principle appears to be of greater importance in EU water governance than the good status objective, though as legal norms, both are central. The roles of compensation or restoration mechanisms are discussed, too, as are temporal aspects and spatiality of the integrated and holistic water management. The chapter concludes by focusing on the rule of law mechanisms entailed by adaptive law or adaptive governance, positing that even in a legal system where judicial review in courts is broad and in-depth and where scientific uncertainty and science in court are analysed with the help of in-house expert judges, the expertise is not enough to secure access to justice in EU water governance. In sum, the continuum of normativity that the EU WFD has created continues to pose a challenge to the legal systems in the Member States and in the EU.