Navigating Centralized Waters: Analyzing the Supply of and Demand for Spatially Differentiated Implementation of the EU Water Framework Directive in Greece

EU environmental legislation purposefully introduced spatially adapted governance layers based on the biophysical boundaries of environmental problems, e.g. river basins, and advocated stronger decentralization of decision-making and implementation. Such regulatory flexibility facilitates responsiveness to diverse local conditions and provides scope for spatially differentiated implementation not only between member states but also within them. Despite renewed attention from EU scholars on differentiated implementation, systematic theoretical and empirical knowledge on differentiated implementation within member states is limited. While spatial differentiation is likely to favor federal or regionalized member states, as they are already more accustomed to cross-level functional cooperation, it remains unclear how centralized polities respond to the need for spatially differentiated implementation. This paper addresses this puzzle by focusing on the implementation of the Water Framework Directive in Greece, a highly centralized member state that nonetheless exhibits strong variation in geographical and environmental conditions. It uses embedded sub-cases of River Basin Districts and analyzes the factors that enable or constrain spatially differentiated implementation. Analytically, it introduces a novel framework that captures the interplay between demand, the need for localized, tailor-made solutions to policy problems, and supply, the legal and institutional opportunities set by the central government and the transposed directive. Drawing on document analysis and semi-structured interviews, our analysis explores whether and under what conditions regional and local adaptation are enabled, ultimately, contributing to broader debates on the compatibility between EU and national regulatory frameworks.