As climate change intensifies water-related challenges, the EU adopts an increasing number of climate change adaptation measures to ensure water security. Because water systems are interconnected, isolated measures are insufficient. This paper examines both vertical and horizontal coordination of adaptation measures in EU water law. It explores wastewater reuse to evaluate coordination between the relevant EU legislation and the implementing legislation of water-stressed Malta. We show that Malta has achieved coordination by prioritizing measures that expand water supply over those reducing demand, made possible by the ambiguities in the EU regulatory framework and the soft nature of the water hierarchy.
