Water Law in Circular Economy: Ultra Vires Actions in Environmental Sector, or when Union Ambition Far Exceed its Abilities

Water management has an important role to play in the circular economy transition, through the water treatment and reuse. Its optimal and coherent regulation is also of vital common interest, since water knows no borders or lines artificially set out by the States and the dramatic overconsumption and pollution of freshwater are threatening irreparable damage to the world's ecosystems. However, States are reluctant to common regulations, which would have important economic impacts. International and regional organizations face with the fundamental principle of permanent sovereignty of States over natural resources. By analysing the European environmental competence, this study examines the role of Union water law in green economic transition. By investigating the interdependent relationships between the several elements of the water management, the essay suggests that territory use and economic town and country planning would be drawn into the scope of Treaties because of the integrated nature of water services. The case of water reuse illustrates limits and perspectives of the European objective to promote rational utilization of natural resources and combat climate change, introducing the idea according to which freshwater is a European res communis on which the sovereign right of European Union Member States over their own natural resources could be lawfully limited.