Résumé
This water accounting study investigates the dynamics of basin closure in Morocco's Oum Er Rbia basin. It highlights how water and agricultural policies, including dam construction, conservation programmes, agricultural intensification and ever expanding supplies to cities and industry, led to wate scarcity. Reversing this trend requires curtailing demand and balancing economic development with ecosystem health. This explains why integrating water circularity principles (reduce, reuse/recycle, regenerate) at basin level is arduous. Local water circularity initiatives may even decrease return flows and increase water use. Water accounting is, therefore, essential to understand complex trade-offs for basins heading for closure.