Vertical fit of water governing systems: A regional assessment

To promote environmentally sustainable water governance, this study emphasizes the necessity of aligning institutional structures with ecological scales. The research focused on the Urmia Lake Basin in Iran facing the serious problem of drying up. Beyond the political and economic determinants shaping the water governance system in the region, the study evaluated the effect of Urmia Lake Restoration Program (ULRP), an environmental movement, on the basin's water governance structure. Employing statistical mechanics methods to scrutinize Hamiltonian system costs related to administrative interactions for water supply-demand, the study assessed the structural fit of the water governance system to the basin across distinct stages: without- and with-including the ULRP. Results revealed diminished costs following ULRP involvement, notably in entities with higher water demands, head offices and the system overall, further improved by water-saving measures. These findings highlighted the efficacy of vertical (re)arrangements and structural reform through ULRP incorporation in enhancing system fit, stressing the significance of its water-saving policy. The methodology provides a fast and explicit scan of the system structure, demonstrating its ability to project the effect of institutional reforms on the system state. Serving as a constructive tool for policymakers, it facilitates rapid, efficient and informed decision-making in water governance. Furthermore, following the UN SDG 6, this framework supports integrated water resources management (IWRM) across sectors and regions, particularly targeting water-stressed contexts.