some of the river basin authorities integrate intraregional stakeholders others function interregionally which increases the complexity and the risk for tension among the various stakeholders they have been established mainly for hydrological issues water scarcity quantity and quality aspects but are still rare for economic and financial information tariffs infrastructure financing etc source oecd water governance in oecd countries a multilevel approach oecd studies on water oecd publishing paris doi en while the strategic environmental evaluations eaes are intended to take into account the impact of prs and other regional plans on ecosystems in practice the eaes have not yet had much effect on mitigating the potential impact of urban expansion on biodiversity