Gradually differentiate opportunity costs by region to reap the full benefit of the instrument. In parallel, the definition of special conditions under which the opportunity cost module would come into play could be devolved to river basin organisations, for instance the Flood Control Offices. Engaging stakeholders at national and local levels is essential, while providing them with robust economic analysis of the (implicit) budgetary, economic and social transfers associated with the three instruments under review'. Equity issues deserve particular attention, to ensure that no particular basin, industry or water user can abuse from a privileged condition.