This study aimed at achieving an organizational solution for improving the governance of water and land use and, consequently, improving the supply-demand water balance. Related modeling applied to diverse scenarios focus on water and land use development in the Mendoza River basin. A strategic analysis of water organization was performed using causal analysis, producing a Strategic Map (SM) and designing a Balanced Scorecard (BS). To assess the basin's water resources supply and demand, the Water Evaluation and Planning (WEAP) model was applied to the Administrative Management Units existing in the basin, taking into consideration the water availability and the granted water rights. The application of the organizational and governance model to various scenarios referring to 2030 show that by reordering allocations and water use criteria, implementing a better farm irrigation water management, improving capacity building of existing human resources, and adopting more adequate hard- and software for dams and canal management, it will be possible to accommodate demand in 2030 better than at present despite climate change impacts on demand and supply. In addition, users' participation will be enhanced.