Efforts to improve the efficiency of irrigation systems in areas which suffer from water scarcity have often failed to reduce water demand owing to the constant expansion of irrigation. Andalusia, in southern Spain, is a clear case in point, as the
publicly funded programs aimed at improving irrigation put forward since the 1990s after recurrent episodes of drought have not been able to meet agrarian demand. This situation has generated an active debate among stakeholders and public managers.
This study aims to investigate the role of public opinion in this debate, as demanded by new water governance models, embodied in the Water Framework Directive. We use the results of a representative annual survey in Andalusia between 2004 and
2013. First, we analyze the evolution of public support for the two most costly public measures: constructing reservoirs and improving irrigation. Second, we analyze some attitudes that may have affected a change in public opinion, including institutional
trust and environmental concern. The results suggest that the public legitimizes the administration's bid for more efficient irrigation systems, essentially for environmental reasons. However, should attempts to control water demand continue to fail, support
for this measure may be withdrawn.