Since the adoption of dramatic national water policy reforms in 1992, Mexico's water governance paradigm has had time to mature. This article analyzes Mexico's experience with water policy transition, based on research in irrigation districts and river basin councils in the northwestern state of Sonora. I examine the trajectory of the water policy transition using the policy sciences framework set forth in the introductory article. The article argues that the transition to a "new culture of water" focused on the three principles of efficiency, decentralization, and sustainability has only minimally fulfilled its goal of establishing a new state-citizen relationship around water policy. Multiple and conflicting agendas are represented in the water policy, and a coherent governance strategy that is sustained over time and place has not been achieved. In particular, legal modifications to the national water law that emphasize integrated watershed planning and local participation were approved in 2004 but have never been formally implemented. Political fragmentation and changing of parties in power has contributed to the challenge of working towards a more democratic, participatory water policy over the last two decades. The article concludes with a critique of the policy sciences approach in the context of the Mexican case and that of other "developing" countries.