This chapter focuses on the last phases of the socio-history of western water policy that have been described in the previous chapter. In the aftermath of the golden age of megaprojects, the Central Arizona Project (CAP) is the culmination of two social com- ponents of the New Deal era; a great belief in the engineering skills to build up big water infrastructures and the politicking practices for territorial sovereignty over water in the West ( Willey & Gottlieb, 1982 ). These prerequisites for success, which are key to under- stand how the idea of Central Arizona Project came up, have deepened in the context of the increased economic development of the West affecting the post Second World War period. Furthermore, the Central Arizona Project mirrors a transitory phase towards a much decentralized and multi-layered decision-making process in water issues. Lastly, choosing to come back to the history of the CAP enables to better appreciate what is going on in the current context of looming water shortage in the West. In addition to be designed as a technical response to an excessive groundwater pumping, the Central Arizona Project is also the product of specific and temporary alliances between elites from the political, economic and administrative spheres, which have structured and still structure social tensions with regard to the existing drought situation.