This article examines the local consequences of the extension of French citizenship to the Kanaks (former “native subjects” of New Caledonia) in 1946, with a special focus on the issue of water. Thanks to an ethnographic and micro-historical fieldword research led in the rural district of Koné (on the North-Western coast), I shall analyse and replace the social and political significance of municipal policies on water in Koné in a context of long-term colonial discriminations. Then I shall study how this particular issue has been politically addressed, problematised, and tackled from 1946. More precisely, this article examines three phenomenons closely related to the issue of water, in New Caledonia and in Koné: first, it deals with the historical significance of unequalities on water as a local feature of the global colonial framework; second, it analyses the dynamics by which the issue of water has become a priority on the postwar political agenda, notably under the pressure of Christian Missions; third, it focuses on the strategical uses and instrumentalisation of water policies within local power relationships. As a matter of fact, the Kanak claims of the 1940s and 1950s on water – elaborated under missionary supervision – have led the Municipality of Koné to intervene in a political space that was strictly controlled by “native chiefdoms” until then. The building of water pipes within Kanak villages has therefore not only improved the standard of living: while symbolising the emergence of Melanesian municipal elected members, it has also created a tremendous change in the internal relations of power within the Kanak world.