This Special Issue explores the politics of heterogeneous waters. Modern technoscientific water management regimes have driven the consolidation of power over water and those who use it through a material, cultural, and political process of centralisation and homogenisation. Despite this expanding uniformity, numerous scholars have called attention to the thriving heterogeneity of waters and water cultures. How do we reconcile these two views? In this introduction to the Special Issue, we propose that the relationship between water and waters is not either/or, as water/waters, but rather something more simultaneous and conjoined: water-waters. This approach displaces conceptual and temporal (before/after, premodern/modern) dichotomies and recognises that the processes through which water is made homogenous or heterogeneous (or both) are distinctly political. We conclude by introducing the anthropological and historical contributions to this special issue, which examine the political effects exercised by various kinds of waters and how people deal with the manifold permutations of water’s multiplicity. The articles assembled here show how uniform'water'rarely fully replaces or displaces' waters' materially or ontologically, but rather that they coexist in a tense and dynamic political balance.