This article presents the results of comprehensive inventories made of water-related conflict and cooperation occurring in five districts in Africa, Asia and Latin America between 1997 and 2007. Following a description of the conceptual and methodological framework developed for undertaking these inventories, the article documents the extent, nature and intensity of water-related conflict and cooperation in the five districts. The article concludes by identifying three challenges relating to the magnitude, complexity and invisibility of local-level conflict and cooperation about water, which efforts to improve local water governance would have to address.