Water scarcity is widely regarded as a key factor linking climate variability and change with conflict. However, existing research on the water-conflict nexus is hampered by poor data that inhibits drawing firm conclusions on the role of water in shaping societal stability and security. This article reports on the construction of a new dataset on subnational and georeferenced events over domestic water-related cooperation and conflict for 35 countries in the Mediterranean, the Middle East, and the Sahel for 1997–2009. The main value of this dataset is in its precision. Its key component, the Water Events Scale (WES), records the exact time, location, and intensity of water-related conflictive and cooperative events, as well as the actors involved. A few descriptive statistics and illustrations serve to demonstrate the usefulness of the new dataset for quantitative analyses of intrastate conflict and cooperation over water resources.