Inspired by the proposal of political scientists and anthropologists to focus on “practice” as the smallest unit of analysis for understanding politics, as well as the renewed scholarly attention to materiality, this paper sets out to show that detailed ethnographic attention to processes and acts of sociotechnical tinkering provides a useful entry-point for understanding water governance. This is so methodologically, because infrastructural forms of tinkering are very visible, and therefore researchable, manifestations of agency and change in water governance. Attention to sociotechnical tinkering helps shift the basis for understanding water realities from official norms, designs and laws to everyday practices. This in turn allows questioning, rather than assuming, how expertise and agency are exercised and distributed in water governance, thereby also providing useful information for re-thinking water politics. In addition, by explicitly engaging with the contingency and capriciousness of actual water flows, a sociotechnical tinkering approach entails a much-needed re-appreciation of the materiality of water, infrastructure and other matter, a re-appreciation that extends to those who design, construct, operate and use water infrastructure.