This paper deploys the concept of unruliness to examine ethnographically how groundwater in karst landscapes resists being rendered knowable and governable. Focusing on the karst spring Klokot and its transboundary groundwater catchment (TGC) between Croatia and Bosnia and Herzegovina, I trace how practitioners and scientists grapple with the epistemic and material indeterminacy of karst. While these actors often frame such conditions as technical challenges to be solved by infrastructural or modeling interventions, I argue that such indeterminacy is not simply a property of karst but is coproduced through the entanglement of hydrogeological processes, technolegal infrastructures, and situated practices of research and governance. Klokot's TGC becomes unruly through the interplay of human and nonhuman actors across subterranean and political terrains. Attending to this unruliness foregrounds how groundwater governance is shaped by material complexity, epistemic uncertainties, infrastructural limits, and political frictions. Conceptually, the paper advances unruliness as a productive STS lens for studying surface–subsurface relationships, highlighting how material resistance and indeterminacy can reconfigure the terms of environmental knowledge and decision-making in transboundary contexts.
Dženeta Hodžić (2026) studied this question.