Understanding the Silala River—Scientific insights from the dispute over the status and use of the waters of the Silala (Chile v. Bolivia)

The flows of surface water and groundwater from the Andes to Atacama Desert are a vital source freshwater, supporting ecosystems human activities, but few substantive studies have addressed hydrological hydrogeological functioning these systems. A dispute between Chile Bolivia concerning transboundary Silala River, recently heard before International Court Justice, Hague, provided unique opportunity for new scientific studies, reviewed in this Special Issue. First, findings field that address geological geomorphological evolution River basin its current status, key processes (including infiltration, actual evaporation wetlands alluvial plains, water-groundwater interactions), characterization major aquifers reviewed. arose because disagreed was river, subject international law. As proceedings evolved, accepted by Bolivia, effects on historical channelization Bolivian headwater remained point legal technical disagreement. asserted large increases flow, based modeling their consultants, DHI. held small. In second part paper, we summarize evidence. Chile's use DHI's models, own basin, fully support position. We conclude with discussion Court's judgment, challenges physically-based small changes complex systems, associated implications judicial practice. This article is categorized under: Human Water > Governance Science Hydrological Processes Environmental Change