Large areas of the rural Lao landscape are being rapidly transformed by infrastructure development projects. Arguably, it is hydraulic development that is contributing most significantly to rural socio-ecological change, due to the profound socio-political ruptures dams precipitate. The nationally iconic Theun-Hinboun Hydropower Project, commissioned in 1998 and expanded in 2012, provides an illustrative case of hydropower's complex social-ecological outcomes. Proponents have argued that the project represents a best-case example of planned, sustainable development, through successful mitigation of negative impacts and benefit-sharing with affected communities, and implemented in accordance with international good practice. This article questions the narratives of sustainability. It is argued that while the project could be considered successful in achieving certain economic objectives defined by the government and investors, evidence of social and environmental sustainability is questionable, raising questions about other dam projects in the country with weaker standards and oversight. Given the extent of negative impacts and associated social trauma in the Nam Hinboun basin, the article considers whether and to what extent such hydraulic development processes under authoritarian rule may be framed as expressions of structural injustice and slow violence.