© 2018 Elsevier Ltd A growing body of research suggests that people's values may be important predictors of their preferences regarding water governance and policy. However, this assertion is rarely tested empirically. The present study summarises the results of a large-scale quantitative study on the link between public water policy preferences and people's values, based on data from a representative sample of the general population collected in a household survey in the Upper Paraguay River Basin, Mato Grosso, Brazil (n = 1067). Structural equation modelling is applied to represent the clusters of values, or ‘value landscapes’ that shape attitudes and water policy preferences, in this case, for or against the construction of the highly controversial Paraguay-Paraná Waterway across the Pantanal wetland. Results demonstrate that opponents of the waterway share a value landscape composed of closely related self-transcendence values, democratic governance-related values, and ecological and cultural water values, whereas supporters hold self-enhancement values, economic governance-related values, and economic water values. Beyond this individual case study and beyond water governance, our findings may explain the protracted nature of, and seeming impossibility to resolve, environmental conservation vs. economic development conflicts more broadly.