Northern Australia contains numerous and diverse freshwater fishes of national and global conservation significance. River systems in northern Australia are considered to be largely undeveloped compared to its southern counterparts. Sustainable water resource development in northern Australia requires an understanding of how potential changes in flows will affect these diverse species assemblages. Because of the remoteness and lack of data and scientific inquiry into northern Australia, this understanding can be difficult to attain. This presentation describes efforts to predict habitat and condition changes of freshwater fishes based on predicted hydrological changes from water resource development. The analysis uses preference curves to capture how components of flow meet the habitat needs of fish species in northern Australia. The preference curves represent a set of hypotheses based on three key flow components: inundation duration, migration and spawning timing, and flow magnitude. Predicted condition scores of freshwater fishes in relation to potential hydrological change from dams and water harvesting are compared to baseline scores. The application of the method can help to foster an understanding of potential changes to freshwater fishes in regions where data and established causal relationships are limited. Preference curves are explored in the broader context of water resource planning when considering flow, habitat and condition relationships of fish in data poor regions. This presentation will show potential changes to functional groups and species of fish in northern Australia catchments, as a consequence of flow change from new infrastructure, including dams and pumps.