The development of New South Wales’ Water Sharing Plans (WSPs) requires understanding the relationship between water regimes and ecosystems, in order to set rules which protect environmental assets. We describe a study in the Belubula, a tributary of the Lachlan River. This study used a combination of field observations and desktop analysis to recommend the preservation of river pools for significant fish species, and to meet human water quality guidelines by protecting base flows. Desktop analyses included use of Landsat imagery to determine the relationship between response of assets (i.e., river pools or wetlands) and reservoir releases. Potential assets were defined as those that were consistently hydrologically and/or photosynthetically active, with a focus on those that responded more after releases of flows from the main reservoir. Wetlands, including swampy meadows, and river pools were observed in the field. There was some evidence that alluvial wetlands need environmental flows to sustain groundwater-dependent plants. Swampy meadows also need protection, in part to improve river water quality. Some ecological risks remain unanswered such as the extent to which riparian tree species and river base flows are affected by groundwater use; especially during drought, and whether some significant frog species exist but have not been detected