Human needs for water in arid and semi-arid regions often conflict with those of aquatic and riparian communities. As human demand increases, more water is being diverted from natural channels, oftentimes severely dewatering streams. Invertebrate assemblages immediately downstream of diversion dams often have reduced species richness and numbers of rheophilic taxa as a result of diminished habitat volume and heterogeneity. Further downstream of diversion structures, discharge is restored to the channel via groundwater or surface-water contributions, and invertebrate communities begin to recover. We developed a landscape model using watershed scale topographic characteristics to quantify and predict discharge recovery downstream of diversion structures in the Fraser River Basin, Colorado. We coupled this modeled discharge with field-derived relationships between invertebrate communities and stream discharge to create a risk-based model that highlights the spatial extent of diversion impacts. For 8 headwater streams in the basin, we measured physical habitat characteristics and sampled benthic invertebrates from one upstream pre-diversion and several downstream segments within each stream. The risk-based model classifies stream segments into “high risk” and “low risk” categories based upon the predicted response of the relative richness of erosional taxa and collector-filterer taxa to changes in discharge volume.