Many Australian Capital Territory (ACT) streams drain rural and urban areas. These land-uses have the potential to degrade water quality and in-stream habitat, which can have consequences for biotic diversity, amenity, and human health. The ACT Water Quality Monitoring Program (WQMP) has since 2001 provided an ongoing targeted assessment of the biological condition of urban and rural streams throughout the ACT using invertebrate communities. Long-established test and reference sites used in this study have provided strong inferential power in determining changes in biological condition of impacted streams, and in determining potential causes. Over the length of the program, streams within the ACT have been subject to disturbance from fires, floods and droughts, in combination with the effects of runoff from urban and rural land-uses. Throughout the assessment program, the biological condition of rural streams was generally better than that of streams with more urbanised catchments. Erosion and sedimentation continue to be the most likely cause of biological impairment in rural catchments, while poor water quality and hydrological change is likely driving the biological condition of urban streams. The ACT WQMP has been successful at informing the ACT Government of the biological condition of ACT streams and the influence of any management actions on stream biological condition within urban and rural land-use areas.