As aspirations for waterways in urban areas increases, and we demand more social and environmental values from them, an increased role exists for applied geomorphology in urban streams of the future. Previously, there has been a strong focus on flood mitigation and water quality in stream management, and even where geomorphology has been used to drive legislation (e.g. stream order, offsets), desired outcomes have not always been achieved. Understanding how physical attributes of channels are altered by urbanisation, and how the physical template and waterways can assist in achieving aspirational goals, is now central to urban landscape managers and planners. South Creek in Western Sydney is in the largest urban growth catchment in Australia. An opportunity currently exists for Sydney Water, local councils, developers, state agencies and regulatory bodies to work together to create a significant 'green and blue' corridor. This opportunity, however, is reliant on understanding landscape-waterway interactions. The greenfield development provides scope to apply advancing understanding of urban geomorphology, but this requires numerous questions to be addressed, including: How feasible is it to maintain desired geomorphic processes in South Creek under urbanisation? What outcomes are we hoping to achieve for the waterway? What broad considerations must be addressed (stormwater runoff, riparian space) and can they be addressed to the extent required? If we are serious about healthy waterways and green spaces how do we prevent the impacts of upstream urbanisation creating enlarged, eroded channels that frequently jeopardise riparian spaces for the community? Assessment of 'alternative waterway states' provides one approach under which aspirations and requirements can feed into management strategies.