Institutional change is fundamental to regime transformation, and a necessary part of moving toward integrated water management. However, insight into the role of institutional change processes in such transitions is currently limited. A more nuanced understanding of institutional frameworks is necessary, both to advance understanding of institutional change in the context of transitions toward improved water management and to inform strategies for guiding such processes. To this end, we examine two contemporary cases of transformative change in Australia's urban water sector, exploring the evolution of institutional change in each city. This paper offers insights into regime transformation, providing guidance on types of institutional structures and the ways structure-change initiatives can be sequenced to support a transition. The results reveal the importance of regulation in embedding regime change and suggest that engagement with structural frameworks should begin early in transition processes to ensure the timely introduction of supporting regulation. Our findings also highlight the inextricable link between culture-based and structure-based change initiatives, and the importance of using a diverse range of institutional change mechanisms in a mutually reinforcing way to provide a strong foundation for change. These findings provide a foundation for further scholarly examination of institutional change mechanisms, while also serving to inform the strategic activities of transition-oriented organizations and actors.