The digital era presents organisations and communities with an opportunity to discover more effective ways of working together with technology to address complex social and environmental challenges. In this paper, we focus on the design approaches and perspectives that can enable leaders of land and water management to better navigate systems complexity. To help us explore the topic, we consider smart rainwater tanks, an emerging system enabled by digital technology that has the potential to shift the way we manage urban catchments towards more distributed systems. We share insights about how different stakeholders perceive and experience smart tank systems, and what they might value in the design of related policies, strategies, products, services and commercial models. We argue that when combined with human-centred and systems-minded design approaches, these insights can help stakeholders identify opportunities and solutions to help deliver the potential benefits of smart tank systems.