The Fluid City project was initiated through a Transforming Cities research grant at the University of Auckland to promote inter-disciplinary urban research for sustainable futures. The premise of Fluid City is that the arts can play an important role in communicating issues of sustainability in novel ways that capture public imagination and provoke alternative understandings and visions of the city. Our motive for undertaking this collaboration was to produce new ways of disseminating hard science knowledge concerning the effects of the urban realm on fresh water catchments and the harbours with the diverse publics of Auckland. Our response then was to generate a mechanism to support a fluid approach to the sharing and exchange of water knowledge and to make a space for the close encounter with water from our urban streams, creeks and rivers.The Fluid City project is anchor-less and mobile, taking the form of three strange, translucent cupboard-like structures each towed by bicycle. Like a stream the bicycle powered Fluid City winds its way through the city’s streets, creating a sense of anticipation and wonder. It then temporarily occupies an urban space and garners the unsuspecting public as audience. The three cupboards open, releasing images, objects, performance, and between them creating a space to pause in the city. Each cupboard and its yellow-aproned attendant invites the passer-by to engage with water; to view, through a diver’s mask, a film showing the passage of water through the city; to don a lab coat and guided by a microbiologist see the usually invisible microbial universe of the city’s waterways, active, alive and full of creatures; to sit on an upturned bucket and listen through headphones to different voices sharing stories and knowledge of the city’s fluid states; to pick up a pen and write or draw your own memories and concerns about water on postcards and contribute this writing to a gently flapping washing line of thoughts; to follow characters through a dance and audio performance evoking the invisible stories of a reclaimed harbour through movement, poetry and sound.