Within the global transition to sustainable urban water management, Dutch polder cities are also contemplating revitalising their water traditions. One of the keys to this task is to integrate water management into urban design, which is explored but not yet practically instrumentalized in the urban design process. This article introduces the concept of hybridity and develops a Hybridity Design Approach as an interdisciplinary methodology to explore the possibility of realising the extreme low impact Closed City Concept. Integration of the water environment and urban space needs interdisciplinary cooperation and sharing knowledge, as well as an innovative way of thinking about water-resilient urban design, maximising the landscape quality of a polder city while minimising its hydrological footprint in the region. Effective visualisation tools and techniques for this collaborative design process are developed and tested in the area of Zevenkamp in Rotterdam.

Global challenges of ongoing urbanization especially in areas with increased coastal, fluvial and pluvial flooding cannot be solved by mere engineering solutions. Reversed Engineering with Nature is a concept that puts the natural system central, but it does seek symbioses with engineering systems into a new hybrid condition. This spatial hybridity is not only about integrating natural and engineered systems but also in considering surface and subsurface as one united space. Anticipating global challenges by synchronizing natural and engineered system and the spatial planning of surface and subsurface means innovating governance processes and products. This paper focusses on the question on how to integrate information the natural and engineered systems in surface and subsurface in urban development plans. The study of a series of plans for the case studies, New York (USA) and Natori (Japan), both struck by natural disasters, should expose the role of technical information. Especially the impact of an disaster to which usually engineering solutions are installed is an important test factor in this study. The conclusions show that the role of the spatial plan defines the visualization, to work consciously with the effects of climate change, it is important to include the subsurface information.