A society that intensifies and expands the use of land and water in urban areas needs to rethink the relation between spatial planning and water management. The traditional strategy to manage land and water under different governance regimes no longer suits the rapidly changing environmental constraints and social construction of the two key elements in urban development. The dynamics of urban development and changing environmental constraints cause an urgent need for innovative concepts in the overlapping field of land and water governance.1 The claim for more space for rivers for flood retention (Hartmann, 2011) and environmental protection (Moss & Monstadt, 2008), the fragmentation of the drinking water sector (Moss, 2009), or unsolved upstream– downstream relations (Scherer, 1990) are illustrative of these dynamics. Therewith, increasingly, water management steps into the governance arena of spatial planning, and spatial planning needs to reconsider its notions of water issues. Particularly in urban regions, engineering and technical solutions of water management reach their boundaries; new frontiers for the common governance of land and water emerge (Figure 1). Although agriculture remains important for land and water governance (Calder, 2005), and it is the biggest consumer of water and occupies large areas of land, this special issue focuses on the urban realm because in the tense relation between water and land, the need for innovative approaches is more urgent. Urban regions are intensively used by many different stakeholders with competing interests, so that frictions between socio-economic dynamics and environmental constraints of land and water are more complex and more intense. Hence, the challenges of finding creative and path-breaking solutions in those areas are most pressing.