Climate change, urbanisation and land subsidence increase the vulnerability of urban areas to flooding and droughts. Despite the availability of reliable and cost effective technologies, the actual implementation remains limited to small scale demonstration projects. Part 1 of this thesis describes how innovations in urban water management can contribute to reduce the vulnerability of cities. Examples are the use of local water resources, the urban surface water as energy source and floating urbanization. Next to showing the technical feasibility, observations are made from the perspective of an action researcher on factors that contribute to the application and mainstreaming of these innovations. Part 2 of this thesis complements the case study specific view ‘from the inside’ with a perspective ‘from the outside’. To unravel the mechanisms of technology application in urban water management this study included a literature survey, in-depth interviews, discussions, seminars, workshops and a national web-based survey on innovation among urban water managers. This thesis brings together the results of these activities. The study identifies two key conditions for application of urban water innovations in practice. The first condition is including urban water management innovations in spatial planning and development. The second condition is stakeholder receptivity to urban water management innovations. This thesis contains multiple recommendations to improve application of innovations in urban water management. It is relevant for scientists, engineers, designers and policy makers in urban water management.