Conventional urban water management approaches are insufficient to meet the current global dynamics and challenges, given trends in water scarcity, demographic growth, pollution, climate change, and extreme weather events. Traditional urban water management can be characterized by large-scale, centralized, and highly engineered infrastructures. These large systems are typically based on a technocratic management approach, and on the assumption that key variables (such as rainfall and water demand) can be predicted and controlled under the principles of linearity and efficiency, and under a strict regulatory framework. However, this approach is not only acknowledged to be inadequate to respond to some uncertainties and complexities of current contextual conditions, but it can also erode urban resilience.

New discourses on urban water management emphasize the need for a transformative change by moving to a system that manages a diversity of water sources and scales of infrastructure in an integrated way. Such an approach requires the capacity of the whole water governance system to cope with, and respond to, contemporary challenges, respecting processes of social learning and plural sources of knowledge and perspectives.

There is consensus about the need for more comprehensive urban planning and integrated urban water management in relation to freshwater, wastewater and stormwater, as links within the resource management paradigm. However, it is also recognized that important aspects affecting themlie outside the control of water managers, mostly because the ultimate drivers are governance, politics, ethics and society (values and equity), and climate change. These factors and drivers operate on different spatial and temporal scales, acting within systemic conditions and constraints that are often intractable for urban planners and very often downplayed if not altogether neglected in policy and action.

The project responds to the aforementioned challenges and discourses, andaims to examine the opportunities and challenges regarding planning for the up-scaling and expansion of rainwater harvesting (RWH) systems as socio-technical devices in order to enhance sustainable water management in European urban areas; although, its lessons and recommendations are expected to have a wider, global impact.

In technical terms, RWH is a raft of technologies used for collecting and storing rainwater from rooftops, land surfaces, road surfaces or rock catchments by using either simple devices such as pots, tanks, and cisterns or more complex technical solutions such as underground dams.

Increasingly, RWH systems are being used for a wide range of urban functions, from providing alternative water supplies and water saving, to stormwater control, groundwater recharge and greening of residential areas. The transition of RWH in Europe from isolated, small-scale pilot projects (socio-technical niches) to more extensive, inter-connected and (in part) larger-scale applications raises a number of relatively new questions regarding planning and policy-making, since up until now RWH was restricted to a small number of enthusiastic stakeholders working in self-contained or isolated contexts. It is here where the project’s most significant contribution lies.