Urban development imposes an increased pressure on existing urban water infrastructure (water supply, wastewater, stormwater), while at the same time existing infrastructure and its expandability represents a critical factor for urban development. Increasing urban water demand, and increasing requirements for levels of service, coupled with uncertain water availability (incl. the potentially increasing occurrence of droughts) leads to water scarcity situations – especially in the Southern EU and Mediterranean countries. This mismatch between supply and demand is usually met with increasingly sophisticated and energy consuming, mostly centralized, infrastructures and often requires the transport of water from remote catchments, with potentially severe disruption to local ecosystems.
Driver-Pressure-State-Impact-Response (DPSIR) studies, undertaken at the EU level, including the ClimWaterAdapt project currently undertaken by DG Environment, suggest that in view of key drivers, such as population growth (incl. migration) and the potential for significant changes in climatic conditions, there is a growing concern that water scarcity will become a major socioeconomic issue in the next decades. On the other hand, it has been suggested that savings of up to 40% can be achieved at the EU level, hence decreasing the vulnerability of populations to water scarcity conditions but there is no specific guidance on how this saving can be achieved.
There is a growing consensus that interventions on the urban water cycle are necessarily associated with local characteristics and constraints (geomorphology, water courses, rainfall patterns) but also importantly the characteristics of the urban environment (occupancy, building density, socio-economic mix, cultural habits etc). This implies an interdisciplinary approach that combines social, economic and natural sciences and more specifically urban and regional