Urbanization and densification of cities make urban stormwater management a critical challenge for communities globally. The interest of drainage issues in the urban environment has increased exponentially in recent decades. Stormwater management has gone from only covering quantity problems to including quality issues. In recent years, the multiple benefits aspect has also gained more attention and stormwater is now regarded as a resource that should, as far as possible, be utilized.
In Sweden, this development has resulted in that nature-based, green-blue stormwater systems are receiving more attention. The focus is on local drainage solutions and so-called sustainable stormwater management. However, the transition has been challenging, and several problems and barriers to this approach have been identified in previous research. In addition, difficulties in evaluating the sustainability aspect have been identified, preventing both planning and implementation of these systems. It is clear that the general goal and vision of more sustainable stormwater management are not corresponding with the actual stormwater management in Sweden today.
To fill the knowledge gap regarding the sustainability aspects of different stormwater systems, we are working on a study within the Vinnova-funded project DRIZZLE. With a multi-criteria analysis method, stormwater solutions will be evaluated regarding various sustainability indicators. The multi-criteria analysis will also include a multidisciplinary approach to cover the interests of different actors and in this way facilitate and enable more sustainable decisions in urban stormwater management in the future. The goal is to increase the knowledge of how sustainable different so-called "sustainable stormwater solutions" really are and to clarify how evaluation of these systems can, in a meaningful way, be performed.