Scaling Water Resilience in the Mediterranean: Lessons on Mainstreaming NbS from the Climate Adaptation and Resilience Demonstrated in the Mediterranean (CARDIMED) Case Studies

Growing concerns with water resilience have contributed to a renewed interest in implementing nature-based solutions (NbS) such as rain gardens, constructed wetlands and riparian corridors. Offering strategies to fulfill both urban resilience and biodiversity restoration goals , NbS are being used to combat environmental degradation, reduce the risk of droughts and improve water quality in the Mediterranean region. However, emerging initiatives currently advancing the implementation of NbS in Mediterranean cities often focus on technical aspects and rarely provide pathways to mainstream these solutions within local institutional, social and economic contexts. For this reason, many gaps remain in our understanding of how NbS can be effectively integrated in existing practices and policy frameworks. Recognising the reliance on pilot projects that has characterised current research on NbS in the region, we examine various case studies to reveal how NbS can gain scale through "mainstreaming pathways". Exploring the experiences from nine different demonstration sites through the Climate Adaptation and Resilience Demonstrated in the Mediterranean project (CARDIMED), we discuss emerging strategies to support the development of NbS for water resilience through practice and policy innovations. Examining “mainstreaming” as an “ongoing, incremental process of creating and re-forming the institutional order of existing governance arrangements that determine how planning takes place”, we conducted 32 interviews with different stakeholders in CARDIMED to identify how industry, government, civil society and academic institutions are learning by implementing NbS. The experiences indicate that the implementation of NbS depends on innovative urban planning practices that are premised on integrating policies, supporting collaborative management and building networks to foster co-stewardship. Examples from different contexts, ranging from Portugal, Greece, Cyprus and France offer insights into how implementers of NbS can gradually change existing procedures, circumvent restrictions and build momentum for water resilience innovations through pilot projects. Different case studies in CARDIMED serve as examples of how the disruption of existing practices can create opportunities for experimentation with new technologies and how the mainstreaming of NbS can also benefit from more inclusive and participatory decision-making processes. The interviews show that the CARDIMED experiences offer insights into how cities in similar social, political and bioclimatic conditions in the Mediterranean region can achieve water resilience goals through policy and technical innovations. Aligned with a growing body of literature on urban policy and NbS design, our experiences show that mainstreaming NbS depends on finding ways for existing institutions to support greening practices and on transforming these institutions to support innovative practices for water resilience.