Integration of nature-based solutions (NBS) in local policy and planning toward transformative change. Evidence from Barcelona, Lisbon, and Turin

The attention given to nature-based solutions (NBS) in urban governance is often hindered by the fragmentation of responsibilities in technical and administrative services and by rigid structural conditions within urban regimes. This drastically harms NBS implementation and their co-benefits. There is limited information regarding NBS integration across levels and scales of urban governance, in particular a lack of studies that access such integration in urban policy and planning. This study aims to address this gap by exploring the integration of NBS in urban policy and planning in Barcelona, Lisbon, and Turin, the three European municipalities participating in the H2020 project CONEXUS. The objectives are: (1) to understand the state of top-down and bottom-up integration of NBS in urban policy and planning in the three cities; (2) to understand barriers in integration that might hinder the evolution of the NBS agenda in said instruments; (3) to identify policy and planning entry points that can catalyze forms of cross-sectoral, multi-level, and interdisciplinary governance of NBS toward transformative change. The methods used include an in-depth analysis of official municipal, metropolitan, regional, and national documents and expert interviews. The results show that NBS integration in urban policy and planning is novel in all cities but advancing considerably with initial dialogues among the public sector, academia, and local actors of various provenances. Planning in silos persists, negatively impacting any possible confluence of actions toward NBS integration and implementation. However, a constellation of national and international plans including NBS, combined with the development of cross-cutting policies and plans, and an increasing interest from the municipalities and citizens, reveal an enabling environment for NBS integration in urban policies. Our findings are translated into insights that can support policy and decision makers to operationalize NBS integration in their municipal agendas, policies, and plans.