Planning for urban adaptation : exploring innovative financing and governance arrangements for nature-based solutions

Abstract

Urban areas are increasingly challenged by the combined impacts of climate change and ecological degradation, prompting growing interest in nature-based solutions (NBS) as a means of supporting urban climate adaptation. Despite their prominence in policy and planning agendas, the implementation of NBS remains largely confined to pilot projects and isolated initiatives, with limited evidence of large-scale integration into urban development processes. This dissertation conceptualizes NBS as a niche innovation operating within an entrenched urban infrastructure regime characterized by institutional lock-ins, sectoral fragmentation, and path dependencies. Focusing specifically on the finance domain, the research investigates how governance and financing arrangements influence the implementation and scaling of NBS. The dissertation addresses the central research question: How can innovative financing and governance arrangements serve as a lever in urban transformation processes to support the scaling and acceleration of NBS implementation? The study combines an analytical research track examining existing governance and financing practices with an experimental, action-oriented track that engages stakeholders in exploring alternative financial arrangements. Structured as a triptych, the dissertation investigates NBS financing from public, private, and integrative planning perspectives. The first part examines public-sector approaches to financing NBS. Comparative analysis of four Flemish cities reveals that distinct financing strategies are employed during the design, implementation, and maintenance phases of NBS projects, highlighting the importance of aligning policy objectives with funding mechanisms. A case study of the Stiemer Valley in Genk further demonstrates how fragmented governance arrangements and sectoral responsibilities constrain the scaling of integrated NBS initiatives. The second part explores the perspectives of private financial actors. Findings indicate a disconnect between municipal needs and the financing logic of banks, whose lending decisions are primarily based on municipal creditworthiness rather than NBS-specific business cases. Similarly, insurers show limited incentives to support NBS due to uncertainty surrounding their risk-reduction benefits and organizational silos separating underwriting, risk management, and investment activities. The final part reflects on entrepreneurial planning approaches and the potential of innovative financing arrangements to bridge public and private interests. The research demonstrates that while entrepreneurial strategies are increasingly embedded in urban planning processes, innovative financing remains underdeveloped. Overall, the dissertation concludes that the upscaling of NBS is fundamentally an institutional design challenge. Innovative financing can support implementation but cannot substitute for reforms addressing fragmented governance, sectoral silos, and entrenched investment practices. Accelerating NBS adoption therefore requires stronger alignment between governance frameworks, financing mechanisms, and spatial planning practices.