International perceptions of urban blue-green infrastructure: A comparison across four cities

Blue-Green infrastructure (BGI) is recognised internationally as an approach for managing urban water challenges while enhancing society and the environment through the provision of multiple co-benefits. This research employed an online survey to investigate the perceptions of BGI held by professional stakeholders in four cities with established BGI programs: Newcastle (UK), Ningbo (China), Portland (Oregon USA), and Rotterdam (The Netherlands) (64 respondents). The results show that challenges associated with having too much water (e.g., pluvial and fluvial flood risk, water quality deterioration) are driving urban water management agendas. Perceptions of governance drivers for BGI implementation, BGI leaders, and strategies for improving BGI uptake, are markedly different in the four cities reflecting the varied local, regional and national responsibilities for BGI implementation. In addition to managing urban water, BGI is universally valued for its positive impact on residents’ quality of life; however, a transformative change in policy and practice towards truly multifunctional infrastructure is needed to optimise the delivery of multiple BGI benefits to address each city’s priorities and strategic objectives. Changes needed to improve BGI uptake, e.g., increasing the awareness of policy-makers to multifunctional BGI, has international relevance for other cities on their journeys to sustainable blue-green futures.