International Perceptions of Urban Blue-Green Infrastructure: A Comparison across Four Cities

Emily O’Donnell,Noelwah Netusil,Simon Gosling,Faith Chan,Nanco Dolman

doi:10.3390/w13040544

Abstract

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.

Highlights

The questions were informed by existing literature on overcoming barriers to Blue-Green infrastructure (BGI) implementation [35,36,39], perceptions of multiple benefits [40,43,67] and research and policy papers detailing the strategies of the four cities [16,68,69]
Perceptions of the water challenges and benefits of BGI are influenced by the geographical and climatological features of each city; all cities are situated along rivers which has raised awareness of fluvial flood risk and declining river health while Ningbo and Rotterdam are delta cities with increased perceived risk of coastal flooding and storm surges
A transformative change in policy and practice towards truly multifunctional infrastructure is needed to optimise the delivery of multiple BGI benefits that address priorities and strategic objectives of cities

Summary

Introduction

International cities are gradually evolving from a sole reliance on centralised grey infrastructure towards decentralised facilities that use BGI to retain, attenuate, store and reuse surface water on site, increasing their resilience to future environmental threats [13,14]. This fundamental change in how cities manage water is driven by increasingly frequent and extreme rainfall events, drier summers, accelerating urbanisation, and reductions in public green spaces that lead to water challenges such as flooding, water scarcity, over-exploitation of groundwater, water pollution, maladaptive drainage systems and wasting of rainwater resources [15,16]. Approaches centred on ‘living with and making space for water’ [17,18]

Methods

Results

Discussion

Conclusion