ABSTRACT Green stormwater infrastructure (GSI) is implemented to mitigate the impacts of urbanization and climate change, including flooding, water pollution, water scarcity, and the urban heat island effect. However, many installations fail to function effectively, and the underlying causes remain poorly quantified, partly due to limited knowledge of how GSI success and failure are evaluated in practice. This study addresses this gap through a survey of 43 municipal managers and semi-structured interviews with 14 managers across Australia, Canada, the UK, and the USA. Results indicate that GSI success and failure are multi-dimensional and extend beyond technical performance metrics. GSI projects were perceived as moderately successful in delivering intended stormwater and ecosystem service benefits. Hydraulic failure due to flow bypassing inlets, clogging-induced infiltration loss, and short-circuiting was the most common failure mechanism. Design issues included undersized inlets and unmaintainable designs. Construction failures were attributed to inadequate construction quality control and contractor experience, while maintenance challenges were dominated by sediment accumulation. Governance issues centred on insufficient funding and organizational resistance, despite growing community and political support. Findings highlight the need to strengthen GSI asset management through adaptive management, dedicated funding, and technical innovations (e.g., artificial intelligence (AI) and internet-of-things (IoT) enabled predictive maintenance).
Khaniya et al. (Mon,) studied this question.