Disentangling ecosystem services perceptions from blue infrastructure around a rapidly expanding megacity

Restoring, maintaining, and developing green and blue infrastructure (GBI) in cities is a key strategy to safeguard ecosystem services and human well-being under conditions of rapid urbanization. Developing “blue infrastructure” is a new concept, but there are diverse historically grown water management systems that have the potential to inform contemporary debates about GBI. The aim of this study is to identify how local people perceive ecosystem services from a historically grown type of blue infrastructure (lakes), considering multiple interactions between ecosystem services categories, lake types, rural-urban environments, and sociodemographic characteristics of respondents. We performed a photo-elicitation survey among 536 residents along two urban-rural gradients in Bengaluru (Bangalore), India, asking about perceptions of ecosystem services from water-filled and dry lakes, challenges, and management options. Our results showed that blue infrastructures provide a multitude of ecosystem services that benefit people, with regulating and cultural services standing out. Both water-filled and dry lakes proved important for local people, but they supply different types of ecosystem services. While urbanisation level had a significant influence on how people perceive different ecosystem services from lakes, sociodemographic differences in the assessments were relatively low. Proposed management options departed substantially from those commonly proposed in the literature. We conclude that lakes are of high societal importance compared to their small surfaces, given their capacity to provide a host of ecosystem services. They should become keystone structures of GBI development for sustainable urbanisation in the Global South.