Willingness-to-pay for sponge city green infrastructure benefits in China based on discrete choice experiment

As urbanization and extreme stormwater events increase, sustainable stormwater management becomes vital. Sponge city green infrastructure offers a solution to flooding and pollution, providing additional benefits like recreation and clean air. However, understanding public preferences for sponge city green infrastructure's ecosystem services and balancing its co-benefits poses challenges, especially regarding financial sustainability. This study used a discrete choice experiment with 1,154 residents from three Chinese sponge cities to assess the monetary value of five sponge city green infrastructure benefits: improving black and malodorous water bodies, flood prevention, mitigating urban heat island effects, rainwater reuse, and landscape recreation. Analyzing data via the mixed logit model, distinct preferences for sponge city green infrastructure benefits emerged. Residents across all cities were significantly willing to pay for rainwater reuse, indicating a gap in existing research. Preferences varied for other benefits, with positive responses for water body improvement and flood prevention but indifference towards heat island effect and mixed views on landscape recreation. This information is crucial for stormwater managers to optimize sponge city green infrastructure design and fee evaluation.