Public perceptions of and willingness to pay for sponge city initiatives in China

- Public perceptions of and knowledge on sponge city were examined.
- Respondents know about urban flooding and sponge cities and supported sponge city construction.
- Government grants and PPP model are deemed to be main financial sources.
- WTP for sponge city construction in a PPP model was 55% of the average annual capital surplus.
- Occupation, education, and income were the main affecting factors.

As a result of global climate change, urban flooding has become a global concern in recent years because of its significant negative impacts on cities. To cope with the frequent occurrence of urban flooding in recent years as well as water shortages, China has started a new nationwide initiative called Sponge City intended to increase urban resilience. This study aimed to examine public perceptions of and knowledge about urban flooding and sponge city construction, as well as the public's willingness to support sponge cities through two options, which includes (1) paying a domestic water fee surcharge and (2) buying government-issued credit securities. We found that most respondents knew about urban flooding and sponge cities, and also supported sponge city construction. Residents believed that government grants and public-private partnerships (PPP) should be the main financial sources for sponge city construction. However, respondents also accepted 17% of the domestic water price as a surcharge to be used for sponge city construction. Meanwhile, the willingness to pay (WTP) for government-issued credit securities for sponge city construction was 55% of the average annual capital surplus. We also found that occupation, education, and income were the main factors affecting respondents' WTP to support sponge city initiatives. Though increasing water prices by a certain amount will be acceptable to the public, a more properly designed PPP model should be considered and promoted by the government to overcome financial insufficiencies and ensure the sustainability of the sponge city initiative.