Advancing Sponge City Implementation in China: The Quest for a Strategy Model

The unbridled expansion of urban development in China has created unsustainable challenges in the management of urban rainwater. In response, the Chinese government has endorsed sponge city (SPC) theory as a sustainable urban development model that aims to enhance urban planning, construction, and sustainable wastewater management. However, despite the issuance of policies and regulations, the envisioned SPC goals remain difficult to achieve in current implementations. This review paper proposes an idealized SPC strategy model that can be adopted by pilot cities in China. This model was developed by thoroughly analyzing policy requirements and in-field achievements, evaluating diverse implementation scenarios, and contrasting the outcomes in three different pilot cities in China. The demonstrated success of city construction has highlighted the potential to simultaneously achieve multiple objectives, including conserving urban water resources, enhancing urban water quality, ensuring water safety, and revitalizing urban water ecosystems. This review supports the use of a planning approach that integrates the drainage division, aligns with project-specific conditions and emphasizes the importance of low-impact development (LID) facility placement within drainage zones. Consequently, this study calls for exploring the impact of catchment topography on LID performance. Finally, the results of this study highlight the necessity of investigating precipitation variations among LID facilities during rainfall events and exploring cost-effective material alternatives to improve the effectiveness of SPC implementations. Contribution to SPC, an idealized stratgy model was proposed.SPC implementation in three different pilot cities were assessed and compared.The groundwater depth affects strategy selection of LID.Integrated planning, LID placement, and the impact of topography on LID should be emphasized for effective SPCs.