Policies for Sponge City Transformation in China's Old Urban Areas and Analysis of Construction and Development Dynamics

After a period of conceptual introduction, pilot exploration, and demonstration and promotion, the sponge transformation of old urban areas in my country has entered a phase of nationwide implementation. With the continuous introduction of supportive policies from national and local governments, the institutional framework for sponge transformation in my country's old urban areas has gradually improved, but implementation still faces certain bottlenecks. This article systematically reviews policy documents and construction data, analyzes the policies and practices supporting this transformation, and offers targeted recommendations. The study finds a positive correlation between the intensity of policy support and the effectiveness of transformation in different regions, with Tianjin, Inner Mongolia, and Jilin making rapid progress, while Tibet and Ningxia lag behind. Financial and credit support accounts for the highest proportion (24.53%), reflecting a common bottleneck for transformation across regions. Project operation and maintenance support accounts for the lowest proportion (3.46%), primarily concentrated in northern China, indicating that insufficient post-project operation and maintenance is a prominent shortcoming. Current bottlenecks include an incomplete policy system, a significant funding gap, an inadequate third-party evaluation mechanism, and insufficient internal motivation among transformation entities. Recommendations include improving the policy and standard support system, developing diversified financing mechanisms, and establishing a full-cycle management system for transformation to facilitate the high-quality development of sponge transformation in old urban areas.