Against the backdrop of China's ecological civilization agenda and the pursuit of high-quality development in the water sector, the integration of water engineering and water culture has become an increasingly important issue. This study adopts a mixed qualitative strategy combining grounded theory and qualitative comparative analysis (QCA). Through open, axial, and selective coding of policy documents and case materials, it develops a progressive logical framework comprising “cultural gene decoding-cultural translation mechanisms-value symbiosis objectives.” Building on this framework, a configurational analysis of 77 cases identifies three pathways to highly effective integration: historical revitalization through closed-loop regeneration, historical revitalization through authentic preservation, and comprehensive utilization through value symbiosis. The first pathway relies on the conversion of cultural capital to establish an economically sustainable closed loop that supports the continued use of water heritage, representing a typical model for integrating culture into traditional water engineering. The second employs low-intensity symbolic interventions under geographical and ecological constraints, emphasizing institutional continuity and the preservation of authenticity, and thus offers a useful reference for water projects in ecologically sensitive areas. The third coordinates policy responsiveness, cultural decoding, and market feedback to generate synergistic ecological, economic, and social value, making it particularly applicable to strategic water projects and comprehensive water-governance initiatives.

Based on the established evaluation indicator system of urban water system, evaluation indicator data collected from six typical pilot sponge cities were analyzed using a coupling coordination model to empirically examine the development status of coupling coordination of the water system of different cities. The key indicators were identified through grey correlation analysis, and a vector autoregression model was established to investigate the mechanism, through which these key indicators impact the development of coupling coordination of the water system. The findings indicate that the water system of the six cities has progressed from serious or moderate incoordination to coordination after the construction of sponge cities, and “sponging” reconstruction had better short-term effectiveness in southern pilot cities, including Wuhan, Shenzhen, and Shanghai, compared to northern pilot cities, including Jinan and Beijing. Furthermore, the coupling coordination degree between the water ecology and water security subsystems is found to be the highest, while river regulation rate and drinking water compliance rate exert fluctuating effects, alternatively impeding or promoting the interrelation between the two sub-systems. By contrast, the coupling coordination degree between the water resources and water culture subsystems is the weakest, while the number of official platform publicity exerts a significant and sustained positive effect on the relationship between the two sub-systems. Additionally, there is a need for further enhancement of the coupling coordination degree between the water resources and water environment subsystems, and the increases of water consumption per 10000 yuan of GDP and sewage treatment rate have significant promoting but short-lived effects on the coordination between the two sub-systems.