Abstract: Revealing the decoupling relationship between water resource utilization and economic growth is crucial for the scientific management of water resources and the formulation of economic policies. This study quantifies the consumption of water capital flows and stocks in East China by constructing a three-dimensional water ecological footprint model. On this basis, the Tapio model is employed to evaluate the decoupling relationship between water resource utilization and economic growth. The results show that Shanghai, Jiangsu Province and Shandong Province have to draw on water capital stocks to support socioeconomic development, indicating unsustainable water resource utilization. In contrast, other provinces can meet their development needs only by relying on water capital flows, demonstrating sustainable water use. The relationship between water resource utilization and economic growth in the study area is characterized by strong and weak decoupling in most years, presenting an ideal or relatively ideal state. Among them, Jiangxi Province achieves the best decoupling performance, while Shandong Province performs the worst. Overall, water supply falls short of water demand in Shanghai, Shandong Province and Jiangsu Province, resulting in a water deficit, whereas water resources in other provinces are sustainably utilized. Nevertheless, with the reform of the economic system and the transformation of growth drivers, society has placed higher demands on water supply capacity. All provinces and cities should adhere to the concept of green development and take measures such as improving water rights and water price management mechanisms, optimizing the spatial allocation of water resources, and upgrading wastewater treatment technologies to ensure the sustainable utilization of water resources.