Smart water conservancy is the product of integrating of traditional hydraulic engineering with emerging intelligent technologies. It leverages sensing data from "space, air, ground, water, and engineering" systems and couples intelligent methods with mechanistic models to support the safe development and efficient operation of the national water governance system. This study examines the conceptual evolution and stage-specific characteristics of smart water conservancy in China and identifies three structural constraints to its development. Building on the traditional nature‒society dualistic cognitive framework of the water cycle, the study deconstructs the functional logic of engineering facilities and management practices to develop a smart water conservancy system framework based on "nature‒engineering‒management" ternary coupling. Within this framework, a reciprocal feedback mechanism among the stochastic evolution of natural systems (input), spatiotemporal scheduling and hydrodynamic reconstruction of engineering systems (execution), and multi-objective optimization of management systems (control) is clarified. Furthermore, it proposes a four-dimensional value objective function encompassing water safety, resource utilization, ecological sustainability, and social benefits. On this basis, a five-level maturity evolution model is developed, encompassing element mapping, mechanistic simulation, robust optimization, closed-loop intelligent control, and value symbiosis. It is also proposed to improve the system framework for smart water conservancy in China from three dimensions: theory, methodology, and pathway, which aims to help address key theoretical challenges including deficiencies in the dynamic coordination of multiple objectives and the insufficient quantification of stakeholder game dynamics, thereby supporting the construction of a safe, efficient, green, and intelligent national water network system.