Abstract: Modern water network operation requires both the translation of scheduling tasks into executable engineering operations and the linking of engineering effects, task outcomes, and deviation information back to the original task to support subsequent judgments. This study defines this continuous relationship between a scheduling task and engineering execution as a task-level control relationship. Starting from an approved task, the relationship is maintained or adjusted as states, constraints, and authorization change, and is ultimately closed through feedback. To address inconsistent object definitions, incomplete measurement–control links, and discontinuities in responsibility handoffs, four theoretical propositions are developed: object correspondence, relationship establishment, state continuity, and organizational formation. The node–channel structure provides a unified object representation for tasks and engineering objects. The task-level measurement–control coordination criterion determines, across four dimensions—objects, boundaries, authorization, and responsibility—whether the relationship can be established, maintained, and closed. Five state categories and three operational domains are used to identify changes in operating conditions and determine when the original control relationship should be maintained, adjusted, or re-established. Basic control units and their multiscale organization enable multiple engineering units to work in coordination on the same task. On this basis, four methods are proposed: state representation, basic measurement and control, coordinated control, and capability enhancement. Within an overall decision-making–scheduling–control–execution architecture, the study further explains how tasks are transformed, how feedback is returned, how control organization is connected across scales, how three types of boundaries are mapped, and how layered verification is conducted during system construction. The study shows that whether a task-level control relationship can be established, maintained, and closed depends on clear correspondence between tasks and engineering objects; complete measurement, control, and feedback links; the continued validity of states, constraints, authorization, and responsibility during execution; and coordination among multiple engineering units working on the same task.