Sustainable water management is one of the key measures to achieve Sustainable Development Goals. Increasing water consumption prompts industrial plants to implement water-saving projects and improve the utilization efficiency of water resources. This paper develops an integrated graphical method for designing an implementation path of water conservation projects that considers both water-saving targets and investment costs with or without subsidies. First, the cost-benefit analysis of each project is carried out. The unit water savings cost diagram is used to rank the priority of the implementation of each project. Then, the project mix which meets the expected water saving goal is determined by pinch analysis. Finally, the water conservation potential and cost-benefit of the optimal project mix are shown by the marginal cost curve diagram. This work presents two scenarios (i.e., with and without government subsidies). A chlor-alkali/ polyvinyl chloride complex is used as an illustrative case study. The complex achieves annual water savings of 3,580.4 kt by implementing the selected water conservation projects under the budget and subsidy constraints.