Water saving effect on integrated water resource management

• An improved integrated water resource management (IWRM) with an emphasis on water saving potential and effect was proposed.
• Customer's economic pressure (EP), which is the ratio of water's cost to the customer's income, was used to evaluate the customer's preference for saving water.
• Agriculture has the most preference for water saving by improving the transportation method, while the public has the least motives.
• Local freshwater will be saved by 21.5% and the total cost for water supplies will decrease by 13% with the improved IWRM in Tianjin.

This study proposes an improved integrated water resource management (IWRM), in which water conservation was analyzed for the entire water use process. A multi-objective optimization method was applied to optimize the IWRM, which investigated the reduction of freshwater consumption and the total water supply cost. Customer's preference for saving water and an end use analysis (EUA) was applied in the water conservation analysis. Taking Tianjin as the study area, a reduction in customer's economic pressure (EP) was utilized to evaluate the degree of the customer's preference for saving water. The results revealed that agriculture had a greater preference for saving water than other sectors, where as the public had the weakest motivation for saving water. Improving the transportation method could contribute 62.1% of the total water savings in the agriculture sector. The optimization of the IWRM demonstrated that the local freshwater savings would be 21.5%, and the total cost for water supplies would decrease by 13%. However, a government subsidy of 87.5 million Yuan would be needed. Additionally, by analyzing the change in the amount of water savings affected by water price, the appropriate water price increase range was suggested to be 1.5–1.7 times the original price.