Prediction of residential water-saving potential based on the implementation of water efficiency standards and labeling scheme

a b s t r a c t With the acceleration of industrialization and urbanization, China’s domestic water consumption has increased year by year. To improve the efficiency of household water use, China has issued man - datory national standards for Minimum Allowable Values of Water Efficiency and Water Efficiency Grades for Water Closets (GB 25502-2017) and Minimum Acceptable Values and Grades of the Energy Efficiency and Water Efficiency for Smart Water Closets (GB 38448-2019) and implemented a water efficiency labeling scheme. Based on scenario analysis, this paper designs a BAU scenario without implementing water efficiency standards and labeling scheme, a Standard Scenario where only water efficiency standards are implemented, and a Standard + Labeling Scenario where water efficiency labeling is carried out based on implementing water efficiency standards. By analyzing the market share and water efficiency distribution of ordinary and smart toilets in 2021–2025, the water consump - tion of toilet flushing and bidet functions in the three scenarios above were calculated. Compared with the BAU scenario, it is estimated that under the Standard Scenario, the annual water savings is 1.393.35 × 10 8 m 3 , and the cumulative water saving is about 10.75 × 10 8 m 3 in five years; Under the Standard + Labeling Scenario, the annual water saving is 1.395.45 × 10 8 m 3 , and the cumulative water saving is about 17.39 × 10 8 m 3 in five years.