Assessing the Efficiency of Industrial Water Use and Wastewater Treatment Across Provinces in China After Considering the Impact of Precipitation

Water resources are fundamental to China’s industrial economic development, and enhancing their utilization and treatment efficiency is essential for achieving SDG 6. This study integrates precipitation into industrial water use and wastewater treatment (IWUWT) processes as an exogenous variable. A meta two-stage dynamic non-radial directional distance function (DDF) is developed under an exogenous data envelopment analysis (DEA) model. Subsequently, the efficiencies of IWUWT, industrial water use (WU) and wastewater treatment (WT) are evaluated. Additionally, the causes of inefficiency are identified, and differentiated improvement strategies are proposed. Key findings include the following. (1) From 2015 to 2020, the overall efficiency of China’s IWUWT is poor. Incorporating precipitation into the analysis framework significantly enhanced efficiency. The efficiency of WU exceeded that of WT, with precipitation having a more positive impact on the latter. (2) The western and eastern regions outperformed the central region. Provinces like Hebei, Hainan, Ningxia, Qinghai and Chongqing performed well, whereas Shandong, Guangdong and Jiangxi exhibited the weakest results. Notably, economically developed provinces such as Jiangsu, Shandong and Guangdong face considerable conflicts between economic growth and wastewater management. (3) Provinces with weaker industrial bases often face insufficient industrial outputs, while capital redundancy and inadequate WT volumes are common across many provinces. In the policy recommendation, we propose that alongside subsidizing industrial water-saving technologies, the government should implement additional mandatory water resource management policies to enhance policy effectiveness.