Reclaimed water, serving as a crucial non-conventional water resource, is of great importance in alleviating the structural imbalance between regional water supply and demand, as well as promoting sustainable utilization and optimized allocation of water resources. Against the complex backdrop of escalating global water scarcity, increasing impacts of climate change, and rapid urbanization, advancing the diversified utilization of reclaimed water in a systematic and large-scale manner has become a topic of widespread concern across society and a prominent challenge in the current practice of integrated water resources management and sustainable governance. This paper systematically analyzes the basic connotation and main characteristics of reclaimed water utilization, profoundly explores its utilization status and influencing factors, and summarizes the practical overview and experience of reclaimed water utilization in China and abroad. Based on the practical dilemmas and bottlenecks in the reclaimed water utilization in China, this paper points out that the promotion and utilization of reclaimed water in China still faces multiple challenges, including the need for optimization in the construction and spatial layout of wastewater treatment and reuse facilities, insufficient governmental publicity and guidance, limited public awareness, inadequate maturity of utilization technologies, and an imperfect water pricing mechanism. In response, it is recommended that innovative research and localized applications of reclaimed water be systematically advanced across four dimensions: utilization mode and layout planning, resource allocation and risk prevention and control, water pricing system and market-oriented utilization, as well as incentive policies and guarantee mechanisms, aiming to transition from a “supplementary water source” to a “strategic water source”, thereby providing solid support for water resources security and sustainable development in China.

Based on the panel data of 11 provinces and municipalities in the Yangtze River Economic Belt from 2007 to 2022, this paper constructs an evaluation system for water resources welfare performance from the two dimensions of human development and water resource utilization, and uses the ordinary panel model, threshold regression model, and spatial Durbin model to empirically test the impact and differences of heterogeneous environmental regulation on water resources welfare performance in the Yangtze River Economic Belt. The research findings are as follows: from 2007 to 2022,the average value of water resources welfare performance in the 11 provinces and municipalities in the Yangtze River Economic Belt showed an overall increasing trend, and there were significant differences in water resources welfare performance levels among various provinces and municipalities. Both the command-and-control environmental regulations and the public participation environmental regulations have a dual-threshold effect, and they have a significant promoting effect on water resources welfare performance at the medium level of regulatory intensity. The market-incentive environmental regulations have a single-threshold effect on water resources welfare performance, and when the threshold value is exceeded, there is a significant positive correlation between them. Environmental regulation has a significant spatial spillover effect on water resources welfare performance, and different types of environmental regulations have a heterogeneous impact on water resources welfare performance. Accordingly, countermeasures and suggestions for improving water resources welfare performance in the Yangtze River Economic Belt are put forward from aspects such as constructing a multi-level environmental regulation implementation system, reasonably regulating the intensity of environmental regulations, and promoting the comprehensive development of regional collaborative governance and water resource management.