围绕水质监测、保护体系、风险防控、应急处置、科技支撑5个方面，综合分析南水北调一期工程通水10年来水质安全保障工作取得的实践经验。在现状基础上对当前水质安全保障工作面临的新挑战和新问题进行深入分析，并围绕提升水质水生态监测监控能力、推进水质安全保障协同机制建设、加强沿线污染风险源动态管理、提升应急处置能力以及做好水质保护科技支撑提出相应的对策建议，可为保障南水北调及后续工程水质安全提供有益参考。

Securing water quality for long-distance water transfer initiatives is imperative for the enduring leveraging of the integrated benefits of such hydrological engineering endeavors. The South-to-North Water Transfers Project stands as the most extensive multipurpose water transfer scheme to date. A rigorous and systematic investigation into the water quality assurance strategies for the South-to-North Water Transfers Project is pivotal in offering critical insights and technological underpinnings for the water quality preservation in trans-basin water diversion undertakings. Over the decade since the full operation of the first phase of the South-to-North Water Transfers Project, the project has been running smoothly with continuously excellent water quality. The water quality of the first phase of Middle Route has remained stable at or above the Surface Water Category Ⅱ standards, while the Eastern Route’s first phase has continuously maintained Surface Water Category Ⅲ standards. This has provided a substantial supply of high-quality water to the recipient areas, yielding significant economic, social, and ecological benefits. It is of great responsibility and importance to plan, organize, and implement water quality safety assurance for the South-to-North Water Transfers Project in the new era. This paper systematically reviewed the practical experience gained in ensuring water quality safety in the first phase of the South-to-North Water Transfers Project. Over the decade since the full operation, the project’s operational management organizations have preliminary established a water quality monitoring system, continuously improved the water quality protection system, steadily advanced the prevention and control of water quality risks, and persistently enhanced emergency response capabilities. Robust efforts have been made in providing scientific and technological support, thereby establishing an initial framework for water quality safety assurance , and effectively enhancing the capability to ensure water quality safety. Over the decade, the role of the South-to-North Water Transfers Project has shifted from a supplementary to a primary one. The national requirements for water quality safety have continuously increased, presenting the project with new challenges and difficulties in ensuring water quality safety. Firstly, there is an urgent need to comprehensively upgrade the monitoring and control system for the aquatic ecological environment. The current aquatic ecological monitoring in the South-to-North Water Transfers Project is in its initial stage, and further optimization of monitoring indicators and frequencies is required. Additionally, the foundation for monitoring emerging pollutants such as endocrine disruptors, antibiotics, and microplastics, which are of national concern, is relatively weak. Secondly, the interlinkage mechanism for water quality protection requires immediate refinement and improvement. Engineering operation and management entities need to further refine the mechanisms for government-enterprise coordination and vertically integrated pollution prevention and control. Thirdly, the capacity for risk prevention and control of water pollution needs to be enhanced.The project still faces risks and hidden dangers to water quality safety, including hazardous chemical transport accidents at bridge crossings, external water entering the canal, internal discharge of groundwater, damage to pipelines crossing oil-contaminated areas, and navigation-related risks. Fourthly, the emergency response capability for sudden water pollution incidents requires strengthening and enhancement. Fifthly, there is an urgent need to coordinate and lead the development of a scientific and technological support system for water quality protection. Confronted with the new situation and requirements, the project operation and management organizations were required to further improve the water quality safety assurance system and enhance management effectiveness. This paper planned the water quality safety assurance work for the project in the new era, aiming to refine and enhance the high-quality water quality protection system. It specifically proposed the next steps in five areas: water quality monitoring, protection system, risk prevention and control, emergency response, and scientific and technological support. These steps included continuously improving the monitoring and control capabilities for water quality and aquatic ecology, promoting the construction of a coordinated mechanism for water quality safety assurance, strengthening the dynamic management of pollution risk sources along the route, enhancing emergency response capabilities, and maintaining scientific and technological support for water quality protection. The research findings provided effective support for ensuring the water quality safety of the South-to-North Water Transfers Project and subsequent projects, safeguarding the continuous flow of clear water to the north.