Achieving Sustainable Development Goals (SDG 6), focused on ensuring the availability and sustainable water management, is a critical global priority. Attaining this target requires sustainable water management, balancing economic, social, and environmental needs to ensure long term water availability and quality. Water quality models help analyse, anticipate, and manage factors affecting water bodies. Among several models, QUAL2K stands out for its ability to simulate river pollution scenarios, identifying pollution sources, and evaluating the effectiveness of various mitigation strategies. While various studies cover water quality models, none comprehensively focus on QUAL2K. This paper explores the applicability of QUAL2K in analysing and managing pollutant impacts, focusing on its core principles, key features, and applications in different water bodies. The article can serve as a reference for researchers and watershed quality managers to plan the best strategies for optimizing use of the QUAL2K model for watershed water quality management.