This paper presents a flood season staging study for the Altash Water Control Project in Xinjiang, aiming to enhance water resource utilization efficiency. A combined qualitative and quantitative analysis approach is adopted to address the challenges posed by complex flood mechanisms in snow-melt-dominated arid basins. This methodology responds to the limitations of traditional fixed flood limit water level operations, which often fail to satisfy optimized management requirements. The study systematically evaluates flood occurrence timing distributions, seasonal runoff variations, and watershed precipitation patterns through both meteorological causation and mathematical statistical methodologies. Qualitative analysis determines the flood stage boundary points, complemented by quantitative calculations utilizing an ordered clustering methodology. The integration of these analytical and computational outcomes facilitates the definitive identification of flood stage boundary points. The findings indicate unique phased characteristics in the project. The proposed phasing scheme corresponds with seasonal weather pattern variations, thereby offering guidance for dynamic reservoir flood limit water level control. This research addresses conventional fixed flood limit water level operational constraints in arid zones while exploring appropriate flood season staging methods for basins primarily influenced by snowmelt. Multiple methods and indicators inform the staging results through a methodology that combines meteorological causation analysis, mathematical statistics, and ordered clustering methods. The research establishes a scientifically justified flood season division for the Altash Basin and proposes a rational staging scheme. These findings offer a scientific foundation for optimized reservoir management and enhanced water resource efficiency in arid environments. In addition, they represent a valuable reference for flood season staging analyses in similar basin systems.