The SWAT model was used to study the Budhigandaki River Basin in Nepal, a complex mountainous area. The researchers aimed to see if the model could accurately predict water flow in this challenging environment. They found that the model performed very well, accurately estimating annual flow and precipitation. Snowmelt was a significant contributor to the water flow, especially before the monsoon season. This study shows that the SWAT model can effectively simulate rainfall-runoff patterns in mountainous regions, providing valuable information for water management and hydroelectric projects in the future.