The American Falls Watershed (HUC 17040206) covers an area of approximately 1,462 square miles in southeastern Idaho. The watershed is dominated by agricultural land use, with some forested areas in the higher elevations. Hydrologically, the area is characterized by a semi-arid climate with low precipitation rates and high evapotranspiration rates. Snowpack in the watershed is essential for water supply, as the runoff from melting snow provides a significant portion of the surface water supply. The American Falls Reservoir is the largest reservoir in the watershed, and its main constituents are sediment, nitrogen, and phosphorus. In recent years, there has been a trend of declining snowpack and increasing temperatures in the region, leading to concerns about water availability and quality in the future. Interesting climatic facts include frequent wind events and occasional summer thunderstorms.