The Little Sioux Watershed is located in western Iowa and covers an area of approximately 2,500 square miles. The hydrology of the watershed is dominated by agricultural land use, with row crop agriculture comprising over 80% of the land area. Snowpack in the area is typically moderate, with an average of 20-30 inches of snowfall per year. Surface water in the watershed is mainly supplied by the Little Sioux River and its tributaries, which are important sources of water for both agricultural and urban uses. The watershed also contains several large reservoirs, including the Saylorville Reservoir and the Okoboji Complex, which are used for flood control, recreation, and water supply purposes. Interesting climatic facts include the area's vulnerability to severe weather events such as tornadoes and flooding, as well as its changing precipitation patterns due to climate change. Trends in the area include a gradual increase in average temperature and a decrease in precipitation during the summer months.