The Middle Kaskaskia Watershed, located in south-central Illinois, covers approximately 1,700 square miles. It is primarily an agricultural area, with land used for crop production and grazing. The watershed is characterized by a humid continental climate, with hot summers and cold winters. The area receives an average of 42 inches of precipitation annually, which includes both rain and snow. The snowpack varies from year to year, with some years experiencing heavy snowfall and others very little. The surface water in the watershed mainly comes from the Kaskaskia River and its tributaries. The river is used for navigation and also serves as a source of drinking water for nearby communities. The reservoirs in the watershed contain various constituents, including sediment and nutrients. Interesting climatic facts for the area include frequent thunderstorms in the summer months and occasional tornadoes. Climate trends show an increase in temperatures and precipitation over the past few decades.