The Upper Walnut River Watershed, located in south-central Kansas, covers approximately 1,200 square miles. The watershed is primarily agricultural with a mix of cropland, pasture, and rangeland. The hydrology of the watershed is influenced by the Flint Hills, which provide a natural filter for the surface water. The river is fed by both surface water and groundwater, with the majority of the flow coming from precipitation runoff. The area experiences a humid subtropical climate with hot summers and cold winters. Snowpack is not a significant factor in the area. The reservoirs in the watershed serve as a source of drinking water, irrigation, and recreation. Interesting climatic trends include an increase in extreme weather events such as heavy precipitation and prolonged droughts. Additionally, there has been a gradual increase in average temperatures over the past few decades.