Harlan County Reservoir Watershed (HUC 10250009) is located in Nebraska and covers an area of approximately 296 square miles. The watershed is characterized by rolling hills and agricultural land use, and it is drained by several creeks and streams that ultimately flow into Harlan County Reservoir. The hydrology of the area is influenced by precipitation, which is highest in the summer months. The watershed receives an average of 27 inches of precipitation annually, with approximately 70% of it occurring as rain and 30% as snow. Snowpack in the area can be variable, with some years experiencing significant snow accumulation while others have minimal. The reservoir is used for irrigation, recreation, and flood control. Water quality monitoring shows that the reservoir contains elevated levels of nutrients, sediment, and bacteria. Climate trends in the area show a warming trend, with temperatures increasing by approximately 1.5°F over the past century.