The Lower Moreau Watershed (HUC 10130306) covers an area of approximately 1,080 square miles in South Dakota. It is a tributary of the Cheyenne River and is primarily a grassland ecosystem. The watershed is characterized by a semi-arid climate with hot summers and cold winters. It receives an average of 16 inches of precipitation annually, with most of the precipitation occurring during the summer months. The snowpack in the watershed is generally light and melts quickly. The surface water in the watershed is dominated by ephemeral streams that flow intermittently throughout the year. The reservoirs in the watershed are utilized for irrigation and domestic water supply. Interesting climatic facts and trends in the watershed include an increase in average temperatures and a decrease in precipitation over the last few decades, leading to drought conditions and decreased water availability.