The Upper Ouachita Watershed covers approximately 5,567 square miles in Central Arkansas and Northeast Louisiana. The watershed is characterized by a humid subtropical climate with average annual precipitation of 50 inches. The hydrology of the watershed is dominated by the Ouachita River, which receives water from numerous tributaries, including Bayou D'Arbonne, Bayou Bartholomew, and the Saline River. The snowpack in the region is generally light, with occasional heavy snowfall events. The surface water in the watershed is used for drinking water, irrigation, and recreational activities. Reservoirs in the watershed, including Lake Ouachita and Lake Degray, are used for hydroelectric power generation and flood control. Interesting climatic facts include the occurrence of severe thunderstorms and tornadoes in the spring, and occasional winter storms that can cause significant disruptions to transportation and commerce. Trends in the watershed include increasing land use changes and urbanization, which impact water quality and aquatic habitat.