The Pickwick Lake watershed (HUC 06030005) covers a land area of approximately 10,723 square kilometers in portions of Alabama, Tennessee, and Mississippi. The watershed is drained by the Tennessee River and its tributaries, including Bear Creek, Cypress Creek, and Shoal Creek. The hydrology of the watershed is influenced by the surrounding terrain, which is characterized by rolling hills and plateaus. The area experiences a humid subtropical climate, with hot summers and mild winters. Snowfall is infrequent but not uncommon in the winter months. Surface water within the watershed is used for a variety of purposes, including irrigation, drinking water, and recreation. Pickwick Lake, which was created by the construction of Pickwick Landing Dam, is a popular recreational destination and a significant source of hydroelectric power. Reservoir constituents include algae, bacteria, and plankton. There are no significant climatic trends affecting the watershed at this time.