The Upper Santa Cruz Watershed has a land area of approximately 1,330 square miles in southern Arizona, USA. The watershed is fed by the winter snowpack from the Santa Catalina Mountains and receives most of its precipitation during the monsoon season from July to September. The watershed is home to several streams, including the Canada del Oro, CDO, and the Tanque Verde. The surface water is used for irrigation, municipal supply, and recreation. The largest reservoir in the watershed is the Roosevelt Lake, which is located downstream. The watershed experiences high temperatures with an average annual temperature of 66°F. Additionally, the watershed experiences drought conditions, which have impacts on the surface water supply. Despite the aridity, the watershed supports diverse flora and fauna, including saguaro cactus, mountain lions, and Gila monsters.