The Middle Gila Watershed (HUC 15050100) covers an area of approximately 11,000 square miles in central Arizona. The watershed is primarily arid, with intermittent streams and shallow aquifers. The hydrology of the Middle Gila Watershed is dominated by the Gila River, which flows through the watershed from east to west. The watershed receives most of its precipitation during the winter months, with snowpack in the higher elevations contributing to surface water flow during the spring and early summer. There are several reservoirs within the watershed, including Theodore Roosevelt Lake, which is the largest reservoir in the watershed and a major source of water for the Phoenix metropolitan area. The water in the reservoirs is mainly used for irrigation of crops in the surrounding areas. In recent years, the Middle Gila Watershed has experienced lower than average snowpack and precipitation, leading to a decline in surface water availability. Climate modeling suggests that these trends are likely to continue, with increased temperatures and decreased precipitation expected in the coming decades.