The Salt Watershed (HUC 10200203) covers approximately 3,900 square miles in central Arizona. Its hydrology is influenced by the Salt River, Verde River, and Tonto Creek. The watershed receives most of its precipitation during the winter months, with much of it falling as snowpack in the higher elevations. This snowpack can accumulate up to several feet in some areas and provides important water resources during the spring and summer months. Surface water in the watershed is primarily used for agricultural and municipal purposes, and the two largest reservoirs in the watershed - Roosevelt Lake and Apache Lake - store water for these uses. Interesting climatic facts include the monsoonal summer storms that bring intense rainfall and flash flooding to the area, as well as a trend of decreasing snowpack due to climate change.