The East Fork San Jacinto Watershed (HUC 12040103) covers approximately 231 square miles in southern California. The hydrology of the watershed is dominated by the San Jacinto River, which is fed by seasonal precipitation and snowmelt from the San Jacinto Mountains. The snowpack in the mountains plays a critical role in sustaining surface water flows throughout the year. The watershed is home to several important reservoirs, including Lake Hemet and Lake Fulmor, which provide water for drinking, irrigation, and recreation. The area experiences a Mediterranean climate, with hot, dry summers and mild, wet winters. Notably, the watershed has experienced drought conditions in recent years, leading to decreased snowpack and surface water availability. Climate change may exacerbate these trends in the future, emphasizing the need for effective water management and conservation practices in the region.