The Upper Yuba Watershed (HUC 18020125) covers an area of approximately 851 square miles in the Sierra Nevada Mountains of California. The hydrology of the watershed is characterized by high precipitation in the winter months, which produces a significant snowpack that serves as a primary source of surface water during the warmer months. The snowpack typically peaks in April, with average depths ranging from 70 to 100 inches. Surface water is primarily stored in reservoirs, with the largest being Bullards Bar Reservoir. The watershed is also known for its rich gold mining history, as well as its unique climatic conditions, which include frequent thunderstorms and a high risk of wildfires. In recent years, the region has experienced prolonged drought conditions, leading to decreased snowpack and surface water availability, as well as increased risk of wildfire.