The root watershed (HUC 07040008) covers an area of approximately 1,232 square miles in the Sierra Nevada mountain range of California. The hydrology of the area is dominated by snowmelt, which provides the majority of the surface water flow during the spring and summer months. The specific snowpack in the watershed varies from year to year, but is generally deep and persistent due to the area's high elevation and abundant precipitation. Surface water in the watershed is primarily sourced from the Sierra Nevada mountains, and is stored in several reservoirs located throughout the area. These reservoirs provide water for both agricultural and urban uses. Interesting climatic facts and trends in the watershed include the fact that it is prone to both drought and flooding, and has experienced significant changes in precipitation patterns in recent years due to climate change.