The Lower Pit Watershed (HUC 18020003) covers an area of approximately 2,710 square miles in Northern California. The watershed is fed by the Pit River and its tributaries and is characterized by diverse topography, including mountains, valleys, and volcanic plateaus. The hydrology of the watershed is influenced by the Sierra Nevada Mountains, which receive heavy snowfall in the winter months, contributing significantly to the snowpack. The surface water is used for irrigation, power generation, and municipal water supply.
The watershed is home to several reservoirs, including Lake Britton, which is a popular recreational area. The primary constituents in the reservoirs are sediment and nutrients, which can impact water quality and aquatic habitat. The watershed experiences a semi-arid climate, with hot summers and cold winters. In recent years, the region has experienced prolonged droughts and increased wildfire activity, likely due to climate change.