Surface Water Characteristics . Many rapid flowing rivers and streams. Rivers flow westerly in deeply incised canyons with bedrock controlled channels to the Great Valley section and Pacific Ocean. Reservoirs for municipal water supply, irrigation and flood control are common. Disturbance Regimes .
Fires are low, moderate and high intensity surface or stand replacing fires.
Land Use . Composition and successional sequence of some communities has changed because of plant and animal species introduced between the mid 1800 s and early 1900 s related to mining, grazing and agriculture. Rapidly expanding foothill urban areas are scattered throughout the section. Large and small water impoundments are common. Cultural Ecology .