At the north end of the State an extensive area is drained by the Klamath, Salmon, Trinity, Eel, and Van Duzen Rivers.  These streams are not yet controlled as much as those on the slopes of the Sierra Nevada.  Plans are being developed for the eventual use of these waters to meet requirements of this immediate area, or of areas to which the water might be transported.

The largest streams on the central coast are the Russian River, which empties into the ocean about 50 miles north of San Francisco, and the Salinas River, which discharges into Monterey Bay.  Other streams along the coast are short and small.

The Central Valley, sometimes called the Great Valley, lies between the Coast Range and the Sierra Nevada.  At the point where the rivers empty through Carquinez Strait into San Francisco Bay the valley floor is only about 10 feet above sea level.  Indeed, some reclaimed farmland within the delta system actually lies at or below sea level.  At the north end of the Central Valley, Red Bluff is approximately 300 feet in elevation, while Bakersfield, near the south end, is around 400 feet.  In length the valley extends nearly 500 miles, while the width of the floor is only about 45 miles; when the gently sloping foothill area is included it extends to about 120 miles.