PUB00109 - Laserfiche WebLink

Home Browse Search

control; (2) irrigation and domestic uses, and (3) power. Water for environmental purposes was not included among the original stated purposes of the project. The Central Valley extends 500 miles, from the convergence of the Coast Range and the Sierra Nevada at Mount Shasta in the north to the Tehachapi Mountains in the south. It has an average width of 120 miles and includes more than one-third of the area of California. As the court wrote in Ivanhoe Irrigation District v. McCracken (1958) 357 U.S. 275, the CVP made possible the full development of the Central Valley- Rainfall on the valley floor comes during the winter months-85% from November to April-and summers are quite dry. . . . The climate is ideal with a frost-free period of over seven months and a mild winter permitting production of SOfie citrus as well as deciduous fruits and other specialized crops. The absence of rain, however, makes irrigation essential, particularly in the southern region. In the mountain ranges precipitation is greater. and the winters more severe. The Northern Sierras average 80 inches of rainfall and the Southern 35 inches.... In the higher recesses of the moun- tains precipitation is largely snow which, when it melts. joins the other runoff of the mountain areas to make up an annual average of 33,000,000 acre-feet of water coming from the mountain regions. Nature has not regulated the timing of the runoff water, however, and it is estimated that half of the Sierra runoff occurs during the three months of April, May, and June. Resulting floods cause great damage, and waste this phenomenal accumulation of water so vital to the valley's rich alluvial soil. The object of the [CVPl plan is to arrest this flow and regulate its seasonal and year- to-year variations, thereby creating salinity control to avoid the gradual encroachment of ocean water, providing an adequate supply of water for municipal and irrigation purposes, facilitating navigation, and generating power. Ivanhoe. pages 280-282. The operating scheme of the Central Valley Project is fairly simple. Shasta Reservoir, which has a capacity of 4,552,000 acre- feet, stores the surplus winter runoff of the Sacramento River. This water, in addition to repelling salinity intrusion and providing water for domestic irrigation and industrial uses in the Delta and Bay areas, is transferred through the Delta Cross-Channel and lifted by the Tracy Pumping Plant into the Delta-Mendota Canal, This canal carries water south by gravity flow to the Mendota Pool. The water The Central Valley Project moves water 500 miles, from Mount Shasta in the north to the Tehachapi Mountains in the south. Chapter 1 A Brief History 19