PROBLEMS FROM DEVELOPMENT 69 



rado River aqueduct. With these importations, plus avail- 

 able local supplies, the metropolitan district now serves 

 3,500,000 people and has reserves sufficient for an estimated 

 8 million population. San Diego also imports Colorado River 

 water to supplement its local supplies of surface and ground 

 water. In addition, the Colorado River furnishes the water for 

 the hot desert valley in southeastern California which is oc- 

 cupied by the Salton Sea. The Imperial Valley, south of Salton 

 Sea, contributes many fresh vegetables and fruits to the na- 

 tion's market basket in the winter; it is underlain by river 

 sediments too fine to form an acceptable ground-water reser- 

 voir, and the water for irrigation of more than 400,000 acres 

 has been diverted from the Colorado River since 1907 (page 

 199). Coachella Valley, north of the Salton Sea and the major 

 producer of domestic dates, has been dependent upon an 

 artesian ground-water reservoir for its irrigation supplies. In 

 the past 50 years, development has increased until most wells 

 have ceased flowing, and even with a high degree of conserva- 

 tion, there has been a gradual depletion of storage in the 

 ground-water reservoir. Water imported from the Colorado 

 River through the Coachella branch of the Ail-American 

 Canal is expected to relieve present conditions of overdraft on 

 that ground-water reservoir. 



The city of Santa Barbara has depended for its water supply 

 upon transmountain diversion from the small Gibraltar res- 

 ervoir on the Santa Ynez River. This supply has been inade- 

 quate for years, and, since 1948, ground water has been 

 pumped increasingly from the reservoir under the city. The 

 ground-water reservoirs in the contiguous Goleta and Car- 

 pinterin Valleys have been overpumped in recent years, and 

 water levels have dropped below sea level, but Goleta Valley 

 is protected from saline intrusion by a fault barrier along the 

 coast. The water shortage in all three valleys will be relieved 

 by diversion from the Cachuma reservoir now under con- 

 struction, which will store up to 210,000 acre-feet of flood 

 waters of the Santa Ynez River. 



The most magnificent project yet undertaken for transfer- 



