PROBLEMS FROM DEVELOPMENT 39 



north by a reach of the Gila River where consumptive waste 

 of water by tamarisk and mesquite was estimated in 1942 to 

 be between 100,000 and 150,000 acre-feet a year. If this 

 vegetation could be replaced with crops or other vegeta- 

 tion that uses less water, the water saved might serve to al- 

 leviate some of the shortage in the lower Santa Cruz Valley. 

 Such salvage would involve both technical and legal prob- 

 lems in connection with established rights to the water in 

 the Gila River. 



The proposed central Arizona project of the Bureau of 

 Reclamation includes the lower part of the Santa Cruz 

 Valley as one of the areas where supplemental water would 

 be imported from the Colorado River. 



Antelope Valley, Calif. 2 Antelope Valley lies north of the 

 San Gabriel Mountains and only about 75 miles north of 

 Los Angeles. Although the setting is real desert, ground 

 water appeared to be inexhaustible in 19.10, when several 

 wells had artesian pressures of more than 10 pounds per 

 square inch and flowed 900 gallons a minute. Many wells 

 had ceased flowing by 1920, however, and since then more 

 and more wells have been pumped for irrigation. Today 

 about 110,000 acre-feet is pumped annually. 



The total replenishment in recent years is estimated to 

 have averaged about 65,000 acre-feet annually, and water 

 levels in wells have been declining at a rate of about 3 feet 

 a year, because of overdraft. The Owens Valley aqueduct 

 to Los Angeles crosses the valley, and in some years as much 

 as 7,000 acre-feet of water has been released within the 

 valley to augment the natural replenishment of the ground- 

 water reservoir. The valley has large underground storage 

 capacity and a great expanse of land suitable for irrigation 

 if more water were available. 



In the San Jacinto Basin, also in the desert region of 



3 References: Gleason, J. B., "Antelope Valley, South Coastal Basin Investi- 

 gations, ' Calif. Div. Water Res., Unpublished data. 

 Calif. Div. Water Res., Personal communication. 



