BETTER GROUND-WATER MANAGEMENT 283 



surface- and ground-water storage and use, or because the 

 legal, fiscal, and administrative machinery to accomplish the 

 required coordination is inadequate. Since these problems 

 have been discussed in previous chapters, their details will not 

 be repeated here. A brief summary of each of the experiences, 

 however, is essential to illustrate the diagnostic and regula- 

 tory characteristics management programs must take into 

 account. 



San Joaquin Valley, Calif. In this valley by far the great- 

 est total use of ground water is made in the United States, a 

 quantity nearly one-quarter of all the water produced by wells 

 throughout the country. About 7,000,000 acre-feet of water is 

 pumped annually from some 40,000 irrigation wells. The 

 ground-water reservoir is recharged either by seepage from 

 stream channels and irrigation canals or by percolation from 

 irrigated lands. The pumping draft exceeds the average 

 ground-water replenishment by about 1,500,000 acre-feet. In 

 many areas the ground-water storage has been progressively 

 declining for many years, yet in other sections the water table 

 has been materially raised and has caused the actual abandon- 

 ment of some farms. The greatest water deficiencies in pre- 

 cipitation, stream flow, and ground-water replenishment are 

 near the south end of the valley and become progressively less 

 toward the north. 



The correction of the situation rests primarily upon im- 

 porting surplus water from the Sacramento Valley in the 

 north for groundwater replenishment, in order to provide 

 annual and cyclical storage. The conditions of infiltration for 

 storage, movement, and discharge of ground water are so 

 diverse that much more study and exploration are essential 

 before the imported water will be utilized to the maximum. 

 Any comprehensive management program for the best utili- 

 zation of the ground and surface waters will involve a com- 

 plex management program incorporating at least the follow T - 

 ing elements: (1) artificial recharge; (2) artificial underground 

 storage over long periods, in extremely large aggregate vol- 

 umes; (3) due caution not to damage the lands extensively 



