FUTURE NEEDS FOR DEVELOPMENT 265 



about 40 per cent of the national total, and the five states to- 

 gether account for more than 65 per cent of the water with- 

 drawn from wells throughout the nation. In none of these 

 states was there any statutory basis for control of ground-water 

 development during the construction of the hundreds of thou- 

 sands of wells that produce this water, although Arizona's 

 1948 statute is designed to prevent further increase in draft 

 in "critical areas." The colossal draft is chiefly for irrigation. 



The lack of regulation shows up in the fact that these five 

 states contain the great majority of the ground-water reser- 

 voirs where the annual pumping is significantly in excess of 

 the average annual replenishment (Plate II). The situation 

 is far from hopeless in many of those areas, however. Correc- 

 tive measures are being taken in several places, notably in 

 California, as pointed out on pages 60-77. It is expected that 

 these corrective measures will bring replenishment into bal- 

 ance with the draft, in some places at considerable cost, but 

 with substantial benefits to those areas where it has been possi- 

 ble to increase the natural perennial yield by artificial means. 

 The success of these corrective measures has been possible, 

 however, because of the finding of additional potential in 

 stream flow or reclaimed sewage or industrial wastes, or in 

 areas from which water could be imported. Without such un- 

 tapped resources and without regulation of pumping, there is 

 no means of preventing a continuation of overdraft until the 

 ground-water reservoir is exhausted. 



There are several reasons for the lesser degree of ground- 

 water development under the statutory regulations of other 

 western states. Some states do not have the potentialities of 

 a California or a Texas, and the quantity of water pumped 

 even when all their ground-water reservoirs are fully de- 

 veloped will not be large. In several states additional ground 

 water is known to be available for development, but it has 

 not yet been applied for. There is little evidence that the stat- 

 utes themselves have been responsible for limitation of de- 

 velopment, because they generally have been broadly framed 

 for the purpose of providing an orderly development in the 



