DRAINAGE BY MEANS OF PUMPING FROM WELLS IN ARIZONA 21 
foot. The average cost of labor, materials, and power for pumping 
149,643 acre-feet of water from October 1, 1922, to September 30, 
1923, was approximately 40 cents per acre-foot. It should be borne 
in mind, however, that the cost of this water varies for the several 
different conditions under which it is pumped, also that an attempt 
to duplicate these costs where economic conditions are not so favor- 
able may prove disappointing. 
The success of drainage by pumping in the Salt River Valley has 
induced other irrigation enterprises to undertake similar ^-velop- 
ments. Several such enterprises, although their records . ot so 
long as those in the Salt River Valley, nevertheless serve to prove 
the practicability of this method of drainage. A few, in fact, have 
disclosed advantages not found in Salt River Valley, such as water 
having very low alkalinity and a possible greater flexibility in choice 
of location of pumps with reference to irrigated lands, permitting 
practically complete utilization of the pumped drainage water for 
irrigation. Hence, although the conditions in Salt River Valley are 
peculiarly adapted to pump drainage, it is possible that the success 
achieved there may be duplicated or even exceeded in many other 
irrigated sections. 
