DUTY AND DIVISION OF WATER 347 



ably represents the average requirement of ordinary farm 

 crops, providing the water is measured at the intake to the 

 farm. Should this be increased to 20 inches it would still 

 be much less than the quantity ordinarily applied. A 

 depth of 12 acre-inches equals a duty of 120 acres per 

 second-foot for sixty days, or 180 acres for ninety days, 

 or 240 acres for one hundred and twenty days. These 

 figures probably approximate the normal duty for western 

 America, under present conditions. 



The new duty of water must be based upon all the 

 knowledge in the possession of man. The water in the 

 streams must be used to cover the largest possible area 

 so that more men may be given employment and more 

 families maintained upon the irrigated lands. 



THE MEASUREMENT OF WATER 



210. Need of measuring water. Farmers keep ac- 

 counts of the area of land under cultivation, the yields of 

 crops per acre and the money received for each bushel of 

 grain or ton of alfalfa, but often fail to keep track of the 

 quantity of water used in irrigation. The whole discussion 

 of the preceding chapters is, however, based on the thesis 

 that irrigation water may be and should be measured. 

 Especially is this necessary where water is more valuable 

 than the land, and where it is, therefore, more important 

 for the farmer to obtain a large yield to the acre-foot of 

 water than to the acre of land. Moreover, if water, from 

 the beginning of irrigation, had been measured, less land 

 would have become water-logged or subjected to the rise 

 of alkali. Finally, there will always be disputes about 

 water-rights, and after water-rights are established the 

 rulings of the courts must be literally obeyed, so that 



