Cooperation in Irrigation 267 



feet of water per acre each year and most other crops 

 more than half as much. 



"Mutual companies are controlled by a Board of Direc- 

 tors elected annually by the stockholders. The directors 

 elect one of their number president. The Secretary keeps 

 the books and records and computes and collects charges 

 for water. The work of water delivery and maintenance 

 is placed in charge of a superintendent. Large companies 

 have zanjeroes to assist in delivering water. 



"When the crops under an irrigation system are of the 

 same class, such as citrus fruits, it is usual to deliver water 

 by rotation. A stream or head is used in succession by 

 stockholders along a lateral pipe or ditch, the complete 

 circuit or rotation being completed in a specified time, 

 usually about thirty days, and the time of use by each 

 stockholder being proportional to the number of his shares. 

 Schedules of rotation are made in advance for the entire 

 season, so that each stockholder knows the time of the 

 month that he is to have the water. The water need 

 be measured only at the head of the lateral, then the num- 

 ber of hours that the water is used by each stockholder 

 when recorded is sufficient to compute the water charge. 

 Heads from thirty to sixty miner's inches are delivered 

 for ten-acre citrus orchards, and the length of an irrigation 

 ranges from twelve to forty-eight hours. Sandy soil 

 requires a large head for a short time, while tight soil 

 requires a small head for a longer time. Where the crops 

 under a system are diversified, delivery by rotation, al- 

 though the most economical, is not always practical on 

 account of the different water requirements of the crops 

 as to time and frequency of irrigation and the size of head. 



