OFFICE OF EXPERIMENT STATIONS. 298 



Because of the complex issues which have to be dealt with, the pri- 

 mary requisite is capable and experienced men, and the Office has 

 enlisted in its service a number of irrigation engineers and scientists 

 having a National and even an international reputation. The serv- 

 ices of men of this character would have entailed a prohibitorj' expense 

 had it been necessary to employ them continuousl3\ This has been 

 avoided, however, through cooperation with the State engineers' offices 

 of the different arid States and with the State agricultural colleges 

 and experiment stations throughout the country. 



MEASUREMENTS OF THE DUTY OF WATER. 



At the beginning of the work the duty of water was made a leading 

 subject for investigation, because, in dealing with irrigation from any 

 standpoint (administrative, engineering, or agricullural), the water 

 master, the engineer, or the farmer soon comes to the point where it 

 is necessar}' to know approximately how much water is needed for an 

 acre of ground. 



Two States, Nebraska and Wyoming, have already passed laws 

 limiting the quantity of water which maybe appropriated for a given 

 area, while all the other States where irrigation is necessary have 

 laws prohibiting waste and limiting rights to water to the quantity 

 which can be used beneficiallj^ Thos.e charged with the distribution 

 of the water supply must know what is beneficial use and where waste 

 begins. 



The irrigation engineer needs to know more than the theoretical 

 carrying capacities of ditches of various sizes and grades and the cost 

 of excavation in different materials and of different classes of con- 

 struction. He must know how much land the water carried by his 

 canal will serve. The basis for all the computations of the engineer 

 must be the quantity of water required for an acre planted to the crops 

 which it is proposed to raise. 



The farmer, at the very beginning of his experience with irrigation, 

 must know how much water he needs and when he needs it. If he 

 builds his own canal, he must know how large to make it; if he buj's 

 water from a large canal, he must know how much to buy. Building 

 too large a canal or paying for more water than he needs is throwing 

 monej" away, while farming with too little water is equally disastrous. 

 The tendency of farmers seems to be to use all the water that can be 

 obtained, often to the injurj^ of their crops and lands. Such farmers 

 need to be shown the better results obtained by others who use water 

 economically. 



This Office is now measuring the water used in irrigation in all of 

 the arid States but one, and in a number of the humid States. The 

 results secured in the past three years, while not conclusive, have 

 already done much to educate farmers and ditch managers as to the 

 direction from which improvement of methods and practices must 

 come. It also shows that it is possible to obtain an average duty 

 which will serve as a basis in the establishment of rights, and be a 

 reliable guide for the planning of irrigation works and for the distri- 

 bution of streams between individuals, communities, and even differ- 

 ent States. 



"While there are wide variations between farms and different locali- 

 ties, the averages show a remarkable uniformity. The records show 

 that nearly one-half of the water diverted from streams is lost through 

 leakage and evaporation in canals. Measured at the head gate, the 



