THE IREIGATION AGE. 



267 



THE SCOPE AND PURPOSE OF THE IRRIGATION 



INVESTIGATIONS OF THE OFFICE OF 



EXPERIMENT STATIONS. 



BY ELWOOD MEAD, IRRIGATION EXPERT IN CHARGE. 

 Courtesy U. S. Department of Agriculture. 



Coniiuucd 



INSTRUMENTS FOR MEASURING WATER. 



In carrying on the measurements of water it was 

 found that the instruments used were in many cases 

 not suited to the work required of them, and were so 

 expensive as to limit their use generally to Government 

 and State work. With the progress of the work of the 

 investigation there has been a growing demand for 

 instruments which will do accurate work and at the 



that is, a person or company can maintain a right to 

 only so much water as he or it can put to a beneficial 

 use in irrigation. It is of first importance, therefore, 

 to know how much water is needed to grow crops on a 

 given area, in order that courts and boards of control 

 may intelligently determine the amount of rights to 

 - water, and officers charged with this duty be able to 

 prevent wasteful use by those who have early rights 01 

 a desire to monopolize the supply. Because of the lack 

 of this information, rights to water have too often been 

 established without any regard to the volume of the 

 stream, the capacity of canals, or the needs of the land 

 to be irrigated. The attempt to utilize such excess 

 rights can lead to nothing else than continued litigation 

 and trouble. The facts gathered in these investigations 

 are already being eagerly sought as a guide in the es- 

 tablishment of water titles, and they are certain to 



IRRIGATION INVESTIGATIONS RESULTS OF IRRIGATION IN WISCONSIN. 



The two central piles show the yield and size of potatoes grown on unirrigated rows. The two end piles show the yield and size of potatoes grown on 



irrigated rows. 



same time be within the reach of canal companies and 

 individual irrigators. The instruments most used are 

 the current meter and the register for keeping a con- 

 tinuous record of depth of water at any point. Efforts 

 have been made to cheapen these instruments and at 

 the same time increase their efficiency. Little has been 

 accomplished with the current meter, but the water 

 register has been so simplified as to reduce its cost by 

 more than half without any sacrifice in accuracy. The 

 appearance and method of using these registers is shown 

 in Fig. 2. 



LEGAL AND SOCIAL PROBLEMS. 



The measurements made to determine the quanti- 

 ties of water used and the losses from canals has an- 

 other object besides the improvement of agricultural 

 practices. It is a principle of irrigation law, in theory 

 at least, that rights to water are based on beneficial use ; 



prove one of the most effective agencies in preventing 

 erroneous or excess decrees in the future. 



A knowledge of the extent of the losses from canals 

 is also necessary to the proper distribution of the sup- 

 ply. Appropriations usually contemplate the measure- 

 ment of the volume allowed at the head of the canal, 

 hence the amount granted should be great enough to 

 meet all the necessities of crops and also to allow for 

 losses in transit. If this estimated loss is too large the 

 volume taken in at the head gate will be greater than 

 the needs of the Jand irrigated, but if too small irriga- 

 tors will suffer. Excessive allowance for these losses 

 puts a premium on poor construction, hence data is 

 needed to show what are reasonable losses and to pre- 

 vent anything above this. Where losses can be stopped 

 appropriations should be cut down in order to compel 

 ditch owners to make them economical water carriers. 

 Losses which can not be stopped should be provided for. 



