THE IRRIGATION AGE. 



373 



the two acre-feet per acre is used, not only are the farm- 

 ers apparently not careful although they ought to be, 

 because they pay for the water used or wasted at the 

 rate of 37!/2 cents an acre-foot but the checks they en- 

 deavor to irrigate are as large as fifteen or sixteen acres 

 in area and frequently far from level. 



The only way to increase the duty of water in Cali- 

 fornia is for farmers to use more intelligent care than 

 they have in the past in the use of water. It is prob- 

 ably true that few farmers would use what they do if 

 they had any conception of its quantity. If this is the 

 case, one of the first practical steps is for farmers to 

 measure the water they use, which is in many cases a 

 very easy matter. The small weir shown in one of the 

 accompanying photographs is a simple device which 

 nearly all farmers can adopt, and by the use of which, 



ments will be necessary, so that it will be doubly effica- 

 cious. 



One of the first endeavors of the Office of Experi- 

 ment Stations in the co-operative irrigation and drainage 

 investigations in California is to gather additional data 

 on the duty of water, in so far as the means at hand will 

 permit. For two years it has been measuring the amount 

 of evaporation from cropped and uncropped soil sur- 

 faces with the idea of determining as best it can by 

 somewhat artificial means how much water would be 

 needed by different crops if losses by percolation through 

 the soil and by evaporation from the soil sur- 

 faces could be eliminated. In other words, it has 

 been endeavoring to learn something of the amount 

 of water plants themselves need and use. Also along the 

 line of the duty of water, the Office is endeavoring to 



oss Twin Falls Laud and Water Co.'s Canal, near Reservoir at Dry Creek. Cassia County, Idaho. 



with such instructions as are readily available on appli- 

 cation to the University of California or the Office of 

 Experiment Stations, quite satisfactory results can be ob- 

 tained. A more carefully constructed weir, intended for 

 permanent use in one place, is also shown. The burden 

 of water measurement should, however, be on those in 

 charge of canal systems as engineers or superintendents, 

 yet it is a fact that water is measured to irrigators in 

 but very few cases in California, and then practically 

 only in Southern California. Another means of increas- 

 ing the duty of water, and the most effective means, is 

 for water to be paid for by quantity used rather than 

 at a flat acre rate. Until water is so paid for the duty 

 will remain low. Canal companies throughout the West 

 which sell water and which formerly charged a flat acre 

 rate have learned that they can nearly if not fully 

 double the duty of water by charging for the water ac- 

 tually used. With such a plan of distribution measure- 



learn more definitely than is now known what becomes 

 of the water that is applied; in other words, how much 

 of it sinks below the point of availability in the soil, 

 how much is lost by surface evaporation from the soil, 

 and how much seems to be utilized by the trees or other 

 crops irrigated. Although this is a matter any energetic 

 farmer could himself learn much about by digging holes 

 .in his field after irrigation and watching how deep the 

 moisture applied sinks, very little is now known about it. 

 In the work now in hand the interest and assistance of 

 the soil experts of the Agricultural Experiment Station 

 at Berkeley have been enlisted. The field of present 

 study is some of the orange orchards of the region 

 around Riverside. Until the sources and character of 

 the waste of water in irrigating are known, no intelligent 

 efforts can be made to end them. 



Nothing has thus far been said about the duty of 

 water as it varies for different crops. To mention this 



