796 EXPERIMENT STATION RECORD. 



"(9) It is wasteful to use 2 ditches or laterals when 1 would serve. 



"(10) The loss iucreases Avith higher temperature, being about twice as much at 

 80° as at 32 . 



" (11) The loss iucreases with greater depth of water, but the exact relation needs 

 further investigation. 



" (12) The loss will be lessened by any process which forms or tends to form an 

 impervious lining or coating of fine material, as of clay or silt. The silt, consisting 

 of fine sand, improves many soils. Clay is better and especially limey clay, the lime 

 with the clay forming an almost impervious coating. 



" (13) Cement linings as used in California and Mexico are not warranted by the 

 conditions in Colorado, nor would the weather conditions be favorable. Nor is the 

 use of wooden stave piping for this purpose likely to be profitable iu many places in 

 the State, if at all on the larger canals at present. The silting process applied with 

 discrimination will accomplish much at smaller cost. 



"(14) On small laterals glazed sewer pipes may save annoyance often connected 

 with the carrying of water in laterals for considerable distances, which, with the 

 saving of water, may make its use an object. One of the supply laterals of the 

 Colorado Agricultural College is of vitrified sewer pipe, over 4,000 ft. of 12-iuch 

 pipe liciug used. 



" (15) Some particular sections iu canals are subject to much greater loss than the 

 canal as a whole. Hence water can be saved by locating the leaky place and reme- 

 dying it. This may be desirable to do while it would be unprofitable to treat the 

 whole canal. 



" (16) There are many places where it would be advantageous to combine 2 ditches, 

 by this means saving not only the loss of water, but saving superintendence and 

 maintenance charges. With increased confidence in the accuracy of water measure- 

 ment, reluctance to such consolidations should lessen. 



"(17) The depth of losses from laterals is probably greater than in the main 

 ditches. The laterals are less permanent, are steeper, have less silt, and are more 

 poorly cared for. 



"(18) There must be some arrangement of ditches and laterals which is the most 

 economical for given conditions, so that the aggregate of the losses of the whole sys- 

 tem will be a minimum. Certainly the location and arrangement of the laterals for 

 carrying water from the main ditch is worthy of consideration by the management 

 of the main canal, and the importance increases with the size of the canal aud the 

 width of the strip it serves. 



" (19) It is not to he understood that the whole of the loss from the ditches is lost 

 to the public wealth of the State. Some, perhaps much, of the loss, may reappear 

 as seepage in lower ditches or iu the main stream and again be used. It is, however* 

 lost to the particular ditch, and incidentally is destructive to much land. With all 

 practicable methods of prevention there will still be abundant loss. It should be to 

 the advantage of the individual ditch to prevent such loss as far as practicable. 



" (20) A general statement of the total amount of loss of water must be made and 

 accepted with reservation. It would appear that in the main canals from 15 to 40 

 per cent is lost, and in the laterals as much more. It would thus appear that not 

 much over one-half, certainly not over two-thirds, of the water taken from the stream 

 reaches the fields. In the most favorable aspect the loss is great, and is relatively 

 greatest when the loss can be least afforded, viz, when the water is low and the 

 ditches are running with reduced heads. 



"(21) There are Some 2,000,000 acres of land irrigated in Colorado, and the value 

 of the water rights at a low estimate is as much as $30,000,000. (The census esti- 

 mates the water rights as worth $28.46 per acre.) On this basis the capital value of 

 the water lost by seepage in the canals and ditches may be put at from $6,000,000 to 

 $10,000,000. From the evidence at hand at present this seems a low estimate." 



Report of trials with insulating materials, E. J. Bonnesen 

 (TidssJcr. LandbJcon., 17 (1898), No. 5-6, pp. 379-394).— The materials 

 tested were placed between zinc cylinders 19 in. in diameter and 3h ft. 



