Thompson. — Irrigation and Trout Culture 111 



Mr. Thompson: What is the size of your pipe? 



Professor Dyche: It is 21-inch pipe carrying 3 l / 2 million gallons 

 of water per day. 



Mr. Thompson: People have a wrong conception of what irriga- 

 ting ditches mean. They are of all sizes, but the main canals are really 

 small rivers. 



Professor Dyche: We have a river big enough to run a flouring 

 mill which we expect to control through the use of wire screens. 



Mr. Thompson: Then again the irrigationist is not necessarily in- 

 terested in the fish-cultural problem, and you have not only sage brush 

 and silt, hut sometimes young trees floating down the streams, which 

 would soon clog the screens since there is no provision made for keep- 

 ing them clean. Of course this is one of the problems we must solve. 

 A revolving paddle wheel 'is one of the devices now being tested, but 

 it does not absolutely keep ail the fish from entering the ditches. It 

 revolves through the force of the current, causing more or less disturb- 

 ance of the water, the idea being that it frightens most of the fish back. 

 As a matter of fact, while some of them escape into the ditches and 

 are eventually lost, a majority are preserved. This device permits the 

 passage of debris of almost any reasonable size. Most of this irriga- 

 tion water comes tumbling down from away up in the mountains, carry- 

 ing all sorts of debris; it would fill up any ordinary screen so quickly 

 you would scarcely know what happened. The ditch riders and the 

 water superintendents have a very large area to cover and frequently 

 are not particularly interested in fish culture, hence do not want to be 

 hampered by any system of screens. Thus far no system of screens 

 has been a success and we are not disposed to blame them for their 

 indifference. The water-user does not care to incur any extra expense. 

 Here, then, is a problem which should properly be taken up by fish cul- 

 turists and angling associations co-operating with the Water Commis- 

 sioners and other proper state officials. Fish culturists have long en- 

 deavored to bring about a sentiment in favor of providing some device. 



Several years ago while in Colorado 1 took up this matter of a 

 campaign of education. The state of Colorado in the blank applica- 

 tions for fish inquired whether the headgates of all the ditches were 

 provided with screens or other devices for preventing the escape of the 

 fish. That was educational, because they could not well refuse to give 

 people fish even if the ditches leading from the streams were not so 

 protected. I suggested to the Washington office that the Bureau of 

 Fisheries take cognizance of the irrigation work, and also insert in its 

 blank applications this same, or a similar, inquiry. This was subse- 

 quently done. We hope to work up a sentiment which will eventually 

 bring about some system of screens or paddle wheels that is both prac- 

 tical and effective. As yet, however, such a system has not been 

 perfected. 



Professor Dyche : You answered the question when you first 

 started out by saying they had no interest in the business and did not 



