FISHWAYS IN BRITISH COLUMBIA 9 



maintaining therein the natural conditions of the water, and in order 

 that the interior may easily be inspected and any foreign matter 

 removed. 



" 5. A fishway in all its parts should, by the action of the current 

 of water passing through it* be as nearly as possible, self-cleaning of all 

 sand, gravel, mud, and rubbish. 



"6. The water supply of a fishway should be ample and the same, 

 or nearly so, at both ordinary high and low water stages, avoiding 

 thereby any regulating gates or other devices calling for the services 

 of an attendant. 



"7. The top and sides of a fishway should be above ordinary 

 high water. 



"8. The fishway should be built very strong and be well pro- 

 tected against the destructive effects of freshets, drift logs, ice, etc. 



"9. The intake and outlet should be well submerged and the 

 former protected against floating debris, etc., by a suitable grating. 



"The location of a fishway must be such that ascending fish will 

 not be alarmed and driven off by disturbance from boats, fishermen, 

 etc. 



"The material of fishways may be wood, stone, concrete, or iron, 

 depending opon the construction of the dam, its size, the topography 

 and nature of the site, the labour and material at hand, and the 

 funds available."* 



It is not the intention here to discuss the merits of various fish- 

 ways, but it is desired most emphatically to point out that great 

 difficulty will be experienced in providing and maintaining satisfactory 

 fishways in power dams of considerable height, say above 25 or 30 

 feet. 



The United States Bureau of Fisheries is alive to the fact that 

 the fisheries of the country have suffered by reason of inadequate 

 provision being made for the fish to overcome obstructions in streams. 

 With commendable enterprise the Bureau had commenced an exten- 

 sive investigation involving observations and experiments to determine 

 the efficiency of all fishways now in use. The research, owing to 

 present exigencies, has been temporarily suspended. 



The Bureau appears to have accepted as a basic doctrine, where 

 matters of advantage or disadvantage are being considered in connec- 

 tion with dams and the construction and maintenance of fishways, 

 that any benefit of doubt should properly be given to the fish; and, 



* Consult Fishways, by H. Von Bayer, C.E., a paper presented before the Fourth 

 International Fishways Congress, held at Washington, U.S.A., Sept. 22-26, 1908. 



