FISHWAY CAPACITY EXPERIMENT, 1956 -i' 



1/ 



by 



Cjtrl H. Elling and Howard L. Raymond 



U. S. Fish and Wildlife Service 



Seattle, Washington 



ABSTRACT 



Prom May 22 to September 7, 1956, eight tests were made involving 

 the passage of varying numbers of fish through an overfall-type fish- 

 way. The fishway, which was 6 feet wide, consisted of 6 pools (1 foot 

 rise between pools) each 16 feet long with an average depth of 6.3 

 feet. In the tests, from 70 to 2886 fish entered the fishway during 

 1-hour periods. The median passage time for fish to ascend the 6-pool 

 fishway ranged from 12 to 35 minutes. The effect of pattern of flow 

 and other criteria on fish passage is discussed. 



INTRODUCTION 



Fishery and water development interests 

 share a mutual concern over the high costs 

 of fishways and fish protection devices at 

 dams and water diversion projects. As an 

 example, the fish passage facilities at The 

 Dalles Dam, completed in 1957, cost in 

 excess of 18 million dollars. Outlays for 

 fish protection structures in some instances 

 amount to as much as 15 percent of the total 

 cost of dam construction exclusive of fish- 

 ways (U. S. Fish and Wildlife Service 

 1953). £/ The question arises then, "How may 

 we seek to reduce these expenditures with- 

 out impairing the safety of fish passage?" 

 A plausible approach lies in the study of 

 fish behavior and the principles involving 

 in fish passage with emphasis on the appli- 

 cation of this knowledge toward the design 

 and construction of more efficient fish- 

 passage facilities. 



Modern fishways on the Columbia River 

 are undoubtedly the largest £Uid most ela- 

 borate to be found anywhere in the world. 

 They contain a host of features which their 

 designers felt were necessary to insure 

 safe passage of fish beyond the man-made 

 obstacles. There was good reason for this. 

 Before the construction of Bonneville Dam, 

 some people expressed serious doubt that 

 runs of the magnitude known to migrate up 

 the Columbia River could be effectively 

 passed. As a result, special precautions 

 were taken to provide ample saifeguards for 

 meeting a number of conceivable conditions 

 (Holmes 1940). Accordingly, the total 

 facilities finally installed may have been 

 far more elaborate than necessary. We find 

 that dual pasfage facilities (i.e., fish 

 ladders and elevators) were provided in the 

 event one or the other failed to pass 

 migrants effectively. Elaborate collection 

 systems and a complex network of auxiliary 



W Research financed by the U. S. Army Corps 

 of Engineers as a part of a broad program 

 of fisheries-engineering research for the 

 purpose of providing design criteria for 

 more economical and more efficient fish- 

 passage facilities at Corps' projects on 

 the Columbia River. 



2/ A statement by the Fish and Wildlife Ser- 

 vice in response to the request, dated 



November 20, 1953, of Senator Styles 

 Bridges, Chairman, Senate Appropriations 

 Committee, for information on the abun- 

 dance, distribution, and value of the 

 Columbia River fish runs, the effect of 

 dams on these runs, and certain other 

 related information. U. S. Fish and 

 Wildlife Service, Office of the Regional 

 Director (Region 1, Portland, Oregon), 

 41 pp., tables, mimeo. 



