water conduits were installed to provide 

 the best known attraction and transportation 

 facilities for fish as they approached and 

 began their ascent over the dam. Special 

 features were also added to assist the out- 

 migrating f ingerlings in descending from 

 forebay to tailrace areas in their journey 

 to the sea. 



Notwithstanding early fears of possible 

 failure, the Bonneville fishways immediately 

 demonstrated their worthiness. Lessons 

 learned here played an important part in the 

 subsequent design of fishways at McNary and 

 The Dalles Dams which are located upstream 

 from Bonneville Dam. Despite the satisfac- 

 tory operationjil records of the Bonneville 

 and McNary fishways, much needs to be done 

 to achieve increased efficiency. 



Heretofore, much of our knowledge of 

 fishway design has been derived empirically. 

 Recently, however, various agencies and in- 

 stitutions have initiated vigorous research 

 programs designed to provide basic data 

 applicable to the solution of the many prob- 

 lems associated with fish passage facilities. 

 One of the more recent developments in this 

 new research era is the construction of the 

 Fisheries-Engineering Research Facility, 

 located on the Washington side of Bonneville 

 Dam. Here, under controlled Ijiboratory con- 

 ditions, prototype fishways and allied 

 structures can be installed and fish behav- 

 ior critically examined by experimental 

 processes. 



One of the fundamental questions in 

 fishway design which has yet to be speci- 

 fically answered is "How large should a 

 fishway be to pass effectively a known or 

 conceivaible maximum number of fish?" If we 

 are presently constructing our fishways far 

 larger than the maximum demand requires, 

 then it is obvious a considerable saving 

 might be realized merely through a reduction 

 in their size. Not only may construction 

 costs be reduced, but concomitant water 

 economies may also be expected. 



Initial research, seeking a basis for 

 the solution of the problem of fishway size, 

 began at the Bonneville facility in the 

 spring of 1956 and was continued intermit- 

 tently until early September of that yeair. 

 The term "fishway capacity" was used to 

 describe the object of these experiments 

 and may be defined as the "maximum number 

 of fish (size and species considered) that 



a fishway of given dimensions and hydraulic 

 conditions can pass per unit time." 



The purpose of this study is (1) to 

 determine experimentEilly the specific capa- 

 city of a prototype overfall fishway and 

 (2) to note factors which may influence 

 this capacity. 



The following is a report of the ini- 

 tial phase of our work which was confined 

 primarily to the development of procedures 

 and techniques whereby capsicity might be 

 measured. No attempt is made to consolidate 

 these initial endeavors into a final deter- 

 mination of capacity. Several observations 

 are made and the significance of each is 

 discussed as it affects a measure of fish- 

 way capacity. These have been included so 

 that they may become readily available for 

 examination and study by those immediately 

 concerned with the problem. 



As this work is essentially preliminary, 

 we emphasize that interpretation of the 

 recent observations can be only tentative, 

 pending further examination of the specific 

 relationships which may control fishway 

 c apacity. 



MATERIALS 



Description of Fisheries-Engineering 

 Research Facility 



A detailed description of the Fisheries- 

 Engineering Research Facility is in prepara- 

 tion by Collins .2' Essentially the structure 

 is a rectangualr flume 200 feet long by 24 

 feet wide with a maximum depth of 24 feet. 

 The flume is a unit of a by-pass structure 

 connecting with the Washington shore fishway. 

 Various prefabricated structures may be in- 

 stalled in the flume to simulate a variety 

 of experimental fishway conditions. An 

 overhead traveling crane is used to install 

 and remove the heavier structures used in 

 the studies. 



Fish for experimental purposes, di- 

 verted from the Washington shore fishway, 

 ascend an entrance fishway to a collection 



3/ Collins, Gerald B. Research in fish 

 passage problems, U. S. Fish and Wild- 

 life Service. Manuscript in preparation. 



