is a major factor in fishway cost. If a 

 steeper slope fishway is found to pass 

 salmonids as efficiently as the standard 

 1:16- slope fishway, substantial savings in 

 the cost of future fishways will be realized. 



The assistance of Dr. Gerald B. Collins 

 and Carl H. Elling in planning these experi- 

 ments and reviewing the manuscript is 

 gratefully acknowledged. Biologists of the 

 Biometrics Unit of the Seattle Biological 

 Laboratory* assisted in the statistical 

 analysis of the data. Corps of Engineers 

 personnel of the Hydraulic Laboratory at 

 Bonneville Dam advised on hydraulic 

 problems encountered. The following indi- 

 viduals participated in the experiment: 

 Richard L. Foust, Robert J. Holcomb, 

 James S. Johnson, Howard L. Raymond, 

 Edwin F. Roby, Robert S. Rupp, and Charles 

 R. Weaver. Credt is due Virginia Coleman 

 for the illustrations and Charles R. Weaver 

 and Edwin F. Roby for the photographs. 

 Acknowledgment is made to Milo C. Bell, 

 who reviewed the manuscript and offered 

 suggestions on its preparation. 



EXPERIMENTAL EQUIPMENT 



by a center wall. A fishway was installed 

 in each channel. The water supply for the 

 fishways enters through a diffusion chamber 

 at the bottom of the flow- introduction pool. 

 The water comes from the Bonneville 

 forebay through a large pipe into a valve 

 chamber where sliding gate valves control 

 the flow of water entering the diffusion 

 chamber. A detailed description of the 

 laboratory is given by Collins.' 



Fishways 



The test and control fishways were 

 constructed side by side in the experimental 

 flume. The slope was 1:16 in the control 

 (Types 1 and lA) fishway and 1:8 in the 

 test (Types 2-4) fishway. Both were pool- 

 and -overfall type fishways without sub- 

 merged orifices. Figure 1 and table 1 give 

 physical comparisons of the test and con- 

 trol fishways. 



Weir 54 



56 57 



116 Slope 



Laboratory 



This study was made in the Fisheries - 

 Engineering Research Laboratory at Bonne- 

 ville Danri during the 1956 fish-migration 

 season. Although it is possible to test full 

 scale fishways in this laboratory, fishway 

 length and gain in elevation were linmited in 

 this study by the necessity of using pre- 

 fabricated fishways that could be readily 

 disassembled. The main features of the 

 laboratory are a collection pool, experi- 

 mental area, and flow -introduction pool. 

 Fish, diverted from the Washington shore 

 fishway into the collection pool, pass through 

 the experimental area and then are free to 

 continue through the flow -introduction pool 

 into the exit fishway and return to the 

 Washington shore fishway. The fish are not 

 handled during their entrance or exit. 



The collection pool was 24 feet wide 

 and 30 feet long and had a water depth of 14 

 feet during the course of the experiments. A 

 picketed divider at the upstream end con- 

 trolled the entry of fish into the fishways. 

 The experimental flume (24 feet wide and 

 104 feet long) was divided into two channels 



Weir 54 



56 



58 

 18 



60 



Slope 



Weir 



58 59 60 

 I 8 Slope 



58.5 60 

 I : 8 Slope 



Scole I inch= 20 feef 



Figure l.--Diagram of control fishway (top) and the three test 

 fishways, comparing relative distance travelled and gain in 

 elevation. (Weir numbers are elevation of weir above mean 

 sea level). 



* Formerly Pacific Salmon Investigations. 



*CoUins, Gerald B. Research on fish passage problems. 

 Manuscript in preparation. 



