Passage of Adult Salmon and Trout Through Pipes^ 



By 



EMIL SLA TICK, Fishery Biologist 



Bureau of Commercial Fisheries Biological Laboratory 

 Seattle, Washington 98102 



ABSTRACT 



Pipes, which are relatively inexpensive and easily installed, are an economical 

 and efficient solution to certain problems of fish passage at dams and at other ob- 

 stacles blocking migratory routes. The purposes of this study (1963-64) were to 

 determine: (1) if adult salmon and trout at Bonneville Dam on the Columbia River 

 would use a pipe as a passageway and (2) how the conditions at the entrance and with- 

 in the pipe, diameter and length, illumination, and flow would influence passage. The 

 pipes were 0.3, 0.6, and 0.9 m. in diameter and were 27.4 to 82.3 m. long. 



Chinook salmon ( Oncorhynchus tshawytscha ), sockeye salmon (O. nerka) , coho 

 salmon (O. kisutch), and steelhead trout ( Salmo gairdneri ) passed through unillumi- 

 nated pipes up to 82.3 m. long. Of the four species tested, only steelhead trout ap- 

 peared to benefit appreciably from illumination. For distances up to 82.3 m., a 

 0.6-m. -diameter pipe was large enoughto pass all salmon and trout. The fish passed 

 through a 0,6-m. -diameter pipe when it was flooded or partly filled with water, but 

 did not readily enter a 0.3-m. pipe until special conditions of water velocity and 

 transition from pool to pipe were provided. 



INTRODUCTION 



Upstream passage facilities for adult salmon 

 and trout at dams frequently require nnoving 

 of the fish from one area to another at ap- 

 proximately the same elevation. Pipes, which 

 are relatively inexpensive and easy to install, 

 offer a potentially economical and efficient 

 means of transport. 



Fish transportation systems at dams on 

 the Columbia River consist of collection facil- 

 ities and channels leading to fish ladders. If 

 salmon were to accept pipe passageways, it 

 might be possible to expand the systems and 

 reduce the number of fishways. This idea was 

 put into effect at the Pelton regulating dam on 

 the Deschutes River, Oreg., where a tunnel 

 under the spillway connects the left bank col- 



Work financed by U.S. Army Corps of Engineers as 

 part of a broad program of fisheries-engineering research 

 to provide design criteria for more economical and effi- 

 cient fish-passage facilities at Corps projects on the 

 Columbia River. 



lection system to the central ladder.^ A sub- 

 merged 1.5-m. -diameter pipe 25.9 rn. long was 

 also used successfully for 3 years as one 

 entrance to the temporary fishway system 

 during construction of Oxbow Dam on the Snake 

 River. ^ 



Another potential application of pipes is to 

 extend fishway exits beyond the immediate 

 influence of spillway gates, which might re- 

 duce or possibly eliminate the loss of fishthat 

 normally fall back over spillways. A signifi- 

 cant number of tagged fish released into the 

 forebay at Bonneville Dam fell back (U.S. 

 Army Corps of Engineers, 1951) as did un- 

 tagged fish (U.S. Army Corps of Engineers, 



^Gunsolus, Robert T., and George J. Elcher. 1962. 

 Evaluation of the fish-passage facilities at the Pelton 

 Project on the Deschutes River in Oregon. Fish. Comm. 

 Oreg. and Portland Gen. Elec. Co., Portland, Oreg. 133 

 pp. [Processed.] 



^Personal communication, Charles H. Wagner, Columbia 

 Fisheries Program, Bureau of Commercial Fisheries, 

 Portland, Oreg., May 29, 1969. 



