Wenatchee River system. Power dam sites 

 listed for study have included sites on the 

 Wenatchee River in Tumwater Canyon and near 

 Plain, and on the Chiwawa River. Dams at 

 these sites would be barriers to migrating 

 fish and to maintain the runs it would be 

 necessciry to find ways of passing fish up- 

 stream and downstream past the dams. The 

 formation of pool areas also posed a prob- 

 lems in maintaining adequate spawning areas. 



For solution of these problems, cer- 

 tain basic data regarding fish runs must be 

 known. The Bureau of Commercial Fisheries 

 therefore undertook to provide basic infor- 

 mation on three specific problems relating 

 to the fish runs: (1) the size and timing 

 of the escapement of adult fish into the 

 upper Wenatchee River system, (2) the dis- 

 tribution of the adults in the spawning 

 streams, and (3) the timing and intensity 

 of the downstream migration of young fish 

 and their length and age composition. 



i'igure 2. — Tumwater Dam and fishway on the 

 Wenatchee River. (Note fish coiinting 

 trap at head of fishway. ) 



Financial support for this study was 

 received from the Public Utility District 

 of Chelan County, Washington. 



ESCAPEMEMT INTO THE UPPER 

 WENATCHEE RIVER SYSTEM 



Daily counts of adult fish migrating 

 to a spawning area provide information on 

 the size and timing of the runs past a 

 given point. For a commercially important 

 species that is the object of a fishery, 

 these counts show the escapement of the 

 species. They also serve to provide some 

 estimate of what may be expected in the 

 future . 



The size and timing of the runs into 

 the upper Wenatchee River system were 

 obtained by trapping and counting adult 

 fish at Tumwater Dam. All fish ascending 

 the Wenatchee River to spawning areas above 

 the dam pass through the fishway installed 

 therein. This dam, approximately 15 feet 

 in height, is located in Tumwater Canyon a 

 short distance below a site proposed for a 

 new dam. A trap was installed at the up- 

 streeim outlet of the fishway in 1954 by the 

 Washington State Department of Fisheries 

 and furnished a place for obtaining the 

 fish counts in 1955, 1956, and 1957. Fish 

 counters were employed to identify and 

 count fish out of the trap on a year-around 

 basis. During periods of little or no 

 migration, a counter was employed from the 

 Town of Leavenworth to visit the trap twice 

 daily. The dam and fish trap are illus- 

 trated in figure 2. 



The fish counting trap was in continu- 

 ous operation during the above years except 

 during flood periods when the trap was 

 completely submerged. In 1955 after the 

 project was initiated in May, the trap was 

 inoperative for short periods in June and 

 October. In 1956 and 1957, counting con- 

 tinued from January 1 through December 31 

 and the trap was in operative for short 

 periods in May and June. 



Size of Escapements 



Yearly totals of the fish escapements 

 counted over Tumwater Dam during 1955-57 

 are listed in table 1. Blueback, Dolly 

 Varden ( Salvelinus malma ) , and whitef ish 

 ( Prosopium williamsoni ) counts are complete 

 for the three seasons. Chinook counts are 



