The power and irrigation dirersion dan near Starbuck, Wash- 

 ington, approximately 5i miles above the mouth, is a barrier at low 

 water to the upstream migration of fish. Almost the entire flow at 

 water stages ia taken by the power diversion, and consequently 

 the main attraction to fish is at the tailrace of the power plant. 

 The 1 mile section of river channel between the intake and the power 

 house tailrace is virtually dry during the summer months. The diver- 

 sion at this point on February 3, 1935, was 66£ c.f.s., of which 

 55i c.f.s. was used for power and 11 c.f.s. for irrigation. The di- 

 version has been screened by the Washington State Fisheries Department. 



The upper De Ruwe dam, located approximately 16 miles above 

 the mouth, is a barrier to fish at low water* This dam is about 5 

 feet high, and is reported to block at least part of the chinook run. 

 The dam was originally built to supply water for a power diversion, 

 but is now used to supply an irrigation diversion. An old fish 

 ladder at one end of the dam was filled with mud and debris and over- 

 grown with willows at the time of the survey, and was entirely use- 

 less. At the time of the survey (February 1935) there was consid- 

 erable discharge over the spillway, and only 2 c.f.s. were being 

 diverted into the irrigation canal. During the summer irrigation 

 season dam boards are placed across the 10 foot wide spillway crest, 

 and most of the flow is diverted into the unscreened irrigation ditch. 



A total of 31 diversions withdrawing 128 c.f.s. were found on 

 the Tucannon River* Irrigation ditches were taking 72 c.f.s., and 

 the remainder was being used for power. It was reported that three 

 of these ditches have been screened by the Washington State Fisheries 

 Department. The total amount of water diverted during the irrigation 

 season was not determined, as many temporary wing dams are then in- 

 stalled. It is doubtful if by-passes are used to return irrigation 

 water to the main river during the irrigation season. There is also 

 little ground return from these ditches in this semi-arid region. 



Steelhead trout appear in the Tucannon in January, February, 

 March, and April, with a small fall run also reported. A considerable 

 run of steelhead still entered the river at the time of the survey 

 (1935), although these fish were not nearly as abundant as in earlier 

 years. 



The last large run of chinook salmon was reported to have 

 occurred in 1915* It was reliably estimated that at that time an 

 average of 500 salmon per day entered the river during the spawning 

 migration, which lasts through May and June. At the time of the survey 

 it was reported that an average of 50 salmon per day entered the stream 

 during the spawning migration, or a total of approximately 3,000 fish. 

 It was reported that chinook salmon spawning is at its peak about the 

 middle of August. Until 1922 or 1923 a run of chinook salmon also was 

 reported to enter the stream in the fall months. Apparently this run 

 also has been greatly depleted. 



