There are numerous irrigation diversions on the Wallowa Hirer, 

 but no dams or other obstructions below the outlet of Lake Wallowa 

 that might interfere with the upstream migration of fish. At the 

 time of the survey none of the water diversions was screened to pre- 

 vent the loss of fish. This condition has been one of the chief 

 causes for the depletion of the runs of salmon in the Wallowa, and 

 has been recognized as such in the annual reports of the Master Fish 

 Warden of Oregon as early as the year 1901. Two of the principal 

 water diversions are located near the town of Wallowa, approximately 

 23 miles above the mouth The lower of these was withdrawing about 

 20 c.f .s. for irrigation at the time of observation. The upper di- 

 version was withdrawing 70 c.f.s, for industrial purposes, the larger 

 portion of this being returned to the river about 1 mile downstream. In 

 addition to a number of small diversions throughout the course, there 

 are four large irrigation diversions and one power diversion occurring 

 in the 2 mile section between the town of Joseph and Lake Wallowa. 

 These diversions take the greater part of the flow in the main stream 

 above Joseph during the late summer and fall months. 



The Granger Canal is located approximately l£ miles below the 

 dam at the outlet of Lake Wallowa. The irrigation diversion flow 

 ranges from to about 300 c.f.s. 



The Big Bend Canal is located about \\ miles below the dam 

 at the outlet of Lake Wallowa. The irrigation diversion flow ranges 

 from to about 120 c.f.s. 



The Farmers Canal is located a short distance below the dam 

 at the outlet of Lake Wallowa. The irrigation diversion flow ranges 

 from to about 1?0 c.f.s. 



The Silver Lake Ditch is located at the Lake Wallowa dam. 

 The irrigation diversion flow ranges from to about 130 c.f.s*, and 

 amounted to about 9 c.f.s. at the time of observation en October 12, 

 19U0. 



The dam at the outlet of Lake Wallowa was built in the year 

 1929. It is of concrete construction, UO feet high, and is a total 

 barrier to the upstream migration of fish. On the lower aide of the 

 dam there is a diversion leading to the power plant at Joseph. The 

 diversion flow ranges from to about 50 c.f.s., but is usually 

 less than 10 c.f.s. The regulated flow in the stream bed directly 

 below the dam ranges from when there is no irrigation demand and 

 water is being impounded, to a maximum of more than £00 c.f.s. during 

 the high water stages in May, June, and July (Water Resources State 

 of Oregon). There is a stationary screen located 203 feet above the 

 dam, completely across the outlet of Lake Wallowa, far the purpose 

 of preventing the young land-locked blueback salmon from passing 

 downstream. The dam has resulted in the destruction of a large part 

 of the run of blueback salmon that formerly ascended to Lake Wallowa, 

 and the land-locking of the remainder. The good runs of Chinook 

 and silver salmon and steelhead trout that formerly utilised the 



42 



