1098 U. S. BUREAU OF FISHERIES 



EFFECTIVENESS OF SCREENS 



P'or the past two years the Division of Fisheries, State of Wash- 

 ington, has done vahiable work in the interests of fish conservation, 

 by maintaining a special investigator in Yakima County during 

 the irrigation season to secure data on the presence of lish. On this 

 work hundreds of miles of ditches and stream channels are patrolled 

 Aveekly. 



In the fall of 1929 the United States Bureau of Fisheries and the 

 State division of fisheries cooperated in the work of the final check 

 on the ditch system, Fred R. Lucas, representing the bureau. In 

 tliis work the projects reported on were covered in their entirety. 

 The results constitute data of a very high degree of accuracy. 



Sunny fiide electric ficreen. — The Sunnyside Canal, main diversion 

 of the Yakima project, United States Reclamation Service, diverts 

 water from the Yalrima River, near Yakima, Wash. The capacity 

 of the canal is 1,500 second-feet. The irrigation season of 1929 

 extended from March 15 to October 21. During the greater part 

 of the season the canal carried from 1,200 to 1,500 second-feet. The 

 check revealed a total of (540 salmon and steelhead left stranded in 

 the sj'stem. Of this ninnber -ISO were actually caught and counted. 

 In length, the fish averaged from 314 inches to 5 inches. It is re- 

 ported that in former years the Sunnyside and Wapato systems 

 were likely to show hunch'eds of thousands of such fish. The results 

 indicate the operation of the electric screen to have been a success 



Tieton electric screen. — The Tieton Canal of the United States 

 Reclamation Service diverts Avater from the Tieton River at a point 

 about 35 miles northwest of Yakima, AVash. Capacity of the canal 

 is 320 second-feet, and this flow is nuiintained throughout most of 

 the irj'igation season. Because this diversion is located in the moun- 

 tains many miles from any power line, it was necessary to install a 

 power unit for furnishing electricity to the screen. This was accom- 

 plished when the United States Reclamation Service, displaying a 

 fine s])irit of cooperation, installed at their own expense a hydro- 

 electric generator on tlie Tieton ditch and built a transmission line 

 tliree-fourths of a mile long to bring the ])ower to the screen. The 

 electric screen went into operation tiiree and one-half months after 

 water diversion started, consecpiently, the effect of the electric screen 

 can not be determined fi-oni check on the fish in the ditch at the end 

 of the season. In comparison with 1928 this year's check showed 

 more snuiU salmon and steelhead and less large ones. The fish in 

 the Tieton River, both above and below the diversion point, were 

 much more numerous this season than in 1928. All factors con- 

 sidered, the use of the electric sci-een is regarded as successful. 



Wapato electric screen. — The Wa])ato Canal of the United States 

 Indian Service diverts water from the Yakima River at a point about 

 314 miles upstream from the Sunnyside Dam. The capacity of the 

 canal is 1,800 second-feet, and throughout the major portion of the 

 irrigation season this huge flow is maintained. The irrigation season 

 is from March 15 to November 18. A check of the system showed 

 the total number of salmon and steelhead to be about 900, of which 

 381 were actually caught and counted. The avei-age length of the 

 fish was from 3Vi inches to 5 inches. 



