TEOGRESS IN BIOLOGICAL INQUIRIES, 19 3 2 113 



current, and those electrocutions were confined to an area where 

 an eddy current prevented fish from escaping to safe water after 

 contact with the electric current. 



This year's success with the Kvichak screen illustrates the great 

 importance of proper location, for the same screen installed in 1930 

 at a downstream site failed to function as a diverter. It is felt that 

 the construction of the wooden racks in separate channels well 

 removed from the electrified area has offered distinct advantages. 



Check offish in Yakima ditches. — This year, as in previous seasons, 

 a comprehensive check on fish left stranded in the Yakima ditch 

 systems was conducted at the end of the irrigation period. These 

 final checks together with special checking operations and close 

 observation of fish migration in the canals and rivers were conducted 

 throughout the summer and fall, and as in previous years, the count 

 indicated that the Tie ton electric screen operates with high efficiency. 

 The effectiveness of this screen is brought out strongly by compari- 

 son with fish conditions on the Selah-Naches Canal (capacity about 

 300 second-feet) which diverts water from Tieton River under con- 

 ditions similar to those existing at the Tieton diversion. A complete 

 check of fish left stranded in the Selah-Naches system showed, by 

 actual count, 855 salmon, 188 trout, 1,027 whitefish, and 129 culls, 

 with an estimated additional total of 450 fish of all kinds that had 

 escaped seining. 



FISH LADDERS 



The Bureau has installed and now supervises the operation of fish 

 ladders at Sunnyside Dam of the Reclamation Service, Yakima River, 

 Wash. ; at Wapato Dam of the Indian Service, Yakima River, Wash. ; 

 and at Sprague River Dam of the Indian Service on Fort Klamath 

 project, Oregon. These installations are all of ample design and of 

 substantial reinforced-concrete construction. All reliable observa- 

 tions point to the thoroughly satisfactory operation of these ladders 

 in passing the fish migrations of 1932. 



Upper Salmon Falls ladder. — The fish ladder for the upper Salmon 

 Falls Dam of the Idaho Power Co. was designed early in 1932, and 

 is located on the Snake River near Hagerman, Idaho. The construc- 

 tion of this development, which will raise the water approximately 

 16 feet, was started in the summer of 1931, but the work has been 

 temporarily suspended due to power market conditions. The power 

 company has worked in close cooperation with the Bureau and the 

 design of the dam includes provisions for the construction of this 

 fishway as an integral part of the dam structure. 



Bock Island fish ladders. — In previous reports this major power 

 development of the Puget Sound Power & Light Co. on the Columbia 

 River near Wenatchee, Wash., has been described in detail. The 

 summer migrations of 1932 provided the first test of the two huge 

 fish ladders installed according to the specification of the Bureau of 

 Fisheries and the State commissions of Washington and Oregon. 

 Throughout the summer there was an abundance of overflow at 

 the dam. 



The west channel ladder, constructed 800 feet downstream from 

 the location originally proposed, possesses marked advantages over 

 the originally planned structure being composed largely of pools 

 excavated in soHd rock and possessing better entrance facilities. 



