PROGRESS IN BIOLOGICAL INQUIRIES, 1931 489 



Naches Canal were made this fall. The first count was made dur- 

 ing the first shutdown of the season, which extended over the period 

 September 16 to 20. The actual count of fish recovered was: 3,748 

 salmon, 543 trout, 1,142 whitefish, and 877 cull fish. 



Upon September 21 the Selah-Natches again began to divert water. 

 Approximately one month later the canal was shut down for the 

 season. Check of fish actually recovered from the system at this time 

 showed 825 salmon, 122 trout, 348 whitefish, and 139 cull fish. 



Thus it is seen that this unscreened diversion taking water from 

 the Naches Eiver under conditions similar to those existing at the 

 Tieton diversion disclosed a total of 5,238 salmon and trout, as 

 against a total of 514 salmon and trout left in the Tieton system in 

 which the electric screen had been in operation for only 141 days 

 out of a total of 251 days. 



FISH LADDERS 



The activities conducted by this investigation in connection with 

 fish ways during 1931 include : 



(1) Operation of fish ladders on Sunnyside and Wapato Dams on 

 Yakima River. 



(2) Design of fishways for North River project, Washington. 



(3) Inspections and supervision of fishway construction at Rock 

 Island project on Columbia River, 



(4) Survey of fishw^ay requirements for the State of Maine. 



(5) Investigations and design of fishway for Sunbeam Dam, 

 Idaho. 



(G) Investigation and designs for improvement of channel at 

 An an Creek, Alaska. 



In 1929 the bureau installed a reinforced-concrete fish ladder of 

 large-pool design at the Sunnyside Dam of the United States Recla- 

 mation Service. In 1930 a similar structure was built to our design 

 at the "Wapato Dam of the United States Indian Service. Both these 

 ladders on the Yakima River have been under the close supervision 

 of the bureau. They have continued to function perfectly in passing 

 the several large runs of salmon up the river without delay. 



Proposed fishway for Suribemii Dmn. — ^Last spring the aid of the 

 Bureau of Fisheries was asked by the Fish and Game Commission 

 of the State of Idaho in the matter of the fishway problem existing 

 at Sunbeam Dam on the upper Salmon River near Yankee Fork. 

 The dam is of the concrete-arch type, approximately 30 feet high. 



The scheme proposed by the bureau utilizes the present diversion 

 tunnel as part of the fishway structure and will not in any way injure 

 or impair the value of the property of the Sunbeam Mining Co. 



Fishioay frohlem at Anan Creefc. — During the season of 1930 it 

 was found that at certain water stages on Anan Creek, Alaska, the 

 upstream-migrating salmon had considerable difficulty in ascending 

 the channel, due to the presence of natural obstructions consisting of 

 rapids and falls. Accordingly, in July, 1931, field examinations and 

 surveys were made and a design worked out for the improvement of 

 this condition. It was found that the principal obstruction occurred 

 along the stretch of channel extending from the present log dam 

 (situated 500 feet downstream from the counting weir) a distance 



