598 U. S. BUKEAU OF FISHERIES 



Gold Ray intake screen. — As detailed in the 1929 report this 

 electric screen of the insulated type Avas installed last September 

 in the intake at the Gold Ray power plant, Roorue River, Oreg. 

 This screen consists of a -double row of 6-inch diameter pipe elec- 

 trodes, spaced 6 feet between rows, the pipes being 4 feet center to 

 center in rows. 



The screen was installed again in the spring of 1930 and operated 

 until the Gold Ray plant shut down for a period to allow the con- 

 struction of a new trash rack and head-Avorks structure. The screen 

 was reelectrified late in the summer and continued in operation until 

 late in the fall. The power plant Avas shut down during the peak of 

 the doAA'nstream migration, and, therefore, conclusions as to the 

 effectiA'eness of the screen are uuAvarranted. 



Gold Ray tailraee screen. — The })urp()se of this screen installation 

 is to prcA'ent the upstream migrant salmon and steelhead from enter- 

 ing the tailraee aa aters at Gold Ray poAver plant and to diA'ert them 

 in fresh condition into the main channel of the riA^er leading to the 

 fish ladders oA'er the dam. This screen, AAdiich AA'as of the grounded 

 type described in detail in the 1929 report, continued its highly 

 effectiA-e operation until May 8, 1930, at Avhich time the poAA^er plant 

 AA'as shut doAvn for the installation of the ncAA' head-AA'orks structure 

 referred to aboA^e. 



Soon after the screen Avas put in operation it AA^as obserA^ed that a 

 number of Chinook salmon and steelhead AA^ere penetrating the screen 

 and that some others AAcre being paralyzed in their passage OA'er the 

 ground pipe. Accordingly, the grounded type of installation was 

 abandoned in favor of the insulated screen. The neAv screen Avas 

 electrified July 17. It consists of a double roAV of 6-inch diameter 

 pipe electrodes of No. 20 gage galvanized iron Avhich are suspended 

 in the Avater from supporting cables. Spacing of the pipes is 4 feet 

 center to center in rows, and the roAvs are spaced 6 feet apart. The 

 loAver end of each electrode is fitted Avith a hemispherical cap of 

 galvanized inm and filled Avith concrete to provide the necessary 

 Aveight to hold the electrode vertically in the Avater. The screen is 

 energized Avith 60-cycle alternating current passed through the 

 special transformer. 



Prior to the electrification of the ncAv screen the tailraee was 

 cleared of fish and since that time none has been found aboA^e the 

 screen. The conditions for observation of the action of the screen 

 are excellent and hundreds of salmon and steelhead have been seen 

 to encounter the screen and be diverted Avithout injury into the main 

 channel. The action of this screen is positive, and its continued 

 operation is held to be a factor of major importance in the conser- 

 vation of fish on Rogue River. 



Experiments icith elect i-ic screens for use at intakes. — Seeking im- 

 proA^ement and simplification of this type of electric screen the 

 experimental field work started in 1929 Avas continued in the 1930 

 season. This year the experimental installations Avere set up at Old 

 Indian Canal on the Yakima River, in the sluiceAvay at the Gold 

 Ray power plant, and at the Fort Klamath hatchery of the Oregon 

 Game Commission. The Yakima tests were conducted by Professor 

 McMillan and Mr. Wagner. The fish used Avere Chinook salmon 

 fingerlings about 4 inches long. These tests demonstrated: (1) The 



