Electrical circuitry was the same as at Hibbards' Creek 

 (Fig. 12). The power source at Carp Creek, However, was similar to 

 that employed at the Squaw Creek site. Two gasoline-engine driven 

 generators of 2,000 watt capacity provided normal supply and standby 

 power. 



In addition to the installation described above, a modifi- 

 cation of this barrier was also tested in Carp Creek. This was an 

 extremely simple affair consisting of two lengths of 1-1/2 inch dia- 

 meter galvanized iron pipe placed on the stream bed, parallel to each 

 other, and set at an angle of approximately 90 degrees to the direction 

 of stream flow. The spacing between these two submerged lateral elec- 

 trodes was 10 feet. Power was provided by the generator source described 

 for the principal electrical barrier installed in the stream. 



Operation and testing procedures 

 (1) Use of checking weirs 



Portable -type, mechanical weirs and traps were installed as 

 checking structures at the four experimental sites both above and below 

 the electrical devices (Fig. 10). Details of the method of construc- 

 tion of these mechanical weirs and traps have been described by Apple gate 

 and Smith (195>1). During the conduct of the various experiments, the 

 contents of the downstream checking weir-trap were removed and counted 

 daily or twice daily. Lampreys and fish were then placed upstream above 

 the lower weir into the test area. Daily records were kept of the numbers 

 of lampreys and/or fish caught in the electrical weir-trap or killed in 

 the electrical field; these data were then analyzed in their relation to 

 the particular experiment in progress. Routine inspections of the check- 

 ing weir and trap above the electrical device substantiated visual obser- 

 vations as to nature and extent of escapement through the electrical 

 barrier (Fig. 13). 



(2) Physical measurements 



Daily records of water temperature, water level, and weather 

 conditions were maintained at each installation. Routine records were 

 made, at varying time intervals, of water velocity (at electrical weir 

 site), and dissolved solids content and pH of the water. Water levels 

 were read from staff gauges installed at each site. Water velocities 

 were determined by one of several conventional methods with a Price current 

 meter. Total dissolved solids present in the water was obtained with a 



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