Table 9. — Distribution of passage times of individual 

 Chinook and coho salmon through a 0.6-m. -diameter 

 pipe 82.3 m. long, partly filled with water under 

 illuminated and nonilluminated conditions; the pipe 

 system included two 180 turns, and water velocity 

 was 0.9 m.p.s., September 1964 



Table 10. — Distribution of passage times of individual 

 Chinook salmon and steelhead trout in a 0.6-m.- 

 diameter pipe 82.3 m. long under flooded and partly 

 full conditions; the pipe system included two 180° 

 turns, and water velocity was 0.9 ra.p.s., September 

 1964 



^ 95 percent confidence intervals about the median. 



95 percent confidence intervals about the median. 



completed passage, however, was greater in 

 the partl-y full pipe (100 percent) than in the 

 flooded one (81 percent), Steelhead trout 

 traveled faster in the partly full than in the 

 flooded pipe (1.5 and 7.4 minutes, respectivel-y), 

 but the difference between median passage 

 times was not statistically significant. Per- 

 centages of steelhead trout that completed 

 passage were 100 percent in the partly full 

 and 78 percent in the flooded pipe. Median 

 passage time of coho salmon through the 

 partly full pipe (1.6 minutes) was significantly 



less than their median passage time (7.7 

 minutes) through the flooded pipe; percentages 

 that completed passage were 100 in the partly 

 full pipe and 83 in the full pipe. 



Comparison of passage times of fall chinook 

 and coho salmon and steelhead trout through 

 the 27.4- and 82.3-m. lengths of 0.6-m.- 

 diameter pipe indicates that the partly full 

 pipe offered the best passage condition. Pas- 

 sage times were generally faster, and greater 

 percentages of fish completed passage when 

 the pipe was partly full than when it was full. 



14 



