o3 



o 

 a. 



a: 



LU 

 Q. 



U.2 



s 

 I- 



z 

 < , 



zm. 



I I Plunging Flow 

 ^3 Streaming Flow 



6 7 



FISHWAY 



8 



POOL 



10 II 



12 



13 



14 



15 16 



Figure 5. — Comparison of average passage time per pool in plunging and streaming flows (18 chlnook salmon, 



Sept. 12-25, 1959). 



longer than did the reverse change from 

 streaming to plunging. In any event, the dif- 

 ference between passage times in pool 2 under 

 the respective flows was clearly apparent and 

 accounted for more than half the difference in 

 total passage time for all pools. 



Under the assumption that delays in pool 2 

 resulted from the changing of flows, we ex- 

 cluded the time spent in this pool to compare 

 passage in established plunging and stream- 



ing flows. Mean passage times for ascent of 

 15 pools under plunging and streaming flows 

 became 24.4 and 26.6 minutes (1.6 and 1.8 

 minutes per pool). 



Passage time per circuit . --Eleven of the 

 18 test fish ascended slightly faster in the 

 streaming flow, and seven ascended faster 

 in the plunging flow (fig. 6). Of the latter 

 group, five (nos. 6, 7, 13, 15, and 18) ascended 



1 I Plunging Flow 

 Streoming Flow 



Figure 6. — Mean times per 

 circuit of 18 Chinook salm- 

 on t e s t e d during plunging 

 and streaming flows in the 

 l-on-16 slope, endless fish- 

 way, Sept. 12-25, 1959. 

 Mean time based on three 

 circuits under each flow 

 condition; passage time In 

 pool 2 Is omitted. 



7 8 9 10 

 FISH NUMBER 



18 All 

 Fish 



