were approximately the same, 119 and 120% N 2 , 

 respectively (Table 5); while the three transect 

 spiilrace samples ranged from 135 to 142% N 2 . 

 Side-to-side mixing had apparently occurred at 

 Rooster Rock (RM 130). As with the April survey 

 there was an approximate 10% decrease in N 2 

 level between Bonneville and Prescott and about 

 18% between Bonneville Dam and Astoria, Oregon. 

 The Bonneville average total flow during June 12- 

 14 was 11.7 KCMS (413 KCFS) while the average 

 spill was 8.1 KCMS (286 KCFS). 



In summary it was noted that: 1) during both 

 surveys side-to-side mixing, in reference to N 2 



level, occurred at Rooster Rock, 15 river miles 

 below Bonneville Dam, 2) both surveys showed 

 approximately 10% equilibration between Bonne- 

 ville Dam and Prescott, Oregon, 3) 18 to 20% 

 equilibration occurred between Bonneville Dam 

 and Astoria, Oregon, 4) no significant gas equili- 

 bration occurred between The Dalles and Bonneville 

 Dams, and 5) side-to-side mixing was charac- 

 teristic in all transects between The Dalles and 

 Bonneville forebay. These conclusions should be 

 considered valid only in relation to flows (total and 

 spill) which occurred during the surveys. 



June 12 



Bonneville 



Forebay 



Bonneville 

 Power House 



Approximately 22-hr time lapse 



146.0 



145.0 



Center 



Center 



07:40 



08:50 



13.6 



13.8 



16.4 



16.5 



118.8 



120.0 



Bonneville 

 Spillway 



145.0 



Ore. 



08:55 



13.8 



18.6 



135.3 



Tanner Creek 



144.4 



18 Blahm, McConnell, Snyder 



