WEATHER AND RIVER DISCHARGE 

 DATA 



on tables 8-12. Daily river discharge 

 data are plotted on figure 3. 



Headwater and tailwater elevations 

 are plotted on figures 1 and 2 respec- 

 tively. Water and air temperatures 

 were taken twice daily by pocket 

 thermometer. Daily records of weather 

 conditions and stream flows are shown 



ACTIYITIES AND OBSERVATIONS 



Never before in the history of fish 

 counting operations at Rock Island Dam 

 have the first arrivals of chinook sal- 

 mon been so late. First arrivals of this 



61 I 



610 



609 



J 608 

 to 



^ 607 



I- 



'^606 

 iii 



u. 



605 



z 



CO 604 



z 



o 



_ 603 



< 



> 602 



UJ 



_i 



'^ 601 



600 



599 



598 



I 1 r 



I I I I I I I I I I 1 r 



"1 — I — r 



-TT 



~\r 



— V \/-s/ — ^/-" 



I 1 I I 



5 10 15 20 25 

 MAY 



I I III \ I I 1 1_L 



5 lb 15 20 25 



JUNE 



5 10 15 20 25 

 JULY 



J L 



1 I I 



1 I I 



10 15 20 25 

 AUGUST 



5 10 15 20 25 

 SEPTEMBER 



Figure 1. --Headwater elevations, Rock Island Dam, 

 May lO-September 30, 1959 



10 



