- 40 - 



1981 



982 



1983 



1984 



1985 1986 

 Year 



1987 



1988 



1989 



1990 



Figure 29. — Sulphate concentrations in Cookson Reservoir 

 at Morrison Dam for the period 1981-90. 



Return groundwater quality and volumes were measured. From startup in 

 September, 1989, through December 1990, the total pumpage was approxi- 

 mately 896 dam 3 - less than 5% of the 1990 reservoir volumes. Water 

 quality measurements have indicated slightly lower concentrations of 

 total dissolved solids and boron than were present in the reservoir. 



In 1990, Sask Power assumed responsibility for the regional dewatering 

 system west of Coronach. Pumped volumes to Girard Creek and water qual- 

 ity measurements immediately downstream of the majority of pump wells 

 were obtained. During 1990, this supplementary water supply provided 

 approximately 4,693 dam 3 , less than 20% of the 1990 Reservoir volume. 

 The water quality is characterized by lower total dissolved salts and 



