Mercury enrichment of mine water is another problem associated with 

 coal nininq. Phillips (1978) has found higher concentrations in Decker 

 mine discharge water; however dilutional rates were high enough so that 

 the mine does not appear to have a detectable influence on the mercury 

 content of the Tongue River or Tongue River Reservoir, tleavy metal 

 contamination of streams in the Beaver Creek drainage and lower Yellowstone 

 River tributaries is however, a possible impact of coal development in 

 this area. 



Intake Water Company, a wholly owned subsidiary of Tenneco, Inc., has 

 proposed construction of an off channel reservoir on Box Elder Creek, and 

 a mainstem reservoir on Beaver Creek. An appropriation for 80,650 acre- 

 feet of Yellowstone River water per year was filed by Intake Water Company. 

 This water will be pumped to the detention reservoir on Box Elder Creek. 

 An impoundment on Box Elder Creek would have a negative effect on the 

 diverse biota of this stream, unless measures are taken to provide 

 adequate instream flow values. Several native Montana species which are 

 of special concern are found in Box Elder Creek: creek chub, sturgeon 

 chub and plains killifish; and their integrity must be maintained. 



Water will then be pumped into the reservoir on Beaver Creek and 

 marketed in industrial areas. However, Intake Water Company is currently 

 involved in a legal battle to obtain permission to transport Yellowstone 

 basin water into the Little Missouri Basin. Not only questions involving 

 states rights, but also questions concerning the Yellowstone Compact 

 are involved. Several locations for the reservoir have been discussed. 

 Depending on the final site and future irrigation demands in the area, 

 the downstream fishery will be dependent on releases from the reservoir. 

 The fishery in Beaver Creek is also diverse and adequate flows must be 

 maintained below the dam if the integrity of the fishery is to be maintained. 

 Instream flows adequate to provide habitat must be maintained. 



It is doubtful if a quality recreational fishery could be maintained 

 in the reservoir. Lamesteer Reservoir has not been able to provide a 

 sustained quality fishery and there is no reason to believe that a mainstem 

 reservoir would be any better. Additionally, the Beaver Creek Reservoir 

 would be subjected to large fluctuations in water levels due to industrial 

 use of the water. 



Baseline information on the current aquatic invertebrate and fish 

 species composition, distribution, and abundance in Beaver Creek, its 

 tributaries and tributaries to the Yellowstone is important and necessary 

 to detect any future changes inihe aquatic cormunities resulting from coal 

 leasing, mining and energy conversion. Additional studies to monitor the 

 aquatic populations should be planned so future effects can be detected 

 and remedial action taken if and where necessary. 



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