For evaluation purposes, the section of river between the Katka Dam site and 

 the Rocky Creek site was considered to be representative of the channel at all 

 the dam sites below the falls. Although this stretch of channel is bedrock 

 influenced, the channel bed materials are primarily alluvial. This stretch is 

 about eight miles long and has approximately 12 pools and 11 riffles (as 

 determined by aerial photos). The average pool length is approximately 2400 

 feet and average riffle length is approximately 1000 feet. These figures can be 

 used to roughly approximate the extent of riffles and pools that would be 

 affected by a dam at any of the sites below the falls. The area above the falls 

 jas r n red separately because of the channel differences mentioned earlier. 

 The. e measurements are shown in Table 1. 



SLACK WATER 



Table 1 gives the approximate slack water areas of all the alternative dams, 

 for comparison purposes. The figures in the table are only approximations, 

 because the backwater curves of the alternative sites have not been determined. 



FISH POPULATIONS AND MOVEMENTS 



INTRODUCTION 



Many more fishery data are available for the applicant's proposal than for 

 the alternatives. The gathering of comparable data for the alternatives would 

 require considerable study beyond the scope of this report. Some of the 

 information given in the following sections is based on a consensus of points 

 mentioned in conversation with the persons listed in Appendix A. The fishermen 

 listed are Libby-area residents who use the river extensively. 



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