FLOWS 



Flow regime data for the Kootenai River below Libby Dam also are contained 

 in the application. From a fisheries point of view, these data are adequate for 

 site comparison purposes at all the dam sites, inasmuch as all the dams 

 considered would be operated at a constant reservoir elevation (the low Katka 

 dam could be an exception under flood conditions). The Rocky Creek and Katka 

 sites would be subject to more unregulated flows than the other sites because of 

 the Yaak River's flow contribution to the Kootenai. 



More flow information is contained in the geology-hydrology report (Dalby 

 1981) . 



CHARACTERISTICS OF THE KOOTENAI RIVER CHANNEL 



There are basic channel differences between the areas that would be 

 inundated by the Kootenai Falls project and those that would be affected by any 

 of the downstream dams. This is because the channel morphology immediately 

 upstream from Kootenai Falls is primarily controlled by bedrock, whereas below 

 the falls it is much more dependent on alluvial processes. As a result, the 

 downstream channel has a more regular and predictable distribution of pools and 

 riffles. Both areas have riffles with a substrate primarily of rubble and 

 cobble, but the river above the falls also has areas with a substrate of large 

 blocks which help form rapids. There is much more bedrock substrate above the 

 falls than below. Further, there generally is more fine sediment (gravel and 

 sand) in channel reaches downstream from the falls than immediately above 

 because of a generally lower gradient (see Table 1) and the cumulative 

 contribution of sediments from tributaries entering the river below Libby Dam. 



