the Falls. The area north of the canyon is used by bighorn sheep in spring; 

 access to free-flowing water could be restricted somewhat by dewatering of the 

 gorge. 



Considerable daily fluctuations in flow, and occasional great daily 

 summer discharges, presently limit the suitability of the gorge area as 

 nesting habitat for birds which nest on rock ledges or cavities (e.g., har- 

 lequin duck, dipper, Canada goose, conmon goldeneye). Nests which are 

 constructed during periods of low, relatively constant spring or sunnier 

 flows are destroyed during the occasional high discharges from Libby Dam 

 (Figure 12). The change to a constant flow regime brought about by the proposed 

 Kootenai Falls Dam may thus allow increased nest success for species not other- 

 wise affected by the project, although some high flows may occur over the dam 

 briefly during the breeding season (Figure 16). 



Low, constant flows through the channels below the Falls would encourage 

 the growth of algae (probably Spirogyra or Ulothrix (May and Huston 1975), 

 which is presently abundant at the head of the Falls) and possibly vascular 

 plants along the shoreline. These changes would probably not significantly 

 affect wildlife populations, other than possibly increasing suitability as 

 amphibian breeding habitat and increasing production of certain invertebrates. 



Effects of low flows on the harlequin duck could be mitigated only by 

 relocating the damsite upstream from the rocky area used as a loafing area 

 and by providing minimum discharges ofU? cms (4,000 cfs) or more over the dam. 

 Since this would orobably not be entirely effective and would also greatly 

 affect overall design of the project, its feasibility as a mitigating measure 

 cannot be evaluated at this time. Such an evaluation can only be made after DNRC's 

 full evaluation of the facility under the MFSA and analysis of public comment. 



Discharge Impacts at the Outlet Structure 



NLI (1978) proposes to divert the entire river flow (except for 21 cr.is 

 (750 cfs) allowed to pass over the dam) up to discharges of 67;^ cms (24,000 

 cfs), and to return these flows to the river gorge roughlyO'tiei mile below the 

 Falls. It is likely that, at high flows, discharge at the outlet structure 

 would cause backflows of water upstream into the canyon, perhaps forming a pool 

 of relatively still water. This pool would probab'y be used by waterfowl, 

 especially during migration. If detritus (such as dead fish which were killed 

 by passage through the powerhouse) accumulate at this pool and near the outlet 

 structure, bald eagles and ravens are like.y to be attracted to the area, althou 

 few suitable perch sites for bald eagles exist in the steep canyon area. Sin-" 

 the amount of fish mortality caused by passage through the powerhouse depends 

 largely on the effort toward mitigation of entrainment impact (Graham 1978b), 

 it is impossible to predict at this time wheth3r or not bald ragles will -^ind 

 a concentrated food source near the outlet. 



DISPLACEMENT 



Displacement, or population redistribution resulting from disturbances or 

 other environmental change, is a special case of habitat alteration that causes 

 animals to avoid an otherwise suitable area. Extended displacement is equivalent 

 to a reduction in carrying capacity, since the amount of habitat availaible to 

 the population is reduced. 



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