Lake Koocanusa area (3rown 1979). j 



The cattail marsh and rooted aquatic vegetation stands which would be inun- 

 dated by the project are the only representatives of these types found in the 

 study area (Olson-Elliott and Associates 1979). Although small in extent, these 

 types are at least seasonally important to dabbling ducks. 



All tree, shrub, end grassland-dominated types, as well as the existing rail- 

 road and powerline ri gnts-of-way , support considerable small mammal populations. 

 Thisp.rey base is used by a number of predators in the area, notably the raven, coy- 

 ote, red-tailed hawk, American kestrel and possibly one or more species of owl. 

 Except for the raven, these predators do not appear to heavily use these habitats 

 at present, and effects of loss of a portion of the p'^ey base would likely be small. 



Mitigating Measures and Their Effectiveness . One of the most effective mea- 

 sures for reducing the amount of riparian habitat lost would be lowering of the 

 forebay elevation. Since the banks of the river are gently sloping, a small change 

 in forebay elevation cculd lead to a substantial decrease in area inundated (Table 

 21). For example, lowering the forebay from 610 m (2,000 ft) to 606.5 m (1990 ft) 

 would reduce the amount o^ habitat flooded from 24.5 ha (60.6 acres) to 9.6 ha 

 (23.7 acres); this would reduce the amount of riparian forests flooded even more 

 dramatically, from 5.9 ha (14.5 acres) to 0.9 ha (2.2 acres). Also, since the 

 railroad wouM not have to be relocated as high upslope, the amount of new right- 

 of-way clearing and the lateral extent of fill slopes would be reduced as well. 

 Such a lowering of pool level would have important effects on other aspects of the 

 project (especially economics, visual impact, and power generation capability), and 

 optimum pool elevation can only be determined by careful consideration of costs and^ 

 benefits of the tradeoffs involved. These tradeoffs are beyond the scope of this 

 analysis, and can only be made after DNRC's full evaluation of the facility under 

 the MFSA and analysis of public comment. 



Prior to the commencement of any clearing operations, NLI should submit for 

 FERC and state review and approval a clearing plan, specifying the timing and ex- 

 tent of vegetation removal along the shoreline. Specific trees to be removed, and 

 those allowed to remain, should be identified in this plan. NLI plans to allow 

 some of the larger conifers which would be inundated to remain as snags in the pool; 

 this would provide attractive perching and possibly nesting sites for eagle and os- 

 prey. The amount of vegetation cleared should be the minimum necessary to allow 

 construction to proceed, and clearing should be postponed as long as possible dur- 

 ing construction (Regan 1979, Fielder 1977). Clearing should be done in stages 

 rather than all at once; the earliest construction stages would require the earli- 

 est clearing. Riparian trees surrounding the construction area at the head of the 

 Falls should be allowed to remain until just prior to final inundation. As mentioned 

 earlier, flood-tolerant shrubs and/or trees should not be cleared from the littoral 

 zone at the upper end of the pool if the extent of inundation does not exceed their 

 tolerances. 



Assuming a forebay elevation of 610 m (2,000 ft), it is possible to partially 

 mitigate some habitat loss by restoration of riparian habitats along the shoreline 

 and relocated railroad right-of-way. _ NLI (1978) proposes to use a portion of the 

 approximately 650,250 m^ (850,000 yd"^) of the material excavated 



92 



