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<br />~. <br /> <br />reaches where small fish arc readily available. "Puddle ducks" such as mallards (Anas nlatvrhvllchos), gadwall <br />(Anas streeera) and teal (Alias spp.) use slack water areas, beaver ponds, or inundated floodplain wetlands for <br />feeding on aquatic plants and invenebrmes. or for resting. Some waterfowl nesting occurs in the lloodplain. <br /> <br />Numerous bird species arc dependent on the tree and shrub habitats of floodplain rlparian and wetland <br />communities. These habitats typically suppon among the highest diversity of species use of all habitats found in <br />the southwest. The following species feed on aquatic river life. depend on dead and dying trees of the riparian <br />cottonwood forest for nest sites or are e10sely tied to riparian shrub communities for nesting and feeding: <br /> <br />Belted Kingfisher (Megacervle alcvon) <br />'. Great blue heron (Ardea herodias tregallzai) <br />Dippers (Cinelus mexicanus unicolor) <br />Woodpeckers (Picidee family) <br />Swallows (Hirundinidae family) <br />Black-Capped Chickadees (Parus atrkaeillus seetelltrionalus) <br />Flycatchers (Tyrannidae family) <br />Warblers (Parulidae family) <br />Sparrows (Fringillidae family) <br /> <br />2. ENVIRONMENTAL CONSEQUENCES - Semi-aquatic species could be affected by changes in <br />physical habitat (e.g., change in wetted perimeter, pool, riffle, and run composition, water temperature, icing, <br />etc.) or a corresponding change in' aquatic food availability (fish prey species, substrate invenebrate communities, <br />or shallow water plants). The proposed action (Alternative 1) would not significantly alter the volume of water <br />in the river downstream of McPhee Dam. The proposed flow release would generally remain within the range of <br />flows under the DPRlFES release criteria. The managed pool would modify the timing of flows to avoid the <br />extreme low flow conditions (20 cfs) which occur in "dry" years under the DPRlFES release criteria, and provide <br />management flexibility for the benefit of downstream fish and wildlife resources. <br /> <br />Higher flows through the summer months would maintain cooler water temperatures, deeper pnol <br />habitats and riffle flows, and may increase the frequency of slack water in reaches where the channel is open and <br />has a low gradient. Flow velocities would increase where the channel becomes more constricted. While the <br />presence of McPhee Dam will continue to restrict the inherent natural variability of instream flows downstream <br />from the dam. the proposed pool management strategy would provide for seasonal flow variation somewhat more <br />natural to lhe system and which should better accommodate the critical needs of aquatic life. <br /> <br />Consequently, it is anticipated that this management strategy shculd, on balance, have positive to neutral <br />benefits for aquatic life throughout the upper reaches of the river, and therefore, those terrestrial and semi-aquatic <br />species closely tied to the aquatic ecosystem. The increase in base flow during dry summer periods shouid <br />especially benefit the aquatic ecosystem and consequently, those species which feed on aquatic life or depend on <br />flooded channel habitat for denning. <br /> <br />A pOlential adverse effect could occur during extended winter periods with formation of ice during <br />"normal" and "wet" years. Because winter base flows would generally be about 30 cfs under the proposed <br />action. flows would be lower in both "normal" and "wet" years than under Alternative 4 when winter flows <br />would typically be around 50 and 78 cfs, respectively. This would decrease base flow and, therefore, flow <br />velocity in approximately 75% of winters, thus increasing icing potential. Base flow would be higher in "dry" <br />years. when it would be 20 cfs. Thus, under the managed pool alternatives, 'icing potential will decrease in "dry" <br />years. Should the linear extent and duration of icing increase in years with greater water supply, due to a <br />decrease in base flow, the area or time of open water availability to waterfowl would decrease. This in turn <br />would decreale prey availabilily to cenain predatory species which feed on waterfowl, such as bald eagles. On <br />the other hand, the pool management strategy would maintain higher summer flows, which should bring the <br />aquatic biotic community into the winler period in beller shape. During "dry" years under Allernative 4, base <br /> <br />I <br /> <br />27 <br />