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IRIS <br />MITIGATION AND DESIGN, INC. <br />SCHWARTZWALDER MINE PHASE 1 - UPSTREAM CUTOFF WALL AND LOW FLOW BYPASS <br />PIPELINE - BIOLOGICAL ASSESSMENT <br />nesting sites for wildlife, and organic matter input for downstream fish and wildlife. Phase 1 of the <br />Project has avoided impacting areas more than 100 feet upstream of the road crossing due to the <br />existing high quality of riparian habitat found at this location and farther upstream. <br />On July 27, 2011, the following native trees were documented within the 100 -foot upstream riparian <br />area: 4 thin -leaf alder (Alnus incana), 26 river birch (Betula fontinalis), 9 narrowleaf cottonwood, and 6 <br />peachleaf willow (Salix amydgaloides). <br />4.2.3 225 Feet Downstream from Road Crossing <br />Extending approximately 225 feet downstream from the upland road crossing, the riparian community <br />is best characterized as a previously disturbed riparian habitat (see Figure 2 and Appendix B). This <br />portion of the stream is in close proximity to a mine waste rock pile to the south. Placement of this <br />mine waste rock pushed the creek to the north and created a narrower and less well- vegetated riparian <br />area than the upstream riparian area. As a result, the riparian community downstream from the road <br />crossing provides fewer functions that are typically associated with more pristine riparian habitats. <br />Most significantly, the riparian area is less able to trap and store sediments, which may carry <br />contamination. Additionally, the riparian area downstream from the crossing provides less wildlife <br />habitat and has a lower capacity for attenuating flood waters. <br />On July 27, 2011, the following native trees were documented in the area 225 feet downstream from <br />the upland road crossing: 7 mountain maples (Acer glabrum), 37 narrowleaf cottonwoods, 35 <br />peachleaf willows, 4 ponderosa pine (Pinus ponderosa), and 1 juniper (Juniperus scopularum). <br />Page 27 August 2011 <br />