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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-109 Bighorn sheep winter range occurs within one mile of Route Segment NNR-4o/NNR-4u and is crossed by the proposed route segment for 0.2 mile on the steep slopes surrounding Lmuma Creek and its tributaries. Potential impacts to bighorn sheep include direct habitat loss, habitat degradation through weed spread and/or changes in fire regime, collision with vehicles during construction and maintenance, and disturbance during construction and maintenance. Adherence to seasonal restrictions on construction activities within designated winter range should minimize disturbance impacts to bighorn sheep. Additional RDFs to minimize disturbance impacts and collision risk are described in Section 4.3.3.2; RDFs to minimize habitat loss and degradation are described in Section 4.3.3.1. Impact levels to bighorn sheep are anticipated to be moderate for the 0.2 mile of the route segment that overlap designated winter range. All habitat disturbance associated with Route Segment NNR-4o/NNR-4u would be located within the Regularly Occupied Habitat MU for Sage-Grouse. For either design option, construction activities would disturb less than one percent of Regularly Occupied Habitat (Table 4.3-7). For NNR-4o, anticipated disturbance includes 11.9 acres of suitable Sage-Grouse habitat, 11.1 acres of marginal habitat, and no unsuitable habitat. Undergrounding NNR-4u would increase the anticipated disturbance to 24.5 acres of suitable habitat and 22.3 acres of marginal habitat (Table 4.3-8). RDFs implemented during construction and operation are anticipated to be effective at reducing impacts to Sage-Grouse habitat (refer to Sections 4.3.3.1 and 4.3.3.2). Habitat impact levels would be low for 0.5 miles and moderate for 4.0 miles. Existing perching, roosting, and nesting sites for avian predators are available along Route Segment NNR-4o/NNR-4u from buildings, trees, and fences associated with developed areas and existing distribution and 230 kV H-frame transmission lines. Construction of Route Segment NNR-4o would require an estimated 35 new structures, all of which would be located within 0.25 mile of an existing transmission line (Table 4.3-5). The underground design option, NNR-4u would need to be overhead for a short-stretch as it crosses I-82. This would require two transmission structures, both within 0.25 mile of existing structures. In addition, at each of the four transitions between above-ground and underground transmission, a transition station would be required resulting in approximately five acres of disturbance at each transition station. The estimated Sage-Grouse population range does not overlap the Route Segment NNR-4o/NNR-4u ROW (Figure 3.3-4). No active leks are known to occur within four miles of Route Segment NNR-4o/ NNR-4u (Table 4.3-6). With the implementation of RDFs (refer to Sections 4.3.3.1 and 4.3.3.2), impacts to lekking Sage-Grouse associated with the construction of Route Segment NNR-4o/NNR-4u, both the Overhead and Underground Design Option, is anticipated to be low for the entire route segment (4.5 miles). Approximately 1.2 miles of Route Segment NNR-4o/NNR-4u crosses private land targeted for mitigation acquisition to offset impacts from the proposed Wymer Dam and Reservoir Project. 4.3.4.14 Route Segment NNR-5 Approximately 8.6 acres of long-term and 0.4 acres of short-term disturbance would occur with the construction of Route Segment NNR-5. Permanently disturbed areas would include 8.4 acres of sagebrush/perennial grassland (Table 4.3-4). The remaining long-term (0.2 acre) and short-term (0.4 acre) disturbance was classified as intermittent stream/dry gully. RDFs would be implemented to minimize habitat loss and degradation, as described in Section 4.3.3.1. Impact levels to habitat are expected to be moderate for all 1.8 miles of the route segment (sagebrush/perennial grassland).