Vantage to Pomona FEIS Index 34 - Laserfiche WebLink

Home Browse Search

Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-100 for 6.5 miles, impact levels on golden eagles are anticipated to be moderate for 2.3 miles, and impact levels on prairie falcons are expected to be moderate for 10.2 miles. Route Segment 3b also crosses 10.2 miles of JBLM YTC’s Bald Eagle Protection Area and 0.6 mile of WDFW’s Bald Eagle Management Zone. Bald eagles are known to winter along the Columbia River’s western edge. Roosting bald eagles have been documented within one mile of Route Segment 3b at Borden Springs, Hanson Creek, and Alkali Canyon Creek. Habitat in Borden Springs and Alkali Canyon has been altered by fires occurring in 1996. Two suitable roost trees remained and were utilized at Borden Springs following the fire, while no evidence of roosting at Alkali Canyon Creek has been documented since the fire. Bald eagles wintering in the area have been observed foraging along Priest Rapids Reservoir during the day. Wintering bald eagles are typically present from between November and April, with peak abundance occurring in February (JBLM YTC 2002). Noise from construction equipment and general construction activities could disturb and displace wintering bald eagles. It is anticipated that no large trees suitable for roosting, perching and nesting would be removed. As described in Sections 4.3.3.1 and 4.3.3.2, RDFs would be implemented to reduce short- and long-term impacts and include avoidance of bald eagle winter roost areas between 8 am and 5 pm during the winter roosting season. With the implementation of RDFs, the impact on wintering eagles is anticipated to include 10.5 miles of moderate and 11.2 miles of low impacts. The majority of the habitat disturbance associated with Route Segment 3b would be located within the Regularly Occupied Habitat MU for Sage-Grouse (107.9 acres) with the remainder of disturbance within Occasionally Occupied Habitat MU (20.5 acres). Construction activities would disturb less than one percent of Regularly Occupied Habitat (Table 4.3-7). Anticipated ground disturbance includes 26.9 acres of suitable Sage-Grouse habitat, 8.0 acres of marginal habitat, and 72.9 acres of unsuitable habitat (Table 4.3-8). With the implementation of RDFs (Sections 4.3.3.1 and 4.3.3.2), the scale of disturbance and degradation to Sage-Grouse habitat is anticipated to be low for 18.4 miles and moderate for 3.3 miles. Construction of Route Segment 3b would require an estimated 181 new structures, of which 160 (88 percent) would be located greater than 0.25 mile of an existing transmission line (Table 4.3-5). The estimated Sage-Grouse population range does not overlap the Route Segment 3b ROW. Approximately seven percent (14,616 acres) of the JBLM YTC 95 percent population range is within four miles of Route Segment 3b (Figure 3.3-4). No active leks are known to occur within four miles of Route Segment 3b (Table 4.3-6). One inactive lek is located approximately 3.9 miles west of Route Segment 3b. This lek was last occupied in 2007. With the implementation of RDFs (Sections 4.3.3.1 and 4.3.3.2), impacts to lekking Sage-Grouse associated with the construction of Route Segment 3b is anticipated to be moderate for the 0.6 miles that are within four miles of the inactive lek. 4.3.4.10 Route Segment 3c Approximately 74.3 acres of long-term and 45.9 acres of short-term disturbance would occur through the construction of Route Segment 3c. Most of the permanently disturbed areas would be sagebrush/perennial grassland (49.6 acres) and agriculture/disturbed ground (32.1 acres). Short-term disturbance would primarily be on agriculture/disturbed land (32.1 acres) and annual grassland (11.5 acres; Table 4.3-4). Riparian/wetland habitat occurs along Lower Crab Creek and estimated disturbance to these areas would be 0.3 acres of long-term and 1.3 acres of short-term disturbance, though this disturbance would be avoided if possible by spanning the riparian area. 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 low for 14.5 miles and moderate for 10.7 miles (sagebrush/perennial grassland). The presence of new transmission line structures, which could provide additional perch and/or nesting sites for avian predators, could negatively impact nearby prey species such as small mammals and avian