Rehabilitation of Highway 62 West, Crater Lake National Park, Klamath County, Oregon
ENVIRONMENTAL CONSEQUENCES
ALTERNATIVE B: RESURFACING, RESTORATION, AND REHABILITATION
This section evaluates the potential impacts of alternative B.
Threatened and Endangered Species, Species of Concern
The threatened northern spotted owl activity center located approximately 900 meters (2,953 feet) north of the highway (within or across the deep Castle Creek Gorge) is screened from the highway by dense forest and has been active over many years while the highway has been in operation. Since the habitat in the project area is suitable for foraging, northern spotted owls may use areas near the construction site to forage or rest, but no construction activities are proposed to take place after dusk. Should disturbance occur, it would be expected to be insignificant and the likelihood of any adverse effects occurring is discountable (USFWS 2002b). There is no designated critical habitat present.
The northern spotted owl activity center is considered a sensitive noise receptor more than 900 meters (2,953 feet) away. At the evaluated distance of 800 feet, ambient noise levels would be less than the 51 to 65 dBA estimated using the 6 dBA drop-off with each doubling of distance, due to shielding by the forested woodlands, and would likely approach, or be slightly above existing levels. The existing noise environment includes an insignificant amount of daily traffic volume, with no additional noise sources, other than the natural soundscape. Construction noise would be minimized through best management practices (see mitigation measures), during daytime hours during the summer months, and is not expected to be constant in duration. Therefore, alternative B may affect, but is unlikely to adversely affect, threatened and endangered species. Section 7 consultation with the U.S. Fish and Wildlife Service is mandatory (see appendix 5).
Cumulative Impacts. Past, present, and reasonably foreseeable future actions that could have an effect on threatened and endangered species include fire management using prescribed burning and construction projects related to waterlines and lagoons in Munson Valley. Prescribed burns would emulate a natural occurrence under controlled conditions that could result in short-term, adverse impacts to threatened and endangered species and/or their habitat; however, the long-term effect from prescribed burns would be beneficial as the health of plant communities would improve and habitat would be more diverse. Construction in the Munson Valley could result in temporary to long-term effects on threatened and endangered species within a localized site. The cumulative effect of this alternative may affect, but is not likely to adversely affect, threatened and endangered species.
Conclusion. Alternative B may affect, but is unlikely to adversely affect the northern spotted owls occupying the activity center approximately 900 meters north of Highway 62 West. The cumulative impact of this alternative may affect, but is unlikely to adversely affect, threatened and endangered species.
Because there would be no major adverse impacts to a resource or value whose conservation is (1) necessary to fulfill specific purposes identified in the park’s establishing legislation, (2) key to the natural or cultural integrity of the park or to opportunities for enjoyment of the park, or (3) identified as a goal in the park’s General Management Plan or other relevant National Park Service planning documents, there would be no impairment of park resources or values related to threatened and endangered species or special concern species at Crater Lake National Park.
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