Rehabilitation of Highway 62 West, Crater Lake National Park, Klamath County, Oregon
ENVIRONMENTAL CONSEQUENCES
ALTERNATIVE C: PREFERRED ALTERNATIVE
This section evaluates the potential impacts of alternative C, the preferred alternative.
Biotic Communities
Under alternative C, impacts would occur to vegetation and wildlife associated with rehabilitation of the Highway 62 West corridor and the realignment of the highway through the switchbacks. Impacts associated with rehabilitation of the roadway would be similar to the impacts described in alternative B, resulting in a short-term, negligible, adverse effect to vegetation and wildlife.
Vegetation
Under this alternative, approximately 0.5 mile of roadway—the switchbacks—would be removed and the road realigned (figure 7). Approximately 2.5 acres (1.0 hectares) of vegetation would be disturbed for the new alignment, resulting in a long-term, negligible, adverse impact to vegetation. Up to six pine trees over 10-feet tall located at or near the toe of the fill slope would be protected with tree wells. Also, six to eight pine trees under 10-feet tall would be saved for transplanting. Following highway rehabilitation work, 1 acre (0.4 hectare) of land previously covered by the existing highway and turnouts would be available for restoration to native habitat resulting in a long-term, negligible, beneficial effect to vegetation.
Wildlife
Wildlife species would be expected to avoid the area during construction or would only travel through the area when traffic and noise had abated. Following highway rehabilitation work, 1 acre (0.4 hectare) of land previously covered by the existing highway and turnouts would be available for restoration to native habitat resulting in a long-term, negligible, beneficial effect to wildlife. Alternative C would result in a short-term, negligible, adverse effect to wildlife during construction.
Cumulative Impacts. Past, present, and reasonably foreseeable future actions that would have an effect on vegetation and wildlife 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 would result in short-term adverse impacts to vegetation, individual wildlife, and habitat; however, the long-term effect from prescribed burns would be beneficial as the health of the plant communities would improve and habitat would be more diverse for wildlife. Construction in the Munson Valley would result in temporary to long-term adverse effects on vegetation and wildlife on a localized site. This alternative would contribute a negligible, long-term, adverse effect to the cumulative impacts on vegetation and wildlife.
Conclusion. Alternative C would have a short-term, negligible, adverse effect on vegetation and wildlife during construction. Long-term, negligible, adverse impacts on vegetation and wildlife would be expected; however, a long-term, negligible beneficial effect would occur where habitat is restored. The cumulative effect would be a long-term, negligible, adverse effect on vegetation and wildlife.
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 biotic communities at Crater Lake National Park.
***previous*** — ***next***
