DOE/EIS-0332; McNary-John Day Transmission Line Project Draft ...

3
3-28
Affected Environment, Environmental
Consequences, and Mitigation
Alternative Impacts
Corridor Mile 32 Alternatives
A. Keep existing and new lines
on tribal land
B. Relocate existing and new
lines away from tribal land
Corridor Mile 35 Alternatives
A. Keep existing and new lines
on tribal land
B. Relocate existing and new
lines away from tribal land
Mitigation
The Columbia River is approximately 3,000 feet to the south, Alder
Creek is approximately 3,000 feet to the west, and a dry wash is
located approximately 1,000 feet to the north of this location.
Therefore, the construction of either of the two Corridor Mile 32
alternatives would not likely affect fish or fish habitat in either the
Columbia River or Alder Creek.
Same as Alternative A.
The Columbia River is located approximately 1,500 feet to the south
of corridor mile 35. One dry wash is located in this area, which
drains to the Columbia River. Potential for delivery of fine sediment
to the Columbia River would be greater with Alternative B
(relocating the line), than with Alternative A due to a greater area of
ground disturbance.
Same as Alternative A.
The following mitigation measures would minimize potential impacts to streams and
fisheries habitat from possible erosion and clearing of vegetation.
� Place towers outside of stream riparian areas and utilize natural landscape features to
span the conductor over existing shrub and tree riparian zones and avoid cutting.
� Place new access roads outside of stream riparian areas, where possible.
� Construct fords instead of culverts at access road crossings of dry washes or seasonal
streams if possible. If culverts are required, design and install to accommodate flows
associated with a 100-year flood event.
� Preserve existing vegetation where practical, especially next to intermittent and
perennial streams.
� Avoid construction within the 200-foot designated stream buffers in Klickitat and
Benton Counties, Washington.
� Maximize the use of existing roads, minimizing the need for new road construction.
� Avoid tower or access road construction on potentially unstable slopes where
feasible.
BPA McNary-John Day Transmission Project
Draft EIS
February 2002