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

BPA McNary-John Day Transmission Project
Draft EIS
February 2002
Streams, Rivers, and Fish
Erosion potential would be greater if towers were sited in areas of steep hill slopes and
dry washes. The steeper sloping areas along the corridor occur generally west of Glade
Creek, with the greatest concentration occurring between Alder Creek and Wood Gulch.
If a tower was sited at a dry wash the potential for delivery of fine sediments would be
greater than most other locations because dry washes provide transport of surface waters
during periods of precipitation and snow melt and typically drain to a larger stream. This
increases the opportunity for sediments to be delivered to a fish bearing, or potentially
fish bearing stream along the corridor. All of the dry washes along the corridor occur
west of Alder Creek, with 66% occurring between Alder Creek and Wood gulch, and the
remaining 34% occurring west of Wood Gulch.
Hazardous Materials
Construction of the proposed project would require the use of several common
construction materials (e.g., concrete and paint) and petroleum products (e.g., fuels,
lubricants, and hydraulic fluids) that could be toxic to fish and other aquatic organisms if
spilled into or near streams.
Access Roads
The project would require approximately 40 miles of existing roads to be reconditioned
and upgraded and 12.5 miles of new “spur roads” constructed from existing access roads.
This new access and spur road construction would include the clearing and grading of an
area 16 feet wide, with an approximate impact area 25 feet wide. The impact area may
include hill slopes where spoils from cut-and-fill road construction may be sent down
slope. Roads would be located on stable hill slopes and road gradients would not exceed
15% in areas with potentially unstable soils. Three miles of new access road would be
constructed from corridor mile 39 to 41. This road would cross 16 dry washes, all
draining to the Columbia River, 2,000 to 3,000 feet downstream.
Where access roads cross a dry wash, the road gradient should be 0% to avoid diverting
surface waters from the channel. The construction of the new access road across dry
washes could potentially affect the Columbia River fisheries from the occurrence of a
catastrophic event such as mass wasting, or from less severe actions such as the delivery
of fine sediment from the exposure of soils, or the potential that a spill of hazardous
materials may enter surface waters flowing within the dry washes.
No fish-bearing streams would be crossed by the construction of new access roads and no
existing access road currently crosses a fish-bearing or potentially fish-bearing stream
that Bonneville owns and/or manages. An additional 0.5 to 1.0 miles of new access road
and spur roads may also be constructed for Alternatives B and C of the Hanford-John
Day Junction Short-Line Routing Alternatives, respectively. Please refer to Table 3-8 for
potential impacts associated with these alternatives.
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