Siting Study - Boardman to Hemingway Transmission Line Project

Siting Study
Boardman to Hemingway Transmission Line Project
3.4.1 Western Route
The Western Route exits the proposed Grassland Substation to the south, heads west for about 6 miles,
and then turns south crossing the western part of Morrow County, continuing southwest across Grant,
Harney, Malheur, and Owyhee Counties to the Hemingway Substation. Table D-15 in Appendix D shows
that, of the three remaining routes for further consideration, the Western Route is the shortest by about 7
to 24 miles and crosses the least private and most public land; however, it parallels the least amount of
existing utility and transportation corridors (46 miles) and would require the most new ROW (229 miles).
Although the shortest alternative, the Western Route crosses about 117.1 miles of what has been
designated as high difficulty construction conditions, 51.8 miles and 17.8 miles more than the Eastern and
Central Routes, respectively. Compared to the Central and Eastern Routes in permitting difficulty, this
alternative requires the most new corridor, parallels the least utility corridor, crosses over 30 more special
status streams, requires over 1,750 acres of clearing, and would cross about 45 miles through the Malheur
and Umatilla National Forests. Overall, the Western Route has 47.1 miles of high permitting difficulty,
compared to 43.7 for the Eastern Route and 64.8 for the Central Route as shown in Table 3.4-2.
3.4.2 Central Route
The Central Route also exits the proposed Grassland Substation to the west and then proceeds south.
However, as this route passes to the south of the Boardman Grasslands Conservation Area it angles to the
east across Morrow and Umatilla Counties and then through the designated utility corridor in the
Wallowa-Whitman National Forest. This alternative then turns southeast through Union County and along
the west side of the Baker Valley in Baker County. It continues southeast through Malheur and Owyhee
Counties into the new Hemingway Substation.
This alternative route is about 7 miles longer than the Western Route and 17 miles shorter than the
Eastern Route. It parallels more existing utility and transportation corridor than the Western Route, but
53 miles less than the Eastern Route and it requires 5 miles less new corridor than the Western Route and
36 more miles of new corridor than the Eastern Route.
The Central Route crosses about 56 miles of slopes over 25 percent and would require clearing of
approximately 1,760 acres about the same as the Western Route and significantly more than the Eastern
Route. The evaluation of construction difficulty shows that the Central Route traverses 22.3 fewer miles
of high construction difficulty than the Western Route and 33.1 more miles than the Eastern Route. Much
of this difficulty would happen along the west side of the Baker Valley.
Significant permitting concerns include the 30 miles through the Wallowa-Whitman National Forests,
potential visibility of the line on the west side of Baker Valley, 224 miles of new corridor, and about
1,760 acres of clearing. As shown on Table 3.4-2, this alternative route crosses more miles of high
permitting difficulty than the Eastern or Western Routes.
3.4.3 Eastern Route
The Eastern Route is similar to the Central Route except that it exits the proposed Grassland Substation to
the north and east around the Boardman Bombing Range and then proceeds southeastward. It joins the
Central Route at the Morrow/Umatilla County line about 2 miles east of Four Corners. The two
alternatives continue together to the southeast end of the Wallowa-Whitman utility corridor. At this point
the Eastern Route proceeds to the southeast across Union County and then into the Baker County
following the east side of the Baker Valley. The Eastern Route rejoins the Central Route in northern
August 2010 3-96