Siting Study - Boardman to Hemingway Transmission Line Project

Siting Study
Boardman to Hemingway Transmission Line Project
3.3.13 Lime Region
The routing analysis within the Lime Region included two routes located on the west side of I-84, just
south of the Weatherby Region, as shown on Figure 3.3.13-1. Similar to the Weatherby Region, much of
this region comprises severe topography and is located on the east side of Table Rock. This is the smallest
region, covering just over 5 miles in the vicinity of Lime, Oregon.
The two CAP routes developed in this area were C4 and S7 and both had the intended purpose of
following existing corridors. CAP route C4 was minimally revised to parallel the west side of an existing
138-kV transmission line through the region and later was designated the West Route, BA14-BA16. CAP
route S7 was intended to immediately parallel I-84 but due to the steep topography adjacent to I-84,
portions of the route in this vicinity were relocated to avoid more difficult engineering and construction
conditions. This route was designated the East Route, BA14-BA15-BA16.
Figure 3.3.13-2 shows the results of the permitting difficulty, construction difficulty and mitigation cost
analyses along each route in the Lime Region. Table 3.3.13-1 is the summary table detailing the totals of
each difficulty analysis. As this table details, the West Route has significantly fewer miles of high
permitting difficulty and high construction difficulty. Additionally, Table D-13 in Appendix D shows the
West Route avoids both the 1,200-foot Historic Trail Buffer Zone and the 1,200-foot Scenic Byway
Buffer Zone that are crossed by the East Route and crosses 1.8 fewer miles of slopes greater than 35
percent as compared to the East Route.
Table 3.3.13-1 Lime Region Summary of Permitting and Construction Difficulty and Mitigation
Cost
Permitting Difficulty
Construction Difficulty
Mitigation Cost
West Route
(BA14-BA16)
East Route
(BA14-BA15-BA16)
Length in Miles
Low 0.0 0.0
Moderate 5.2 2.9
High 0.7 3.1
Exclusion 0.0 0.0
Low 0.0 1.7
Moderate 5.9 0.0
High 0.0 4.3
Low 0.0 0.0
Moderate 5.9 6.0
High 0.0 0.0
The result of the Lime Regional analysis was that the West Route, BA14-BA16 (CAP route C4), was
recommended as more reasonable than the East Route, BA14-BA15-BA16 (CAP route S7).
August 2010 3-71