The transmission line is needed to replace an aging 69-kV line, owned by Tri-State member cooperative San Miguel Power Association, Inc. The line, originally constructed in 1948, is at the end of its useful life, is vulnerable to lightning strikes and is costly to maintain. Additionally, this line cannot support the electric load during peak energy usage times in the Telluride area if the line's primary source from Durango goes out.
Tri-State’s new 115-kV line will replace this 69-kV line. Per Federal Energy Regulatory Commission regulations, Tri-State will own and operate the line as it is a transmission operator. The old line will be removed and the new line will be constructed, following some of the original alignment.
Construction during the remainder of this year will include:
• Construction of transmission line outside the Nucla Switchyard (Montrose County) to the Norwood substation (San Miguel County). This will include 16 miles of transmission in Montrose County and 3.8 miles in San Miguel County.
• Trench installation for the underground portions of the line at Specie Mesa and the west end of the West Wilson Mesa.
Construction is scheduled to last through 2012. A timeline listing project milestones, construction activities and associated road closures will be updated regularly on the project Web page.
The new line will start at Tri-State’s Nucla substation, located west of Naturita, and will terminate at the Sunshine substation near Telluride. The Nucla-Sunshine Project encompasses approximately 50 miles of new line and transmission facilities, including:
• Construction of a new 19.9-mile-long, 115 kV line from the Nucla Substation to the Norwood Substation, across portions of Montrose and San Miguel counties.
• Construction of a new 30.4-mile-long, 115 kV transmission line from the Norwood Substation to the Sunshine Substation near Mountain Village on Ilium Road (AKA South Fork Road). This will include 20.4 miles of overhead line and 10 miles of underground line (across portions of Specie and Wilson mesas in San Miguel County).
• Expansion of the Norwood Substation on two acres of private land.
• Rebuild a larger substation located next to the existing Wilson Mesa Substation in San Miguel County.
• Modification of the existing Nucla and Sunshine substations.
• SMPA will remove the Oak Hill Substation on Wrights Mesa and Specie Mesa Substation, reclaiming the property to its original state.