What is the Montrose-Nucla-Cahone Upgrade Project?
Tri-State Generation and Transmission Association, Inc. (Tri-State) is proposing to rebuild the existing Montrose-Nucla-Cahone 115-kV transmission line to a 230-kV. The existing line was built in 1958, and is becoming more difficult to maintain. The age of the poles makes them more susceptible to cracking, rotting, insect infestation and woodpecker damage. A new line would reduce safety risks associated with maintenance of the existing line and address reliability issues. The line will strengthen the ‘transmission backbone’ that provides electricity to individuals, farms and businesses in the region. It will also minimize maintenance costs, reduce outages and allow our members to provide the reliable power that the region is dependent on for future economic development.
What will be different about the line and right of way?
The H-frame structures would be approximately 25 feet taller and 10 feet wider than the existing poles. Tri-State proposes to use the existing 115-kV 100-foot right-of-way (ROW) for the rebuild to the greatest extent possible. The new 230-kV transmission line would require an additional 50 foot of ROW clearing for a total of 150 feet wide corridor. The 150‐foot ROW would be centered on top of the existing 100‐foot easement. The additional 25 feet on either side of centerline is required by the National American Electric Reliability Corporation to provide for electrical clearance and safe operation of the transmission line.
What is the purpose of the reroute over the Dolores River?
Tri-State is proposing a new crossing of the Dolores River Canyon; this crossing would be just west of the existing crossing, which would be reclaimed. The proposed crossing may partially cross a short section of undeveloped land. Tri-State is proposing this crossing to address maintenance and erosion issues with the existing access roads and transmission poles, which are partially built on steep slopes of ridges that step down the canyon walls. Existing roads used to maintain the structures have grades of 20 to 25% and require use of winches and tracked bulldozers to tow maintenance vehicles and navigate the steep unstable slopes. The structures associated with the current crossing require significant stabilization work to keep them from sliding into the canyon.
Does the upgrade affect the Gunnison Sage Grouse?
The U.S. Fish and Wildlife Service’s (USFWS) issued final rules designating the Gunnison Sage-Grouse (GuSG) as a threatened species and designated areas of critical habitat under the Endangered Species Act on November 20, 2014. Prior to the listing, local, state and federal stakeholders developed voluntary plans to build species populations with the goal of avoiding the listing. Tri-State is required to avoid, minimize, and mitigate project related ad-verse effects to GuSG and their designated critical habitat.