Electrical service will be interrupted in Yellow Pine and the Warm Lake area from 7 a.m. to 6 p.m. on four days, Sept. 16, 18, 19 and 22, so Idaho Power crews can safely perform transmission line maintenance.
This work is necessary to maintain and improve the reliability of the electrical service in the area. Project dates were determined by Idaho Power, local businesses and community leaders to minimize impact and provide advance notice.
Idaho Power’s 69-kV Emmett to Warm Lake line, Line 328, was built in 1943 to supply electricity to mining operations in Idaho’s backcountry. These mines provided tungsten and antimony needed for the manufacture of radar, rifles, and other weapons during World War II.
Today, line 328 is the sole source of power to the city of Yellow Pine, Idaho, which sits high in the River of No Return country east of McCall. This line also serves approximately 300 customers in remote locations around Warm Lake.
Age and exposure to the elements have taken their toll on the transmission structures and access roads over the past 70 years. As part of its ongoing effort to improve the reliability of its electrical system, Idaho Power conducts multi-year maintenance programs on these remote lines. We are now in the second year of a three-year maintenance program on this line, said Joe Samer, Idaho Power Engineering Project Leader.
Maintenance in 2014 includes replacement of approximately 30 wooden H-frame structures in rugged mountainous terrain. Approximately 20 of these structures can be replaced with the 69-kV line energized. Ten of the structures are so remote and difficult to access that to safely replace them requires turning the power off.
Idaho Power personnel met with the impacted residents of Yellow Pine and the surrounding area in early August and identified four days when the power would be turned off from 7 a.m. until 6 p.m. In addition to replacing H-frame structures during the outage, Idaho Power will upgrade distribution equipment at North Shore Lodge at Warm Lake as well as clear hazard trees that are threatening the power line in more isolated wilderness locations. The entire effort in 2014 will use crews from Boise as well as regional crews from McCall lead by Idaho Power Area Manager Steve Moser.
The H-frame transmission structures are designed for 138-kV construction and vary in height from 55 to 85 ft. No new conductor is being installed as part of this maintenance. In 2015, approximately 50 transmission structures will be replaced in even more challenging terrain. The results from the 3-year effort will result in improved reliability and service to customers, according to Moser.
“We understand that outages of this length have a real impact on our customers and their daily lives, and we appreciate the time the community took to meet with us to find the best possible dates to power down,” said Moser. “Our goal for the work that’s completed during the planned outages is to help ensure fewer unplanned outages in the future.”