Our service territories are located in an exceptional natural environment. At NorthWestern Energy, we have the unique opportunity to live and work in areas that are often described as majestic and peaceful. From the mountains to the prairies, people visit our communities from all over the world to experience a taste of what we enjoy every day – clean air, clean water, beautiful scenery, abundant wildlife and scores of recreational opportunities.
While we work to deliver the power our customers need, we also work to protect our native birds that sometimes interact with our electric system. As stewards of this shared environment, we must balance our obligations as an electric utility with the needs of our service areas and the safety of its unique bird habitat.
In addition to learning about how we are protecting our native osprey, you can find out about two of our most recent conservation projects: the 2011 swan diverter effort and the 2012 bird reflector install.
Our bird protection plan addresses the safety of birds in flight, focusing on collisions with overhead power lines. Such collisions are uncommon. When collisions do occur, they typically involve large-bodied, less-maneuverable birds such as Canadian geese and waterfowl species. This was the case in the fall of 2011 when a bevy of trumpeter swans decided to make a pond in the Ruby River Valley their home. Here is the story from the 2011 (quarter 4) NorthWestern Energy employee publication .
In mid-March 2012, between snowstorms and strong winds, a contractor piloted a helicopter within 18 inches of the company’s 500 kV line near Broadview, Mont., so a lineman sitting on the skids of the copter could manually attach bird-flight diverters to the static lines above the energized spans of conductor crossing a shallow lake and wetlands.
This project is part of the company’s effort to make the transmission lines more visible to the thousands of birds that frequent Lake Broadview, a 5- to 10-thousand acre lake that fills only during very wet years.
By decreasing the number of collisions with the lines, the company also reduces the opportunity for bacteria to develop on the decaying birds and subsequently kill many more birds on the lake surface.
In January, NorthWestern Energy and the Montana FWP, DEQ and the USFWS decided to install bird diverters on the line. Although birds can see the larger three wires carrying electricity on NorthWestern Energy’s 500 kV line and avoid them, there are also two static wires above the other lines that are used to divert lightning strikes. Birds have trouble seeing those smaller lines and sometimes hit them and die. The new diverters are designed to be visible in low-light situations and even glow in the dark for a few hours. Studies show a collision reduction rated of between 40% and 87% when diverters are installed.
Montana FWP estimated approximately 7,000 birds were on the lake on March 20, the day the company began installing markers.