June 14, 2012
AltaLink's environment team is always looking for ways to reduce the impact of our transmission facilities on Alberta's natural habitats.
The recent completion of the Castle Rock Ridge Wind Farm Connection project provides one example of how AltaLink works to protect Alberta's feathered friends.
The Castle Rock Ridge Wind Farm Connection project will connect more wind-generated power to Alberta's electric system and includes a new transmission line, nine kilometres (5.6 miles) in length, and a substation located north of Pincher Creek.
"Portions of the new transmission line were located near water bodies, which are common for bird breeding and feeding. These types of areas can have a higher risk for bird collisions, so before energization it was important to install marking devices to make the transmission line more visible to birds," says Monique Wilkinson, Senior Environmental Advisor.
Studies of the project area were conducted during construction planning to understand the use of the surrounding water bodies by waterfowl such as ducks and geese, as well as other wildlife in the area.
"We also consulted with Environment and Sustainable Resource Development (ESRD) about our species-specific mitigation plans, which are developed to reduce the impact of our transmission facilities on wildlife," explains Monique.
Transmission line wires are often difficult for birds to see and can sometimes appear invisible due to background or low light conditions. The risk of a collision is highest for waterfowl, which have difficulty maneuvering around transmission line wires due to their large bodies and small wings.
Bird marking devices make the wires more visible so that the birds can see and avoid the wire. AltaLink uses two types of marking devices, the Bird Flight Diverter and the Firefly. "Both devices have been shown to be effective in reducing bird collisions," says Monique.
Bird Flight Diverters were the device used for this project and were installed using a helicopter on the topmost two wires (Overhead Shield Wire and the Optical Ground Wire) of the transmission line. The diverters are approximately 20 centimetres (eight inches) long and were installed 10 metres (33 feet) apart.
Alberta's natural landscapes are home to many diverse animals, including more than 400 different species of birds. "We recognize the importance of conserving these species and are committed to mitigating the impact of our transmission facilities on their natural habitat," adds Monique.