Mayo Generating Station Upgrades

Over the next five years, we are planning to complete a number of upgrades to the Mayo Generating Station. At the same time, we are also going through the relicensing process for the Mayo dam, so we can continue to generate renewable electricity.

A note that the below timelines can change based on varying factors.

Mayo A Slope and Surge Chamber

In 2022, a rockslide occurred behind the Mayo A plant, followed by another slide in 2023. While we are actively monitoring the slope, its instability is presenting safety concerns for Yukon Energy staff and is creating challenges in accessing the plant. We need to work on a permanent solution to stabilize the slope. The surge chamber absorbs sudden pressure changes in the penstock to protect the generating station equipment. It is reaching end-of-life and needs to be replaced.

Planned completion: 2026

Wareham Dam Spillway

The Wareham spillway is a critical component of the Mayo Generating Station. When there is too much water to use to generate electricity, it flows down the spillway and into the Mayo River. The spillway needs to be repaired or replaced. We completed temporary repairs in 2024 and are now working on a permanent solution.

Planned completion: 2027

Mayo A Plant Refurbishment

The Mayo A plant is one of two plants that house the turbines and related equipment at the Mayo Generating Station. The Mayo A Plant has been in service since the early 1950s and is nearing its end of life. To continue operating safely into the future, it requires an upgrade. Options for the plant, including the building and its equipment, will be considered.

Planned completion: 2029

Mayo Lake Control Structure

The Mayo Lake Control Structure is located 35 km upstream from Wareham Lake. Currently, the structure is in poor-to-fair condition and needs to be replaced. As part of the replacement, we will include fish passage. 

Design to begin: 2029