Ice jam knocks Aishihik hydro plant offline

An ice blockage knocked the Aishihik hydroelectric plant offline Jan. 17, causing brief power outages throughout the territory.

An ice blockage knocked the Aishihik hydroelectric plant offline Jan. 17, causing brief power outages throughout the territory.

Yukon Energy spokesperson Janet Patterson told the News the ice “starved the hydrogenerators of water,” resulting in the plant’s shutdown.

The power went off just after 7:35 a.m. that day, causing outages in Dawson City, Carcross, Tagish, Marsh Lake, Teslin and subdivisions south of Whitehorse.

Yukon Energy and ATCO crews restored power about 40 minutes later.

When the News spoke with Patterson the afternoon after the outage, the Aishihik plant was still offline.

Crews sent an underwater camera last night to have a better look at the ice blockage.

“There is six to eight inches of what appears to be slushy ice … covering the whole trash-rack,” Patterson said late last night via email.

“Divers will be coming in on the late flight tonight and we will dispatch a crew along with the City of Whitehorse steam truck out to Aishihik tomorrow morning.”

She said she hopes to have the ice removed by end of day today or tomorrow.

The Aishihik plant, 140 kilometres north of Whitehorse, is a hydro plant built 120 metres below ground. The water drops 174 metres before reaching the plant’s turbines.

The ice jam blocked the aboveground water intake tunnel.

Backup LNG and diesel generators have been providing electricity to the grid. Operations at the Mayo and Whitehorse dams continued without interruption.

The Aishihik plant can generate up to 37 megawatts of electricity. In comparison, the Whitehorse dam generates up to 40 megawatts during its peak production period in the summer.

Right before it went offline, the Aishihik plant was generating about 30 megawatts for the grid, Patterson said.

“This is an example of why we need backup power,” Patterson said. “Even though we don’t like to use LNG or diesel, it gets people’s power back on.”

At press time, about 30 per cent of the grid’s electrical output was coming from diesel and LNG, according to the Yukon Energy website. That figure typically averages between zero and eight per cent of total generation.

Contact Pierre Chauvin at

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Premier Sandy Silver, left, and Yukon’s Chief Medical Officer of Health Dr. Brendan Hanley speak at a COVID-19 update press conference in Whitehorse on Nov. 19. On Nov. 24, Silver and Hanley announced masks will be mandatory in public places as of Dec. 1, and encouraged Yukoners to begin wearing masks immediately. (Crystal Schick/Yukon News file)
Masks mandatory in public places starting on Dec. 1

“The safe six has just got a plus one,” Silver said.

Dr. Brendan Hanley, Yukon’s chief medical officer of health, speaks at a press conference in Whitehorse on March 30. Hanley announced three more COVID-19 cases in a release on Nov. 21. (Crystal Schick/Yukon News file)
Three more COVID-19 cases, new exposure notice announced

The Yukon’s Chief Medical Officer of Health, Dr. Brendan Hanley, announced three… Continue reading

Yukonomist Keith Halliday
Yukonomist: COVID-19 strikes another blow at high-school students

They don’t show up very often in COVID-19 case statistics, but they… Continue reading

The Cornerstone housing project under construction at the end of Main Street in Whitehorse on Nov. 19. Community Services Minister John Streicker said he will consult with the Yukon Contractors Association after concerns were raised in the legislature about COVID-19 isolation procedures for Outside workers at the site. (Crystal Schick/Yukon News)
Concerns raised about alternate self-isolation plans for construction

Minister Streicker said going forward, official safety plans should be shared across a worksite

Beatrice Lorne was always remembered by gold rush veterans as the ‘Klondike Nightingale’. (Yukon Archives/Maggies Museum Collection)
History Hunter: Beatrice Lorne — The ‘Klondike Nightingale’

In June of 1929, 11 years after the end of the First… Continue reading

Samson Hartland is the executive director of the Yukon Chamber of Mines. The Yukon Chamber of Mines elected a new board of directors during its annual general meeting held virtually on Nov. 17. (Joel Krahn/Yukon News file)
Yukon Chamber of Mines elects new board

The Yukon Chamber of Mines elected a new board of directors during… Continue reading

The Yukon Hospital Corporation has released its annual report for 2019-20, and — unsurprisingly — hospital visitations were down. (Crystal Schick/Yukon News file)
Annual report says COVID-19 had a large impact visitation numbers at Whitehorse General

The Yukon Hospital Corporation has released its annual report for 2019-20, and… Continue reading

Whitehorse City Hall. (Joel Krahn/Yukon News file)
City hall, briefly

A look at decisions made by Whitehorse city council this week

City council was closed to public on March 23 due to gathering rules brought on by the COVID-19 pandemic. The council is now hoping there will be ways to improve access for residents to directly address council, even if it’s a virtual connection. (Crystal Schick/Yukon News file)
Solution sought to allow for more public presentations with council

Teleconference or video may provide opportunities, Roddick says

Megan Waterman, director of the Lastraw Ranch, is using remediated placer mine land in the Dawson area to raise local meat in a new initiative undertaken with the Yukon government’s agriculture branch. (Submitted)
Dawson-area farm using placer miner partnership to raise pigs on leased land

“Who in their right mind is going to do agriculture at a mining claim? But this made sense.”

Riverdale residents can learn more details of the City of Whitehorse’s plan to FireSmart a total of 24 hectares in the area of Chadburn Lake Road and south of the Hidden Lakes trail at a meeting on Nov. 26. (Ian Stewart/Yukon News file)
Meeting will focus on FireSmart plans

Riverdale residents will learn more details of the City of Whitehorse’s FireSmarting… Continue reading

The City of Whitehorse is planning to borrow $10 million to help pay for the construction of the operations building (pictured), a move that has one concillor questioning why they don’t just use reserve funds. (Crystal Schick/Yukon News)
Councillor questions borrowing plan

City of Whitehorse would borrow $10 million for operations building

Most Read