Crews from Yukon Energy and ATCO Electric Yukon responded to five power outages in Whitehorse, Dawson City and Mayo and over the Canada Day long weekend, says a report provided by Yukon Energy this morning.

The power outages were unrelated to each other and caused by either lightning or issues with a hydro unit in the Whitehorse Rapids Dam. 

With numerous fires and storms occurring throughout the territory, Yukon Energy and ATCO Electric Yukon are reminding Yukoners to stock up on their 72-hour emergency preparedness kit in case of extended power outages.

Lightning can strike at any time. With the heightened fire situation, utility crews must visually patrol all power lines before trying to re-energize them – extending response times.

Guy Morgan, Yukon Energy’s vice-president of operations, told the Star this morning technicians are still investigating the specifics of what caused the generating issues with the Whitehorse #4 hydro generating unit, the largest hydro unit at the local dam. The unit remains off-line, he said.

“We just want to confirm the sequence of events,” Morgan said.

“We really have not found the cause, and until we have it confirmed, we do not want to put it back on just because of the impact it has on the system.”

Morgan pointed out Yukon Energy were set to re-energize the transmission line between Pelly Crossing and Stewart Crossing early this afternoon, after it was shut down in recent days because of forest fires.

The following is a summary of power outages over the long weekend provided by Yukon Energy:

Friday, July 1 – Dawson City

The outage on Friday at 4:39 p.m. was caused by lightning, and affected approximately 1,400 customers.

Partial restoration to about 900 customers was achieved at 4:47 p.m.and full restoration occurred at 5:27. 

Saturday, July 2 – Mayo, parts of Whitehorse, Southern Lakes region (about 10,000 customers)

A trip at the Whitehorse #4 unit, the largest of the four hydro units at the dam with a generating capacity of 20 megawatts, was the cause of the first of two outages on Saturday, occurring at 2:48. The outage affected approximately 10,000 customers.

Partial restoration to approximately 500 customers in Mayo occurred at 2:52 p.m. Full restoration was achieved at 3:45.

At the time of the outage, Whitehorse #4 was generating 16.48 MW, or approximately a third of the 47.5 MW being generated on the grid at the time.

The parts of Whitehorse affected included Riverdale, the south end of downtown, Porter Creek, Takhini and subdivisions between Robert Service Way and Teslin, as well as Carcross and Tagish but not Teslin.

Saturday, July 2 – Dawson City

Lightning caused Saturday night’s outage in Dawson at 9:12 p.m., affecting approximately 1,400 customers.

Partial restoration to approximately 900 customers occurred at 9:30 p.m. and full restoration was achieved at 9:38 p.m.

Sunday, July 3 – Mayo, parts of Whitehorse, Southern Lakes region

A trip at the Whitehorse #4 generating unit caused Sunday afternoon’s outage beginning at 2:45 p.m., affecting approximately 10,000 customers.

Partial restoration to the 500 customers in Mayo occurred at 2:48 p.m. and full restoration to the 10,000 customers was achieved at 3:25 p.m.

Whitehorse #4 was generating about a third of the load on the grid.

Monday, July 4 – Porter Creek and Takhini

A trip at the Whitehorse #2 generating unit caused the outage early this morning at 12:08.

Full restoration to the approximately 2,959 customers affected was achieved 21 minutes later at 12:29.

The Whitehorse #2 unit generates about six megawatts of power during the summer.