Canada crews battle wildfires; all Yellowknife residents evacuate

Aug 17 (Reuters) - Canadian fire crews battled early on Thursday to prevent wildfires from reaching the northern city of Yellowknife, where all 20,000 residents are leaving after an evacuation order was declared.

Water bombers flew low over Yellowknife as thick smoke blanketed the capital of the vast and sparsely populated Northwest Territories.

Prime Minister Justin Trudeau plans to convene a meeting of the Incident Response Group to discuss the fires later on Thursday, his office said. The group is comprised of senior officials and ministers and meets in cases of crisis.

This is Canada's worst-ever wildfire season with more than 1,000 active fires burning across the country, including 265 in the Northwest Territories. Experts say climate change has exacerbated the wildfire problem.

The Territories, with a population of just 46,000 people, have limited infrastructure and there is only one two-lane road out of Yellowknife to the province of Alberta to the south, a trip of some 540 km (335 miles).

The deadline for residents to leave Yellowknife is noon local time on Friday (1800 GMT). The fire is about 16 km northeast of the city and authorities say it could reach the outskirts by Saturday if there is no rain.

Yellowknife mayor Rebecca Alty said special teams were clear cutting trees close to the city in a bid to prevent flames from spreading. They also planned to use fire retardant while ensuring sprinkler systems in the city are working, she told the Canadian Broadcasting Corp.

"But a big big focus is still on the fire breaks to slow the progress of the fire," she said.

Alty said five flights would be leaving the airport on Thursday to transport those who did not have vehicles or did not feel able to make the long drive to Alberta.

So far about 134,000 square kilometers (52,000 square miles) of land in Canada have been scorched, more than six times a 10-year average. Nearly 200,000 people have been forced to evacuate at some point this season.

In a social media post, the Territories fire service said a fire that had been threatening Hay River, a community of some 3,000 further south on Great Slave Lake, had stalled overnight.

"The territories have never seen anything like this before in terms of wildfire ... it's an unimaginable situation for so many," Mike Westwick, the territories' fire information officer, told the CBC.

The blazes have also affected industrial and energy production. Diamond producer De Beers said in a statement that its Gahcho Kue mine, some 280 km northeast of Yellowknife, continued to operate although a number of employees from the surrounding communities had been evacuated.

In May 2016, a huge fire destroyed 10% of structures in the northern energy-producing Alberta city of Fort McMurray, forcing the evacuation of 90,000 residents and shut in more than a million barrels per day of oil output.

In June 2021, 90% of the structures in the British Columbia village of Lytton burned down, a day after it recorded Canada's hottest-ever temperature.

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Covers Canadian political, economic and general news as well as breaking news across North America, previously based in London and Moscow and a winner of Reuters’ Treasury scoop of the year.