City crews in Yellowknife scrambled to fill in a sinkhole on Forrest Drive near Burwash Drive Monday morning.

Forrest Drive sinkhole

City crews in Yellowknife scrambled to fill in a 2-metre deep sinkhole that appeared on Forrest Drive near Burwash Drive around 9:30 a.m. (Elizabeth McMillan/CBC)

The hole, about two metres deep and 1.5 metres square, appeared at approximately 9:30 a.m. Crews have since filled in the area with gravel. 

The city's department of public works says it was likely either a water main or a sewage main break that caused the section of road to collapse. They are investigating what exactly happened. 

Chris Greencorn, director of public works, says the sewer line in that area is in extremely bad shape. It's in such bad shape that the city no longer flushes the sewer main with water to clear it for fear the deteriorating pipes will collapse. 

The corrugated pipes are scheduled to be replaced next year. The line was previously scheduled to be replaced but it was put off because other areas were considered more pressing.

Depending on the cause of the sinkhole, the line may require an emergency replacement this year, Greencorn says.