A large sinkhole keeps opening on a Prince George road and no one knows why

A recurring sinkhole near downtown Prince George has left city workers at a loss despite several weeks of trying to solve the problem, and the cost of repair will now be "certainly over $100,000," according to Dave Dyer, the manager of engineering and public works.

So far, city crews have dug nearly fivemetres into the ground to try and find the root cause of the hole, which was discovered shortly after a major storm hit the cityon June 20.

It's also cut off two lanes of traffic, and it is believed the entire intersection at Winnipeg Streetand Carney Streetmay have to be closed before the hole is refilled.

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It's the fourth time in as many years a sinkhole has opened at the intersection of Winipeg Streetand Carney Street. A holefirst opened at the location in 2014, following a watermain break, then again that year and once more earlier in 2018.

Although city staff believe the cause of the current sinkhole is either a damagedstormwaterpipe or manhole, so far that's simply an educated guess, Dyer said.

To find the cause, the city needs to dry the area out and cleanup sediment in order to fully expose the pipe. Work is now underway on building a sheet pile dam in order to cut off water flow from the nearby Carrie Jane Gray Park.

"Hopefully, we find [the problem]," he said. "Then we have to figure out how we're going to fix it."

Safety regulations mean that for every metre dugthe hole needs to be widenedas well, so it's likely the entire four lanes of traffic will be blocked off, Dyer said.

The city will also have to put temporary infrastructure in place to divert water in case of another major storm.

Dyer said should everything go according to plan, it will stillbe up to sixto eightweeks before the road is reopened.

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With files from Audrey McKinnon.

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