That sinking feeling

City doing battle with recurring problem on Winnipeg Street

Digging will continue “into next week for sure” as the city tries to get to the bottom of what’s causing a sinkhole to repeatedly open at the same spot on Winnipeg Street. For the second time in a bit more than a month, city workers were at the site just north of Carney-20th Avenue after the trouble reemerged following Wednesday night’s torrential rain.

With the help of a backhoe, they have dug down about eight feet to a watermain. A section was to be removed and the line capped off so they can go down further – to about 20 feet to get at a storm drain.

It means the northbound lane on Winnipeg will be off limits to traffic for some time yet.

“We’re going to have to keep this closed off for a number of days so we can get at this step-by-step,” city engineering and public works manager Dave Dyer said. “Not only do we have the watermain, but we’re going to hit groundwater, so we’re going to have to figure out how we’re going to deal with that.”

Dyer said his guess is that the pipe has simply worn out, particularly along the bottom, over the decades since it was installed. Similar trouble has erupted elsewhere due to aging and he predicted there will be more to come, and noted much of the piping was made of metal.

“That was the cheaper way to go back in the ’60s and ’70s and we had a manufacturer right here in town, so we used it a lot,” Dyer said. “Unfortunately, we’re not getting the life out of it.”

Crews were at the same spot twice in 2014, first in August, then in October.

“They couldn’t get down deep enough because of the waterline,” Dyer said. “So they backfilled it all and put drain rock in to see if it would hold up and in October that watermain broke because it was an old pipe as well.”

He said the hole that appeared in May this year was dry.

“For some reason it had settled out and it had dropped and all the gravels in the road base had gone somewhere,” Dyer said.

A crew backfilled the hole and repaved the section only to see the problem pop up once again, this time creating a “huge cavity” beneath the road. Dyer would like to see the trouble solved once and for all.

“We’ve got to get this figured out because it’s just too prevalent now,” he said.

CITIZEN PHOTOS BY BRENT BRAATEN Dave Dyer, engineering and public works manager for the City of Prince George, explains the process of trying to find the cause of a persistent sink hole, right, on Winnipeg at Carney Street on Friday morning.