One month after a sinkhole under Highway 16 started restricting traffic through a single-lane section just east of Topley, the almost $1 million in repairs to fully reopen the highway are nearly done.
Carl Lutz, the Ministry of Transportation’s district manager for Bulkley-Stikine, says crews expect traffic to start moving normally again by June 30.
Dubbed the Topley sinkhole, the highway surface 2 km southeast of Topley dipped dramatically on April 26 when a 0.6 m culvert channeling water beneath the road suddenly failed.
Rising spring water levels were too much for the broken culvert to handle, and crews quickly set up a detour around the area.
Construction work was delayed four days because heavy transport trucks were unable to take the initial detour.
Crews have worked steadily since then to replace the broken culvert with one twice the diameter, wide enough to handle spring water levels.
Lutz said the sinkhole location is a challenging place to work. The highway is built quite high up from the valley floor at that spot, and the culvert lies about 15 m under the road.
It took five days for the crew to dig out the smaller culvert and another two weeks to replace it and fill the lower area back in.
Working with two excavators and seven dump trucks, the crew is now is slowly refilling the dug-out road with gravel.
Lutz explained that the stretch of highway is being refilled in six-inch layers to ensure it is firmly packed and will last for many years to come.
Good weather has helped the construction move smoothly, said Lutz. The rain held off in the early stages of the repair work, and more recent rainfall has helped to pack down the new layers of gravel.
When asked about the bear sow and cub that have been regularly spotted in the field beside where the crew is working, Lutz shrugged.
“I’m used to bears,” he said. “Maybe some of the crew are a bit on edge but the bears don’t really bother me.”
A flagger at the site also sounded unconcerned by the bears.
“I’m surprised that I’m not, because I’m not really used to wild animals, but we are all just careful to clean up our garbage so the bears don’t come that close or bother us,” the flagger said.
To keep traffic moving, work crews have only closed the highway for 10 minutes at a time.
“We are working hair straight back now,” said Lutz, adding that crews will be at work seven days a week until the repairs are done.