Mine sink hole forces closure of Nanaimo road

Nanaimo’s buried past has surfaced once again, this time as a sink hole that has forced the closure of Westwood Road to traffic, with work crews shutting off gas and water mains.  Bill Sims, city general manager of engineering and public works, said the hole, which formed between Cathers Drive and Kawartha Place, was reported to the city at about 8 p.m. Thursday, Oct. 2, and is the result of a cave-in roof of an old coal mine. “As most folks know, we’ve got a number of coal mines around the city,” Sims said. “They underlay the city and, over time, those mines fail. What happens is the roof starts to fall in and collapse and it, essentially radiates upwards to a point where we see a sink hole on the surface and that’s exactly what’s happened here.”  City workers closed the section of Westwood Road Thursday night and continue to reroute traffic through Cathers Drive and Kawartha Place. Once the section of Westwood Road was secured, Sims said workers arrived Friday morning to assess the hole, estimated to be about five-by-five metres wide and about six metres deep and begin repair work by filling the hole with concrete and rocks. Sims said the void appears to be located on the edge of a mine working and extends in a northwesterly direction toward the Nanaimo Parkway.  “What we’re not seeing is beyond the bottom of the hole,” Sims said. “There’s an evident void beyond that and so when we put the first load of concrete in there, which is about six cubic metres … a lot of it disappeared into that void, so we know the void extends further than what we could see and that’s exactly why we use concrete, so it can sort of flow into that void.”  A gas main and water main are located on either side of the hole and were not damaged. The gas line was shut off as a precaution and crews have maintained water service to the area.  “If the earth moved anymore we just didn’t want to see those pipe fall into the hole, essentially,” Sims said.  Work will continue throughout the day Friday, Oct. 3, and possibly into Saturday, Oct. 4, if required.  Sims said it was fortunate to have such a short detour loop around the work site and also that no vehicles or pedestrians fell into the hole before the road could be closed. He anticipates the costs for the repair work will tally up into the “low tens of thousands” of dollars. It appeared early Friday afternoon that the additional concrete had hit bottom and was starting to refill the empty space.  “It’s an unfortunate and relatively expensive fix to pour a bunch of concrete into it, but at the same time, we’re all really grateful it’s only just the road, the sidewalk and nobody was hurt, nobody drove into the hole and we’re not affecting any nearby homes,” Sims said.