Two rock slides in as many weeks on a short section of the Malahat have prompted B.C.’s Ministry of Transportation to inspect mountain walls for other potential risks.
About five cubic metres of rock fell into the ditch and on the Trans-Canada Highway near Goldstream Park just after midnight Friday.
The slide was smaller than the one in late December, when about 13 cubic metres of rock fell onto a section of the highway. But because the two incidents were only about 800 metres apart, ministry staff say they are taking no chances.
Having two slides so close to each other in just two weeks is probably “more of a coincidence” than anything, said Patrick Livolsi, south coast regional director for the Ministry of Transportation, “but we want to make sure.”
Police spotted the debris on the road just after midnight Friday.
Traffic disruption was minimal while maintenance contractors cleaned up.
The highway was closed again by 9:30 a.m. Saturday for about half an hour as workers returned for more clean-up work. Flaggers and spotters were on the scene, about 250 metres south of Goldstream bridge, until the area had been inspected.
The rock fall in December was near the first curve heading into Goldstream Park, just north of the Ice Cream Mountain shop. A thick slab of rock broke from the cliff and landed onto the northbound lane.
No one was injured in that incident, either, which was pure luck, said the firefighters who discovered the slab on the highway.
Rock slides in this area are unusual, compared with other parts of the province, Livolsi said. Most are caused by freezing and thawing cycles, which can loosen rocks. Tree roots can also loosen rock.
“There’s no way to predict it. We don’t know until it happens,” Livolsi said.
After the December slide, rock scalers were called in. Hanging from ropes over the slopes, they use pry bars to remove loose rock.
When crews inspect this section of the highway in the next week, they will be looking for areas where scalers can again go in and remove any loose rock.
