Frank Baumann has watched with professional interest, and a sense of alarm, as one natural disaster after another has hit British Columbia this summer.
Over the course of a few catastrophic weeks, a flash flood washed away vehicles and homes in Sicamous, a debris flow killed four people in Johnsons Landing, and then another raced through the middle of Fairmont Hot Springs, miraculously missing crowds of shocked tourists.
“I heard the Premier saying on the news the other day that none of this was predictable. But you know, that’s absolute BS,” said Mr. Baumann, a geological engineer who makes his living advising government and industry on the hazards posed by B.C.’s steep terrain.
He is not claiming that experts like him can predict when specific landslides will occur, any more than they can say when a tsunami or earthquake will strike. But the flurry of natural disasters that has struck this year, mostly in southeast B.C., are part of a long continuum of events that stretches into the distant past – and will continue into the future, he said.
In B.C., slides and floods have always poured down out of the mountains. Tsunamis have always been, and always will be, a threat on the coast. And earthquakes are simply part of the natural order of things for a province that sits nearly atop two colliding tectonic plates. But if you identify the hazards, Mr. Baumann said, you can predict when the most dangerous times and places are for people to be, and take measures to mitigate the risks.
As a case in point, he refers to the Mount Meager landslide, which came thundering down a steep volcanic mountain near Pemberton, just north of Whistler, in the summer of 2010.
A short time before that event, the BC Forest Service had adopted recommendations made by Mr. Baumann to close campgrounds in the area when there were several successive hot days.
After studying the impact of glacial melt on unstable slopes, Mr. Baumann worked out a formula that predicted the slide risk would go up whenever there were more than five days of 26-degree weather.
“When that event happened [the Forest Service] had just closed the valley because the threshold had been met and the only people up there had snuck in,” he said. “If that hadn’t been the case, the campground would have been full and there probably would have been 50 deaths.”
A few hikers were in the valley, but what may have been the biggest slide in Canadian history rumbled to a halt without harming anyone.
Mr. Baumann credits the government for doing work along the Sea-to-Sky Highway to identify creeks that were prone to flash floods. That study was spurred by a series of washouts during the 1980s, including one that took out a bridge at night, causing five vehicles to plunge into an abyss, killing nine people.
“They identified the hazard, and they build catchment basins,” he said. “You still get those debris torrents, but they are stopped before they reach the highway or houses below. So we’ve taken these natural events and have managed them.”
But not enough work is being done to identify the hazards, he said, and too often local governments give in to pressure from developers to build in areas that are at risk.
“There is constant pressure,” he said, to allow development on the limited amount of flat land found in mountainous B.C.
A paper on landslide hazards along the Sea-to-Sky corridor – written by Andrée Blais-Stevens of the Geological Survey of Canada, and Oldrich Hungr, Earth and Ocean Sciences at the University of British Columbia – comments on the difficulty posed by that dynamic.
“Overestimation of the risks … estranges developable land which is rare and extremely valuable in this mountainous terrain. Underestimation of the risk could, of course, lead to major disasters,” the authors state.
Greg Utzig, a soil specialist who owns a cabin in Johnsons Landing, said climate change is altering the risk factor across the province, bringing not only more rain annually, but also more intense rainstorms. He said the government should be doing more work to assess and mitigate risks.
A City of Vancouver report on climate change adaptation, which was released this week, underscores that concern. “Scientists project that Vancouver will experience increased annual precipitation and temperatures, with hotter, drier summers. More intense and frequent rain and wind storms are anticipated and sea level rise may pose a significant challenge by mid-century,” it states.
Among other things, the report calls for a complete flood risk assessment, both along the coast and on the Fraser River.Report Typo/Error