How to Re-Invent Roads
Building highways in British Columbia can bring challenges not always faced in other provinces. Mountains and snowpack and raging rivers can do that sort of thing.
When, last Wednesday, a massive atmospheric river took down all four of BC's mountain highways and both rail lines it was obvious that engineering standards of the past were no longer acceptable. This is no longer the Holocene. This is the Anthropocene.
You may have head that some of these roads are re-opening. That doesn't mean they're repaired. Temporary, limited traffic routes have been established but fixing the highways will take until 2022, perhaps longer.
The old roads won't return. The new roads will be designed by highway engineers but, this time, the road-builders will be guided by climate scientists.The Pacific Climate Impacts Consortium (PCIC), a climate analysis group based at the University of Victoria, projects a nearly fourfold increase in atmospheric rivers hitting western North America by the end of the 21st century and a median precipitation increase of 7 per cent by the 2050s. Regional variations in those projections vary wildly. In short: Sudden, levee-busting rains will be far more frequent.
“What we’re seeing right now bears out and validates a lot of the research that has been going on,” said Markus Schnorbus, lead hydrologist with PCIC. “Bouncing from one extreme to the next is a hallmark of climate change. Our historic experience will have no bearing on what we’ll experience in the future.”
Based on the modelling, engineers might integrate bigger culverts and higher bridge decks to accommodate greater water volumes. To prevent instability in water-logged hills, designs might call for shallower slopes and drainage blankets, permeable material that controls seepage. And roadbeds can be armoured with boulders to prevent the kind of river erosion that washed away sections of the Coquihalla this week.