IMAGINE SEVERAL HUNDRED THOUSAND PEOPLE, living on some of Canada’s most expensive real estate, trapped by cold, swirling water. Picture jets grounded at the low-lying Vancouver International Airport; visualize the TransCanada highway impassible in either direction; conjure three rail lines underwater. Phone and internet systems are down. Food supplies in local grocery stores are decimated within four days. Freight has difficulty getting in and out of the Port of Vancouver, causing nationwide economic disruptions. After all of that has sunk in, mix in sewage from several medium-to-large cities as well as 600,000 metric tonnes of floating cars, dead animals and other debris.
This could happen if British Columbia’s Fraser River, the tenth-longest river in the country, rises to levels last seen in the late 1800s, when the worst flood in the Lower Mainland’s recorded history deluged flat farmland and burgeoning riverside communities with water as far as the eye could see. The Fraser Basin Council (FBC), a non-profit organization concerned with flood management, predicts that with climate change and sea level rise, there’s a one in three chance this could happen in the next fifty years.
Most people think “ocean” when they think of Vancouver, forgetting about the broad river rolling by the city’s back door. But the Fraser—whose tributaries drain a third of the province—plays a key role in the city’s geography. At 1,375 kilometres long, its headwaters start in the Rockies, near the Alberta border, and rush northwest through mountain valleys, picking up volume all the way to Prince George. Just past the dry Chilcotin, the Fraser squeezes into a deeply incised canyon. Kilometres of white water later, including a contortion through a narrow passage called Hells Gate, the river finally widens at Hope. At this point, barely five metres above sea level, the mighty Fraser sweeps through 160 kilometres of flat, floodable cities such as Chilliwack and Port Coquitlam, before meeting up with Richmond and Vancouver at the river’s mouth.
The danger time on the Fraser is during the spring freshet, when meltwater from the winter snow races out of the mountains and down towards the sea. Most years the flow is manageable, but every once in a while the rushing river becomes unwieldy. A new report, released in May 2016 by the FBC, tallies the vulnerability that communities face in British Columbia’s otherwise idyllic but ever-growing Lower Mainland. Adding it all up, the FBC report predicts that when the Fraser breaches its banks, it can cause losses valued at $2.6 billion to private houses, $3.8 billion in commercial buildings, $880 million in public institutions, $4.6 billion in infrastructure and $1.6 billion in agricultural lands—approximately $13.5 billion in total.
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