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Anatomy of One of Canada s Worst and Most Costly Natural Disasters

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Canadian officials taking stock of the deluge that occurred in mid-June in Alberta have started to characterize it as the worst flood in the province’s history. Some are even calling it Canada’s second-largest natural disaster, after the 1998 ice storm that hit Quebec and eastern Ontario. Analysts think that the cost of the flood, which claimed four lives and displaced over 100,000 Albertans from their homes, will top $3 billion dollars and could cost as much $5 billion. But numbers like these can be hard to grasp without a bit of context. And, in this case, context is all you need to understand why this disaster blows all recent Canadian inundations right out of the water.

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If the cleanup does end up costing $3 billion, this year’s event will cost four times that of all flooding in the province between 1970 and 2009, according to data obtained from Public Safety Canada. In fact, the number is so high that the only way to find a comparable expense with other recent events is to sum the costs of all the flooding events that took place in the nearby province of Manitoba during the same period, which totaled about $1.4 billion, less than half the cost of the Alberta disaster.


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Although a huge blow to Canada’s richest province in per capita income, the flood’s price tag is still much smaller than the cost of some of the biggest flooding worldwide during the past five years. The Mississippi flood of 2011 in the U.S., for example, topped out at an estimated $9 billion, and the Pakistani cataclysm of 2009 ended up with a price tag of about $10 billion. Right now, however, western Canadians aren’t exactly in the mood to compare notes. Many have already called on the Ottawa to send relief money, but it will take some time before federal dollars arrive. Since 2007 the national government, led by Conservative Prime Minister Stephen Harper, has taken an average of three years to provide relief aid to flood-devastated communities, according to data gathered from Public Safety Canada press releases. This means that Albertans might have to wait until 2016 or 2017 to receive money through the Canadian Disaster Financial Assistance Arrangements program.

The other issue has to do with how this flood could have occurred in the first place. According to Uldis Silins, a hydrologist at the University of Alberta who spoke with reporters at the CBC (Canadian Broadcasting Corp.), the deluge might have caused fewer problems had there been less rainfall in the days leading up to it. The 40 millimeters of rain that fell at the beginning of June meant that the ground was unable to absorb the up to 200 millimeters that fell starting June 20. Others are blaming the slow mountain snowmelt for the ground’s saturation. But, like most storms, it was a combination of factors that made this one so overwhelming—factors like heavy rainfall, unusual wind patterns and high-pressure systems. These ingredients explain the storm’s devastation and why roads and fields turned into streams and lakes in an area spanning 400 kilometers over 25 communities, including the city of Calgary, the province’s economic capital.

As with most extreme weather events these days, many scientists and activists are pointing to climate change as a factor. David Suzuki, arguably Canada’s most famous living biologist, wrote in the Huffington Post Canada that although it isn’t quite acceptable for scientists to blame climate change for individual events like this one, “we can say we should expect more of the same—and worse if we don't do something to get our emissions under control.” Whether global warming is to blame or not, the road to recovery is going to be a long one for the devastated communities, where Alberta Premier Alison Redford says the damage could take up to 10 years to repair.