Article content
Water policy guru Jim Bruce perhaps best captured the relationship between climate change and water when he said, “Like a fish that doesn’t notice the shark until it feels its sharp bite, humans will first feel the effects of climate change through water.”
According to the Insurance Bureau of Canada, the country has been hit with 35 catastrophic flooding events over the past decade costing on average close to $800 million in total insured losses annually. The 2022 report Aquanomics by consulting firm GHD further predicts that water-related disasters — flooding, drought and storms — could cost Canada’s economy $139 billion over the next 30 years.
Article content
Flood forecasting is complex. Predictions of streamflow — the volume of water passing through an area under different weather scenarios — are used in decisions about irrigation and hydroelectricity generation. But turning streamflow predictions into flood forecasts involves the added complexity of factoring in soil moisture, groundwater saturation, the state of glaciers and snowpack, the topology of the river network, river pinch points, and the state of riverbank erosion. Human decisions pertaining to the regulation of dams and reservoirs must also be considered.
In Canada, flood forecasting is further complicated by the fact we are a northern country with mountainous regions and lots of ice. River ice jams can raise water levels many metres above the norm. And they don’t occur only during springtime ice-cover breakup — they can happen in the fall freeze-up and mid-winter breakups too.
John Pomeroy, Canada research chair in water resources and climate change, has recently highlighted another factor impacting flood risk: wildfires. Wildfires destroy tree canopy leading to much denser snowpack as more snow accumulates on the ground. Loss of canopy also translates into less shade and more direct sunlight hitting snow, causing it to melt faster. The result is earlier and stronger spring runoff and a greater risk of downstream flooding.
Article content
Advances in flood forecasting have given rise to bespoke forecasting models, versus the practice of adapting and applying “off-the-shelf” ones. These more sophisticated tailor-made models use large quantities of data covering wider geographic areas, which in turn creates a need for collaboration across jurisdictions and for the enhanced power of supercomputers to crunch the data.
While the U.S. has a federal flood-forecasting system, Canada’s constitutional realities have resulted in a more fragmented, decentralized approach to flood-risk modelling across provinces and territories. This poses an obstacle to the sharing and transfer of skills and expertise necessary to narrow the gaps in forecasting capacity across jurisdictions. As Pomeroy has pointed out, while some modellers may predict major floods every year, others may not be called on to predict even one in their entire career. A national collaborative approach would create opportunities for shared experiences and professional development among flood forecasters.
If we look to Europe, we see that even independent nations can achieve the kind of unity of purpose necessary for accurate flood forecasting on a continental scale. According to Pomeroy, the prototype European flood-forecasting system being broadly tested at the time would have given a reasonably accurate prediction of the 2013 Calgary floods about 10 days beforehand; unfortunately, provincial forecasters were not able to predict a major flood in the headwaters until it was too late.
Canada can mirror Europe’s success through a national flood-forecasting system that brings together practitioners from the federal government, the provinces and territories, and academia to make common cause in foreseeing damaging and costly flooding events.
The climate change shark is not going anywhere soon. But with a clearer advance picture of flood risk, we can have a better chance of reducing how often we feel its bite.
Francis Scarpaleggia is the member of Parliament for Lac-Saint-Louis and chair of the House of Commons environment committee. His private member’s bill calling for a national flood and drought forecasting strategy is currently making its way through Parliament.
Recommended from Editorial
Share this article in your social network
