Written by Cyrus Lau, MASc Candidate,  Civil Engineering, University of Toronto. Cyrus is currently conducting research on incorporating probabilistic hydrological analysis into deterministic hydraulic design for urban stormwater systems.


What is a “Sustainable City”? A simple google search will quickly reveal that there is no single agreed upon definition. In fact, the number of definitions are as numerous and varied as our cities themselves. However, if there’s one thing that’s clear, it’s that water plays an important role. Whether it be access to clean drinking water, preventing the pollution of our water resources, or preventing mass flooding, water frequently finds itself in the limelight of sustainability.

At first glance, water may seem simple. It’s what you drink, where you swim, what you use to take a shower, but it’s also so much more than that. Water embodies two sides of a coin, a duality between preservation and destruction. On one hand, water is one of the fundamental building blocks of life. Too little water and there are no plants, no animals, no people. Too much of it and you get flooding that can devastate areas and destroy infrastructure. And while the former is an issue that has been on the table for a long time, the latter is becoming all too common as well. Thus, it seems fitting that the second chapter of the Global Sustainable Cities seminars be dedicated to water, flooding, and climate change. The panel of experts presenting their views on these topics included Blair Feltmate, head of the Intact Centre on Climate Change at University of Waterloo, Krystyn Tully, vice president of Lake Ontario Waterkeeper, Jim Young, senior consultant at RWDI for Air Quality & Weather, and David Lapp, practice lead of Globalization & Sustainable Development for Engineers Canada.

Climate Change

Regardless of what some skeptics may say, climate change is real and unavoidable. In the past century, mankind has caused a 1° increase in global average temperatures – a number that is only going to continue increasing in the future. Nearly 80% of global energy is still produced through oil, natural gas, and coal. And even with improvements to renewable energy, projections show that value is going to remain constant for the foreseeable future.

But how do we know all this? We as a species have gotten very good at predicting the future. We’ve traditionally done it by looking at what has happened in the past. Historical birth rates, energy consumption, and temperatures give us a very good idea of how things typically behave, and we can make predictions of the future based on that. Climate change is no different. By understanding the natural relationships that exist and observing patterns in emissions we can predict how those relationships will evolve given various scenarios. Today’s climate change models are a complex network of chemistry, currents, emissions, wind patterns, and more. And all of them show that if we continue on as we are currently, things are only going to get worse.

Climate Induced Issues

There are many issues that we currently face that will become even more prevalent as climate change continues. Already, sewage and stormwater is the most common source of water pollution. Two thirds of water health outbreaks occur after large rainfalls where combined sewer overflows and water treatment facility bypasses cause untreated sewage to spill directly into our roads and water bodies. In the past 4 years, Toronto has had 148 water treatment bypasses due to our treatment plants being over-capacity. This year, 36,000 Ontarians will get sick from being in contact with contaminated water. RBC has committed $50 million towards helping to provide and insure drinkable, swimmable, and fishable water through its Blue Water Project initiative, and plans to continue on this front in the future, but more attention still needs to be brought to this issue. At the very least, we need to be able to communicate better with the public to inform them of the potential hazards they face.

Infrastructure failure is another issue that will only increase with climate change. Almost all major risks to infrastructure are environment related, and failure of one component can often cascade and impact other aspects of our infrastructure. For example, when the Toronto flood in 2005 knocked out a large section of Finch, it also damaged electrical cables, telecommunication cables, water mains, and the nearby parks.

With infrastructure failures, there tends to be a threshold for damages where after a certain point the cost of damages can increase exponentially. As climate change continues, the likelihood of these thresholds being exceeded increases as well. Without properly assessing these risks for futuristic scenarios, more and more catastrophic failures are bound to occur. If we don’t put the money into these systems to ensure their reliability and resilience in the face of climate change, it’s going to cost us many times more in the future.

Are Canada’s largest cities prepared for the floods that haven’t happened yet?

In short – No.

Recently we’ve seen an increase in major floods in cities. Just in the past decade in Toronto there have been several major floods causing hundreds of millions of dollars in damages. From catastrophic insurable losses alone, we’ve gone from $200-500 million/year on average to over $1 billion/year for the past 7 years, and storms are only going to continue getting worse. It’s estimated that by 2040 the severity of our large storms will double.

While it’s true that many of Canada’s largest cities are working to ensure they are prepared in the case of major floods, the focus is on floodplain mapping and public-sector infrastructure. However, there is very little being done to ensure that many of the key functions of the city, such as telecommunications, food supply, and electricity, will be functional in the case of a major flood. The issue lies in that these functions are not controlled directly by the city, and thus a “not my problem” mentality is being adapted.

Adaptation to climate change needs to happen, and it needs to happen now. Cities need to assume a leadership role in coordinating adaptation and preparation of all critical functions, not just those they have direct control over. And for an issue as big as this, dragging our feet will only hurt us in the long run.

The presentation slides from this seminar are available at: http://mindfirst.com/presentations-from-sustainable-cities-part-2-of-3-june-15/


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