One Size Doesn’t Fit All

Climate-driven urban flooding is becoming an increasingly critical issue as a result of a multitude of factors, including aging sewer infrastructure, urban intensification and flood mitigation design practices that have not stood the test of time. In Toronto, some sewer and drainage systems are approaching 100 years old, making them unlikely to be able to withstand above average rainfall, not to mention extreme weather events, which have been happening on an increasing frequency in Canada over the last ten years.

Drainage and sewer systems that are unable to mitigate stormwater flow and sewer backup result in urban flooding, an issue that has accounted for nearly $2 billion in average annual property damage claims in Canada between 2009 and 2021.

For municipal agencies looking to mitigate the issue of flooding in their area, a combination of collaboration and technology are key to solving this issue. 2D flood modelling helps engineers better understand flood risks in their area and enables a comprehensive assessment of potential flood zones. However, many agencies run the risk of placing too much reliance on 2D models when the best solution can be found by working with other municipalities tackling the same issue. Confirming a mixture of technology and collaboration will be the key to solving Canada’s growing urban flooding problem.

Associate Director, Infrastructure Planning, Philip Gray’s article starts on page 16 of Water Canada’s July/August 2022 issue.