Not so long ago, when a deluge fell on our heads, we immediately remembered the dates of July 14, 1987 (in Montreal) and July 20, 1996 (in Saguenay). These milestones in recent history remind us how severe storms over a century have caused major damage to infrastructure, homes and even caused the death of people.
What we know about the impacts of global warming is that these centuries-old bad weather will no longer be. Their interval will be reduced and we risk seeing them occur more than once in the same year. You can imagine the explosion of costs related to these torrential storms! Do you think local governments and the state will be able to pay forever to fix and rebuild everything?
We suspect that they will inevitably have to pass on to us the bill for the stratospheric increase in costs related to these impacts of the climate crisis. This should make us realize that the economic consequences of inaction in the face of drastic climate impacts will be incalculable compared to those of radical action now to effect an inclusive ecological transition.
The other sword of Damocles hanging over our heads is home insurance coverage. Already these blankets have melted away for more than a decade. An insurance company covers risks based on statistical probabilities. If these risks become more recurrent, their statistical probability will increase, reducing their insurability accordingly.
I have already spoken to you about making our cities sponges to better manage stormwater. The more we succeed in acting on soil permeability in cities, the more we will reduce the pressure on our underground infrastructures.
As I mentioned last week, to better adapt to climate change and reduce the collective costs of weather management, we will also have to stop destroying natural assets such as wetlands.
It is essential to explore other solutions for land use planning by setting up new standards. A key measure is to better manage water from private buildings to collective sewers. Until now, gray water and storm water are systematically directed to municipal sewers.
However, during heavy rains, there may be backflows of clean water in houses equipped with valves. This happens when water that collects on flat roofs cannot drain normally, causing the flapper to clog with sewage. Thus, rainwater can come out of the toilet, sink or other access points. To prevent these problems, it is recommended to install check valves on all sanitary installations and water pipes.
It is important to be aware of the overall impact of our individual actions during torrential rains. Simultaneous use of household appliances (dishwasher, shower, washing machine, etc.) during these events can put additional pressure on underground infrastructure. It is therefore crucial to exercise moderation by avoiding any unnecessary addition of water to the sewer lines.
Various measures can help to reduce this pressure on collective sanitation systems. For example, it is possible to divert discharges from flat roofs to micro-rainwater retention basins built near residences, whether on private land or in common areas. In addition, gray water management can be improved through recovery systems allowing its reuse, for example for toilets.
However, it is essential to ensure the absence of chemicals in the gray water before sending it to the ground. A regulatory amendment concerning cleaning products could be considered to quickly resolve this problem, provided there is political will to do so.
In order to generalize such practices and solutions, it is necessary that local governments act by modifying their urban planning regulations. Fortunately, they have full powers in this area. Cities could easily incorporate gray and stormwater management requirements into all new construction, whether real estate, commercial, industrial, institutional or residential.
Each new project adds additional pressure on already overstretched municipal underground infrastructure. Designing a city as a sponge requires better overall water management, which must be done in collaboration between the public and private sectors. In other words, there should be no boundary for water whether it falls on private land or public land.
Much importance is attached to the supply of electricity for real estate, commercial and industrial development, but it is equally crucial to consider water management. The torrential rains should alert us and push us to engage in the necessary collective reflection, because we will not experience the last of the climatic disasters. Promoting adaptation to climate change means reviewing each of our habits.
CEO of the Institute for Urban Resilience and Innovation, professor and associate researcher, François William Croteau was mayor of Rosemont–La Petite-Patrie.