Across the country communities are experiencing rainfall related incongruities. It’s only early July but Vancouver has been in stage 3 water restrictions since June 8. Conversely, Edmonton, Montreal and Regina are experiencing flooding. In late June Edmonton experienced severe flooding and washouts, breaking a 100-year record for the highest amount of rainfall ever recorded in June. Around the same time, Montreal saw major flooding from heavy rainfall that overwhelmed sewer infrastructure and flooded homes . Communities in southern Saskatchewan including Regina, experienced thunderstorms and heavy rainfall that led to severe flooding on June 28. What the heck is going on?
Climate change is what’s going on and it is driving the extreme weather events we are increasingly experiencing.
The Bigger Picture
Lower than normal snowfall in the British Columbia mountains this past winter means less water available at the base of the mountains this spring and summer. As a result, Vancouver and the lower mainland bypassed Stage 2 water restrictions earlier this spring due to severe drought. As of June 8, the severity increased to Stage 3 water restrictions, impacting homeowners, nurseries, garden centers, and other businesses. Recent rainfall helped and allowed plants and areas high in organic matter to store water for later use. But it wasn’t enough to replenish the water table. Despite the rain, the area remains in Stage 3 water restrictions. Summer droughts in Vancouver and the lower mainland are not unheard of. What is unusual is the early onset as summer hadn’t even officially started when the area moved to Stage 3 restrictions. The entire Vancouver area and lower mainland may be in for a very dry summer if this continues. This will impact gardens and ecosystems across the region.
Meanwhile, Edmonton, Montreal and Regina all saw close to 100 mm of rain over a few days in June. Streets and neighbourhoods in all three major cities experienced flooding. Climate change, and cyclical weather patterns are responsible for the rainfall. The flooding however, may be due to aging infrastructure or poor urban planning that allows water to repeatedly pool in certain streets or neighbourhoods. Additionally, a lack of green infrastructure and rainwater management systems in urban settings are contributing factors .
What needs to happen
Climate change is occurring faster than cities can adapt. It may look like municipalities aren’t doing much to prepare for climate change when all we see is a few trees planted each year. They are taking action, just not fast enough. Climate change projections have become more severe as global emissions remain high and mitigation efforts have fallen behind. On top of that, there are competing priorities for governments to direct money and resources to. The current cost of living crisis is just one example. Climate change has been a crisis much longer than the cost of living. But climate change isn’t showing up in personal bank accounts each month and governments can ignore it while they sort out other issues. Governments are still talking about climate goals and projections, or pushing it down the road for another government to deal with. But we need a solution, yesterday - no, last year. Green infrastructure and climate change adaptation measures should have been tested when 100 mm of rain fell on 3 cities. The amount of rain should have been something municipalities anticipated and prepared for years ago.
Some cities have made great strides - Regina’s urban forest, Vancouver’s rainwater boulevard and Montreal’s urban forests are just a few examples. Other cities are acting way too slowly. Edmonton is planning to increase its urban tree canopy from 13% to 20% by 2071. The rain is coming now, not in 45 years. An increase in tree canopy of 7% means more trees to absorb carbon today, but it also means more trees to soak up excessive rainfall in 10 years.
Which is why cities and citizens need to do more, now. Urban centers (concrete jungles) are not suitable for heavy rains. There needs to be green infrastructure interspersed throughout the city. A park with a playground and a paved pathway is no longer enough. Plants need to be included. The ground needs to be high in organic matter to absorb heavy rains. Then, during a heat wave with temperatures in the danger zone, the same area that’s absorbing heavy rains will act as a refuge from the heat. Trees will drink water during heavy rain, provide shade during the heat, and release the water back to the ecosystem during a drought. We need to move towards more urban and suburban greenspaces with sponge-like soils across city centers and all neighbourhoods. We need to design neighbourhoods to direct rainwater to holding ponds or rain gardens instead of to the sewer, while also providing green spaces to help absorb the water.
We (people and all governments), need to capture and store rainwater to keep it off streets and make it available during droughts. Like this BC couple who saved their farm from drought by capturing rainwater.
Green infrastructure vs effective green infrastructure
All cities have greenspaces and many pride themselves on the amount of greenspace available. Regina, for example, has 830 hectares of greenspace, roughly 4.5% of the area of the city. But if the ground is compacted and water is running off the surface instead of into the ground, the greenspace isn’t being used to its full capacity. Rainwater is going back to the sewer rather than replenishing groundwater. Large swaths of grass that is cut weekly isn’t able to absorb heavy rains. Trees, shrubs, native ornamental plants and organic matter are all better options for absorbing rain. Greenspaces can’t just be grassy areas and a playground. They should include native plants, organic matter, rain gardens, stormwater ponds, trees, or wetlands. Neighbourhoods can be designed to direct water to a stormwater pond or large rain garden. Trees throughout a neighbourhood will help (trees clustered into small forests will be more effective, but a few trees are better than no trees if space is limited). We need small greenspaces throughout a city with diverse plant species and soil that can act as a sponge; rain boulevards along major roads with enough entryways for large amounts of water to enter; rain barrels to capture run-off instead of directing it to the sewer. That is how we are going to manage 100 mm of rain.
Ironically, when we think about ways to direct the water back to the ground during flooding and heavy rainfall, we’re also able to address droughts. The little bit of rain that fell in Vancouver may be enough for a garden that’s high in organic matter and properly mulched to reduce water evaporation until the next brief rainfall. It was likely enough to replenish The Gunners’ cisterns.
Author’s note: In the few days between this article being written and published, Ottawa also experienced significant rainfall of 99 mm, causing highways, streets, neighbourhoods, and houses to flood.
Written by Julia Dupuis