This aerial image of Echo Drive to Main Street south of Graham Avenue shows the extent of hard asphalt and concrete surfacing that creates runoff and possible flooding. Using permeable “sponge” materials instead is one of the ways that NBS can help to manage adverse climate change effects. Image by Google Maps
Kelly Allen & Peter Croal
Did you know that our close neighbour Montreal is fast becoming a “sponge city”?
What is a sponge city, you might ask? If you see a hard sidewalk or park surface of asphalt or concrete, you’ll notice that, when it rains, the water runs off to join water from other hard surfaces and into storm drains. But if the sidewalk or park surface is made of permeable material that acts like a sponge (such as soil or grass), the water seeps into the ground below, which helps reduce the risk of flooding. Montreal has taken this concept to heart and is creating 400 more sponge sidewalks and 30 sponge parks, in addition to what it already has.
Climate change is having an increasingly profound impact on our cities due to increased rain, snow, storms, wind, heat and ice. Cities in Canada and around the world are using nature-based solutions (NBS) such as sponge parks to help manage these effects. NBS ranges from wetland restoration and tree planting to community gardens and green roofs.
Natural assets help reduce the effects of climate events, such as flooding and extreme weather, and protect and enhance ecosystems. Forests, grasslands and wetlands are also living systems. They grow stronger and more effective as they age, and most require little or no maintenance and will function in perpetuity.
Nature-based solutions are often more economical than engineered solutions and are a more sustainable way forward. By adopting NBS, Ottawa can reduce its climate risks, create a more livable city and decrease the need for engineered assets that have higher acquisition, maintenance and replacement costs.
Ottawa has responded to some degree in using NBS to address climate change impacts. Rain Ready Ottawa is a pilot program that supports and encourages residents to take action on their property to address rainwater runoff (such as building rain gardens and permeable driveways). The pilot is currently confined to the east and west ends of the City in areas that can directly affect the Ottawa River. However, owing to its popularity, there have been numerous calls by residents to expand the program, which is currently oversubscribed, beyond the designated priority area of the pilot.
But Ottawa still lags behind many Canadian cities. For example, White Rock, BC recently passed a by-law requiring that all new and existing municipal parks be developed and managed using NBS. Why can’t Ottawa have a similar by-law?
Not only does NBS address climate change in an economical and sustainable way, but it’s also good for our community too. Families and children can get involved directly with NBS activities in their homes and schools. It’s a great way to discover the benefits of nature, learn about the plants, trees and animals in our neighbourhoods, and encourage all of us to have more nature time and less screen time. By fully adopting NBS, Ottawa has a significant opportunity to become a more resilient and livable city.
Kelly Allen and Peter Croal are members of the Citizen Climate Counsel.
Readers may wish to encourage City Council to be more proactive in using NBS to address climate change issues. And the next time you notice how much water a sponge can hold, just remember how that principle can help Ottawa with future flooding! If you wish to know more about NBS, please scan the QR Code below to access an informative Government of Canada website:
