From China to Montreal, urban planners are embracing innovative green solutions to tackle the growing problem of flooding in cities. As climate change leads to more frequent and severe rainfall, traditional drainage systems in urban areas are becoming overwhelmed, resulting in flooding and sewage overflow. In response to this challenge, cities like Montreal are adopting nature-based solutions to manage stormwater and prevent flash floods.
Montreal has introduced the concept of "sponge parks" as a creative and sustainable approach to water management. One such park, Pierre Danserau Park, situated in a densely populated neighborhood, effectively absorbs rainwater during heavy downpours. The park features an intricate system of grasses, shrubs, and rocks that naturally filter and store the rainwater, preventing it from inundating streets and homes. Over time, the water gradually infiltrates the soil and stormwater systems, nourishing the park's vegetation.
The City of Montreal recognizes the need for these innovative green spaces, especially in light of the increasingly frequent and intense rainfall events caused by climate change. The success of Pierre Danserau Park has spurred the city to plan the construction of 30 more sponge parks to mitigate flooding and prevent the contamination of the St. Lawrence River by sewage-laden floodwaters.
This approach is not limited to Montreal but has gained momentum in various cities worldwide. In Toronto, green rooftops are being used to manage stormwater, while Berlin has incorporated lakes and wetlands into housing developments. However, the origins of this innovative water management approach can be traced back to Chinese landscape architect Kongjian Yu.
Inspired by his childhood village's resilience in the face of monsoon flooding, Yu has made it his mission to develop green solutions to water management. He has transformed 20 cities in China into "sponge cities" by implementing extensive changes to infrastructure, allowing green spaces to absorb excess water and combat urban heat island effects during heatwaves.
Yu's vision for these sponge cities goes beyond traditional parks, incorporating vast areas of green and blue spaces. These cities feature ponds and wetlands integrated with highways and high-rises, offering a new perspective on the coexistence of urban infrastructure and natural environments. In these cities, traditional grey infrastructure, such as pipes and concrete, is replaced by resilient green solutions that enhance the relationship between humans and nature.
While green solutions to water management are gaining traction globally, Canada is also exploring these alternatives as part of a broader shift toward more creative urban planning. According to Alexandra Lesnikowski, the head of the climate adaptation lab at Concordia University in Montreal, older drainage systems are no longer sufficient to protect cities from the impacts of climate change.
Lesnikowski emphasizes the importance of considering the location and design of green infrastructure projects, like sponge parks, for their effectiveness. While these nature-based solutions hold promise, she stresses the need for robust evidence regarding their suitability for different contexts and their limits in addressing larger-scale climate risks. Municipalities must carefully assess and strategically invest in these projects to ensure their success in managing urban flooding and safeguarding their communities.
