Green infrastructure is a key element of building more resilient cities through parks. Green infrastructure includes engineering natural spaces, like bioswales and rain gardens, that better capture, soak up, and treat rainwater where it falls as opposed to whisking it away into grey infrastructure, like pipes. This helps reduce the flooding associated with heavy rain events, but also improve water quality.
While we found cities across Canada are experimenting with green infrastructure in parks, only 48% of cities we surveyed have a citywide strategy for integrating this into park planning at a systems scale. As we reported in our 2017 Resilient Parks, Resilient Cities report, an integrated strategy is critical for making green infrastructure standard practice.
As a city that is forecasted to experience increasingly heavy rainfall due to climate change, Vancouver leads the way with its citywide green infrastructure strategy. The strategy includes plans for streets, trees, parks, developments, and the City’s maintenance practices. Staff reported that “without comprehensive policy, green infrastructure projects have mainly been staff-led pilot initiatives...rather than as an integral part of City capital programs.”
Approved in 2016, the Rain City Strategy pushes Vancouver to evolve beyond pilots, using an ecosystem approach to integrate green infrastructure citywide and treat rainwater as a resource. According to the City, over half of Vancouver is made up of impervious surfaces that cannot absorb water. The strategy’s target is to divert 90% of rainfall before it meets waterways.
The plan’s implementation is a partnership between City departments, including Planning, Engineering, and the Vancouver Park Board. Cameron Owen, who works in the Engineering Department’s Green Infrastructure Branch, said that the sweet spot is when a project can help meet water management, biodiversity, and park access goals in one.
Two recent examples:
The department’s hope is that this green infrastructure work can also help connect existing parks together by creating more park-like experiences along streets, contributing to an overall better green network in the city.
There are lots of co-learning opportunities between the Park Board and Engineering, Cameron said, adding that it's the diversity of knowledge within the department and its ability to work closely with Park Board colleagues that leads to innovative solutions.
The Green Infrastructure Branch includes landscape architects, planners, green infrastructure engineers, water engineers, and more. “When we start looking at how to solve a problem, some people are detail-focused and some are systems-focused,” Cameron said. “Which really led us in a different direction than if we had just been a group of landscape architects or engineers to solve the problem.”
Ever since a devastating flood in 2013 caused over $400 million in damage and the evacuation of thousands of people, Calgary has been working on ways to better protect itself.
Following those floods, the City approved a Flood Resilience Plan, which included both upstream and community-level risk mitigation measures along the Bow and Elbow Rivers, which run through the city. One of those community-level projects, West Eau Claire Park, completed its first phase in 2018.
West Eau Claire Park is a revitalized linear waterfront park along the Bow River. The $10.6 million project puts 30% of those costs towards flood mitigation elements.
Daniel England, Project Manager within Parks, Planning, and Development at the City of Calgary said that the project was an exercise in “how to change design to protect the downtown” from floods.
“We want to make sure people embrace the waterfront,” he said, providing an accessible promenade and maintaining as many mature trees as possible, but at the same time build infrastructure to protect from major floods. Elements couldn’t be included within the design, for example, that could be lifted up and damaged by rising water.
The park is designed to protect against a 200-year flood, which exceeds what occurred back in 2013 by about 35%. It achieves this not by building huge retaining walls, but by nestling flood mitigation infrastructure into the design so that it becomes a part of a new public amenity, rather than a barrier to the riverfront. A second phase, funded by the Province of Alberta, will extend the project to Reconciliation Bridge.
The park’s design includes an earthen berm to raise land to protect against high waters and cement walls with benches where raising land wasn’t feasible. It also includes systems built into the river’s edge that conceal panels that can be dropped into place during a potential flood.
As well as acting as a barrier, the park itself is a sponge, with bioswales located to catch run-off. “We wanted to make sure any of the water that drained off the hard surfaces was collected and utilized onsite,” Daniel said.
A new report by the Canadian Biodiversity Action Council sounds the alarm on biodiversity loss, arguing that the “three critical drivers augmenting biodiversity loss are our disconnected relationship to the land, over consumption and habitat loss.”
Their calls to action include setting concrete conservation targets, dealing with landscape and parks connectivity, collaborating with Indigenous peoples, integrating biodiversity strategies with community planning practices, and repositioning conservation as an urban initiative.
We found that 83% of cities have a biodiversity strategy, but that many are engaging in small-scale efforts to increase biodiversity and, in particular, habitat for pollinators.
Pollinators have been a particular area of focus within biodiversity work. The use of pesticides, loss of habitat from urbanization, and threats from invasive species have resulted in urgent calls for action from experts about the ongoing health of pollinators like bees and butterflies.
Canadian researchers recently sounded alarm bells about possible extinction for certain bee species, leading to “cascading impacts” across Canada. Approximately three-quarters of food crops rely on pollinators.