What is Green Infrastructure?

Constructed WetlandConstructed Wetland

From a landscape perspective, green infrastructure is an effective tool for mitigating the negative impacts development has on the natural heritage and agricultural systems of the Greenbelt. A prime example is helping to clean and cool water before it enters the river systems, which is important for rivers as a habitat and as a resource.

Green infrastructure is also relevant to the rural towns and villages in and around the Greenbelt for helping to reduce infrastructure costs, playing an important role in rural economic prosperity.

But, did you also know that the Greenbelt itself can be thought of as a regional scale green infrastructure? The Greenbelt includes over 290,000 hectares of protected natural features, such as wetlands, hedgerows, and forests. These protected spaces provide a multitude of services to our communities, ranging from reducing the risk of floods, reducing health care costs, to storing carbon.

To get a better understanding about what green infrastructure is all about; we sat down with Tom Bowers, the Foundation’s Research Manager.

What is green infrastructure?

Green infrastructure is the natural vegetative systems and green technologies that provide a multitude of economic, environmental and social benefits, in addition to managing stormwater. Examples includes:

  • Urban forests and woodlots;
  • Bioswales, engineered wetlands and stormwater ponds;
  • Wetlands, ravines, waterways and riparian zones;
  • Meadows and agricultural lands;
  • Green roofs and green walls;
  • Urban agriculture;
  • Parks, gardens, turf, and landscaped areas.

Native Plants

How does it compare with grey infrastructure?

Grey infrastructure refers to constructed infrastructure, like pipes, pumps, and ditches that are engineered to manage stormwater. Green infrastructure uses natural processes to provide the same services as grey infrastructure, by using natural processes. Importantly, green infrastructure provides additional co-benefits that grey infrastructure cannot

The classic example is storm water management. A green infrastructure approach typically involves a treatment train approach, where water is collected and held on many different sites within a catchment area by wetlands, ponds, rain gardens, trees, bioswales, soil cells etc. and slowly released into the sewer system or rivers. 

This treatment train approach helps prevent flooding, cleans water, provides a natural habitat and more green spaces for people to enjoy. The grey infrastructure alternative typically aims to move water off the ground and into sewers as quickly as possible, bypassing the natural water filtration process.

What are four successful green infrastructure projects?



Hamilton's school water garden program. I love it because it brings nature into schools and raises awareness among all the parents.


Toronto Region Conservation Authority's Sustainable Neighbourhood Retrofit Action Plan program. The program aims to accelerate the creation of sustainable neighbourhoods in older urban areas.


Credit Valley Conservation Area's award winning retrofit of Elm Drive in Mississauga. The retrofit includes implementation of permeable parking lots and sidewalks, and a series of rain gardens that improve stormwater management.


Conservation Halton's renovated staff parking lot. The parking lot includes green infrastructure features that now reduce runoff volume from 100-year storms by 56%!

Read the next blog in the series.

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