Urban tree canopies and green spaces have become unwitting casualties of current environmental planning and engineering standards, says leading urban planning and design practice Hatch RobertsDay.

Despite the focus on sustainable development, the green cover has declined in 69 per cent of Australia’s urban areas, precipitating a rise in temperature.[1] According to Hatch RobertsDay, developers and planners must prioritise urban tree canopy in their projects to increase the liveability of Australian cities and reduce the urban heat island effect.

Hatch RobertsDay WA urban designer Peter Ciemitis and WA planner Dan Pearce had recently presented on the topic at the WA Local Government Association’s ‘Trees in a Liveable City: An Urban Forest Conference’.

“Our cities continue to reach extreme temperatures and bushfires are occurring more frequently year on year. There is a growing urgency to mitigate the urban heat island effect, and tree canopies are a vital component to ensure we can reduce temperatures across the country. The Black Saturday bushfires in 2009, for example, sadly resulted in 173 deaths; however, many are unaware that 374 deaths occurred due to heat during that same week. Those deaths were clustered in Melbourne’s northern and western suburbs where there are fewer or no trees at all. Similarly, suburbs in Sydney’s west grow hotter every year, with some areas reporting temperatures above 50 degrees. We will begin to see a knock-on effect throughout Australia if we don’t act quickly to reduce heat in communities,” Ciemitis observed.

“Prioritising ways to retain and introduce more green cover across projects also fast-tracks the evolution of new estates, so that they feel more established and homely. Designing with liveability in mind will have a positive effect on the community, improve land and property market values, and ensure projects are more sustainable and financially viable,” Pearce added.

Ciemitis and Pearce shared their 5 recommendations for increasing urban tree canopies and green spaces:

1. Retain trees in developments, parks and public spaces.

Earthworks executed during most modern land development projects require trees and other natural vegetation to be cleared away for levelling prior to development. One way to minimise the destruction of the existing green cover is to identify the best trees for retention. However, since trees retained on private lots are at greater risk of removal down the road, developers should focus on retaining trees in parks, streets and other public spaces to create a permanent urban canopy.

2. Work closely with councils to minimise tree removals.

Local council policies require minimum distances to be maintained between street trees and drainage pits, lights, crossovers or street corners. However, adhering to these rules could reduce the number of trees that the developer plans to retain on the property. Developers should work with their local council to determine ways to maximise tree retention. By working with councils early in a project, developers can avoid excessive and unnecessary tree removal.

3. Plan more ‘destination parks’.

The increase in residential apartment projects has seen a corresponding reduction in single-occupancy homes while the average home lot size has declined by 16 per cent since 2009.[2] With the availability of backyard spaces on the decline, more ‘community backyards’ in the form of high-quality green spaces and neighbourhood parks are required. Also, instead of designing neighbourhood parks as ‘cookie cutter’ spaces without walking and cycling tracks, playgrounds and a body of water, developers must focus on creating smaller, green destination parks within walking distance to residential properties that can bring relief, relaxation and amenity to almost every street in a neighbourhood while also increasing the tree cover.

4. Involve the community in increasing urban canopy in neighbourhoods.

To increase the tree canopy in a neighbourhood, involve the local residents and make planting trees a community effort. This involvement will ensure residents are well-informed and aware of the importance of an urban canopy in their neighbourhoods. In collaboration with planners and developers, councils must consult with residents and allow them to choose trees for their streets. Residents must also be educated about the value these street trees add to their properties, so that they remain invested in the initiative.

5. Take advantage of Government initiatives to increase tree cover.

Various State governments across the country have initiated special programmes designed to increase tree cover and green spaces. For instance, the NSW government plans to increase tree canopy across Greater Sydney to 40 per cent by 2030 and is providing funding to local councils to plant trees in public spaces, streets and parks.[3] The WA government recently published its draft Medium Density Code, which emphasises the role of gardens and deep root zones for tree planting on development sites. Planners and developers should utilise programmes initiated by local governments to introduce more trees in and around their developments.

References:

[1] Greenlife Industry Australia, 2020 https://www.greenerspacesbetterplaces.com.au/media/163315/where-will-all-the-trees-be-benchmarking-report-2020.pdf

[2] Housing Industry Association, 2020

https://hia.com.au/-/media/HIA-Website/Files/IndustryBusiness/Economic/fact-sheet/window-into-housing.ashx?la=en&hash=984BFC3393B3F2F997E099A71545B151044C2B50

[3] NSW Government, 2020

https://www.planning.nsw.gov.au/Policy-and-Legislation/Open-space-and-parklands/5-million-trees

Image: https://waterbucket.ca/rm/2016/02/06/urban-tree-canopy-water-experts-welcome-plan-to-cool-australias-cities/