Addressing the urban heat island effect

What is the urban heat island effect (UHIE)?

The urban heat island effect (UHIE) refers to the way built up areas trap heat. It results from a lot of activity in the one area and from the dense, dark and solid surfaces in urban environments which absorb and retain heat.

The UHIE is a significant issue for Merri-bek due to the highly urbanised environment. Factors including climate change and an ageing population make Merri-bek particularly vulnerable to extreme heat.

 Photo of street with dark areas showing shade and bright white areas showing exposed tar road surfaceHeat sensor image showing colour variants depending on where shade is falling on road surface. Areas with tree cover are darker indicating cooler temperatures. Same position as previous photo.

Shade from trees plus other smart urban design strategies can significantly reduce the UHIE in extreme weather as shown in the images below.

What is Merri-bek City Council’s plan to address the UHIE?

Urban Heat Island Effect Action Plan

To help reduce the impacts and prepare for a hotter future, Council developed the Urban Heat Island Effect Action Plan  (PDF 2Mb) in 2016 in consultation with the Merri-bek community and industry experts including input from the University of Melbourne and Monash University.

The Action Plan includes municipal-wide strategies to reduce overall temperatures and projects targeting specific locations. The Action Plan is Council’s first step of a long term commitment to respond to the UHIE.

The Urban Heat Island Effect Action Plan will help to create a city more resilient to urban heat and climate change. Taking action will produce multiple benefits including decreased energy costs, improved air quality and reduce health risks.

Council won the 2017 Premier’s Sustainability Award (Government Category) for the Merri-bek Urban Heat Island Effect Action Plan. See Moreland wins Premier’s Sustainability Award – Government Category for further details.

What actions are Merri-bek City Council currently taking?

Council is working across the city to minimise urban heat and is introducing new projects and programs to contribute towards cooling our city. These actions help reduce temperatures across the city and reduce the heat risk to people on very hot days.

Research and mapping

Council has carried out research to understand the impacts of heat across the municipality using techniques such as heat and vulnerability mapping. This has helped Council to identify the hottest areas in the city and where to take action.

Expanding canopy cover

Increasing tree canopy and greenery is one way to keep the city cooler. A 10% increase in tree cover can drop ambient temperatures by one degree. The Moreland Urban Forest Strategy  (PDF 9Mb)Moreland Street Tree Planting Plan and the Moreland Open Space Strategy  (PDF 5Mb) all aim to increase canopy cover and include a commitment to plant 5,000 trees a year.

Council is working to protect trees, incorporate new green space in new developments and prioritising tree planting in parks and on streets that are most vulnerable to urban heat. We are also investigating and trialling the most cost effective approach to passively water street trees and maintain tree health.

Conserving water

Water is critical to ensure open spaces remain green and plantings survive hot summers. Watermap 2020 is Council’s Integrated Water Management Plan that outlines both corporate and community projects required to achieve improvements in stormwater quality and also water conservation. An example of a water project completed in Merri-bek is the stormwater harvesting project at Hosken Reserve in Coburg North.

Sustainable building design

Through implementation of the Sustainable Buildings Policy  (PDF 936Kb), Council are applying the heat mitigation techniques to buildings across the municipality and encouraging it in new developments through Sustainable Design in the Planning Process. For example, cool roofs reflect the sun’s heat and reduce the amount of heat transferred to the building below and the surrounding environment. Cool buildings include green walls and facades, effective shading and insulation which improve the thermal comfort for occupants in extreme heat. Solar pergolas on a roof top can turn it into a cooler, comfortable space where plants can grow.

Strategic transport initiatives

Cool road materials can increase the reflection on the sun’s rays and reduce the build up of urban heat. Cool roads are best located where people do not congregate because of increased UV reflectivity. Council is monitoring the latest research on how cool road materials are used in Australia.

By prioritising our tree planting, Council can support a more walking and cycling friendly environment. We also intend to advocate for a reduction of traffic along Sydney Road and Lygon Street and promote electric vehicles to reduce car exhaust. Council has 16 free publicly available electric vehicle recharging points and has adopted a zero emissions vehicle fleet policy.

Collaboration and advocacy

In order for Merri-bek to transition to a cooler, greener and more liveable city a collaborative effort and commitment from the whole Merri-bek community, including residents, businesses and community groups, as well as all levels of Government is required.

Community consultation has demonstrated to us that advocacy to State Government authorities is very important – school infrastructure, naturalisation of Moonee Ponds creek, thermally comfortable social housing are very important to the community. Council is committed to encouraging the community to take action on urban heat.

What can I do to address the urban heat island effect?

To contribute to a cooler, greener and safer place in extreme heat, you can:

  • Apply reflective roof painting or (if re-roofing) reflective roofing materials to reduce indoor heat absorption.
  • Install bulk and reflective insulation and shading to improve indoor comfort.
  • Install a rainwater tank or a downpipe diverter with a raingarden to capture more water and keep the garden greener.
  • Use your car less by using public transport or walking. Consider buying an electric vehicle to reduce heat from the car engines.
  • If renovating, access free advice on sustainable design and product choices from the Australian Energy Foundation.
  • Plant trees in your garden to increase tree canopy and provide shading. Search the Moreland Tree Finder tool to select a suitable tree species for your space.