Post by Jem Wilson, City of Melbourne
The City of Melbourne is looking forward to attending the ICLEI World Congress in Seoul. Melbourne became an ICLEI member back in 1998, and in 1999 we launched a successful bid to host ICLEI’s Oceania Secretariat in Melbourne. The City of Melbourne’s involvement with ICLEI catalysed our journey towards sustainability and in particular, a new way of managing water in our city.
In November 2001, we signed up to the ICLEI Water Campaign and were one of five councils in Australia to trial the campaign. As part of the campaign, we made a commitment to develop a sustainable water management strategy for the municipality through the campaign milestone frameworks. The following year, we began practising total water-cycle management.
We undertook research to ascertain the amount of water that lands on Melbourne annually and to quantify how much of this water was landing on soft surfaces and hard surfaces. We worked out how much of our rain water was running into rivers and the ocean. More than 4,200 litres of water per year runs off the rooftops in our municipality – an abundance of water to be harvested. We worked out that if we could capture our rainfall, it would service 80 per cent of our municipality’s water requirement.
In 2004 we produced Total Watermark, City in A Catchment the City of Melbourne’s first water strategy based on the findings of this research and I’m proud to say this is a strategy that remains deeply embedded in the way we work at Council. We’ve kept this strategy alive and updated it in both 2008 and again last year.
As one of the biggest water users in the municipality, the City of Melbourne has a leadership role to play in ensuring that we have a healthy city in a healthy catchment.
In the decade known as the Millennium Drought, Victoria experienced rainfall 14 per cent below average. This drought, combined with severe water restrictions really affected the health of our urban forest and sent many of our trees into decline.
To future proof our urban forest and secure a reliable non-potable water supply, we undertook the development of a number of stormwater harvesting projects across the city.
We have also implemented several other large stormwater harvesting schemes including in Fitzroy Gardens, the Docklands development, Birrarung Marr, and the Alexandra and Queen Victoria Gardens.
We have invested $20 million in our stormwater harvesting network, which is now delivering 25 per cent of our annual landscape water requirements and is reducing our reliance on potable water.
We aim to source 50 per cent of our water requirements from non-potable sources by 2030.
Climate Change and Melbourne
The role of water in cooling the city is a fundamental focus for our city for several reasons. Australian heatwaves in are becoming hotter and longer, they are occurring more often, and starting earlier in the season. Research has shown our heatwaves are occurring 17 days earlier, they have become 1.5 degrees hotter, and the maximum temperature of the hottest day is 2 degrees higher. This has highlighted a compelling and urgent need to cool the city to save lives and protect vulnerable populations.
Many people know that 173 lives were lost in the Black Saturday bushfires in 2009. What’s less well known is that in the lead up to Black Saturday, 374 people died across metropolitan Melbourne in one heatwave. This figure is higher than the annual road toll for the State.
Urban Forest Strategy
The way we manage water in our city will determine our resilience into the future. Through our Urban Forest Strategy and the urban landscapes adaptation program, we have a goal to cool summertime temperatures our city by 4°C in 2040 by doubling our tree canopy to 40 per cent and increasing permeability of our city’s surfaces.
To achieve that cooling we need to ensure we have a secure non potable water supply and that we are using and reusing our water efficiently, which is why developing our stormwater harvesting network has been an important focus for us.