C Agnew, P Mulley, N Quinn, N Thatcher, D Lambert
Publication Date (Web): 13 May 2016

Sydney Water has a rich history in demand management. 

Water efficiency began in 1999 with Waterfix, the first and largest program in terms of customer participation. In 2007, water scarcity was the most important customer sentiment issue above cost of living, housing, transport, education and health.

During the Millennium Drought the focus from government, community and water utilities in New South Wales was unprecedented. As the crisis abated, however, the concern and effort in water conservation tapered off rapidly to focus on other asset management priorities that had been temporarily put on hold. By 2011, much of the low-hanging fruit in demand management had been exploited, the drought had come and gone, and investment was reduced. 

Customers now use 25% less water than they did before the Millennium Drought and have maintained water-efficient behaviour despite the lifting of restrictions. This lack of “bounceback” in demand is thought to be related to the length and severity of water restrictions, as well as greater regulation. 

QuoteSydney Water has become a victim of its own success, so how do we justify ongoing investment in demand management? After the success of the water savings programs of the Millennium Drought cheap and easy savings were no longer available. The (largely unintended) benefit of big reductions in demand during the drought was large amounts of spare capacity in water and wastewater systems. The approach of the future will proactively target parts of Sydney Water’s network that are capacity constrained or difficult and expensive to service. 

Like many similar organisations, Sydney Water is rich in data but can be information poor. It was decided that a robust decision framework in line with current asset management practices would be the best way to justify investment. 

To put this together existing spatial, cost, energy and demand data was collated. A major innovation in this piece of work was to map publicly available census information to Sydney Water’s water and wastewater networks. By correlating demographic data with demand management information, it is possible to find some of the underlying trends influencing customer participation (for example, low-income areas are less likely to participate in demand management). The three-step process of opportunity identification, program investigation and prioritisation allows Sydney Water to exploit cost-effective programs at a range of scales from the entire area of operations to specific parts of the network. 

This new approach will be tested through application and will inform a number of asset strategies. Exploring all viable options to meet customer expectations is good due diligence on part of utilities. By investigating demand side, non-asset solutions it is possible to overcome a widely acknowledged “capital bias” of regulated utilities. 

To embed this approach into long-standing and functional asset management processes takes time and a cultural shift in organisations with a traditional engineering focus. The robust assessment of costs and benefits provides an evidence base to justify investment and construct an effective portfolio of water savings to meet future challenges such as drought and population growth. 

The key steps in Sydney Water’s demand management decision framework.

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